glycogen and Body-Weight

The nutritional and immunologic properties of human milk, along with clear evidence of dose-dependent optimal health outcomes for both mothers and infants, provide a compelling rationale to support exclusive breastfeeding. US women increasingly intend to breastfeed exclusively for 6 months. Because establishing lactation can be challenging, exclusivity is often compromised in hopes of preventing feeding-related neonatal complications, potentially affecting the continuation and duration of breastfeeding. Risk factors for impaired lactogenesis are identifiable and common. Clinicians must be able to recognize normative patterns of exclusive breastfeeding in the first week while proactively identifying potential challenges. In this review, we provide new evidence from the past 10 years on the following topics relevant to exclusive breastfeeding: milk production and transfer, neonatal weight and output assessment, management of glucose and bilirubin, immune development and the microbiome, supplementation, and health system factors. We focus on the early days of exclusive breastfeeding in healthy newborns ≥35 weeks' gestation managed in the routine postpartum unit. With this evidence-based clinical review, we provide detailed guidance in identifying medical indications for early supplementation and can inform best practices for both birthing facilities and providers.

Topics: Algorithms; Birth Weight; Blood Glucose; Body Weight; Breast Feeding; Breast Milk Expression; Colostrum; Dietary Supplements; Evidence-Based Practice; Female; Glycogen; Humans; Hyperbilirubinemia; Infant, Newborn; Kangaroo-Mother Care Method; Lactation; Lactation Disorders; Microbiota; Milk, Human; Mothers; Phototherapy; Risk Factors; Time Factors

During a soccer season, athletes tend to play intense and light matches such as decisive and qualifying games. The amount of muscle glycogen stores is a determining factor of performance during exercise, and manipulation of carbohydrate intake during the soccer season to enhance muscle glycogen stores can improve the performance of elite soccer players. The purpose of this review is to provide a holistic view of the periodization of carbohydrates and their effects on sports performance, based on what the literature recommends for the periodization of carbohydrates for endurance athletes, and of muscle glycogen recovery and compensation among professional soccer players.. The ingestion of large amounts of carbohydrates (CHO;10 g/kg of body weight (BW)/day) is important 36 h before a match for the elite soccer player to ensure muscle glycogen supercompensation. In addition, elite soccer players should intake 1 to 1.5 g/kg BW/h within the first 4 h after a soccer game to maximize glycogen resynthesis. However, the season is comprised of away and home games that require different intensities; thus, soccer players need to periodize CHO intake based on evidence-based recommendations such as "train low," "train low, compete high," and/or "sleep low." The goal is to induce training adaptations by alternating with high or low CHO availability based on seasons, matches, and training intensities. The strategy can result in improved performance during games. Periodizing the consumption of carbohydrates, based on the intensity of training and matches, should include more carbohydrates when the matches require higher intensity and fewer carbohydrates when they require lower intensity; this is a strategy that will improve the performance of elite soccer athletes.

Topics: Adaptation, Physiological; Athletes; Athletic Performance; Body Weight; Dietary Carbohydrates; Dietary Supplements; Energy Metabolism; Exercise; Glycogen; Humans; Muscles; Nutritional Status; Soccer

The optimization of post-exercise glycogen synthesis can improve endurance performance, delay fatigue in subsequent bouts, and accelerate recovery from exercise. High carbohydrate intakes (1.2 g/kg of body weight/h) are recommended in the first 4 h after exercise. However, athletes may struggle to consume carbohydrates at those levels. PURPOSE OF REVIEW: Thus, we aimed to determine whether the consumption of non-carbohydrate dietary factors (creatine, glutamine, caffeine, flavonoids, and alcohol) enhances post-exercise glycogen synthesis. RECENT FINDINGS: Trained athletes may not realize the benefits of creatine loading on glycogen synthesis. The impacts of caffeine, glutamine, flavonoids, and alcohol on post-exercise glycogen synthesis are poorly understood. Other ergogenic benefits to exercise performance, however, have been reported for creatine, glutamine, caffeine, and flavonoids, which were beyond the scope of this review. Evidence in trained athletes is limited and inconclusive on the impact of these non-carbohydrate dietary factors on post-exercise glycogen synthesis.

Topics: Alcohols; Athletes; Athletic Performance; Body Weight; Caffeine; Creatine; Databases, Factual; Dietary Carbohydrates; Exercise; Fatigue; Flavonoids; Glutamine; Glycogen; Humans; Muscle, Skeletal; Performance-Enhancing Substances; Randomized Controlled Trials as Topic

The way in which metabolic fuels are utilized can alter the expression of behaviour in the interests of regulating energy balance and fuel availability. This is consistent with the notion that the regulation of appetite is a psychobiological process, in which physiological mediators act as drivers of behaviour. The glycogenostatic theory suggests that glycogen availability is central in eliciting negative feedback signals to restore energy homeostasis. Due to its limited storage capacity, carbohydrate availability is tightly regulated and its restoration is a high metabolic priority following depletion. It has been proposed that such depletion may act as a biological cue to stimulate compensatory energy intake in an effort to restore availability. Due to the increased energy demand, aerobic exercise may act as a biological cue to trigger compensatory eating as a result of perturbations to muscle and liver glycogen stores. However, studies manipulating glycogen availability over short-term periods (1-3 days) using exercise, diet or both have often produced equivocal findings. There is limited but growing evidence to suggest that carbohydrate balance is involved in the short-term regulation of food intake, with a negative carbohydrate balance having been shown to predict greater ad libitum feeding. Furthermore, a negative carbohydrate balance has been shown to be predictive of weight gain. However, further research is needed to support these findings as the current research in this area is limited. In addition, the specific neural or hormonal signal through which carbohydrate availability could regulate energy intake is at present unknown. Identification of this signal or pathway is imperative if a casual relationship is to be established. Without this, the possibility remains that the associations found between carbohydrate balance and food intake are incidental.

Topics: Appetite Regulation; Body Weight; Energy Intake; Energy Metabolism; Exercise; Feeding Behavior; Food; Glycogen; Homeostasis; Humans; Hunger

All animals face the possibility of limitations in food resources that could ultimately lead to starvation-induced mortality. The primary goal of this review is to characterize the various physiological strategies that allow different animals to survive starvation. The ancillary goals of this work are to identify areas in which investigations of starvation can be improved and to discuss recent advances and emerging directions in starvation research. The ubiquity of food limitation among animals, inconsistent terminology associated with starvation and fasting, and rationale for scientific investigations into starvation are discussed. Similarities and differences with regard to carbohydrate, lipid, and protein metabolism during starvation are also examined in a comparative context. Examples from the literature are used to underscore areas in which reporting and statistical practices, particularly those involved with starvation-induced changes in body composition and starvation-induced hypometabolism can be improved. The review concludes by highlighting several recent advances and promising research directions in starvation physiology. Because the hundreds of studies reviewed here vary so widely in their experimental designs and treatments, formal comparisons of starvation responses among studies and taxa are generally precluded; nevertheless, it is my aim to provide a starting point from which we may develop novel approaches, tools, and hypotheses to facilitate meaningful investigations into the physiology of starvation in animals.

Topics: Amino Acids; Animals; Body Temperature; Body Weight; Energy Metabolism; Fasting; Glucose; Glycogen; Ketone Bodies; Lipid Metabolism; Organ Size; Proteins; Respiratory Physiological Phenomena; Starvation; Weight Loss

Recently, diets low in carbohydrate content have become a matter of international attention because of the WHO recommendations to reduce the overall consumption of sugars and rapidly digestible starches. One of the common metabolic changes assumed to take place when a person follows a low-carbohydrate diet is ketosis. Low-carbohydrate intakes result in a reduction of the circulating insulin level, which promotes high level of circulating fatty acids, used for oxidation and production of ketone bodies. It is assumed that when carbohydrate availability is reduced in short term to a significant amount, the body will be stimulated to maximize fat oxidation for energy needs. The currently available scientific literature shows that low-carbohydrate diets acutely induce a number of favourable effects, such as a rapid weight loss, decrease of fasting glucose and insulin levels, reduction of circulating triglyceride levels and improvement of blood pressure. On the other hand some less desirable immediate effects such as enhanced lean body mass loss, increased urinary calcium loss, increased plasma homocysteine levels, increased low-density lipoprotein-cholesterol have been reported. The long-term effect of the combination of these changes is at present not known. The role of prolonged elevated fat consumption along with low-carbohydrate diets should be addressed. However, these undesirable effects may be counteracted with consumption of a low-carbohydrate, high-protein, low-fat diet, because this type of diet has been shown to induce favourable effects on feelings of satiety and hunger, help preserve lean body mass, effectively reduce fat mass and beneficially impact on insulin sensitivity and on blood lipid status while supplying sufficient calcium for bone mass maintenance. The latter findings support the need to do more research on this type of hypocaloric low-carbohydrate diet.

Topics: Animals; Blood Glucose; Blood Pressure; Body Weight; Cardiovascular Diseases; Diet, Carbohydrate-Restricted; Diet, Reducing; Dietary Carbohydrates; Energy Metabolism; Glycogen; Humans; Insulin; Insulin Resistance; Insulin Secretion; Lipids; Neoplasms; Osteoporosis, Postmenopausal; Risk Factors

The etiology of type I and type II diabetes differs and so do the nutritional challenges during and after exercise. For type I diabetics, exercise may cause hypoglycemia. To avoid hypoglycemia, a carbohydrate-rich meal should be eaten 1 to 3 hours prior to exercise and the insulin dose reduced. During exercise, at least 40 g glucose per hour should be ingested; more if the insulin dose is not reduced. After exercise, it is important to rebuild the glycogen stores to reduce the risk for hypoglycemia. Carbohydrates should always be available during training and in the recovery period. Despite these difficulties, exercise is recommended for type I diabetics and competition at high level is possible. Exercise prevents development of type II diabetes and improves metabolic regulation. For type II diabetics, exercise is normally performed to improve insulin sensitivity and to reduce body weight. Carbohydrates should only be supplied to prevent hypoglycemia.

Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exercise; Glycemic Index; Glycogen; Homeostasis; Humans; Hypoglycemia; Muscle, Skeletal; Nutritional Physiological Phenomena; Physical Endurance

Carbohydrate (CHO) is the body's most limited fuel and the most heavily metabolized during moderate-intensity exercise. For this reason it is recommended that endurance athletes consume a high-CHO diet (8-10 g CHO . kg body weight-1 . day-1) to enhance training and performance. A review of the literature supports the benefits of CHO supplementation on endurance performance. The benefits of chronic high-CHO diets on endurance performance are not as clear. Recent evidence suggests that a high-CHO diet may be necessary for optimal adaptations to training. However, the paucity of date in this area precludes any concrete conclusions. The practicality of high-CHO diets is not well understood. The available evidence would indicate that a high-CHO diet is the best dietary recommendation for endurance athletes.

Topics: Adaptation, Physiological; Body Weight; Dietary Carbohydrates; Dietary Fats; Glycogen; Humans; Liver; Muscle, Skeletal; Physical Endurance; Psychomotor Performance; Sports

Topics: Animals; Body Weight; Dietary Carbohydrates; Dietary Fats; Energy Intake; Energy Metabolism; Glycogen; Humans; Obesity

Topics: Adipose Tissue; Adult; Body Composition; Body Constitution; Body Water; Body Weight; Carbohydrates; Child; Dietary Proteins; Energy Metabolism; Glycogen; Humans; Lipid Metabolism; Male; Methods; Potassium; Proteins

Topics: Anemia, Hypochromic; Animals; Body Weight; Carbohydrate Metabolism; Energy Intake; Energy Metabolism; Feeding Behavior; Female; Glycogen; Humans; Iron; Lipid Metabolism; Longevity; Male; Nutritional Physiological Phenomena; Nutritional Requirements; Proteins; Sports; Sweat; Vitamins

In a survey, the pharmacological and clinical documentation of metformin is presented and discussed, and the present state of knowledge relating to metformin-associated lactic acidosis is reviewed. The use of metformin in the treatment of diabetes is based on clinical experience over twenty years. It has been well documented that metformin is effective in maturity-onset diabetes both as monotherapy and in combination with a sulphonylurea. An advantage of metformin treatment is the tendency to weight reduction and the absence of significant hypoglycaemia; blood glucose levels are reduced only to normal. The disadvantages are the gastro-intestinal side effects and the potential risk of vitamin B 12 and folic acid deficiency during long-term use. Metformin-associated lactic acidosis is a very rare complication, which has mainly occured in patients with serious renal insufficiency or other contra-indications to the use of metformin. The association between phenformin and lactic acidosis has led to withdrawal of this biguanide in several countries. Metformin differs from phenformin in certain important respects, and the normal use of metformin does not involve the risk of side effects disproportionate to the intended effect. Further experimental studies are required to substantiate pharmacokinetics and metabolic effects of metformin in man.

Topics: Animals; Body Weight; Diabetes Mellitus; Gluconeogenesis; Glucose; Glycogen; Humans; Insulin; Insulin Secretion; Intestinal Absorption; Islets of Langerhans; Lipid Metabolism; Metformin; Muscles

Starvation entails a progressive selection of fat as body fuel. Soon after a meal glucose utilisation by muscle ceases and fatty acids are used instead. Ketoacid levels in blood become elevated over the first week, and the brain preferentially uses these instead of glucose. The net effect is to spare protein even further, as glucose utilisation by brain is diminished. Nevertheless, there is still net negative nitrogen balance, but this can be nullified by amino acid or protein supplementation. Insulin appears to be the principal regulatory hormone. Recent data suggest that decreased levels of active T3 may play a role by sparing otherwise obligated calories by decreasing metabolic needs.

Topics: Adipose Tissue; Body Weight; Brain; Cyclic AMP; Energy Metabolism; Fatty Acids; Glucagon; Gluconeogenesis; Glycogen; Humans; Insulin; Ketosis; Kidney; Liver; Muscles; Oxygen Consumption; Proteins; Splanchnic Nerves; Starvation; Triglycerides; Urea

Topics: Amino Acids; Body Weight; Carbohydrate Metabolism; Carbohydrates; Deamination; Dietary Carbohydrates; Dietary Proteins; Fatty Acids, Nonesterified; Glycogen; Humans; Lipid Metabolism; Male; Metabolism; Muscles; Nutritional Requirements; Oxidation-Reduction; Oxygen Consumption; Physical Exertion; Sports Medicine; Triglycerides

Topics: Body Weight; Diet; Dietary Carbohydrates; Dietary Fats; Glycogen; Humans; Muscles; Nutritional Physiological Phenomena; Physical Exertion; Respiration; Sports

Creatine (Cr) and carbohydrate loadings are dietary strategies used to enhance exercise capacity. This study examined the metabolic and performance effects of a combined CR and CHO loading regiment on time trial (TT) cycling bouts.. Eighteen well-trained (~65 mL·kg·min V˙O2peak) men completed three performance trials (PT) that comprised a 120-km cycling TT interspersed with alternating 1- and 4-km sprints (six sprints each) performed every 10 km followed by an inclined ride to fatigue (~90% V˙O2peak). Subjects were pair matched into either CR-loaded (20 g·d for 5 d + 3 g·d for 9 d) or placebo (PLA) groups (n = 9) after the completion of PT1. All subjects undertook a crossover application of the carbohydrate interventions, consuming either moderate (6 g·kg body mass (BM) per day; MOD) or CHO-loaded (12 g·kg BM·d; LOAD) diets before PT2 and PT3. Muscle biopsies were taken before PT1, 18 h after PT1, and before both PT2 and PT3.. No significant differences in overall TT or inclined ride times were observed between intervention groups. PLA + LOAD improved power above baseline (P < 0.05) during the final 1-km sprint, whereas CR + MOD and CR + LOAD improved power (P < 0.05) during the final 4-km sprint. Greater power was achieved with MOD and LOAD compared with baseline with PLA (P < 0.05). CR increased pre-PT BM compared with PLA (+1.54% vs +0.99% from baseline). CR + LOAD facilitated greater [total CR] (P < 0.05 vs baseline) and muscle [glycogen] (P < 0.01 vs baseline and MOD) compared with PLA + LOAD. Mechanistic target of rapamycin decreased from baseline after glycogen depletion (~30%; P < 0.05).. Power output in the closing sprints of exhaustive TT cycling increased with CR ingestion despite a CR-mediated increase in weight. CR cosupplemented with carbohydrates may therefore be beneficial strategy for late-stage breakaway moments in endurance events.

Topics: Adult; Bicycling; Body Weight; Creatine; Cross-Over Studies; Diet, Carbohydrate Loading; Glycogen; Humans; Male; Muscle, Skeletal; Oxygen Consumption; Physical Endurance; Sports Nutritional Physiological Phenomena

We examined whether carbohydrate-protein ingestion influences muscle glycogen metabolism during short-term recovery from exhaustive treadmill running and subsequent exercise. Six endurance-trained individuals underwent two trials in a randomized double-blind design, each involving an initial run-to-exhaustion at 70% VO

Topics: Adolescent; Adult; Blood Glucose; Body Mass Index; Body Weight; Dietary Carbohydrates; Dietary Proteins; Double-Blind Method; Exercise Test; Fatigue; Fatty Acids, Nonesterified; Female; Glycogen; Glycogenolysis; Humans; Insulin; Lactic Acid; Male; Muscle, Skeletal; Oxygen Consumption; Physical Endurance; Running; Sports Nutritional Physiological Phenomena; Urea; Urinalysis; Young Adult

(1) OBJECTIVE: To compare the effects of isomaltulose (Palatinose™, PSE) vs. maltodextrin (MDX) ingestion on substrate utilization during endurance exercise and subsequent time trial performance; (2) METHODS: 20 male athletes performed two experimental trials with ingestion of either 75 g PSE or MDX 45 min before the start of exercise. The exercise protocol consisted of 90 min cycling (60% VO₂max) followed by a time trial; (3) RESULTS: Time trial finishing time (-2.7%, 90% CI: ±3.0%, 89% likely beneficial; p = 0.147) and power output during the final 5 min (+4.6%, 90% CI: ±4.0%, 93% likely beneficial; p = 0.053) were improved with PSE compared with MDX. The blood glucose profile differed between trials (p = 0.013) with PSE resulting in lower glycemia during rest (95%-99% likelihood) and higher blood glucose concentrations during exercise (63%-86% likelihood). In comparison to MDX, fat oxidation was higher (88%-99% likelihood; p = 0.005) and carbohydrate oxidation was lower following PSE intake (85%-96% likelihood; p = 0.002). (4) CONCLUSION: PSE maintained a more stable blood glucose profile and higher fat oxidation during exercise which resulted in improved cycling performance compared with MDX. These results could be explained by the slower availability and the low-glycemic properties of Palatinose™ allowing a greater reliance on fat oxidation and sparing of glycogen during the initial endurance exercise.

Topics: Adult; Athletes; Bicycling; Blood Glucose; Body Height; Body Mass Index; Body Weight; Cross-Over Studies; Double-Blind Method; Exercise; Glycogen; Heart Rate; Humans; Isomaltose; Lipid Metabolism; Male; Oxygen Consumption; Physical Endurance; Polysaccharides; Rest; Sports Nutritional Physiological Phenomena

Intermittent high (+3°C) and low (-3°C) temperature treatments for 4 h on embryonic day (E) 16, E17, and E18 showed differential effects on embryonic metabolism, without influencing embryonic growth or hatchability. Embryos in the high-temperature group shifted to a more anaerobic metabolism, as indicated by a lower partial pressure of O(2) and a higher partial pressure of CO(2) in the air cell, lower blood pH, and higher lactic acid production. Three hours after the end of the high-temperature treatment, a decrease in metabolism was observed, as indicated by the lower partial pressure of CO(2) and higher partial pressure of O(2) in the air cell and increased plasma triglyceride levels. The embryos in the low-temperature group responded by temporarily slowing down their metabolism, especially the metabolism of carbohydrates and lipids, as indicated by altered air cell gases, a higher relative yolk weight, higher plasma triglyceride level, and higher liver glycogen level. Three hours after the end of the temperature treatment, the metabolism of embryos in the low-temperature treatment had increased to the level of the control temperature group. However, for both temperature treatments, during the hatching process, all the shortages and excesses created were restored to control levels, which would explain the lack of change in embryo growth and hatchability and the slight delay in the hatching process. These mild consequences of the intermittent temperature treatment indicate that the different metabolic shifts made by the embryos seem to be efficient in overcoming the challenges of the intermittent high- or low-temperature treatment during late incubation.

Topics: Animals; Blood Glucose; Body Weight; Chick Embryo; Chickens; Egg Yolk; Glycogen; Hydrogen-Ion Concentration; Liver; Oxygen; Temperature; Time Factors

Energy turnover was assessed in two conditions of mixed ultra-endurance exercise. In Study 1, energy expenditure and intake were measured in nine males in a laboratory over 24 h. In Study 2, energy expenditure was assessed in six males during an 800-km Adventure race (mean race time 152.5 h). Individual correlations between heart rate and oxygen uptake (VO(2)) were established during pre-tests when kayaking, cycling, and running. During exercise, energy expenditure was estimated from continuous heart rate recordings. Heart rate and VO(2) were measured regularly during fixed cycling work rates to correct energy expenditure for drift in oxygen pulse. Mean energy expenditure was 18,050 +/- 2,390 kcal (750 +/- 100 kcal h(-1)) and 80,000 +/- 18,000 kcal (500 +/- 100 kcal h(-1)) in Study 1 and Study 2 respectively, which is higher than previously reported. Energy intake in Study 1 was 8,450 +/- 1,160 kcal, resulting in an energy deficit of 9,590 +/- 770 kcal. Body mass decreased in Study 1 (-2.3 +/- 0.8 kg) but was unchanged in Study 2. Fat mass decreased in Study 2 (-2.3 +/- 1.5 kg). In Study 1, muscle glycogen content decreased by only 60%. Adventure racing requires a high energy expenditure, with large inter-individual variation. A large energy deficit is caused by inadequate energy intake, possibly due to suppressed appetite and gastrointestinal problems. The oxygen pulse, comparing start to 12 h of exercise and beyond, increased by 10% and 5% in Study 1 and Study 2 respectively. Hence, estimations of energy expenditure from heart rate recordings should be corrected according to this drift.

Topics: Adipose Tissue; Adult; Bicycling; Body Weight; Energy Intake; Energy Metabolism; Exercise; Exercise Test; Glycogen; Heart Rate; Humans; Male; Muscle, Skeletal; Oxygen; Running; Sports; Young Adult

The purpose of this study was to determine whether exercise prescriptions differing in volume or intensity also differ in their ability to retain insulin sensitivity during an ensuing period of training cessation. Sedentary, overweight/obese subjects were assigned to one of three 8-mo exercise programs: 1) low volume/moderate intensity [equivalent of approximately 12 miles/wk, 1,200 kcal/wk at 40-55% peak O(2) consumption (Vo(2peak)), 200 min exercise/wk], 2) low volume/vigorous intensity ( approximately 12 miles/wk, 1,200 kcal/wk at 65-80% Vo(2peak), 125 min/wk), and 3) high volume/vigorous intensity ( approximately 20 miles/wk, 2,000 kcal/wk at 65-80% Vo(2peak), 200 min/wk). Insulin sensitivity (intravenous glucose tolerance test, S(I)) was measured when subjects were sedentary and at 16-24 h and 15 days after the final training bout. S(I) increased with training compared with the sedentary condition (P < or = 0.05) at 16-24 h with all of the exercise prescriptions. S(I) decreased to sedentary, pretraining values after 15 days of training cessation in the low-volume/vigorous-intensity group. In contrast, at 15 days S(I) was significantly elevated compared with sedentary (P < or = 0.05) in the prescriptions utilizing 200 min/wk (low volume/moderate intensity, high volume/vigorous intensity). In the high-volume/vigorous-intensity group, indexes of muscle mitochondrial density followed a pattern paralleling insulin action by being elevated at 15 days compared with pretraining; this trend was not evident in the low-volume/moderate-intensity group. These findings suggest that in overweight/obese subjects a relatively chronic persistence of enhanced insulin action may be obtained with endurance-oriented exercise training; this persistence, however, is dependent on the characteristics of the exercise training performed.

Topics: Anaerobic Threshold; Body Mass Index; Body Weight; Dyslipidemias; Exercise; Female; Glucose Tolerance Test; Glycogen; Homeostasis; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Mitochondria, Muscle; Muscle, Skeletal; Obesity; Oxygen Consumption; Physical Fitness

This study examined the effects of 3 recovery drinks on endurance performance following glycogen-depleting exercise. Nine trained male cyclists performed 3 experimental trials, in a randomized counter-balanced order, consisting of a glycogen-depleting trial, a 4-h recovery period, and a cycle to exhaustion at 70% power at maximal oxygen uptake. At 0 and 2 h into the recovery period, participants consumed chocolate milk (CM), a carbohydrate replacement drink (CR), or a fluid replacement drink (FR). Participants cycled 51% and 43% longer after ingesting CM (32 +/- 11 min) than after ingesting CR (21 +/- 8 min) or FR (23 +/- 8 min). CM is an effective recovery aid after prolonged endurance exercise for subsequent exercise at low-moderate intensities.

Topics: Adolescent; Adult; Animals; Beverages; Body Weight; Cacao; Dietary Carbohydrates; Energy Intake; Glycogen; Heart Rate; Humans; Isotonic Solutions; Lactic Acid; Male; Milk; Muscle Contraction; Muscle, Skeletal; Oxygen Consumption; Physical Endurance; Recovery of Function; Time Factors; Young Adult

A clinical trial was conducted to evaluate the safety and efficacy of alglucosidase alfa in infants and children with advanced Pompe disease.. Open-label, multicenter study of IV alglucosidase alfa treatment in 21 infants 3-43 months old (median 13 months) with minimal acid alpha-glucosidase activity and abnormal left ventricular mass index by echocardiography. Patients received IV alglucosidase alfa every 2 weeks for up to 168 weeks (median 120 weeks). Survival results were compared with an untreated reference cohort.. At study end, 71% (15/21) of patients were alive and 44% (7/16) of invasive-ventilator free patients remained so. Compared with the untreated reference cohort, alglucosidase alfa reduced the risk of death by 79% (P < 0.001) and the risk of invasive ventilation by 58% (P = 0.02). Left ventricular mass index improved or remained normal in all patients evaluated beyond 12 weeks; 62% (13/21) achieved new motor milestones. Five patients were walking independently at the end of the study and 86% (18/21) gained functional independence skills. Overall, 52% (11/21) of patients experienced infusion-associated reactions; 95% (19/20) developed IgG antibodies to recombinant human lysosomal acid alpha-glucosidase; no patients withdrew from the study because of safety concerns.. In this population of infants with advanced disease, biweekly infusions with alglucosidase alfa prolonged survival and invasive ventilation-free survival. Treatment also improved indices of cardiomyopathy, motor skills, and functional independence.

Topics: alpha-Glucosidases; Body Height; Body Weight; Child, Preschool; Cough; Echocardiography; Enzyme-Linked Immunosorbent Assay; Female; Glycogen; Glycogen Storage Disease Type II; Humans; Immunoglobulin G; Infant; Kaplan-Meier Estimate; Male; Muscle, Skeletal; Skin Diseases; Time Factors; Treatment Outcome

The main aim of this study was to examine the hypothesis that creatine (Cr) feeding enhances myocellular glycogen storage in humans undergoing carbohydrate loading. Twenty trained male subjects were randomly assigned to have their diets supplemented daily with 252 g of glucose polymer (GP) and either 21 g of Cr (CR-GP, n = 10) or placebo (PL-GP, n = 10) for 5 days. Changes in resting myocellular glycogen and phosphocreatine (PCr) were determined with Magnetic Resonance Spectroscopy (13C- and 31P-MRS, respectively). After CR-GP, the levels of intramyocellular glycogen increased from 147 +/- 13 (standard error) mmol x (kg wet weight(-1)) to 172 +/- 13 m mol x (kg wet weight)(-1), while it increased from 134 +/- 17 mmol x (kg wet weight)(-) to 182 +/- 17 mmol x (kg wet weight)(-1) after PL-GP; the increments in intramyocellular glycogen concentrations were not statistically different. The increment in the PCr/ATP ratio after CR-GP (+ 0.20 +/- 0.12) was significantly different compared to PL-GP (- 0.34 +/- 0.16) (p < 0.05). The present results do not support the hypothesis that Cr loading increases muscle glycogen storage.

Topics: Adenosine Triphosphate; Adult; AMP-Activated Protein Kinases; Body Weight; Carbohydrate Metabolism; Carbon Isotopes; Creatine; Diet; Dietary Supplements; Double-Blind Method; Energy Intake; Glucans; Glycogen; Humans; Magnetic Resonance Spectroscopy; Male; Muscle Fibers, Skeletal; Phosphates; Phosphocreatine; Phosphorus Isotopes; Young Adult

Due to the current lack of clarity, we examined whether 5 days of dietary creatine (Cr) supplementation per se can influence the glycogen content of human skeletal muscle. Six healthy male volunteers participated in the study, reporting to the laboratory on four occasions to exercise to the point of volitional exhaustion, each after 3 days of a controlled normal habitual dietary intake. After a familiarization visit, participants cycled to exhaustion in the absence of any supplementation (N), and then 2 wk later again they cycled to exhaustion after 5 days of supplementation with simple sugars (CHO). Finally, after a further 2 wk, they again cycled to exhaustion after 5 days of Cr supplementation. Muscle samples were taken at rest before exercise, at the time point of exhaustion in visit 1, and at subsequent visit time of exhaustion. There was a treatment effect on muscle total Cr content in Cr compared with N and CHO supplementation (P < 0.01). Resting muscle glycogen content was elevated above N following CHO (P < 0.05) but not after Cr. At exhaustion following N, glycogen content was no different from CHO and Cr measured at the same time point during exercise. Cr supplementation under conditions of controlled habitual dietary intake had no effect on muscle glycogen content at rest or after exhaustive exercise. We suggest that any Cr-associated increases in muscle glycogen storage are the result of an interaction between Cr supplementation and other mediators of muscle glycogen storage.

Topics: Adenosine Triphosphate; Administration, Oral; Adult; Blood Glucose; Body Weight; Carbonated Beverages; Creatine; Cross-Over Studies; Dietary Carbohydrates; Dietary Supplements; Exercise; Glycogen; Humans; Male; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal; Phosphocreatine; Reference Values; Time Factors

Thirty-three Holstein cows averaging 687 kg of body weight were allotted 6 wk before the expected date of parturition to 11 groups of 3 cows blocked within parity for similar calving dates to determine the effects of feeding different sources of fatty acids on blood parameters related to fatty liver and profile of fatty acids in plasma and liver. Cows were fed lipid supplements from 6 wk before the expected date of parturition until d 28 of lactation. Cows within each block were assigned to 1 of 3 isonitrogenous and isoenergetic dietary supplements: control with no added lipids (CO); unsaturated lipids supplied as whole flaxseed (FL; 3.3 and 11.0% of the dry matter in prepartum and postpartum diets, respectively); and saturated lipids supplied as Energy Booster (EB; 1.7 and 3.5% of the DM in prepartum and postpartum diets, respectively). Diets EB and FL had similar ether extract concentrations. Multiparous cows fed EB had lower dry matter intake and milk production, higher concentrations of nonesterified fatty acids and beta-hydroxybutyrate in plasma and triglycerides (TG) and total lipids in liver, and lower concentrations of plasma glucose and liver glycogen than those fed FL and CO. Production of 4% fat-corrected milk was similar among treatments. Multiparous cows fed FL had the highest liver concentrations of glycogen on wk 2 and 4 after calving and lowest concentrations of TG on wk 4 after calving. Liver C16:0 relative percentages in multiparous cows increased after calving whereas those of C18:0 decreased. Relative percentages of liver C16:0 were higher in wk 2 and 4 postpartum for multiparous cows fed EB compared with those fed CO and FL; those of C18:0 were lower in wk 4 postpartum for cows fed EB compared with those fed CO and FL. Liver C18:1 relative percentages of multiparous cows increased after calving and were higher in wk 4 for cows fed EB compared with those fed CO and FL. The inverse was observed for liver C18:2 relative percentages. In general, diets had more significant effects on plasma concentrations of nonesterified fatty acids, beta-hydroxybutyrate, and glucose and liver profiles of fatty acids, TG, total lipids, and glycogen of multiparous than primiparous cows. These data suggest that feeding a source of saturated fatty acids increased the risk of fatty liver in the transition cow compared with feeding no lipids or whole flaxseed. Feeding flaxseed compared with no lipids or a source of saturated fatty acids from 6 wk before calvin

Topics: Animals; Blood Glucose; Body Weight; Cattle; Cattle Diseases; Diet; Dietary Supplements; Fatty Acids; Fatty Acids, Nonesterified; Female; Flax; Glycogen; Lactation; Lipid Metabolism; Lipids; Liver; Milk; Pregnancy; Puerperal Disorders; Time Factors

(-)-Hydroxycitrate (HCA) might promote weight maintenance by limiting the capacity for de novo lipogenesis (DNL). It was investigated whether HCA may reduce DNL in humans during a persistent excess of energy intake as carbohydrate. In a double-blind, placebo-controlled, randomized and cross-over design, 10 sedentary lean male subjects (mean+/-S.D., age: 24+/-5 years, BMI: 21.8+/-2.1 kg/m2) performed a glycogen depletion exercise test followed by a 3-day high-fat diet (F/CHO/P, 60/25/15% energy; 100% of energy expenditure (EE)) and a 7-day high-CHO diet (F/CHO/P, <5/>85/10% energy; 130-175% of EE; overfeeding). During overfeeding, they ingested 3 x 500 mg/day HCA or placebo (PLA). Each intervention ended with a 60-h stay in the respiration chamber (days 9 and 10). Body weight increased during overfeeding (mean+/-S.E., HCA: 2.9+/-0.2 kg, PLA: 2.8+/-0.2 kg). Respiratory quotient (RQ) was >1.00 in all subjects indicating that DNL was present. On day 9, 24-h EE was lower with HCA compared to PLA (P < 0.05). On day 10, resting metabolic rate and RQ during night were lower (P < 0.01 and P < 0.05, respectively). Non-protein RQ, fat balance and net fat synthesis as DNL tended to be lower (P < 0.1) with HCA compared to PLA indicating lower DNL; activity-induced EE was higher with HCA (P < 0.05) indicating the urge to eliminate the excess of energy ingested. We conclude that an experimental condition resulting in DNL in humans was created and that treatment with HCA during overfeeding with carbohydrates may reduce DNL.

Topics: Adult; Affect; Anthropometry; Attitude; Body Composition; Body Weight; Calorimetry, Indirect; Citrates; Cross-Over Studies; Dietary Carbohydrates; Double-Blind Method; Energy Metabolism; Exercise; Glycogen; Humans; Lipid Metabolism; Lipids; Male; Oxidation-Reduction; Respiratory Mechanics

To conduct an open-label, multinational, multicenter study examining the safety and efficacy of recombinant human acid alpha-glucosidase (rhGAA) in treatment of infantile-onset Pompe disease.. We enrolled 8 infant patients who had Pompe disease with GAA activity <1% of normal, cardiomyopathy, and hypotonia. In the 52-week initial phase, rhGAA was infused intravenously at 10 mg/kg weekly; an extension phase continued survivors' treatment with 10 to 20 mg/kg of rhGAA weekly or 20 mg/kg every 2 weeks for as long as 153 weeks. Safety measurements included adverse events, laboratory tests, and anti-rhGAA antibody titers. Efficacy evaluations included survival, ventilator use, echocardiograms, growth, and motor and cognitive function.. After 52 weeks of treatment, 6 of 8 patients were alive, and 5 patients were free of invasive ventilator support. Clinical improvements included ameliorated cardiomyopathy and improved growth and cognition. Five patients acquired new motor milestones; 3 patients walked independently. Four patients died after the initial study phase; the median age at death or treatment withdrawal for all patients was 21.7 months, significantly later than expected for patients who were not treated. Treatment was safe and well tolerated; no death was drug-related.. rhGAA improved ventilator-free survival, cardiomyopathy, growth, and motor function in patients with infantile-onset Pompe disease compared with outcomes expected for patients without treatment.

Topics: alpha-Glucosidases; Body Height; Body Weight; Cardiomyopathy, Hypertrophic; Child Development; Europe; Female; Glycogen; Glycogen Storage Disease Type II; Hearing Disorders; Humans; Infant; Infant, Newborn; Infusions, Intravenous; Male; Muscle Hypotonia; Muscle, Skeletal; Respiration, Artificial; Treatment Outcome; United States

Women use less carbohydrate during endurance exercise, as compared with men. In rodents, 17beta-estradiol (E2) supplementation robustly increases lipid use and lowers muscle and liver glycogen use during exercise. E2 supplementation has been found to influence substrate selection by decreasing glucose rate of appearance (Ra), disappearance (Rd), and metabolic clearance rate during exercise in humans; however, neither a change in total carbohydrate use nor a sparing of muscle glycogen was demonstrated.. We investigated the effect of 8 d of E2 (2 mg/d) supplementation on glucose turnover and net muscle glycogen use in 11 men using a randomized, double-blind, placebo-controlled, crossover design. Subjects underwent primed constant infusion of [6,6-(2)H]glucose, and muscle biopsies were taken before and after 90 min of cycling at 65% maximal oxygen uptake.. E2 supplementation decreased the respiratory exchange ratio (P = 0.03) and glucose Ra and Rd (both P = 0.04) during exercise, as compared with placebo. E2 supplementation lowered proglycogen (P < 0.05) and total glycogen (P = 0.04) concentration, as compared with placebo; however, there was no effect of E2 on net muscle glycogen use during exercise.. These findings show that E2 supplementation alters fuel selection in exercising men by increasing lipid use and reducing carbohydrate use, glucose Ra (primarily liver glucose production), and Rd (primarily muscle glucose uptake). Furthermore, E2 reduces the basal level of total muscle glycogen, particularly the proglycogen form.

Topics: Adult; Body Weight; Double-Blind Method; Estradiol; Exercise; Glucose; Glycogen; Humans; Lactic Acid; Lipid Metabolism; Male; Metabolic Clearance Rate

The present study was undertaken to explore the effects of creatine and creatine plus protein supplementation on GLUT-4 and glycogen content of human skeletal muscle. This was investigated in muscles undergoing a decrease (immobilization) and subsequent increase (resistance training) in activity level, compared with muscles with unaltered activity pattern. A double-blind, placebo-controlled trial was performed by 33 young healthy subjects. The subjects' right legs were immobilized with a cast for 2 wk, followed by a 6-wk resistance training program for the right knee extensor muscles. The participants were supplemented throughout the study with either placebo (Pl group) or creatine (Cr group) or with creatine during immobilization and creatine plus protein during retraining (Cr+P group). Needle biopsies were bilaterally taken from the vastus lateralis. GLUT-4 protein expression was reduced by the immobilization in all groups (P < 0.05). During retraining, GLUT-4 content increased (P < 0.05) in both Cr (+24%) and Cr+P (+33%), which resulted in higher posttraining GLUT-4 expression compared with Pl (P < 0.05). Compared with Pl, muscle glycogen content was higher (P < 0.05) in the trained leg in both Cr and Cr+P. Supplements had no effect on GLUT-4 expression or glycogen content in contralateral control legs. Area under the glucose curve during the oral glucose tolerance test was decreased from 232 +/- 23 mmol. l(-1). min(-1) at baseline to 170 +/- 23 mmol. l(-1). min(-1) at the end of the retraining period in Cr+P (P < 0.05), but it did not change in Cr or Pl. We conclude that creatine intake stimulates GLUT-4 and glycogen content in human muscle only when combined with changes in habitual activity level. Furthermore, combined protein and creatine supplementation improved oral glucose tolerance, which is supposedly unrelated to the changes in muscle GLUT-4 expression.

Topics: Adolescent; Adult; Blood Glucose; Body Weight; Cell Count; Creatine; Dietary Proteins; Double-Blind Method; Female; Functional Laterality; Glucose; Glucose Tolerance Test; Glucose Transporter Type 4; Glycogen; Humans; Immobilization; Male; Monosaccharide Transport Proteins; Muscle Contraction; Muscle Fibers, Fast-Twitch; Muscle Fibers, Slow-Twitch; Muscle Proteins; Muscle, Skeletal; Physical Fitness

The hypermetabolic response to burn increases protein catabolism. Euglycemic hyperinsu-linemia with exogenous insulin maintains muscle protein by continued stimulation of net protein synthesis. Our aim was to determine the effect of euglycemic hyperinsulinemia over the entire hospitalization on muscle anabolism by investigating lean body mass (LBM) as the primary endpoint.. Eighteen subjects between the ages of 2 and 18 with burns of more than 40% were prospectively randomized into 2 groups, a control (n = 9) and a treatment group (n = 9). The treatment group was given continuous intravenous insulin at a rate of at least 1.5 microU/kg/min to maintain serum glucose levels between 100 to 140 mg/dL. Treatment was instituted 24 to 48 hours after arrival and continued until the patient's injury was 95% healed. All patients received continuous enteral feeding. Patients underwent body composition studies by dual-energy x-ray absorptiometry (DEXA) scan on postoperative day 6 after initial burn excision and when 95% healed.. Nutritional intakes were not different between groups. In the control, subjects continued catabolism resulted in peripheral muscle wasting and centripetal obesity with diminished truncal LBM. The treatment group had improvement in lean body mass (P =.004) and bone mass (P =.025). The treatment group also had less peripheral muscle wasting with overall increases in upper/lower extremity LBM (P =.005). Hospital length of stay in days per percent of total body surface area burned was decreased in the insulin group (control = 1.03 +/- 0.1 vs 0.7 +/- 0.9 for insulin patients; P <.05).. Euglycemic hyperinsulinemia throughout the hospital course mitigates muscle catabolism and preserves lean body mass.

Topics: Adult; Blood Glucose; Body Composition; Body Weight; Burns; Calorimetry, Indirect; Child; Child, Preschool; Electrolytes; Energy Metabolism; Female; Follow-Up Studies; Glucose Clamp Technique; Glycogen; Humans; Hyperinsulinism; Hypoglycemic Agents; Insulin; Male; Muscle, Skeletal; Nutrition Assessment; Prospective Studies

The effects of long-term athletic training are associated with excessive skeletal muscle turnover attributable to increased rates of myofibrillar protein synthesis and proteolysis, which are mechanisms poorly understood in the athletic dog. A physiologic field study using 44 English pointers and Labrador retrievers that had been purposely bred for bird hunting and retrieving was conducted to examine changes in the ubiquitin-proteasome (UP) pathway, which has been implicated in exercise-induced proteolysis. Muscle biopsy samples were collected from all dogs in September (preseason, pretraining) and February (peak season, peak activity). Western blot analysis was used to assess changes in expression of various components of the UP pathway in the biopsy samples. Citrate synthase and glycogen levels were also measured in a subset of these samples. Results across the population indicated pronounced up-regulation of ubiquitinated conjugates and the p31 regulatory capping subunit during the peak hunting period compared with the preseason period. In contrast, the catalytic core of the proteasome (beta-subunits) showed no apparent up-regulation in response to increased physical activity. Increased physical activity during the hunting season was associated with increased muscle glycogen levels and citrate synthase activity in these dogs. Overall, up-regulation of specific components of the UP pathway was an indication that it plays a role in the proteolytic process associated with skeletal muscle turnover during long-term athletic training, as previously believed.

Topics: Animals; Blotting, Western; Body Weight; Citrate (si)-Synthase; Dogs; Female; Glycogen; Male; Motor Activity; Muscle, Skeletal; Peptide Hydrolases; Proteasome Endopeptidase Complex; Ubiquitin; Up-Regulation

We determined whether a low-fat diet reduces intramuscular triglyceride (IMTG) concentration, whole body lipolyis, total fat oxidation, and calculated nonplasma fatty acid (FA) oxidation during exercise. Seven endurance-trained cyclists were studied over a 3-wk period during which time they exercised 2 h/day at 70% of maximum O2 uptake VO(2 max) and consumed approximately 4,400 kcal/day. During the 1st wk, their fat intake provided 32% of energy. During the 2nd and 3rd wk, they were randomly assigned to eat 2 or 22% of energy from fat (2%FAT or 22%FAT). Compared with 22%FAT, 2%FAT lowered IMTG concentration and raised muscle glycogen concentration at rest (P < 0.05). Metabolism was studied during 1 h of exercise at 67% VO(2 max) performed in the fasted state. 2%FAT resulted in a 27% reduction (P < 0.05) in total fat oxidation vs. 22%FAT without altering the stable isotopically determined rates of plasma free fatty acid or glucose disappearance. Therefore, 2%FAT reduced calculated nonplasma FA oxidation by 40% in association with a 19% reduction in whole body lipolysis while increasing calculated minimal muscle glycogen oxidation compared with 22%FAT (all P < 0.05). In summary, an extremely low fat (2% of energy) and high-carbohydrate diet lowers whole body lipolysis, total fat oxidation, and nonplasma FA oxidation during exercise in the fasted state in association with a reduced concentration of intramuscular triglyceride.

Topics: Adult; Bicycling; Blood Glucose; Body Composition; Body Weight; Diet, Fat-Restricted; Dietary Carbohydrates; Energy Intake; Exercise; Fasting; Fatty Acids; Fatty Acids, Nonesterified; Glycogen; Humans; Kinetics; Lipid Metabolism; Lipolysis; Male; Muscle, Skeletal; Oxidation-Reduction; Oxygen Consumption; Physical Endurance; Triglycerides

The hypotheses that postexercise replenishment of intramyocellular lipids (IMCL) is enhanced by endurance training and that it depends on fat intake were tested. Trained and untrained subjects exercised on a treadmill for 2 h at 50% peak oxygen consumption, reducing IMCL by 26-22%. During recovery, they were fed 55% (high fat) or 15% (low fat) lipid energy diets. Muscle substrate stores were estimated by (1)H (IMCL)- and (13)C (glycogen)-magnetic resonance spectroscopy in tibialis anterior muscle before and after exercise. Resting IMCL content was 71% higher in trained than untrained subjects and correlated significantly with glycogen content. Both correlated positively with indexes of insulin sensitivity. After 30 h on the high-fat diet, IMCL concentration was 30-45% higher than preexercise, whereas it remained 5-17% lower on the low-fat diet. Training status had no significant influence on IMCL replenishment. Glycogen was restored within a day with both diets. We conclude that fat intake postexercise strongly promotes IMCL repletion independently of training status. Furthermore, replenishment of IMCL can be completed within a day when fat intake is sufficient.

Topics: Adult; Body Composition; Body Weight; Carbon Isotopes; Dietary Fats; Exercise Test; Glycogen; Humans; Insulin Resistance; Lactic Acid; Lipid Metabolism; Lipids; Magnetic Resonance Spectroscopy; Male; Muscle, Skeletal; Oxygen Consumption; Physical Exertion; Physical Fitness; Time Factors

We evaluated the effect of carbohydrate (CHO) loading on cycling performance that was designed to be similar to the demands of competitive road racing. Seven well-trained cyclists performed two 100-km time trials (TTs) on separate occasions, 3 days after either a CHO-loading (9 g CHO. kg body mass(-1). day(-1)) or placebo-controlled moderate-CHO diet (6 g CHO. kg body mass(-1). day(-1)). A CHO breakfast (2 g CHO/kg body mass) was consumed 2 h before each TT, and a CHO drink (1 g CHO. kg(.)body mass(-1). h(-1)) was consumed during the TTs to optimize CHO availability. The 100-km TT was interspersed with four 4-km and five 1-km sprints. CHO loading significantly increased muscle glycogen concentrations (572 +/- 107 vs. 485 +/- 128 mmol/kg dry wt for CHO loading and placebo, respectively; P < 0.05). Total muscle glycogen utilization did not differ between trials, nor did time to complete the TTs (147.5 +/- 10.0 and 149.1 +/- 11.0 min; P = 0.4) or the mean power output during the TTs (259 +/- 40 and 253 +/- 40 W, P = 0.4). This placebo-controlled study shows that CHO loading did not improve performance of a 100-km cycling TT during which CHO was consumed. By preventing any fall in blood glucose concentration, CHO ingestion during exercise may offset any detrimental effects on performance of lower preexercise muscle and liver glycogen concentrations. Alternatively, part of the reported benefit of CHO loading on subsequent athletic performance could have resulted from a placebo effect.

Topics: Adult; Bicycling; Body Weight; Dietary Carbohydrates; Glycogen; Humans; Liver Glycogen; Male; Muscle, Skeletal; Oxygen Consumption; Placebos

Three experiments were conducted with turkey poults to determine the effects of diet and delayed placement on growth and selected aspects of carbohydrate metabolism. Immediately after hatch, poults were placed in batteries and allowed either immediate access to feed and water (FED) or feed and water withdrawal for 48 h (WH). In the first two experiments, diets contained a high proportion of carbohydrate from corn (CHO; 60% of diet) or a lower proportion of corn (26%) and 10% supplemental animal-vegetable fat (FAT). The WH poults weighed less than FED poults at 5 d postfeeding (DPF; P < or = 0.05) but not at 13 DPF. Similarly, poults fed the CHO diet were heavier 5 DPF, whereas poults fed the FAT diet were heavier at 13 DPF (P < or = 0.05). Regardless of feeding regimen (WH vs FED), all poults were nearly depleted of hepatic glycogen prior to feeding. At 2 DPF, poults fed the CHO diet had more hepatic glycogen concentrations compared with those fed the FAT diet (P < or = 0.002). In addition, one-half of the WH poults fed the CHO diet had plasma glucose concentrations in excess of 500 mg/dL at 2 DPF. In Experiment 3, similar feeding regimens and diets were used with the addition of a third diet containing a synthetic medium-chain triglyceride emulsion (MCT) as the supplemental fat source. Poults fed the FAT and MCT diets were 41 g heavier than poults fed the CHO diet at 13 DPF (P < or = 0.05). Similar to the results of Experiment 2, poults fed the CHO diet had increased hepatic glycogen concentrations at 2 DPF, and within the WH treatment at 2 DPF, 30% of the poults had plasma glucose concentrations in excess of 500 mg/dL. Metabolic consequences of delayed placement were also found. At both 4 and 7 DPF, WH poults had a reduced capacity for glucose clearance 60 min after a glucose load (250 mg; P < or = 0.05). The current experiments demonstrate that supplemental fat may ease the metabolic shift toward glycolysis after hatching, thereby improving growth through 2 wk of age.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Weight; Dietary Carbohydrates; Dietary Fats; Female; Glycogen; Liver; Male; Time Factors; Turkeys

The physiological and behavioural effects on cattle of transporting them for periods of 14, 21, 26 and 31 hours, including a stop for a rest and drink on the lorry after 14 hours, were studied in 120 transported animals and 48 control animals. The physiological measurements indicated that a journey lasting 31 hours was not excessively physically demanding, but many of the animals chose to lie down after approximately 24 hours. The animals that lay down had higher plasma cortisol levels than those that remained standing. Many animals chose not to drink during the rest stop. Physiological measurements made after the journeys indicated that 24 hours in lairage, with hay and water freely available, allowed the animals to recover substantially, although not completely, irrespective of the journey time.

Topics: 3-Hydroxybutyric Acid; Animals; Behavior, Animal; Blood Glucose; Blood Proteins; Body Weight; Cattle; Creatine Kinase; Fatty Acids, Nonesterified; Female; Glycogen; Hematocrit; Humidity; Hydrocortisone; Male; Motor Vehicles; Muscle, Skeletal; Osmolar Concentration; Temperature; Time Factors; Urea

It is controversial whether food intake in humans is under day-to-day regulation to maintain constant body glycogen stores. In eight white males with a mean (+/-SD) age of 30 +/- 4 y, body weight of 82 +/- 20 kg, and percentage body fat of 22 +/- 5%, exercise and diets were used to produce either high (HG) or low glycogen (LG) stores in a randomized crossover design. After each treatment a vastus lateralis muscle biopsy was obtained. Subsequent ad libitum food intake was measured with an automated food-selection system during 2 d in a respiratory chamber. Despite a 46 +/- 21% difference in muscle glycogen between the two treatments, ad libitum 2-d food intakes (energy, weight, or macronutrients) were similar between treatments (HG: 23.80 +/- 4.67 MJ/d; LG: 21.20 +/- 6.73 MJ/d). However, energy intake on the second day of ad libitum feeding was negatively correlated with carbohydrate balance on the first day, adjusted for the effect of total energy intake and treatment. Adjusted carbohydrate balance on day 1 only explained 9% of the variance in energy intake on day 2. The 24-h respiratory quotient on the first day after treatment was higher after the HG than after the LG treatment: 0.94 +/- 0.04 and 0.88 +/- 0.07 (P < 0.001). The findings suggest that 1) body glycogen stores play at most a minor role in short-term food intake regulation, and 2) in the short term, imbalances in glycogen stores are corrected by adjustments of macronutrient oxidation rates.

Topics: Adult; Biopsy; Body Weight; Calorimetry, Indirect; Cross-Over Studies; Dietary Carbohydrates; Eating; Energy Metabolism; Exercise; Feeding Behavior; Glucose; Glycogen; Humans; Infusions, Intravenous; Lipids; Male; Muscle, Skeletal; Respiration

Eight international class lightweight rowers were examined to determine the efficacy of rehydrating with water following 24 h of dehydration on body fluid balance, metabolic function, and rowing performance. The rowers performed a maximal rowing trial on a Gjessing rowing ergometer (4200 revs, 3-kg resistance) while euhydrated (ET) and following partial rehydration (RT). Body weight was reduced using exercise together with food and fluid restriction over 24 h and was followed by consumption of 1.5 l of water over 2 h. Body weight decreased 5.16 +/- 0.14% (P < 0.05) and plasma volume decreased 12.5 +/- 1.4% (P < 0.05) after dehydration. Rehydration restored plasma volume by 6.02 +/- 0.62%. Rowing trial time increased significantly from 7.02 +/- 0.17 min for the ET to 7.38 +/- 0.21 min for the RT (P < 0.05). The net plasma lactate accumulation decreased significantly from 8.77 +/- 0.31 mmol.l-1 for the ET to 6.77 +/- 0.24 mmol.l-1 for the RT (P < 0.05). Glycogen content (glycosyl units) of the vastus lateralis decreased by 203.6 +/- 18.6 mmol.kg-1 DW during the ET compared with 139.9 +/- 13.4 mmol.kg-1 DW during the RT (P < 0.05). These results demonstrate that the dehydration/rehydration protocol reduced maximal rowing performance due to lowered plasma volume and decreased muscle glycogen utilization.

Topics: Adult; Body Weight; Dehydration; Fluid Therapy; Glycogen; Humans; Male; Muscles; Plasma Volume; Sports; Water-Electrolyte Balance

Early weight gain by starving patients managed with total parenteral nutrition has been regarded as spurious - that is, merely an increase in body water. We designed an experiment to mimic the starved state in which glycogen stores are depleted and sodium intake is very low. The subjects were then repleted with a sodium-free, high carbohydrate intake. All subjects who received potassium gained weight and switched to a respiratory exchange ratio which suggested mainly carbohydrate oxidation. From changes in weight and total body water the weight gain was calculated to be the consequence of glycogen storage with 1 g of glycogen obligating 3.21 +/- 0.57 g water. Two patients with total dysphagia showed a similar pattern. Two subjects who did not receive potassium showed a rise in respiratory exchange ratio but failed to store glycogen. Early weight gain in patients who received high-carbohydrate feeding after starvation is a normal phenomenon and represents a return to a more hydrated state consequent upon glycogen repletion.

Topics: Body Water; Body Weight; Deglutition Disorders; Dietary Carbohydrates; Female; Glycogen; Humans; Male; Parenteral Nutrition; Parenteral Nutrition, Total; Potassium; Sodium; Starvation

Topics: Adolescent; Adult; Blood Glucose; Body Weight; Female; Fructose; Glucose; Glycogen; Hepatic Veins; Humans; Infusions, Parenteral; Injections, Intravenous; Male; Middle Aged; Musculoskeletal System; Physical Exertion

Topics: Body Weight; Chlorthalidone; Diuresis; Diuretics; Furosemide; Glycogen; Humans; Muscles; Water-Electrolyte Balance

The concept of lactate shuttle is widely accepted in exercise physiology. Lactate transport is mediated by monocarboxylate transporters (MCT), which enable cells to take up and release lactate. However, the role of lactate during exercise has not yet been fully elucidated. In this study, we investigated the effects of lactate transport inhibition on exercise capacity and metabolism in mice. Here, we demonstrated that MCT1 inhibition by α-cyano-4-hydroxycinnamate administration (4-CIN, 200 mg/g of body weight) reduced the treadmill running duration at 20 m/min. The administration of 4-CIN increased the blood lactate concentration immediately after exercise. With matched exercise duration, the muscle lactate concentration was higher while muscle glycogen content was lower in 4-CIN-administered mice. Further, we showed that MCT4 inhibition by bindarit administration (50 mg/kg of body weight) reduced the treadmill running duration at 40 m/min. Bindarit administration increased the muscle lactate but did not alter the blood lactate and glucose concentrations, as well as muscle glycogen content, immediately after exercise. A negative correlation was observed between exercise duration at 40 m/min and muscle lactate concentration immediately after exercise. Our results suggest that lactate transport via MCT1 and MCT4 plays a pivotal role in sustaining exercise.

Topics: Animals; Body Weight; Exercise Tolerance; Glycogen; Lactic Acid; Mice; Monocarboxylic Acid Transporters; Muscle Proteins; Muscle, Skeletal; Symporters

Fatigue syndrome is a major health problem that affects the voluntary activities of an individual. Particularly, exercise-induced fatigue has become a serious concern in people's health. Since polysaccharides from various medicinal plants have been reported for anti-fatigue effect, the current study deals with the anti-fatigue potential of water-soluble polysaccharides of the Chinese medicinal plant Semen cassiae (Cassia obtusifolia L.) in BALB/c mice. Water-soluble polysaccharides from Semen cassiae were extracted using aqueous solvent (water). An orthogonal test design was employed for the optimization of polysaccharide extraction. The conditions optimized through this design unveiled the raw materials to solvent ratio as 1:30. The optimal temperature and time duration were found to be 80°C and 3.5 h, respectively. The yield of soluble polysaccharides at these specified conditions was 5.42%. Strikingly, the water-soluble polysaccharide from S. cassiae exhibited strong anti-fatigue activity at 100 mg/kg in BALB/c mice. S. cassiae polysaccharide extended the weight-loaded swimming duration in BALB/c mice. In addition, it ameliorated the level of antioxidant enzymes (SOD, GPX) while decreased the blood urea nitrogen, creatine phosphokinase, triglyceride, lactic acid, lactate dehydrogenase, and malondialdehyde levels in blood serum. Moreover, the assessment of the immunomodulatory effect of S. cassia polysaccharides unveiled the enhancement of B-cell and T-cell lymphocytes, denoting the positive effect on physical immunity.

Topics: Animals; Body Weight; Cassia; Cell Proliferation; Fatigue; Glycogen; Liver; Lymphocytes; Male; Mice, Inbred BALB C; Motor Activity; Muscle, Skeletal; Plant Extracts; Plants, Medicinal; Polysaccharides; Solubility; Swimming; Water

This study investigated the role of GABA in attenuating liver insulin resistance (IR) in type 2 diabetes parents and reducing its risk in their descendants' liver. Both sexes' rats were divided into four groups of non-diabetic control, diabetic control (DC), GABA-treated (GABA), and insulin-treated (Ins). The study duration lasted for six months and the young animals followed for four months. Consequently, hyperinsulinemic-euglycemic clamp was performed for all animals. Apart from insulin tolerance test (ITT), serum and liver lipid profile were measured in all groups. Glycogen levels, expression of Foxo1, Irs2, Akt2, and Pepck genes in the liver were assessed for all groups. Overall, GABA improved ITT, increased liver glycogen levels and decreased lipid profile, blood glucose level, and HbA1c in parents and their offspring in compared to the DC group. GIR also increased in both parents and their offspring by GABA. Moreover, the expression of Foxo1, Irs2, Akt2, and Pepck genes improved in GABA-treated parents and their descendants in compared to DC group. Results indicated that GABA reduced liver IR in both parents and their offspring via affecting their liver insulin signaling and gluconeogenesis pathways.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Endocrinology; Female; gamma-Aminobutyric Acid; Gluconeogenesis; Glucose; Glucose Clamp Technique; Glucose Tolerance Test; Glycogen; Hyperinsulinism; Insulin; Insulin Resistance; Liver; Male; Rats; Rats, Wistar; Signal Transduction

In the present study, we explored the anti-fatigue activity and its potential mechanism of a purified Polygonatum cyrtonema polysaccharide (PCP) on mice using weight-loaded swimming test. Results showed that PCP remarkably prolonged the exhaustive swimming time of mice when compared with normal control group. Meanwhile, PCP decreased serum levels of lactic acid (LA), blood uric nitrogen (BUN), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA), and increased the contents of liver glycogen, muscle glycogen and muscle ATP. These results revealed that PCP had good anti-fatigue ability. The histomorphologic analysis showed that PCP increased the cross-section area of the muscle fibers. Furthermore, PCP significantly enhanced the protein levels of bone morphogenetic protein-2 (BMP-2), phosphor-Smad1, Runt-related transcription factor 2 (Runx2) and osteocalcin (OC) in skeleton. Similar variation was also observed in the expression of osteocalcin signaling mediators of phosphorylated cAMP-response element binding protein (p-CREB) and phosphorylated hormone-sensitive lipase (p-HSL) in skeletal muscle. These results suggested that PCP resisted fatigue possibly via regulating osteocalcin signaling.

Topics: Animals; Body Weight; Catalase; Fatigue; Glutathione Peroxidase; Glycogen; Male; Malondialdehyde; Mice; Mice, Inbred C57BL; Muscle, Skeletal; Plant Extracts; Polygonatum; Polysaccharides; Signal Transduction; Superoxide Dismutase

Cistanche tubulosa (Schrenk) R. Wight (Orobanchaceae) is a frequently prescribed component in many traditional herbal prescriptions which are used to treat diabetes in China. In recent studies, the antidiabetic activity of Cistanche tubulosa extracts have been confirmed. However, no systematic investigation has been reported on the total glycosides of Cistatnche tubulosa (TGCT).. The present study aimed to investigate the hypoglycemic and hypolipidemic effects of TGCT and the potential mechanisms in diet/streptozotocin (STZ)-induced diabetic rats, and to chemically characterize the main constituents of TGCT.. The major constituents of TGCT were characterized by HPLC/Q-TOF-MS and the analytical quantification was performed with HPLC-DAD. Type 2 diabetic rats were induced by high-fat high-sucrose diet (HFSD) and a single injection of STZ (30 mg/kg). TGCT (50 mg/kg, 100 mg/kg and 200 mg/kg) or metformin (200 mg/kg) were orally administered for 6 weeks. Body weight and calorie intake were monitored throughout the experiment. Fasting plasma glucose (FPG), oral glucose tolerance test (OGTT), area under curve of glucose (AUC-G), glycosylated hemoglobin (HbA1c), fasting insulin, serum C-peptide, glycogen content and insulin sensitivity index were tested. The levels of phosphorylated protein kinase B and phosphorylated glycogen synthase kinase 3β, the activities of hexokinase and pyruvate kinase were assayed. Meanwhile, the changes in serum lipid profiles, superoxide dismutase, glutathione peroxidase, malondialdehyde and inflammatory factors were measured. Histological of pancreas were also evaluated by haematoxylin-eosin stain.. Our investigation revealed the presence of phenylethanoid glycosides (PhGs): echinacoside (500.19 ± 11.52 mg/g), acteoside (19.13 ± 1.44 mg/g) and isoacteoside (141.82 ± 5.78 mg/g) in TGCT. Pharmacological tests indicated that TGCT significantly reversed STZ-induced weight loss (11.1%, 200 mg/kg); decreased FPG (56.4%, 200 mg/kg) and HbA1c (37.4%, 200 mg/kg); ameliorated the OGTT, AUC-G and insulin sensitivity; increased glycogen content (40.8% in liver and 52.6% in muscle, 200 mg/kg) and the activities of carbohydrate metabolizing enzymes; regulated lipid profile changes and the activities of antioxidant enzymes; diminished serum markers of oxidative stress and inflammation in a dose-dependent manner (p < 0.05).. This study confirmed that TGCT was an effective nutritional agent for ameliorating hyperglycemia and hyperlipidemia in diet/STZ-induced diabetic rats, which might be largely attributed to the activities of TGCT on inhibitions of oxidative stress and inflammation.

Topics: Animals; Blood Glucose; Body Weight; C-Peptide; Cistanche; Diabetes Mellitus, Experimental; Diet; Eating; Glycated Hemoglobin; Glycogen; Glycosides; Hypoglycemic Agents; Hypolipidemic Agents; Inflammation; Insulin; Male; Oxidative Stress; Pancreas; Phosphotransferases; Plant Extracts; Rats, Sprague-Dawley; Streptozocin

The hypoglycemic effects and potential mechanism of sweet potato leaf polyphenols (SPLP) on type 2 diabetes mellitus (T2DM) were investigated. Results showed that oral administration of SPLP to mice could alleviate body weight loss, decrease fasting blood glucose levels (by 64.78%) and improve oral glucose tolerance compared with those of untreated diabetic mice. Furthermore, increased fasting serum insulin levels (by 100.11%), ameliorated insulin resistance and improved hepatic glycogen (by 126.78%) and muscle glycogen (increased by 135.85%) were observed in the SPLP treatment group. SPLP also could reverse dyslipidemia, as indicated by decreased total cholesterol, triglycerides, low density lipoprotein-cholesterol and promoted high density lipoprotein-cholesterol. Histopathological analysis revealed that SPLP could relieve liver inflammation and maintain the islet structure to inhibit β-cell apoptosis. A quantitative real-time polymerase chain reaction confirmed that SPLP could up-regulate the phosphatidylinositol 3-kinase/protein kinase B/glycogen synthase kinase-3β signaling pathway to improve glucose metabolism and up-regulate the phosphatidylinositol 3-kinase/protein kinase B/glucose transporter 4 signaling pathway in the skeletal muscle to enhance glucose transport. This study provides useful information to support the application of SPLP as a natural product for the treatment of T2DM.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Eating; Glucose Transporter Type 4; Glycogen; Glycogen Synthase Kinase 3 beta; Hyperglycemia; Hypoglycemic Agents; Insulin; Ipomoea batatas; Islets of Langerhans; Lipids; Liver; Liver Glycogen; Male; Mice; Pancreas; Phosphatidylinositol 3-Kinase; Plant Leaves; Polyphenols; Proto-Oncogene Proteins c-akt; Signal Transduction

Evolution has created different castes of females in eusocial haplodiploids. The difference between them lies in their functions and vulnerability but above all in their reproductive potentials. Honeybee queens are highly fertile. On the other hand, the workers are facultatively sterile. However, rebel workers, i.e. workers that develop in a queenless colony, reproduce more often than normal workers. As a result, the fat body of these bees, which apart from acting as the energy reserve, is also the site of numerous metabolic processes, had to specialize in different functions perfected over millions of years of eusocial evolution. Assuming that the variety of functions manifests itself in the pleomorphic structure of the fat body cells, we predicted that also different parts of the fat body, e.g. from different segments of the abdomen, contain different sets of cells. Such differences could be expected between queens, rebels and normal workers, i.e. females with dramatically different reproductive potentials. We confirmed all these expectations. Although all bees had the same types of cells, their proportion and segmental character corresponded with the caste reproductive potential and physiological characteristics shaped in the evolutionary process. The females with an increased reproductive potential were characterized by the presence of oenocytes in the third tergite and high concentrations of compounds responsible for energy reserves, like glucose, glycogen and triglycerides. Queens had very large trophocytes, especially in the third tergite. Only in workers did we observe intercellular spaces in all the segments of the fat body, as well as high protein concentrations-especially in the sternite. As expected, the rebels combined many features of the queens and normal workers, what with other findings can help understand the ways that led to the origin of different castes in females of eusocial Hymenoptera.

Topics: Animals; Bees; Body Weight; Cell Nucleus; Fat Body; Female; Glucose; Glycogen; Insect Proteins; Integumentary System; Reproduction; Triglycerides

Spexin (SPX) is a 14 aa peptide discovered in 2007 using bioinformatics methods. SPX inhibits food intake and regulates lipid, and carbohydrate metabolism. Here, we evaluate the ability of SPX at improving metabolic control and liver function in obese and type 2 diabetic animals. The effects of 30 days SPX treatment of mice with experimentally induced obesity (DIO) or type 2 diabetes (T2DM) on serum glucose and lipid levels, insulin sensitivity and hormonal profile (insulin, glucagon, adiponectin, leptin, TNF alpha, IL-6 and IL-1β) are characterized. In addition, alterations of hepatic lipid and glycogen contents are evaluated. We report that SPX decreases body weight in healthy and DIO mice, and reduces lipid content in all three animal groups. SPX improves insulin sensitivity in DIO and T2DM animals. In addition, SPX modulates hormonal and metabolic profile by regulating the concentration of adiponectin (concentration increase) and leptin (concentration decrease) in the serum blood of DIO and T2DM mice. Lastly, SPX decreases lipid content as well as IL-6 and TNF-α protein levels in liver of DIO and T2DM mice, and reduces IL-6 and TNF-alpha concentrations in the serum derived from T2DM mice. Based on our results, we conclude that SPX could be involved in the development of obesity and type 2 diabetes mellitus and it can be further evaluated as a potential target for therapy of DIO and T2DM.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Female; Glycogen; Insulin Resistance; Lipid Metabolism; Lipids; Liver Function Tests; Mice; Obesity; Peptide Hormones

The objective of our study was to evaluate the effect of Physalis peruviana L. fruits in the management of diabetes and diabetic nephropathy in relation to its metabolic profile. In-vitro α-amylase, β-glucosidase, and lipase inhibition activities were assessed for the ethanolic extract (EtOH) and its subfractions. Ethyl acetate (EtOAc) fraction showed the highest α-amylase, β-glucosidase, and lipase inhibition effect. In vivo antihyperglycemic testing of EtOAc in streptozotocin (STZ)-induced diabetic rats showed that it decreased the blood glucose level, prevented the reduction in body weight, improved serum indicators of kidney injury (urea, uric acid, creatinine), and function (albumin and total protein). EtOAc increased autophagic parameters (LC3B, AMPK) and depressed mTOR contents. Histopathology revealed that EtOAc ameliorated the pathological features and decreased the glycogen content induced by STZ. The immunohistochemical analysis showed that EtOAc reduced P53 expression as compared to the STZ-diabetic group. UPLC-ESI-MS/MS metabolite profiling of EtOAc allowed the identification of several phenolic compounds. Among the isolated compounds, gallic acid, its methylated dimer and the glycosides of quercetin had promising α-amylase and β-glucosidase inhibition activity. The results suggest that the phenolic-rich fraction has a protective effects against diabetic nephropathy presumably via enhancing autophagy (AMPK/mTOR pathway) and prevention of apoptosis (P53 suppression).

Topics: Animals; Antioxidants; Apoptosis; Autophagy; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Fruit; Glycogen; Hypoglycemic Agents; Kidney; Liver; Male; Pancreas; Phenols; Physalis; Plant Extracts; Rats, Wistar; Tumor Suppressor Protein p53

Pandemic vitamin D deficiency is associated with insulin resistance and type 2 diabetes. Vitamin D supplementation has been reported to have improved glucose homeostasis. However, its mechanism to improve insulin sensitivity remains unclear.. Male C57BL/6J mice are fed with/without vitamin D control (CD) or Western (WD) diets for 15 weeks. The vitamin-D-deficient lean (CDVDD) and obese (WDVDD) mice are further subdivided into two groups. One group is re-supplemented with vitamin D for 6 weeks and hepatic insulin signaling is examined. Both CD and WD mice with vitamin D deficiency developed insulin resistance. Vitamin D supplementation in CDVDD mice significantly improved insulin sensitivity, hepatic inflammation, and antioxidative capacity. The hepatic insulin signals like pAKT, pFOXO1, and pGSK3β are increased and the downstream Pepck, G6pase, and Pgc1α are reduced. Furthermore, the lipogenic genes Srebp1c, Acc, and Fasn are decreased, indicating that hepatic lipid accumulation is inhibited.. The results demonstrate that vitamin D deficiency induces insulin resistance. Its supplementation has significant beneficial effects on pathophysiological mechanisms in type 2 diabetes but only in lean and not in the obese phenotype. The increased subacute inflammation and insulin resistance in obesity cannot be significantly alleviated by vitamin D supplementation. This needs to be taken into consideration in the design of new clinical trials.

Topics: Animals; Body Weight; Diet, High-Fat; Forkhead Box Protein O1; Gluconeogenesis; Glucose; Glycogen; Hepatitis; Insulin Resistance; Liver; Male; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Oxidative Stress; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Vitamin D; Vitamin D Deficiency

Tylorrhynchus heterochaetus (Hechong in Chinese) has been used in Chinese traditional medicine for treating various diseases. This study was aimed to assess the anti-fatigue effect of T. heterochaetus on Kunming mice and its primary mechanism of action using forced running, rotating rod and weight-loaded swimming tests. Low (2.70 mg/0.5 mL/20 g), medium (5.41 mg/0.5 mL/20 g) and high (6.58 mg/0.5 mL/20 g) doses of T. heterochaetus aqueous extract were treated to mice for 28 days. Among the doses, the low and medium doses showed significant (p ≤ 0.05) anti-fatigue effect on the weight-loaded swimming test. Also, T. heterochaetus extract showed significant (p ≤ 0.05) effects on fatigue-related blood parameters by increasing the GLU, TG and LDH levels and decreasing the LA, CK and BUN levels. The levels of liver and skeletal muscle glycogen were also significantly (p ≤ 0.05) increased after treatment. Further, on Western blot analysis, it has been found that T. heterochaetus enhanced the expressions of AMPK and PGC-1α in the liver and skeletal muscles of mice. From the study, our outcomes suggest that T. heterochaetus possess an anti-fatigue effect through the AMPK-linked pathway and thereby it can regularize the energy metabolism.

Topics: Adenylate Kinase; Animals; Biological Products; Blood Urea Nitrogen; Body Weight; Creatine Kinase; Fatigue; Glucose; Glycogen; L-Lactate Dehydrogenase; Lactic Acid; Liver; Mice; Muscle, Skeletal; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Polychaeta; Rotarod Performance Test; Running; Swimming; Triglycerides

Glycogen shortage during fasting coincides with dramatic changes in hepatic adenine nucleotide levels. The aim of this work was to study the relevance of liver glycogen in the regulation of the hepatic energy state during food deprivation. To this end, we examined the response of mice with sustained increased liver glycogen content to prolonged fasting. In order to increase hepatic glycogen content, we generated mice that overexpress protein targeting to glycogen (PTG) in the liver (PTG

Topics: Adipose Tissue; Animals; Body Weight; Energy Metabolism; Fasting; Food Deprivation; Gluconeogenesis; Glycogen; Insulin; Insulin Resistance; Ketones; Lipid Metabolism; Liver; Mice; Muscle, Skeletal; Organ Size

Flowering tops of Trifolium pratense L. (Fabaceae) are known for its traditional medicinal values. In present study, our aim was to investigate effect of standardized aqueous extract of flowering tops of Trifolium pratense L. on insulin resistance and SIRT1 expression in type 2 diabetic rats. Type 2 diabetes was induced by feeding high fat diet and administering low dose of streptozotocin. Diabetic animals were treated with standardized aqueous extract at three different doses. Parameters such as blood glucose, lipid profile, glycohemoglobin, insulin sensitivity, HOMA-IR and liver glycogen content were measured. Changes in morphology and expression of SIRT1 in pancreatic tissue were measured in histopathological and immunohistological studies. Aqueous extract treatment showed reduction in hyperglycemia and improved insulin sensitivity. Extract treatment also showed reduction in formation of glycated hemoglobin and improved liver glycogen level. Histopathological study revealed protecting effect of extract in pancreatic tissue against hyperglycemia induced damage. Treatment increased expression of SIRT1 in rat pancreatic tissue. Results indicate that the aqueous extract of Trifolium pratense had beneficial role in improving insulin sensitivity and SIRT1 expression.

Topics: Animals; Blood Glucose; Body Weight; Chromatography, High Pressure Liquid; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Flowers; Glycogen; Hyperglycemia; Isoflavones; Male; Pancreas; Plant Extracts; Protective Agents; Rats; Rats, Sprague-Dawley; Sirtuin 1; Streptozocin; Trifolium

Harmonia axyridis is a major bio-control agent of pests in agriculture and forest ecosystems. It is also a globally important invasive insect species. To test whether dark elytra colour is associated with greater cold hardiness, we compared the survival rate of prolonged cold exposure in both yellow and black colour morphs of female and male H. axyridis. We determined the trehalose and glycogen content, trehalase activity, and the dynamics of genes associated with the trehalose metabolic pathway. Yellow forms predominated before winter began, however black forms increased from 11.15 to 30.46% after overwintering. There was no significant difference in trehalose content between the females and males during overwintering. Glycogen content in over-wintering yellow females and black males increased significantly, while it decreased in black females. Soluble trehalase activity increased significantly in all the insects except black females. Membrane-bound trehalase activity increased in black males, and decreased in black females. Trehalose and glycogen content and trehalase activity were regulated by differential expression of TRE and TPS genes. Female beetles weighed more than males and survived in low temperatures for longer periods of time, regardless of elytra colour, suggesting that mass is a stronger predictor of overwintering survival rather than colour morph. Our results provide a guide for comparing cold resistance in insects and a theoretical basis for cold storage of H. axyridis for use as natural enemies of pests in biological control programs.

Topics: Animals; Body Weight; Cold Temperature; Coleoptera; Female; Gene Expression Regulation; Genes, Insect; Glycogen; Male; Phenotype; Seasons; Survival Analysis; Time Factors; Trehalase; Trehalose

Non-alcoholic fatty liver disease and steatohepatitis are highly associated with obesity and type 2 diabetes mellitus. Cotadutide, a GLP-1R/GcgR agonist, was shown to reduce blood glycemia, body weight and hepatic steatosis in patients with T2DM. Here, we demonstrate that the effects of Cotadutide to reduce body weight, food intake and improve glucose control are predominantly mediated through the GLP-1 signaling, while, its action on the liver to reduce lipid content, drive glycogen flux and improve mitochondrial turnover and function are directly mediated through Gcg signaling. This was confirmed by the identification of phosphorylation sites on key lipogenic and glucose metabolism enzymes in liver of mice treated with Cotadutide. Complementary metabolomic and transcriptomic analyses implicated lipogenic, fibrotic and inflammatory pathways, which are consistent with a unique therapeutic contribution of GcgR agonism by Cotadutide

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide-1 Receptor; Glycogen; Lipogenesis; Liver; Liver Cirrhosis; Male; Mice; Mice, Knockout; Mitochondria; Non-alcoholic Fatty Liver Disease; Peptides; Proteomics

Constitutional thinness (CT) is a nonpathological state of underweight. The current study aimed to explore skeletal muscle energy storage in individuals with CT and to further characterize muscle phenotype at baseline and in response to overfeeding. Thirty subjects with CT (15 females, 15 males) and 31 normal-weight control subjects (16 females, 15 males) participated in the study. Histological and enzymological analyses were performed on muscle biopsy specimens before and after overfeeding. In the skeletal muscle of CT participants compared with controls, we observed a lower content of intramuscular triglycerides for type I (-17%,

Topics: Adaptation, Physiological; Adult; Body Weight; Dietary Supplements; Energy Intake; Female; Glycogen; Humans; Hyperphagia; Male; Muscle Fibers, Skeletal; Muscle, Skeletal; Thinness; Triglycerides; Weight Gain; Young Adult

Red ginseng (RG) ingestion reportedly affects body weight, food intake, and fat accumulation reduction. It also induces changes in energy metabolism regulation and glycemic control. Previously, 2-week RG ingestion with endurance training was found to enhance fat oxidation during exercise. However, such effects on energy metabolism and the expression of mRNAs related to energy substrate utilization in resting mice (untrained mice) are still unclear. Here, we determined the effect of RG on energy metabolism and substrate utilization in untrained male mice. Twenty-four mice were separated into an RG group that received a daily dosage of 1 g/kg RG for 2 weeks, and a control (CON). Energy expenditure, blood and tissue glycogen levels, and expression of mRNAs related to energy substrate utilization in muscles were measured before and 2 weeks after treatment. Total food intake was significantly lower in the RG than in the CON group (

Topics: Animals; Body Weight; Dietary Supplements; Eating; Energy Metabolism; Glycogen; Male; Mice; Mice, Inbred ICR; Muscle, Skeletal; Panax; Physical Conditioning, Animal; Plant Extracts; RNA, Messenger

Codonopsis pilosula is a traditional Chinese medicine and food supplement that is widely used in China. This study aimed to investigate the antifatigue and antihypoxia activities of different extracts and fractions from C. pilosula, including ethanol extract (ETH), water extract (WAT), polysaccharides (POL), inulin (INU) and oligosaccharides (OLI). Different extracts and fractions were orally administered to mice at the doses of 0.25, 0.5 and 1.0 g kg-1 once a day for 21 days. Antifatigue activity was assessed through the weight-loaded swimming test on the 21st day, and antihypoxia activity was evaluated through the normobarie hypoxia test on the following day. Finally, biochemical parameters, such as liver glycogen (LG), muscle glycogen (MG), blood urea nitrogen (BUN), lactic dehydrogenase (LDH), malondialdehyde (MDA), and glutathione (GSH) levels, were determined. The results showed that, compared with the control treatment, only POL treatment significantly prolonged the swimming time of the mice. POL groups had the strongest hypoxia tolerance, followed by the OLI and WAT groups. The levels of LG and MG were significantly increased by treatment with POL at the doses of 0.5 and 1.0 g kg-1, whereas BUN and LDH levels in POL groups were significantly lower than those in the control group. MDA under POL and OLI treatment was significantly lower than that under the control treatment. In addition, treatments with POL and OLI, except for treatment with a low dose of OLI, significantly increased GSH levels. In conclusion, POL could efficiently enhance antifatigue and antihypoxia abilities by increasing energy resources, decreasing detrimental metabolite accumulation, and enhancing antioxidant activity. OLI could improve antihypoxia activity by preventing lipid peroxidation and enhancing antioxidant activity.

Topics: Animals; Antioxidants; Body Weight; China; Codonopsis; Dietary Supplements; Disease Models, Animal; Eating; Energy Metabolism; Fatigue; Glutathione; Glycogen; Hypoxia; Lipid Peroxidation; Liver; Male; Malondialdehyde; Mice; Mice, Inbred ICR; Oligosaccharides; Plant Extracts; Polysaccharides; Swimming

Most studies routinely use overnight or 6 h of fasting before testing metabolic glucose homeostasis in mice. Other studies used empirically shorter fasting times (<6 h). We attempted to determine the shortest fasting time required for optimal insulin responsiveness while minimizing metabolic stress.. A course of fasting for up to 24 h (0, 2, 4, 6, 12, and 24 h) was conducted in C57Bl/6J male mice. Body weight, metabolic parameters, and insulin tolerance were measured in each experimental group. The organs were collected at the same time on separate occasions and glycogen and metabolic gene expression were measured in the liver and skeletal muscle.. Our data show that blood glucose levels do not significantly change during a 6 h fast, while plasma insulin levels decrease to similar levels between 2 h and 6 h of fasting. During overnight (12 h) and 24 h fasts, a robust decrease in blood glucose and plasma insulin was observed along with a profound depletion in liver glycogen content. Insulin tolerance was comparable between baseline and 6 h fasts while 4 h and 6 h fasts were associated with a greater depletion of liver glycogen than 2 h fasts, impacting the glucose counter-regulatory response. Fasting induced progressive weight loss that was attenuated at thermoneutrality. Fasting longer than 4 h induced major body weight loss (>5%) and significant changes in catabolic gene expression in the liver and skeletal muscle.. Collectively, these data suggest that 2 h of fasting appears optimal for the assessment of insulin tolerance in mice as this duration minimizes major metabolic stress and weight loss.

Topics: Animals; Blood Glucose; Body Weight; Fasting; Glucose; Glucose Tolerance Test; Glycogen; Insulin; Insulin Resistance; Liver; Male; Mice; Mice, Inbred C57BL; Muscle, Skeletal

We aimed to evaluate the anti-fatigue effects of the oyster polypeptide (OP) fraction and its regulatory effect on the gut microbiota in mice. Our exhaustive swimming experiment showed that the swimming time of the low-, middle- and high-dose groups of the OP fraction was increased by 1.82, 2.18 and 2.44 times compared with the control group, respectively. Besides, the liver glycogen levels of the three groups were increased by 19.3%, 42.02% and 65.07%, while the lactate levels were decreased by 18.85%, 21.18% and 28.74%, respectively. Moreover, administration of the OP fraction upregulated the expressions of PEPCK and AMPK, but downregulated the TNF-α expression. Correlation analysis between the gut microbiota and fatigue-related biochemical indicators showed that Faecalibacterium, Desulfovibri and Intestinibacter were negatively correlated with the swimming time, blood lactate, blood urea nitrogen, liver glycogen and muscle glycogen, while Yaniella and Romboutsia were positively correlated. Therefore, the OP fraction had anti-fatigue effects, and could regulate the abundance of gut microbiota and maintain its balance.

Topics: Animals; Blood Urea Nitrogen; Body Weight; Fatigue; Gastrointestinal Microbiome; Gene Expression; Glutathione Peroxidase; Glycogen; Lactic Acid; Liver; Liver Glycogen; Male; Mice; Muscle, Skeletal; Ostreidae; Peptides; Physical Exertion; Superoxide Dismutase; Swimming

This study investigated the effect of non-periodized training performed at 80, 100 and 120% of the anaerobic threshold intensity (AnT) and a linear periodized training model adapted for swimming rats on the gene expression of monocarboxylate transporters 1 and 4 (MCT1 and 4, in soleus and gastrocnemius muscles), protein contents, blood biomarkers, tissue glycogen, body mass, and aerobic and anaerobic capacities. Sixty Wistar rats were randomly divided into 6 groups (n = 10 per group): a baseline (BL; euthanized before training period), a control group (GC; not exercised during the training period), three groups exercised at intensities equivalent to 80, 100 and 120% of the AnT (G80, G100 and G120, respectively) at the equal workload and a linear periodized training group (GPE). Each training program lasted 12 weeks subdivided into three periods: basic mesocycle (6 weeks), specific mesocycle (5 weeks) and taper (1 week). Although G80, G100 and G120 groups were submitted to monotony workload (i.e. non-modulation at intensity or volume throughout the training program), rodents were evaluated during the same experimental timepoints as GPE to be able comparisons. Our main results showed that all training programs were capable to minimize the aerobic capacity decrease promoted by age, which were compared to control group. Rats trained in periodization model had reduced levels of lipid blood biomarkers and increased hepatic glycogen stores compared to all other trained groups. At the molecular level, only expressions of MCT1 in the muscle were modified by different training regimens, with MCT1 mRNA increasing in rats trained at lower intensities (G80), and MCT1 protein content showed higher values in non-periodized groups compared to pre-training and GPE. Here, training at different intensities but at same total workload promoted similar adaptations in rats. Nevertheless, our results suggested that periodized training seems to be optimize the physiological responses of rats.

Topics: Adaptation, Physiological; Adipose Tissue, Brown; Anaerobic Threshold; Animals; Biomarkers; Body Weight; Glycogen; Male; Monocarboxylic Acid Transporters; Muscle Proteins; Muscle, Skeletal; Rats; Rats, Wistar; RNA, Messenger; Swimming; Symporters; Up-Regulation

The aim of the research was to evaluate the dynamic changes of early posthatch starvation on residual yolk absorption, synthesis of macronutrients (protein, lipid, and glycogen), and organ development in broiler chicks. A total of 720 1-day-old chicks (Lingnan Yellow) were randomly assigned to 3 treatments: group A (nonfasted), group B (fasting for 24 h after placement), and group C (fasting for 48 h after placement). The trial lasted for 168 h, and water was provided ad libitum all the time. Sampling was performed at 0, 24, 48, 72, 120, and 168 h. Nonfasting (group A) promoted (P < 0.05) the absorption of amino acids, fatty acids, mineral elements, protein, and maternal antibody in the residual yolk of broiler chicks. The concentration of insulin-like growth factor 1 in plasma and the liver was higher (P < 0.05) in group A. Nonfasting enhanced (P < 0.05) the synthesis of protein and glycogen in the breast muscle and liver; the relative weights of the liver, pancreas, and spleen; and body weight, but retarded (P < 0.05) the synthesis of triglyceride in the liver. The results indicated that nonfasting (group A) after placement promoted the absorption of residual yolk and synthesis of protein and glycogen in the breast muscle and liver, whereas early feed deprivation promoted the synthesis of lipid in the liver. Thereby, nonfasting after placement promoted organ development and body growth of broiler chicks.

Topics: Animal Structures; Animals; Body Weight; Chickens; Egg Yolk; Food Deprivation; Glycogen; Nutrients; Protein Biosynthesis; Random Allocation

Bakery products made by cereal and edible fungi powder have a unique flavor and health benefits, dramatically enhancing the nutritional value of the products. In this study, we investigated the antifatigue effect of a novel Tricholoma matsutake cookie (TMC) by the exhaustive swimming test. Male Kunming ICR mice were randomly divided into seven groups (each group, n = 10), fed with saline, ordinary cookies (4, 8, 16 g/kg B.W./day), and TMC (4, 8, 16 g/kg B.W./day) by gavage. After 30-day administration, the weight-loaded swimming test was carried out on the mice to evaluate the antifatigue effect of TMC. In comparison with the effect of ordinary cookies, the intake of TMC significantly prolonged the exhaustive swimming time of mice and increased the level of muscle glycogen and liver glycogen, accompanied by the reduction of lactic acid and urea nitrogen level in serum. Additionally, TMC dramatically improved the activity of superoxide dismutase and glutathione peroxidase in serum and largely decreased the level of malondialdehyde. All in all, TMC could enforce exhaustive swimming tolerance, accelerate the decomposition of sports-related metabolites such as lactic acid and urea nitrogen, and increase the activity of the antioxidant enzyme, thereby improving sports-related energy storage and relieving fatigue. Our findings broadened the application of T. matsutake in the processing of bakery products and provided the theoretical basis and technical support for the development of antifatigue products. PRACTICAL APPLICATION: In this study, we investigated the antifatigue effect of a novel Tricholoma matsutake cookie by the exhaustive swimming test. Collectively, the results of the present study suggested that the cookies fortified with T. matsutake could be considered as an antifatigue bakery product. Furthermore, our findings broadened the application of T. matsutake in the processing of bakery products and provided the theoretical basis and technical support for the development of antifatigue products.

Topics: Agaricales; Animals; Antioxidants; Body Weight; Edible Grain; Fatigue; Functional Food; Glutathione Peroxidase; Glycogen; Male; Malondialdehyde; Mice; Mice, Inbred ICR; Powders; Random Allocation; Superoxide Dismutase; Swimming

General control nonderepressible 2 (GCN2) is a kinase that detects amino acid deficiency and is involved in the control of protein synthesis and energy metabolism. However, the role of hepatic GCN2 in the metabolic adaptations in response to the modulation of dietary protein has been seldom studied. Wild-type (WT) and liver GCN2-deficient (KO) mice were fed either a normo-protein diet, a low-protein diet, or a high-protein diet for 3 wk. During this period, body weight, food intake, and metabolic parameters were followed. In mice fed normo- and high-protein diets, GCN2 pathway in the liver is not activated in WT mice, leading to a similar metabolic profile with the one of KO mice. On the contrary, a low-protein diet activates GCN2 in WT mice, inducing FGF21 secretion. In turn, FGF21 maintains a high level of lipid oxidation, leading to a different postprandial oxidation profile compared with KO mice. Hepatic GCN2 controls FGF21 secretion under a low-protein diet and modulates a whole body postprandial oxidation profile.

Topics: Adipose Tissue; Animals; Body Composition; Body Weight; Diet, High-Protein; Diet, Protein-Restricted; Energy Metabolism; Feeding Behavior; Fibroblast Growth Factors; Glucose; Glycogen; Lipid Metabolism; Liver; Mice; Mice, Knockout; Muscle, Skeletal; Oxidation-Reduction; Postprandial Period; Protein Serine-Threonine Kinases; RNA, Messenger; Triglycerides

Replacing part of glucose with galactose in the post-weaning diet beneficially affects later life metabolic health in female mice. The liver is the main site of galactose metabolism, but the direct effects of this dietary intervention on the liver in the post-weaning period are not known. The aim of this study was to elucidate this. Weanling female mice (C57BL/6JRccHsd) were fed a starch containing diet with glucose (32 en%) monosaccharide (GLU), or a diet with glucose and galactose (1:1 both 16 en%) (GLU+GAL). Body weight, body composition, and food intake were determined weekly. After 3 weeks, mice were sacrificed, and serum and liver tissues were collected. Global hepatic mRNA expression was analyzed and hepatic triglyceride (TG) and glycogen contents were determined by enzymatic assays. Body weight and body composition were similar in both groups, despite higher food intake in mice on GLU+GAL diet. Hepatic TG content was lower in GLU+GAL-fed than GLU-fed females, while glycogen levels were unaffected. Analysis of global expression patterns of hepatic mRNA showed that mainly inflammation-related pathways were affected by the diet, which were predominantly downregulated in GLU+GAL-fed females compared to GLU-fed females. This reduction in inflammation in GLU+GAL-fed females was also reflected by decreased serum concentrations of acute phase protein Serum amyloid A 3. In conclusion, replacing part of glucose with galactose in the post-weaning diet reduces hepatic TG content and hepatic inflammation.

Topics: Animals; Body Composition; Body Weight; Diet; Eating; Female; Galactose; Gene Expression; Glucose; Glycogen; Hepatitis; Liver; Mice; Mice, Inbred C57BL; RNA, Messenger; Triglycerides; Weaning

Insulin resistance (IR) is the impaired insulin response that causes decreased glucose tolerance. Electrical stimulation (ES) can improve insulin sensitivity in the skeletal muscle. However, the underlying molecular mechanisms remain to be elucidated. In the present study, the effect of ES and diet therapy on IR and the role of the mammalian target of rapamycin (mTOR) pathway in the improvement of IR by ES were investigated. A total of 70 Sprague‑Dawley male rats were divided into five groups: Normal (n=10), IR control (n=15), diet (n=15), ES (n=15) and ES + diet (n=15) groups. An IR rat model was established by high‑fat and high‑carbohydrate diet for 5 weeks and confirmed by measurement of fasting plasma glucose (FPG), insulin, insulin sensitivity index (ISI) and IR index. ES on the Zusanli (ST36), Sanyinjiao (SP 6) and Weiwanxiashu (EX‑B3) acupoints and the low‑fat and low‑carbohydrate diet demonstrated protective effects. The body weight, concentrations of FPG, insulin, triglycerides (TG), free fatty acids (FFA) and total cholesterol (TC) of the rats were detected. Pathologic changes in the liver and pancreatic tissues were assessed. Western blotting and immunohistochemistry were performed to determine the role of PI3K/Akt/mTOR signaling. Results demonstrated that ES and diet therapy significantly increased ISI and reduced FPG, IR index, FFA, TG, TC and weight. Inflammatory cell infiltration in the liver and pancreatic tissues was ameliorated and lipid droplets and cavitation in hepatocyte were decreased after ES and diet therapy. The administration of ES and diet therapy also enhanced glucose transport by the upregulation of glucose transporter 4 and accelerated glycogen synthesis through the suppression of glycogen synthase kinase 3α/β via PI3K/Akt/mTOR signaling. Hence, the present results demonstrated that ES combined with diet therapy improved IR through PI3K/Akt/mTOR signaling. The proposed therapy was superior to the method of diet alone.

Topics: Animals; Body Weight; Diet Therapy; Diet, Carbohydrate-Restricted; Diet, Fat-Restricted; Electric Stimulation; Glycogen; Insulin; Insulin Resistance; Islets of Langerhans; Liver; Male; Muscles; Phosphatidylinositol 3-Kinases; Rats; Rats, Sprague-Dawley; Signal Transduction; TOR Serine-Threonine Kinases; Triglycerides

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Diet, High-Fat; Enzyme Inhibitors; Fructose; Glycogen; Kidney; Lipase; Lipids; Liver; Male; Mice; Obesity; Phytoestrogens

Macamides, the main active components contained in maca, have attracted increasing attention due to their various bioactivities. In this study, crude macamide extract (CME) and purified macamide extract (PME) were prepared by enzyme-assisted extraction and macroporous resin separation, and the anti-fatigue effects of CME and PME were evaluated in a forced swimming model.. The composition analysis results revealed that both CME and PME mainly contain eight kinds of macamide. Based on the results of a weight-loaded forced swimming test, compared with a control group, CME and and PME groups could prolong exhaustive swimming time, increase levels of liver glycogen (LG) and muscle glycogen (MG), accelerate fatty acid oxidation in serum to provide energy, eliminate the accumulation of blood lactic acid (BLA) and blood urea nitrogen (BUN), and decrease the serum biomarkers for muscle damage, such as lactate dehydrogenase (LDH) and creatine kinase (CK). Histological analysis also indicated that CME and PME attenuated damage to skeletal muscle and the myocardium in mice during exercise.. Two macamide extracts have a beneficial effect on relieving physical fatigue by attenuating the damage of skeletal muscle and myocardium during exercise, and a better effect was observed in the PME group. © 2018 Society of Chemical Industry.

Topics: Amides; Animals; Blood Urea Nitrogen; Body Weight; Creatine Kinase; Fatigue; Glycogen; Humans; L-Lactate Dehydrogenase; Lepidium; Male; Mice; Muscle Fatigue; Muscle, Skeletal; Plant Extracts; Swimming

Polysaccharides comprise the major bioactive components in Momordica charantia L. We here synthesized and characterized a novel M. charantia polysaccharide‑chromium (III) complex (MCPIIaC) and assessed its anti-diabetic effects in mice with streptozotocin (STZ)-induced diabetes mellitus (DM) and its mechanism underlying hypoglycemia. MCPIIaC is a novel polysaccharide‑chromium (III) complex containing 14.68% elemental chromium. A Fourier transform infrared (FTIR) spectrogram experiment showed that the chromium ions are linked to the polysaccharide's hydroxyl groups. Combined circular dichroism (CD) and atomic force microscopy (AFM) analyses indicated that after linking with chromium ions, the flexibility of the three-dimensional structure of the polysaccharide increased. After the treatment of MCPIIaC for four weeks, the mice with STZ-induced DM exhibited significantly lower fasting blood glucose levels and body weight, whereas higher insulin levels and antioxidant enzyme activity than in the diabetic group. Optimal effects were obtained with a dosage of 30 mg MCPIIaC/kg body weight. Histological analysis indicated that MCPIIaC alleviated the oxidative tissue damage in STZ-lesioned mice. An acute toxicity experiment indicated that MCPIIaC was safe at a dose of 1500 mg/kg. These results suggest that MCPIIaC might be an excellent candidate hypoglycemic agent for the prevention of diabetes.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Chromium; Diabetes Mellitus, Experimental; Fasting; Glycogen; Hypoglycemic Agents; Insulin; Liver; Male; Mice; Molecular Weight; Momordica charantia; Organometallic Compounds; Polysaccharides

Glycogen is a complex branched glucose polymer. Liver glycogen in db/db mouse, a type-2 diabetic mouse model, has been found to be more molecularly fragile than in healthy mice. Size-exclusion chromatography was employed in this study to investigate the molecular structure of liver glycogen in two types of type 1 diabetic mouse models (NOD and C57BL/6J mice), sacrificed at various times throughout the diurnal cycle, and the fragility of liver glycogen after exposure to a hydrogen-bond disruptor were tested. Type 1 diabetic mice exhibit a similar glycogen fragility with that observed for db/db mice. This eliminates many of the potential causes for glycogen molecular fragility; the most likely explanation is that it is caused by high blood-glucose level and/or insulin deficiency, both phenotypes being common to both type 1 and type 2 diabetic mice. This result suggests ways towards new drug targets for the management of diabetes.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Glycogen; Liver; Male; Mice; Mice, Inbred C57BL

Menopause is associated with changes in body composition (a decline in lean body mass and an increase in total fat mass), leading to an increased risk of metabolic syndrome, nonalcoholic fatty liver disease, and heart disease. A healthy diet to control body weight is an effective strategy for preventing and treating menopause-related metabolic syndromes. In the present study, we investigated the effect of long-term feeding of edible oils (soybean oil (SO), tea seed oil (TO), and lard oil (LO)) on female ovariectomized (OVX) mice. SO, TO, and LO comprise mainly polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), and saturated fatty acids (SFA), respectively. However, there have been quite limited studies to investigate the effects of different fatty acids (PUFA, MUFA, and SFA) on physiological adaption and metabolic homeostasis in a menopausal population. In this study, 7-week-old female Institute of Cancer Research (ICR) mice underwent either bilateral laparotomy (sham group,

Topics: Animals; Anti-Obesity Agents; Body Weight; Diet, High-Fat; Disease Models, Animal; Fatigue; Fatty Acids, Monounsaturated; Fatty Acids, Unsaturated; Glycogen; Liver; Mice; Motor Activity; Obesity; Organ Size; Plant Oils; Seeds; Tea

Type-2 diabetes mellitus and its related complications including dyslipidemia and oxidative stress have been threating the health of a large number of patients all over the world. In this study, FCPC, one polysaccharide fraction separated from the polysaccharides of Chinese medicine Fructus Corni (FCPs), revealed obvious inhibitory effects against α-amylase and α-glucosidase, and marked insulin-sensitizing effect by increasing insulin secretion and promoting pancreatic β cell proliferation. In addition, in streptozotocin (STZ)-induced diabetic rats, the polysaccharide fraction not only significantly restrained the increase of food (p < 0.05) and water (p < 0.01) intake at 800 mg/kg, but also significantly controlled the increase of levels for sugar (p < 0.01), insulin (p < 0.05) and HOMA-IR value (p < 0.05) in blood at 800 mg/kg on 42th day. Meanwhile, the reduced glycogen contents in liver (p < 0.01) and skeletal (p < 0.01) muscle caused by STZ were prominently improved, while the dyslipidemia status and oxidative damage were markedly ameliorated. Therefore, FCPC could be developed to natural medicines and functional foods in the treatment of diabetes and its complications including dyslipidemia status and oxidative stress.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Carbohydrate Metabolism; Cell Proliferation; Cornus; Diabetes Mellitus, Experimental; Drinking; Glycogen; Hydrolysis; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Lipids; Liver; Male; Muscles; Oxidative Stress; Polysaccharides; Rats; Rats, Sprague-Dawley

Topics: Animals; Antioxidants; Basidiomycota; Blood Glucose; Body Weight; Cobalt Radioisotopes; Drinking; Fasting; Forkhead Box Protein O1; Fruiting Bodies, Fungal; Fungal Polysaccharides; Glycogen; Insulin; JNK Mitogen-Activated Protein Kinases; Lipid Peroxidation; Lipids; Liver; Male; Mice; Phosphorylation; Proto-Oncogene Proteins c-akt

Korean pine nut protein (PNP) has a variety of biological activities, which are good for human health, but its ability to preventing diabetes has not been reported. This study evaluated the effects of water-soluble proteins of Korean pine nut obtained from a dilute alkali extract on carbohydrate metabolism of type 2 diabetic mice on a model of diabetes induced using a high fat diet combined with streptozotocin. The results showed that the hypoglycemic effect of PNP at a middle dose was the most significant, which was 38.7% lower than that of control. The extract significantly improved the oral glucose tolerance and liver indexes, increased the activity of the carbohydrate metabolism enzymes, and regulated the expression of the function of key genes for carbohydrate metabolism. It had a positive effect on both insulin resistance and glycolytic/gluconeogenesis signaling. In conclusion, PNP can regulate fasting blood glucose, improve insulin resistance, correct the glucose metabolism disorder in diabetic mice, and have a positive regulatory role. As the functional food, it has the potential to be beneficial in the treatment of type 2 diabetes mellitus as a new hypoglycemic functional food.

Topics: Administration, Oral; Amino Acids; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Type 2; Diet; Drinking Behavior; Fasting; Feeding Behavior; Gene Expression Regulation; Glucose Tolerance Test; Glycogen; Hypoglycemic Agents; Insulin; Insulin Resistance; Liver; Male; Mice; Muscles; Nut Proteins; Pinus; Solubility; Water

Antrodia camphorata and Panax ginseng are well-known medicinal plants in Taiwan folk and traditional Chinese medicine, which have been reported for multifunctional bioactivities. However, there is limited evidence that a fixed combination formula of these two plant extracts is effective for the exercise improvement or anti-fatigue. We aimed to evaluate the potential beneficial effects of the mix formulation of these two herbal medicines (AG formulation) on fatigue and ergogenic functions following physiological challenge. Male Institute of Cancer Research (ICR) mice from four groups (n=10 per group) were orally administered AG formulation for 4 weeks at 0.984, 2.952 and 5.904 g/kg/day, which were designated the Vehicle, AG-1X, AG-3X and AG-6X groups, respectively. The anti-fatigue activity and exercise performance were evaluated using exhaustive swimming time, forelimb grip strength, and levels of serum lactate, ammonia, glucose, blood urea nitrogen (BUN) and creatine kinase (CK) after a swimming exercise. The exhaustive swimming time of the 1X, 3X or 6X AG group was significantly longer than that of the Vehicle group, and the forelimb grip strength of the 1X, 3X or 6X AG group was also significantly higher than that of the Vehicle group. AG supplementation also produced decreases in serum lactate, ammonia, BUN and CK activity after the swimming test, as well as increases in glucose. Therefore, the AG complex could be a potential formulation with an anti-fatigue pharmacological effect.

Topics: Animals; Antrodia; Body Weight; Dietary Supplements; Drinking; Drugs, Chinese Herbal; Eating; Fatigue; Glycogen; Lactates; Liver; Male; Mice, Inbred ICR; Muscle, Skeletal; Panax; Performance-Enhancing Substances; Phytotherapy; Swimming

Six polysaccharides were extracted from different parts (whole plants, roots and leaves) of Anoectochilus roxburghii and Anoectochilus formosanus (ARPs, ARPs-1, ARPs-2, AFPs, AFPs-1 and AFPs-2). Their primary characteristics were identified and their antidiabetic activities were evaluated in STZ-induced diabetic mice. Root polysaccharides (ARPs-1and AFPs-1) and leaf polysaccharides (ARPs-2 and AFPs-2) were distinct from each other in terms of the Mws, monosaccharide compositions and functional groups. Notably, the primary structures of ARPs and AFPs were similar to those of ARPs-1and AFPs-1, respectively. In animal experiment, after feeding with polysaccharides samples, the body weight, blood glucose, glycogen, insulin, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), malondiadehyde (MDA) and antioxidant enzyme activities in liver and kidney of mice were tested to investigate the antidiabetic activities. All polysaccharides exhibited varying antidiabetic activities (antihyperglycemic, antioxidant and antihyperlipidemic activities), which were closely related to their primary characteristics. Furthermore, root polysaccharides with higher Mws and glucose content in both A. roxburghii and A. formosanus, exhibited better antidiabetic activities than leaf polysaccharides, and ARPs which showed the best antidiabetic activities had the potential to be used as functional food or medicine for diabetes treatment.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Glycogen; Hypoglycemic Agents; Insulin; Kidney; Lipids; Liver; Male; Malondialdehyde; Mice, Inbred ICR; Molecular Weight; Monosaccharides; Orchidaceae; Polysaccharides; Spectroscopy, Fourier Transform Infrared; Streptozocin; Uronic Acids

This study was performed to evaluate antifatigue effect of hydrogen water (HW) drinking in chronic forced exercise mice model.. Twelve-week-old C57BL6 female mice were divided into nonstressed normal control (NC) group and stressed group: (purified water/PW-treated group and HW-treated group). Stressed groups were supplied with PW and HW, respectively, ad libitum and forced to swim for the stress induction every day for 4 consecutive weeks. Gross antifatigue effects of HW were assessed by swimming endurance capacity (once weekly for 4 wk), metabolic activities, and immune-redox activities. Metabolic activities such as blood glucose, lactate, glycogen, blood urea nitrogen (BUN), and lactate dehydrogenase (LDH) as well as immune-redox activities such as reactive oxygen species (ROS), nitric oxide (NO), glutathione peroxidase (GPx), catalase, and the related cytokines were evaluated to elucidate underlying mechanism. Blood glucose and lactate were measured at 0 wk (before swimming) and 4 wk (after swimming).. HW group showed a higher swimming endurance capacity (. This study shows antifatigue effects of HW drinking in chronic forced swimming mice via metabolic coordination and immune-redox balance. In that context, drinking HW could be applied to the alternative and safety fluid remedy for chronic fatigue control.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Blood Glucose; Blood Urea Nitrogen; Body Weight; Cytokines; Drinking Water; Fatigue; Female; Glycogen; Hydrogen; Inflammation Mediators; L-Lactate Dehydrogenase; Lactic Acid; Mice, Inbred C57BL; Nitric Oxide; Oxidation-Reduction; Physical Endurance; Reactive Oxygen Species; Swimming

Dehydroepiandrosterone (DHEA) is a steroid hormone that presents several effects on metabolism; however, most of the studies have been performed on male animals, while few authors have investigated possible sex differences regarding the metabolic effects of DHEA. Therefore, the aim of this study was to evaluate the effect of different doses of DHEA on metabolic parameters of male and ovariectomized female Wistar rats. Sex differences were found in the metabolism of distinct substrates and in relation to the effect of DHEA. In respect to the glucose metabolism in the liver, the conversion of glucose to CO

Topics: Adipose Tissue; Animals; Body Weight; Dehydroepiandrosterone; Female; Glucose; Glycogen; Lipids; Lipogenesis; Liver; Male; Models, Animal; Muscle, Skeletal; Rats; Rats, Wistar; Sex Factors

American ginseng (Panax quinquefolium L.) was reported to have extensive biological activities and pharmaceutical properties. In most of the studies, the anti-fatigue effects of American ginseng are attributed to ginsenoside, and in only a few studies, they have been attributed to oligopeptides. Therefore, the aim of this study was to observe the anti-fatigue effects of small-molecule oligopeptides isolated from Panax quinquefolium L. (QOPs) in mice. At first, mice chosen for the study were randomly divided into four experimental groups; each group of mice was further divided into five subgroups: vehicle control group, whey protein group (450 mg per kg BW), and three groups of QOPs at different doses (225 mg per kg BW, 450 mg per kg BW, and 900 mg per kg BW). Test substances were given by gavage once a day for 30 days. QOPs can significantly prolong the forced swimming time, decrease the serum urea nitrogen (SUN) and blood lactate (BLA) levels, and increase the lactate dehydrogenase (LDH) activity and hepatic glycogen content. QOPs also markedly enhanced the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity and attenuated the malondialdehyde (MDA) levels. Notably, QOPs enhanced the activity of succinate dehydrogenase (SDH), Na+-K+-ATPase, and Ca2+-Mg2+-ATPase and increased the mRNA expression of nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM) and the mitochondrial DNA (mtDNA) content in skeletal muscles. These results indicate that treatment with QOPs induces anti-fatigue effects, which may be due to the inhibition of oxidative stress and the improvement of mitochondrial function in skeletal muscles. QOPs can be used as a novel natural agent for relieving physical fatigue.

Topics: Adenosine Triphosphatases; Animals; Blood Urea Nitrogen; Body Weight; DNA, Mitochondrial; Drug Administration Schedule; Fatigue; Glycogen; L-Lactate Dehydrogenase; Lactic Acid; Liver; Male; Mice; Mitochondria; Muscle, Skeletal; Oligopeptides; Oxidative Stress; Panax; Swimming

Background Iodine is a nonpareil constituent of thyroid hormones (THs) and a prime regulator of thyroid gland functioning. Although essential at recommended levels for the prevention of iodine deficiency disorders (IDDs), exposure to excess iodine reportedly causes hypothyroidism, hyperthyroidism, and several other emerging deleterious impacts. The objective of the present study is to explore the influence of excess iodide exposure on carbohydrate and lipid metabolism along with the histoarchitecture of certain associated organs such as the pancreas, liver, kidney, and skeletal and cardiac muscle because information on those aspects was found to be scanty. Methods Twelve rats were taken, six were fed with iodine through gavage at a dose of 3.5 mg potassium iodide (KI)/100-g body weight, which corresponded to 500 times of the physiological daily dosage of iodide for a period of 60 days, while the other six formed the control group. Results KI-treated rats presented high body weight and urinary iodine with low TH levels, suggesting a primary thyroid dysfunction. There was an increase in blood glucose, cholesterol, triglycerides, low density lipoprotein (LDL), and very low density lipoprotein (VLDL), while high density lipoprotein (HDL) levels decreased. Tissue glycogen content in the liver and skeletal muscle was decreased and was increased in the heart and kidney. Histological sections of the pancreas showed a complete disruption with hardly recognizable histoarchistructure. Treated liver sections displayed the broadened central vein with degenerated hepatocytes, while skeletal muscle sections showed dissolution of muscle fibre cells linked with loss of glycogen from these organs. Histological changes in the heart include features similar to those of a fatty heart with cardiac muscles mutilation, while that of the kidney shows an increase in glomerular tuft size and Bowman's space expansion with general deterioration. Conclusions It may thus be concluded that excess iodine exposure for a long duration causes the development of a biochemical state of hypothyroidism. The developed hypothyroidism was found responsible for the hyperglycaemic and hypercholestromic status evident by high blood glucose and cholesterol levels and the depletion of glycogen at its storage sites in the liver and skeletal muscle but the extra deposition in the cardiac muscle and kidney; histomicrophotographs showed severe destruction of the pancreatic structure. All these alterations

Topics: Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Drug Overdose; Glycogen; Hypercholesterolemia; Hyperglycemia; Hypothyroidism; Lipid Metabolism; Male; Potassium Iodide; Rats; Rats, Wistar; Thyroid Hormones; Time Factors

The aim of this research was to evaluate the anti-exercise-fatigue and promotion of sexual interest of total flavonoids from drone pupae of wasps. DPTF was prepared by ethanol extracting and its extraction conditions were optimized by response surface methodology. Then, anti-exercise-fatigue and promotion of sexual interest of DPTF were evaluated. The optimums extraction conditions by RSM were ethanol concentration 65%, extraction time 3 h and solid-to-liquid 20:1(mL/g). No mortality and general symptoms of toxicity were observed in the DPTF treated mice(1 g/kg,3 g/kg,5 g/kg body weight) the body weight and food consumption were not significantly changed compared with the normal control group. The relative weights of main organ did not markedly change. DPTF can significantly extend the duration of the swimming time to exhaustion and the times of capture the female in mice, decrease BUN, LAC and Cr levels, increase LG, GG and T activities in the DPTF treated mice. The dose of 5 g/kg body weight is the optimal dose for anti-exercise-fatigue activity and promotion of sexual interest in male mice. In conclusion, DPTF is promising traditional natural-based therapeutic remedy for relieving exercise-fatigue with high safety.

Topics: Analysis of Variance; Animals; Blood Urea Nitrogen; Body Weight; Creatinine; Fatigue; Feeding Behavior; Female; Flavonoids; Glycogen; Lactic Acid; Liver; Male; Mice; Muscles; Organ Size; Physical Conditioning, Animal; Pupa; Sexual Behavior, Animal; Swimming; Testosterone; Wasps

Plant extracts or pure alkaloids were added to the food of the larvae for three days. The lipid, glycogen, and protein content in the fat body and the midgut were determined, and the contractility of the heart, hindgut, and oviduct muscles was tested using the video-microscopy technique. Finally, the ultrastructure of the fat body and the midgut was observed using electron microscopy.. No lethal effects were noted. Sublethal changes were observed in the content of biomolecules, malformations of organelles, chromatin condensation, and heart and oviduct contractility. The observed effects differed between the tested glycoalkaloids and the extract.. Both the extract and pure GAs have a wide range of effects that may result in impaired development, food intake, and reproduction. Some early effects may be used as bioindicators of stress. The effects of the extract and pure alkaloids suggest that the substances produced by the plant may act additively or synergistically.

Topics: Alkaloids; Animals; Body Weight; Fat Body; Female; Fruit; Glycogen; Heart; Insect Proteins; Intestines; Larva; Lipid Metabolism; Muscle Contraction; Oviducts; Plant Extracts; Solanum nigrum; Tenebrio

Although a ketogenic diet (KD) is used to treat various metabolic diseases, the organ-specific metabolic changes that occur in response to a KD remain unclear. Therefore, we tested the hypothesis that duration of KD consumption and regular exercise in addition to KD consumption affect metabolic fuel selection at gene levels in heart and skeletal muscle. Six-week-old male C57BL/6J mice were divided into 2 groups, one fed a standard diet and the other fed a KD, and maintained for either 4 weeks (short term) or 12 weeks (long term). The long-term group was further divided into 2 subgroups, and mice in 1 of the 2 groups had an exercise load 5 days a week. Body weight decreased significantly in the KD groups during the first few weeks only. Plasma ketone levels rose and muscle glycogen levels declined significantly in the KD groups, but these changes were less severe in the KD plus exercise group. KD consumption decreased the expression of genes related to glucose utilization in heart and skeletal muscle; however, this decrease did not occur with KD consumption plus exercise. Long-term but not short-term KD consumption increased the expression of genes related to lipid utilization, regardless of exercise. In the KD groups, the expression of genes related to ketolysis was suppressed, and that of genes related to ketogenesis was increased. These results indicate that KD exposure and pairing a KD with exercise have differential impacts on energy substrate selection at gene expression levels in energy-consuming organs, the heart and skeletal muscle.

Topics: Animals; Body Weight; Diet, Ketogenic; Gene Expression; Glucose; Glycogen; Heart; Ketones; Lipid Metabolism; Male; Metabolic Diseases; Mice, Inbred C57BL; Muscle, Skeletal; Myocardium; Physical Conditioning, Animal

Diabetes mellitus (DM) is a serious chronic metabolic disorder. Various diseases are being treated with medicinal plants and that is because of the less side effects of the current therapy. The diversity of plants in Armenia is due to the singularity of natural environment. However, biochemical activity of these plants has not been studied well. Thus, the goal was to investigate biochemical activity and antihyperglycemic properties of

Topics: Animals; Area Under Curve; Blood Glucose; Body Weight; Fasting; Glucose Tolerance Test; Glycogen; Hypoglycemic Agents; Lipids; Liver; Male; Medicine, Traditional; Muscles; Phytochemicals; Plant Extracts; Rabbits; Rumex; Seeds

In this study, we investigated the effects of non-nutritive sugars and sugar alcohols on the survivorship of spotted wing drosophila, Drosophila suzukii, and found erythritol and erythrose as potentially insecticidal to the fly. In a dose-dependent study, erythritol and erythrose significantly reduced fly longevity, with 100% mortality with 1, 0.5, 0.1 & 0.05M doses after feeding for 7days. When sucrose and erythritol solutions were provided separately to flies for 7days, there was no effect on survivorship regardless of erythritol concentrations. However, with a serial combination of sucrose and erythritol solutions, fly survivorship was significantly decreased for the same period. Also, the higher dose of erythritol regardless of the sucrose dose combined showed greater mortality. In a no-choice assay, D. suzukii ingested more erythritol than sucrose or water, indicating the fly continuously fed on erythritol for 72h. Also under no-choice conditions, erythritol and sucrose-fed flies gained more weight than water-fed flies. However, in two-choice assays, the amount of erythritol ingested was less than sucrose or water. Total sugar and glycogen levels among erythritol and erythrose-fed flies were significantly less than mannitol, sorbitol, xylitol, and sucrose-fed flies after 48h. This indicates that these two non-nutritive sugars can't be used a substrate for enzymes involved in sugar metabolism. Although the metabolism of erythritol and erythrose is unknown in insects, the mortality of D. suzukii flies ingesting these sugars might be caused by two potential physiological changes. The fly is starved by feeding of non-metabolizable erythritol and erythrose, or experiences abnormally high osmotic pressure in the hemolymph with erythritol molecules diffused from the midgut. Non-nutritive sugars might be used as an insecticide alone or combined with conventional or biological insecticides to enhance efficacy. If other sugar sources are present, a palatable sugar might be mixed with erythritol to elicit feeding.

Topics: Age Factors; Animals; Behavior, Animal; Body Weight; Choice Behavior; Drosophila; Erythritol; Female; Glycogen; Insecticides; Male; Sucrose; Survival Rate; Tetroses

Non-alcoholic fatty liver disease (NAFLD) has become a predictive factor of death from many diseases. The purpose of the present study is to investigate the protective effect of glycyrrhizic acid (GA), a natural triterpene glycoside, on NAFLD induced by a high-fat diet (HFD) in mice, and further to elucidate the mechanisms underlying GA protection. GA treatment significantly reduced the relative liver weight, serum ALT, AST activities, levels of serum lipid, blood glucose and insulin. GA suppressed lipid accumulation in liver. Further mechanism investigation indicated that GA reduced hepatic lipogenesis via downregulating SREBP-1c, FAS and SCD1 expression, increased fatty acids β-oxidation via an increase in PPARα, CPT1α and ACADS, and promoted triglyceride metabolism through inducing LPL activity. Furthermore, GA reduced gluconeogenesis through repressing PEPCK and G6Pase, and increased glycogen synthesis through an induction in gene expression of PDase and GSK3β. In addition, GA increased insulin sensitivity through upregulating phosphorylation of IRS-1 and IRS-2. In conclusion, GA produces protective effect against NAFLD, due to regulation of genes involved in lipid, glucose homeostasis and insulin sensitivity.

Topics: Animals; Body Weight; Cytoprotection; Diet, High-Fat; Fatty Acids; Gene Expression Regulation; Gluconeogenesis; Glucose Tolerance Test; Glycogen; Glycyrrhizic Acid; Insulin Resistance; Liver; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Organ Size; Receptors, Cytoplasmic and Nuclear; Triglycerides

Hyperglycemia and dyslipidemia are classic features for diabetes mellitus (DM). In this study, one fraction of the crude polysaccharides extracted from Lonicera japonica flower buds (LJP) were investigated for its hypolipidaemic and hypoglycaemic activities by means of streptozotocin (STZ)-induced diabetic rats. Interestingly, after orally administrated with 800mg/kg body weight (B.W.) LJP for 42 days, the food and water intake and the levels of sugar and insulin in blood for the diabetic rats were drastically decreased, while the contents of liver and skeletal muscle glycogen and the concentrations of hepatic pyruvate kinase and hexokinase were obviously increased (p<0.01 or p<0.05). The levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterin (LDL-C) and very-low-density lipoprotein-cholesterin (VLDL-C) were significantly descended, while high-density lipoprotein-cholesterin (HDL-C) was significantly ascended (p<0.01 or p<0.05). In addition, the oxidant stress in liver was restored as well. The results suggested that LJP could be considered as an ingredient of functional foods for diabetes, and this is the first report about the hypoglycemic and hypolipidemic effects of the polysaccharides extracted from Lonicera japonica.

Topics: Animals; Body Weight; Diabetes Mellitus, Experimental; Drinking; Flowers; Glycogen; Hexokinase; Hydrolysis; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Liver; Lonicera; Male; Muscle, Skeletal; Oxidative Stress; Polysaccharides; Pyruvate Kinase; Rats; Rats, Sprague-Dawley; Sugars

Pancreatic lesions can produce metabolic disorders. Light-emitting diode (LED) has been used as a safe and effective phototherapy for cell proliferation and regeneration. We investigate the effects of phototherapy using LED irradiation on the pancreas after the injection of streptozotocin (STZ) to induce experimental diabetes and evaluate that the β cells can regenerate in the pancreas in an in vivo model and observe its implications on the control of carbohydrate metabolism. Twenty Wistar rats were randomized into three groups: non-diabetic control, diabetic control, and diabetic treated with LED. Except for the non-diabetic control group, all were induced to diabetes type I by streptozotocin injection. Treated groups were irradiated by LED: λ = 805 nm; 40 mW, 22 s; spot diameter 5 mm, spot area 0.196 cm

Topics: Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Glucose Tolerance Test; Glycogen; Light; Liver; Male; Mice; Muscles; Pancreatic Ducts; Rats, Wistar; Regeneration; Streptozocin

The objective of the study was to evaluate the efficacy of garcinol as an antidiabetic candidate in streptozotocin-induced diabetic Wistar rats. Diabetic rats showed a significant increase in the biochemical parameters such as fasting blood glucose, glycated haemoglobin, urea, alanine aminotransferase and aspartate aminotransferase, malondialdehyde, total cholesterol, triglycerides, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, atherogenic index and a significant decrease in plasma insulin, HOMA-β-cell functioning index, glycogen, high-density lipoprotein cholesterol, body weight and antioxidant enzyme activities, viz. superoxide dismutase, catalase and reduced glutathione. Oral administration of garcinol (10 and 20 mg/kg body weight/day) for 30 days improved the above-mentioned alterations. The effect produced by the drug was compared with that of glibenclamide, a standard hypoglycaemic drug. These findings reveal that garcinol can be a promising antidiabetic candidate in the future.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Catalase; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Fasting; Glutathione; Glycated Hemoglobin; Glycogen; Homeostasis; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Insulin-Secreting Cells; Kidney; Liver; Male; Malondialdehyde; Rats; Rats, Wistar; Superoxide Dismutase; Terpenes; Urea

The anti-fatigue effect was investigated of the probiotic supplement, OM-X®, on forced swimming capacity in mice. Mice were administered either vehicle (distilled water; DW) or OM-X® (85 mg/kg body weight) by gavage for 4 weeks. Forced swimming tests were conducted weekly using the Ishihara-modified Matsumoto swimming pool. The endurance swimming time of the final forced swimming exercise in mice fed with OM-X® group showed an approximately 2-fold increase compared with the vehicle control group. Biomedical parameters, including blood lactate, blood superoxide dismutase (SOD) activity, serum triacylglycerol (TG), hepatic total lipids (TL), TG and phospholipid (PL) were significantly lower in mice fed-with OM-X® than those in the vehicle control group. Furthermore, the mRNA expression levels of carbamoyl phosphate synthetase 1 (Cpsl) and arginase I (Argl), in the urea cycle, were increased by OM-X® feeding. Thus, our findings suggest promotion of lipid metabolism and up-regulation of the urea cycle, at least in part, for the anti-fatigue effect mediated by OM-X®.

Topics: Animals; Arginase; Body Weight; Dietary Supplements; Drinking; Eating; Fermentation; Glycogen; Lactic Acid; Lipids; Male; Mice; Muscle Fatigue; Physical Endurance; Plant Extracts; Superoxide Dismutase; Swimming; Urea

Intermittent fasting (IMF) is a relatively new dietary approach to weight management, although the efficacy and adverse effects have not been full elucidated and the optimal diets for IMF are unknown. We tested the hypothesis that a one-meal-per-day intermittent fasting with high fat (HF) or protein (HP) diets can modify energy, lipid, and glucose metabolism in normal young male Sprague-Dawley rats with diet-induced obesity or overweight. Male rats aged 5 weeks received either HF (40% fat) or HP (26% protein) diets ad libitum (AL) or for 3 h at the beginning of the dark cycle (IMF) for 5 weeks. Epidydimal fat pads and fat deposits in the leg and abdomen were lower with HP and IMF. Energy expenditure at the beginning of the dark cycle, especially from fat oxidation, was higher with IMF than AL, possibly due to greater activity levels. Brown fat content was higher with IMF. Serum ghrelin levels were higher in HP-IMF than other groups, and accordingly, cumulative food intake was also higher in HP-IMF than HF-IMF. HF-IMF exhibited higher area under the curve (AUC) of serum glucose at the first part (0-40 min) during oral glucose tolerance test, whereas AUC of serum insulin levels in both parts were higher in IMF and HF. During intraperitoneal insulin tolerance test, serum glucose levels were higher with IMF than AL. Consistently, hepatic insulin signaling (GLUT2, pAkt) was attenuated and PEPCK expression was higher with IMF and HF than other groups, and HOMA-IR revealed significantly impaired attenuated insulin sensitivity in the IMF groups. However, surprisingly, hepatic and skeletal muscle glycogen storage was higher in IMF groups than AL. The higher glycogen storage in the IMF groups was associated with the lower expression of glycogen phosphorylase than the AL groups. In conclusion, IMF especially with HF increased insulin resistance, possibly by attenuating hepatic insulin signaling, and lowered glycogen phosphorylase expression despite decreased fat mass in young male rats. These results suggest that caution may be warranted when recommending intermittent fasting, especially one-meal-per-day fasting, for people with compromised glucose metabolism.

Topics: Adipose Tissue; Animals; Body Composition; Body Weight; Diet, High-Fat; Diet, High-Protein; Energy Metabolism; Fasting; Glucose; Glucose Tolerance Test; Glycogen; Insulin Resistance; Lipid Metabolism; Lipids; Liver; Male; Rats, Sprague-Dawley

Three new meroterpenoids, ganoleucin A-C (1-3), together with five known meroterpenoids (4-8), were isolated from the fruiting bodies of Ganoderma leucocontextum. The structures of the new compounds were elucidated by extensive spectroscopic analysis, circular dichroism (CD) spectroscopy, and chemical transformation. The inhibitory effects of 1-8 on HMG-CoA reductase and α-glucosidase were tested in vitro. Ganomycin I (4), 5, and 8 showed stronger inhibitory activity against HMG-CoA reductase than the positive control atorvastatin. Compounds 1, and 3-8 presented potent noncompetitive inhibitory activity against α-glucosidase from both yeast and rat small intestinal mucosa. Ganomycin I (4), the most potent inhibitor against both α-glucosidase and HMG-CoA reductase, was synthesized and evaluated for its in vivo bioactivity. Pharmacological results showed that ganomycin I (4) exerted potent and efficacious hypoglycemic, hypolipidemic, and insulin-sensitizing effects in KK-A

Topics: Adipose Tissue; Alanine Transaminase; alpha-Glucosidases; Animals; Aspartate Aminotransferases; Blood Glucose; Body Weight; Female; Ganoderma; Glycogen; Glycoside Hydrolase Inhibitors; Hydroquinones; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemic Agents; Insulin Resistance; Kinetics; Liver; Male; Mice; Molecular Docking Simulation; Protein Conformation

Type 2 diabetes is likely to be an independent risk factor for hippocampal-based memory dysfunction, although this complication has yet to be investigated in detail. As dysregulated glycometabolism in peripheral tissues is a key symptom of type 2 diabetes, it is hypothesised that diabetes-mediated memory dysfunction is also caused by hippocampal glycometabolic dysfunction. If so, such dysfunction should also be ameliorated with moderate exercise by normalising hippocampal glycometabolism, since 4 weeks of moderate exercise enhances memory function and local hippocampal glycogen levels in normal animals.. The hippocampal glycometabolism in OLETF rats (model of human type 2 diabetes) was assessed and, subsequently, the effects of exercise on memory function and hippocampal glycometabolism were investigated.. OLETF rats, which have memory dysfunction, exhibited higher levels of glycogen in the hippocampus than did control rats, and breakdown of hippocampal glycogen with a single bout of exercise remained unimpaired. However, OLETF rats expressed lower levels of hippocampal monocarboxylate transporter 2 (MCT2, a transporter for lactate to neurons). Four weeks of moderate exercise improved spatial memory accompanied by further increase in hippocampal glycogen levels and restoration of MCT2 expression independent of neurotrophic factor and clinical symptoms in OLETF rats.. Our findings are the first to describe detailed profiles of glycometabolism in the type 2 diabetic hippocampus and to show that 4 weeks of moderate exercise improves memory dysfunction in type 2 diabetes via amelioration of dysregulated hippocampal glycometabolism. Dysregulated hippocampal lactate-transport-related glycometabolism is a possible aetiology of type-2-diabetes-mediated memory dysfunction.

Topics: Animals; Blood Glucose; Blotting, Western; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Eating; Glycogen; Hippocampus; Male; Memory; Physical Conditioning, Animal; Rats; Rats, Inbred OLETF

Cinnamon has a history of use for medicinal purposes and its major benefits have been linked to cinnamaldehyde. The present study aimed to investigate the hypoglycemic action of cinnamaldehyde against fatty-sucrosed diet/streptozotocin (FSD/STZ)-rat model of gestational diabetes. Female albino rats were divided into three groups. Group I fed with normal diet (ND) while group II and III were fed with FSD for eight weeks (five weeks pre-gestational and three weeks gestational). Rats of group III were administered with a daily oral dose of 20mg/kg cinnamaldehyde one week before mating onward. At the 7th day of gestation, FSD-fed rats were injected intraperitoneally with STZ (25mg/kg b.wt.) to induce gestational diabetes. Pre-mating treatment of cinnamaldehyde controls hyperphagia and glucose intolerance during the gestational period than in diabetic rats. It also reduced levels of fructosamine, total cholesterols, triglycerides, leptin, tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA) and nitric oxide (NO), while it significantly increased levels of high-density lipoprotein (HDL)-cholesterol, adiponectin, liver glycogen, reduced glutathione (GSH) and catalase activity at term pregnancy. In addition, cinnamaldehyde administration up-regulated the mRNA expression of peroxisome proliferated activated receptor-gamma (PPARγ) and also ameliorated the number of viable fetuses, implantation loss sites, fetal glucose and insulin levels. In conclusion, cinnamaldehyde has safe hypoglycemic action on gestational diabetes by potentiating insulin secretion and sensitivity through activating the antioxidant defense system, suppressing pro-inflammatory cytokines production, upregulating PPARγ gene expression and alleviating the reproductive performance.

Topics: Acrolein; Adipose Tissue; Animals; Antioxidants; Biomarkers; Blood Glucose; Body Weight; Cholesterol; Cytokines; Diabetes, Gestational; Feeding Behavior; Female; Fetus; Fructosamine; Glucose Tolerance Test; Glycogen; Hyperglycemia; Inflammation Mediators; Insulin; Leptin; Liver; Oxidative Stress; PPAR gamma; Pregnancy; Pregnancy Outcome; Rats; RNA, Messenger; Triglycerides

Betanin, a chromoalkaloid of beetroot, has shown significant biological effects of antioxidants, anti-inflammatory and anticarcinogenic activities. So, we attempted to determine whether betanin (a natural pigment) would be protective against hyperglycemia in streptozotocin (STZ) - nicotinamide (NA) induced diabetic rats. Rats were injected with STZ (40mg/kgb.w.) 15 mins after the administration of NA (110mg/kgb.w.) by intraperitonially (i.p.) 30days for the induction of experimental diabetes mellitus. After 72h diabetic rats were treated with betanin orally at a doses of 10, 20 and 40mg/kg b.w., respectively in a dose dependent manner and glibenclamide (600μg/kgb.w.). The promising character of betanin against diabetic rats was evaluated by performing the various biochemical parameters and histomorphological changes in liver and pancreas. Among the three doses, 20mg/kgb.w. of betanin was able to positively regulate plasma glucose, insulin, glycosylated hemoglobin (HbA

Topics: Animals; Betacyanins; Biomarkers; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Feeding Behavior; Glucose Tolerance Test; Glycated Hemoglobin; Glycogen; Glycolysis; Immunohistochemistry; Insulin; Lipogenesis; Liver; Male; Models, Biological; Niacinamide; Organ Size; Rats, Wistar; Streptozocin

More than 95% of the body carnitine is located in skeletal muscle, where it is essential for energy metabolism. Vegetarians ingest less carnitine and carnitine precursors and have lower plasma carnitine concentrations than omnivores. Principle aims of the current study were to assess the plasma and skeletal muscle carnitine content and physical performance of male vegetarians and matched omnivores under basal conditions and after L-carnitine supplementation.. Sixteen vegetarians and eight omnivores participated in this interventional study with oral supplementation of 2 g L-carnitine for 12 weeks. Before carnitine supplementation, vegetarians had a 10% lower plasma carnitine concentration, but maintained skeletal muscle carnitine stores compared to omnivores. Skeletal muscle phosphocreatine, ATP, glycogen and lactate contents were also not different from omnivores. Maximal oxygen uptake (VO2max) and workload (P max) per bodyweight (bicycle spiroergometry) were not significantly different between vegetarians and omnivores. Sub-maximal exercise (75% VO2max for 1 h) revealed no significant differences between vegetarians and omnivores (respiratory exchange ratio, blood lactate and muscle metabolites). Supplementation with L-carnitine significantly increased the total plasma carnitine concentration (24% in omnivores, 31% in vegetarians) and the muscle carnitine content in vegetarians (13%). Despite this increase, P max and VO2max as well as muscle phosphocreatine, lactate and glycogen were not significantly affected by carnitine administration.. Vegetarians have lower plasma carnitine concentrations, but maintained muscle carnitine stores compared to omnivores. Oral L-carnitine supplementation normalizes the plasma carnitine stores and slightly increases the skeletal muscle carnitine content in vegetarians, but without affecting muscle function and energy metabolism.

Topics: Administration, Oral; Adolescent; Adult; Body Mass Index; Body Weight; Carnitine; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Dietary Supplements; Energy Intake; Energy Metabolism; Exercise; Glycogen; Humans; Male; Muscle, Skeletal; Vegetarians; Young Adult

Hypoglycemic effects of grapefruit juice (GFJ) are widely recognized, but the mechanism(s) by which GFJ lowers blood glucose levels have not previously been investigated.. Wistar rats [250-300 g body weight (BW)] were divided into eight groups (n = 7). Group 1 animals were orally treated with 3.0 ml/kg BW of distilled water for 60 days, while groups 3, 4, 5, 6 were similarly treated with 3.0 ml/kg BW of GFJ. Groups 4 and 7 as well as 2, 5, 6 and 8 were given 45.0 and 60.0 mg/kg BW intraperitoneal injections streptozotocin, respectively, while groups 2 and 6 animals were additionally injected with insulin (4.0 units/kg, S.C., b.d), respectively. Fasting blood glucose (FBG) and glucose tolerance tests were done. Hepatic glycogen content and glucokinase, glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) activities were measured in homogenized liver tissues.. Diabetic rats, groups 2 and 4-8 exhibited significantly reduced weight gain but increased polydipsia compared to controls. FBG was significantly increased in diabetic rats compared to controls but were significantly improved in GFJ-treated-compared to non-treated-diabetic rats. Similarly, diabetic rats showed significant glucose intolerance compared to controls which was improved by GFJ treatment. GFJ treatment did not improve fasting plasma insulin in diabetic rats. GFJ treatment significantly elevated glucokinase activity and hepatic glycogen concentrations but suppressed the activities of G6Pase and PEPCK, respectively, in diabetic animals.. These findings show that GFJ is not insulinotropic but improves glucose intolerance in diabetic rats by suppressing hepatic gluconeogenesis.

Topics: Animals; Blood Glucose; Body Weight; Citrus paradisi; Diabetes Mellitus, Experimental; Fruit and Vegetable Juices; Glucokinase; Gluconeogenesis; Glucose Intolerance; Glucose Tolerance Test; Glucose-6-Phosphatase; Glycogen; Insulin; Linear Models; Liver; Male; Phosphoenolpyruvate Carboxykinase (ATP); Rats; Rats, Wistar; Streptozocin

The objective of the current study was to determine associations between the severity of systemic inflammation during the early postpartum period and performance, energy metabolism, and immune function in dairy cows. Cows were assigned to categorical quartiles (Q; Q1=0.18-0.59, Q2=0.60-1.14, Q3=1.15-2.05, and Q4=2.06-2.50 g of haptoglobin/L) based on the highest plasma haptoglobin (Hp) concentration measured during wk 1 postpartum. Although cows were assigned to different categories of inflammation during the postpartum period, we detected a quadratic relationship of inflammation on prepartum dry matter intake (DMI) and body weight (BW) such that cows in Q2 had lower prepartum DMI and cows in Q2 and Q3 had lower prepartum BW compared with cows in the other quartiles. We also detected a quadratic association of inflammation with postpartum DMI and BW such that cows in Q2 and Q3 also had generally lower postpartum DMI and BW compared with cows in Q1. There was a tendency for a Q × time interaction for milk yield and Q × time interactions for 3.5% fat-corrected milk and energy-corrected milk yields; quadratic relationships suggested decreased milk yield for Q2 and Q3 cows. We also found Q × parity and Q × time interactions for plasma glucose and insulin concentrations, suggesting alterations with differing degrees of inflammation. There was also a Q × time interaction for plasma nonesterified fatty acids concentration. In addition, alterations in liver triglyceride and glycogen contents for cows with inflammation as well as alterations in [1-(14)C]propionate oxidation in vitro were observed. Although we observed limited effects of inflammation on neutrophil and monocyte phagocytosis at d 7 postpartum, inflammation appeared to alter neutrophil and monocyte oxidative burst. Overall, cows with any degree of elevated haptoglobin in the first week after calving had alterations in both pre- and postpartum intake and postpartum metabolism.

Topics: 3-Hydroxybutyric Acid; Animals; Blood Glucose; Body Weight; Cattle; Cattle Diseases; Energy Metabolism; Fatty Acids, Nonesterified; Female; Glycogen; Haptoglobins; Inflammation; Insulin; Lactation; Liver; Monocytes; Neutrophils; Phagocytosis; Postpartum Period; Triglycerides

An important regulator of fatty acid oxidation (FAO) is the allosteric inhibition of CPT-1 by malonyl-CoA produced by the enzyme acetyl-CoA carboxylase 2 (ACC2). Initial studies suggested that deletion of Acc2 (Acacb) increased fat oxidation and reduced adipose tissue mass but in an independently generated strain of Acc2 knockout mice we observed increased whole-body and skeletal muscle FAO and a compensatory increase in muscle glycogen stores without changes in glucose tolerance, energy expenditure or fat mass in young mice (12-16 weeks). The aim of the present study was to determine whether there was any effect of age or housing at thermoneutrality (29 °C; which reduces total energy expenditure) on the phenotype of Acc2 knockout mice. At 42-54 weeks of age, male WT and Acc2(-/-) mice had similar body weight, fat mass, muscle triglyceride content and glucose tolerance. Consistent with younger Acc2(-/-) mice, aged Acc2(-/-) mice showed increased whole-body FAO (24 h average respiratory exchange ratio=0.95±0.02 and 0.92±0.02 for WT and Acc2(-/-) mice respectively, P<0.05) and skeletal muscle glycogen content (+60%, P<0.05) without any detectable change in whole-body energy expenditure. Hyperinsulinaemic-euglycaemic clamp studies revealed no difference in insulin action between groups with similar glucose infusion rates and tissue glucose uptake. Housing Acc2(-/-) mice at 29 °C did not alter body composition, glucose tolerance or the effects of fat feeding compared with WT mice. These results confirm that manipulation of Acc2 may alter FAO in mice, but this has little impact on body composition or insulin action.

Topics: Acetyl-CoA Carboxylase; Aging; Animals; Body Composition; Body Weight; Energy Metabolism; Fatty Acids; Glucose Clamp Technique; Glucose Tolerance Test; Glycogen; Housing, Animal; Insulin; Male; Mice; Mice, Knockout; Muscle, Skeletal; Oxidation-Reduction; Phenotype; Temperature; Triglycerides

Due to the limitations of existing anti-diabetic drugs, the treatment of diabetes mellitus remains a significant challenge. The present study aimed to investigate the hypoglycemic, hypolipidemic and antioxidant effects of Paecilomyces tenuipes N45 extracts on alloxan-induced type I diabetes mellitus in mice. Diabetic Kunming mice were orally administered with water extract (WE) at doses of 2.50, 0.25 and 0.05 g/kg) or alcohol extract (AE) at doses of 2.00, 0.20 and 0.04 g/kg, for 3 weeks, following which the levels of factors associated with blood glucose, lipids and free radicals were determined. The anti-diabetic activities of AE and WE were further confirmed via an oral glucose tolerance test. Similar to the effects of metformin, Paecilomyces tenuipes N45 extracts led to a significant reduction in blood glucose levels, increase in serum insulin concentration and normalization in the densities of low-density lipoprotein cholesterol and high density lipoprotein cholesterol. The Paecilomyces tenuipes N45 extracts exerted antioxidative effects, indicated by regulation in the levels of superoxide dismutase, malondialdehyde and glutathione peroxidase. Taken together, the results of the present study demonstrated that Paecilomyces tenuipes N45 extract, a safe pharmaceutical agent, exerted anti-diabetic and anti-nephropathic activities and, thus, offers potential as a novel therapeutic agent in the treatment of diabetes.

Topics: Alloxan; Animals; Antioxidants; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Disease Models, Animal; Glucose Tolerance Test; Glycogen; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Liver; Organ Size; Paecilomyces; Phytotherapy; Plant Extracts

Mulberry (Morus alba L.) is a tree species of Moraceae widely distributed in Southern China. In the present study, the white crystal of γ-aminobutyric acid (GABA) was purified from mulberry leaves, and its bioactivity was also investigated. The main results were as follows: first, the crude GABA was extracted from mulberry leaves by using biochemical methods. Then, the crude was purified by chromatography over an S-8 macroporous resin, Sephadex G-10, and 732 cation exchange resin to yield a white crystal. Lavage administration and exposure of GABA to male NIH mice showed no adverse effects on their growth and development. In an endurance capacity test, the average loaded-swimming time of medium dose was 111.60% longer than the control (P < 0.01). Further investigations showed that relative to that of model control, the respective blood lactate (BL) concentrations of low- and medium-dose were 28.52% and 28.81% lower (P < 0.05), whereas the levels of blood urea nitrogen (BUN) were 36.83% and 40.54% lower (P < 0.05), and that of liver glycogen (LG) levels were 12.81% and 17.22% lower (P < 0.05). The results indicated that GABA has an advantage over taurine of anti-fatigue effect. These findings were indicative of the anti-fatigue activity of GABA.

Topics: Animals; Blood Urea Nitrogen; Body Weight; Fatigue; gamma-Aminobutyric Acid; Glycogen; Lactic Acid; Liver; Male; Mice; Morus; Physical Conditioning, Animal; Physical Endurance; Plant Extracts; Plant Leaves; Taurine

Increasing studies have shown protective effects of intermittent hypoxia on brain injury and heart ischemia. However, the effect of intermittent hypoxia on blood glucose metabolism, especially in diabetic conditions, is rarely observed. The aim of this study was to investigate whether intermittent hypoxia influences blood glucose metabolism in type 1 diabetic rats. Streptozotocin-induced diabetic adult rats and age-matched control rats were treated with intermittent hypoxia (at an altitude of 3 km, 4 h per day for 3 weeks) or normoxia as control. Fasting blood glucose, body weight, plasma fructosamine, plasma insulin, homeostasis model assessment of insulin resistance (HOMA-IR), pancreas β-cell mass, and hepatic and soleus glycogen were measured. Compared with diabetic rats before treatment, the level of fasting blood glucose in diabetic rats after normoxic treatment was increased (19.88 ± 5.69 mmol/L vs. 14.79 ± 5.84 mmol/L, p < 0.05), while it was not different in diabetic rats after hypoxic treatment (13.14 ± 5.77 mmol/L vs. 14.79 ± 5.84 mmol/L, p > 0.05). Meanwhile, fasting blood glucose in diabetic rats after hypoxic treatment was also lower than that in diabetic rats after normoxic treatment (13.14 ± 5.77 mmol/L vs. 19.88 ± 5.69 mmol/L, p<0.05). Plasma fructosamine in diabetic rats receiving intermittent hypoxia was significantly lower than that in diabetic rats receiving normoxia (1.28 ± 0.11 vs. 1.39 ± 0.11, p < 0.05), while there were no significant changes in body weight, plasma insulin and β-cell mass. HOMA-IR in diabetic rats after hypoxic treatment was also lower compared with diabetic rats after normoxic treatment (3.48 ± 0.48 vs. 3.86 ± 0.42, p < 0.05). Moreover, intermittent hypoxia showed effect on the increase of soleus glycogen but not hepatic glycogen. We conclude that intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats and its regulation on muscular glycogenesis may play a role in the underlying mechanism.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Fructosamine; Glycogen; Humans; Hypoxia; Insulin; Insulin Resistance; Insulin-Secreting Cells; Liver; Male; Muscle, Skeletal; Rats

The leaf extract of Urtica dioica L. (UT) has been reported to improve glucose homeostasis in vivo, but definitive studies on efficacy and mechanism of action are lacking. We investigated the effects of UT on obesity- induced insulin resistance in skeletal muscle. Male C57BL/6J mice were divided into three groups: low-fat diet (LFD), high-fat diet (HFD) and HFD supplemented with UT. Body weight, body composition, plasma glucose and plasma insulin were monitored. Skeletal muscle (gastrocnemius) was analyzed for insulin sensitivity, ceramide accumulation and the post translational modification and activity of protein phosphatase 2A (PP2A). PP2A is activated by ceramides and dephosphorylates Akt. C2C12 myotubes exposed to excess free fatty acids with or without UT were also evaluated for insulin signaling and modulation of PP2A. The HFD induced insulin resistance, increased fasting plasma glucose, enhanced ceramide accumulation and PP2A activity in skeletal muscle. Supplementation with UT improved plasma glucose homeostasis and enhanced skeletal muscle insulin sensitivity without affecting body weight and body composition. In myotubes, UT attenuated the ability of FFAs to induce insulin resistance and PP2A hyperactivity without affecting ceramide accumulation and PP2A expression. UT decreased PP2A activity through posttranslational modification that was accompanied by a reduction in Akt dephosphorylation.

Topics: Animals; Body Composition; Body Weight; Cell Line; Diet, High-Fat; Glucose; Glycogen; Insulin; Insulin Resistance; Male; Mice; Muscle, Skeletal; Obesity; Plant Extracts; Protein Phosphatase 2; Signal Transduction; Urtica dioica

Long-term high-fat diet increases muscle mitochondrial enzyme activity and endurance performance. However, excessive calorie intake causes intra-abdominal fat accumulation and metabolic syndrome. The purpose of this study was to investigate the effect of an alternating day high-fat diet on muscle mitochondrial enzyme activities, protein content, and intra-abdominal fat mass in rats. Male Wistar rats were given a standard chow diet (CON), high-fat diet (HFD), or alternate-day high-fat diet (ALT) for 4 weeks. Rats in the ALT group were fed a high-fat diet and standard chow every other day for 4 weeks. After the dietary intervention, mitochondrial enzyme activities and protein content in skeletal muscle were measured. Although body weight did not differ among groups, the epididymal fat mass in the HFD group was higher than those of the CON and ALT groups. Citrate synthase and beta-hydroxyacyl CoA dehydrogenase activities in the plantaris muscle of rats in HFD and ALT were significantly higher than that in CON rats, whereas there was no difference between HFD and ALT groups. No significant difference was observed in muscle glycogen concentration or glucose transporter-4 protein content among the three groups. These results suggest that an alternate-day high-fat diet induces increases in mitochondrial enzyme activities and protein content in rat skeletal muscle without intra-abdominal fat accumulation.

Topics: Adipose Tissue; Animals; Body Weight; Dietary Fats; Drug Administration Schedule; Fatty Acids, Nonesterified; Gene Expression Regulation; Glucose Transporter Type 4; Glycogen; Male; Mitochondria; Muscle Proteins; Muscle, Skeletal; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Rats; Rats, Wistar

Obesity and impairments in metabolic health are associated with reductions in exercise capacity. Both whey protein isolates (WPIs) and vitamin E tocotrienols (TCTs) exert favorable effects on obesity-related metabolic parameters. This research sought to determine whether these supplements improved exercise capacity and increased glucose tolerance in diet-induced obese rats.. Six week old male rats (n = 35) weighing 187 ± 32g were allocated to either: Control (n = 9), TCT (n = 9), WPI (n = 8) or TCT + WPI (n = 9) and placed on a high-fat diet (40% of energy from fat) for 10 weeks. Animals received 50mg/kg body weight and 8% of total energy intake per day of TCTs and/or WPIs respectively. Food intake, body composition, glucose tolerance, insulin sensitivity, exercise capacity, skeletal muscle glycogen content and oxidative enzyme activity were determined.. Both TCT and WPI groups ran >50% longer (2271 ± 185m and 2195 ± 265m respectively) than the Control group (1428 ± 139m) during the run to exhaustion test (P<0.05), TCT + WPI did not further improve exercise endurance (2068 ± 104m). WPIs increased the maximum in vitro activity of beta-hydroxyacyl-CoA in the soleus muscle (P<0.05 vs. Control) but not in the plantaris. Citrate synthase activity was not different between groups. Neither supplement had any effect on weight gain, adiposity, glucose tolerance or insulin sensitivity.. Ten weeks of both TCTs and WPIs increased exercise endurance by 50% in sedentary, diet-induced obese rats. These positive effects of TCTs and WPIs were independent of body weight, adiposity or glucose tolerance.

Topics: Adiposity; Animals; Antioxidants; Blood Glucose; Body Weight; Diet, High-Fat; Energy Intake; Glucose Tolerance Test; Glycogen; Male; Obesity; Physical Conditioning, Animal; Physical Endurance; Rats; Rats, Sprague-Dawley; Tocotrienols; Whey Proteins

Severe caloric restriction (CR), in a setting of regular physical exercise, may be a stress that sets the stage for adiposity rebound and insulin resistance when the food restriction and exercise stop. In this study, we examined the effect of mifepristone, a glucocorticoid (GC) receptor antagonist, on limiting adipose tissue mass gain and preserving whole body insulin sensitivity following the cessation of daily running and CR. We calorically restricted male Sprague-Dawley rats and provided access to voluntary running wheels for 3 wk followed by locking of the wheels and reintroduction to ad libitum feeding with or without mifepristone (80 mg·kg(-1)·day(-1)) for 1 wk. Cessation of daily running and CR increased HOMA-IR and visceral adipose mass as well as glucose and insulin area under the curve during an oral glucose tolerance test vs. pre-wheel lock exercised rats and sedentary rats (all P < 0.05). Insulin sensitivity and glucose tolerance were preserved and adipose tissue mass gain was attenuated by daily mifepristone treatment during the post-wheel lock period. These findings suggest that following regular exercise and CR there are GC-induced mechanisms that promote adipose tissue mass gain and impaired metabolic control in healthy organisms and that this phenomenon can be inhibited by the GC receptor antagonist mifepristone.

Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Adiposity; Animals; Blood Glucose; Blotting, Western; Body Weight; Caloric Restriction; Gluconeogenesis; Glucose Intolerance; Glucose Tolerance Test; Glycogen; Glycogenolysis; Hormone Antagonists; Insulin; Insulin Resistance; Intra-Abdominal Fat; Lipolysis; Liver; Male; Mifepristone; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; Receptors, Glucocorticoid

Polysaccharides, which are the main bioactive constituents of edible mushrooms, have been shown to have a variety of useful biological activities. In this study, a polysaccharide fraction from the edible mushroom Catathelasma ventricosum was purified using anion exchange and size exclusion chromatographies. The structure of the resulting polysaccharide, named CVP-1S, was characterized on the basis of partial acid hydrolysis, periodic acid oxidation, methylation analysis, gas chromatography-mass spectrometry, Fourier-transform infrared spectroscopy, 1D/2D NMR spectroscopy, scanning electron microscopy, and atomic force spectroscopy. The results showed that CVP-1S is a heteropolysaccharide consisting of glucose (94.2%), galactose (3.51%) and fucose (1.3%) with a molecular weight of 1.5×10(4)Da. Its backbone is mainly linked by (1→6)-β-d-Glcp glycosidic bonds, and branches are attached to the backbone through 1,3-linked glycosidic bonds. CVP-1S was also found to have antioxidant, hypoglycemic, and hypolipidemic activities in the streptozoicin-induced diabetic mouse model. From these results, we conclude that CVP-1S should receive further attention as a potential agent for the treatment and prevention of diabetes.

Topics: Agaricales; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Glucose; Glycogen; Hypoglycemic Agents; Insulin; Lipids; Liver; Mice; Polysaccharides

Mobilization of glycogen stores was examined in the anoxic crucian carp (Carassius carassius Linnaeus). Winter-acclimatized fish were exposed to anoxia for 1, 3, or 6 weeks at 2 °C, and changes in the size of glycogen deposits were followed. After 1 week of anoxia, a major part of the glycogen stores was mobilized in liver (79.5 %) and heart (75.6 %), and large decreases occurred in gill (46.7 %) and muscle (45.1 %). Brain was an exception in that its glycogen content remained unchanged. The amount of glycogen degraded during the first anoxic week was sufficient for the anaerobic ethanol production for more than 6 weeks of anoxia. After 3 and 6 weeks of anoxia, there was little further degradation of glycogen in other tissues except the brain where the stores were reduced by 30.1 and 49.9 % after 3 and 6 weeks of anoxia, respectively. One week of normoxic recovery following the 6-week anoxia was associated with a complete replenishment of the brain glycogen and partial recovery of liver, heart, and gill glycogen stores. Notably, the resynthesis of glycogen occurred at the expense of the existing energy reserves of the body in fasting fish. These findings indicate that in crucian carp, glycogen stores are quickly mobilized after the onset of anoxia, with the exception of the brain whose glycogen stores may be saved for putative emergency situations.

Topics: Acclimatization; Acetates; Ammonia; Animals; Body Weight; Brain; Carps; Ethanol; Gills; Glycogen; Heart; Hypoxia; Lactic Acid; Liver; Organ Size; Spleen

Topics: Animals; Body Weight; Endocannabinoids; Energy Metabolism; Enzymes; Fatty Acids; Gene Expression Regulation; Glucose; Glycogen; Goldfish; Injections, Intraperitoneal; Lipid Metabolism; Liver; Locomotion; Oleic Acids; PPAR alpha

A low carbohydrate diet (LCHD) as well as sodium glucose cotransporter 2 inhibitors (SGLT2i) may reduce glucose utilization and improve metabolic disorders. However, it is not clear how different or similar the effects of LCHD and SGLT2i are on metabolic parameters such as insulin sensitivity, fat accumulation, and especially gluconeogenesis in the kidney and the liver. We conducted an 8-week study using non-diabetic mice, which were fed ad-libitum with LCHD or a normal carbohydrate diet (NCHD) and treated with/without the SGLT-2 inhibitor, ipragliflozin. We compared metabolic parameters, gene expression for transcripts related to glucose and fat metabolism, and glycogen content in the kidney and the liver among the groups. SGLT2i but not LCHD improved glucose excursion after an oral glucose load compared to NCHD, although all groups presented comparable non-fasted glycemia. Both the LCHD and SGLT2i treatments increased calorie-intake, whereas only the LCHD increased body weight compared to the NCHD, epididimal fat mass and developed insulin resistance. Gene expression of certain gluconeogenic enzymes was simultaneously upregulated in the kidney of SGLT2i treated group, as well as in the liver of the LCHD treated group. The SGLT2i treated groups showed markedly lower glycogen content in the liver, but induced glycogen accumulation in the kidney. We conclude that LCHD induces deleterious metabolic changes in the non-diabetic mice. Our results suggest that SGLT2i induced gluconeogenesis mainly in the kidney, whereas for LCHD it was predominantly in the liver.

Topics: Animals; Body Weight; Cyclic AMP Response Element-Binding Protein; Diabetes Mellitus, Experimental; Diet, Carbohydrate-Restricted; Energy Intake; Fatty Acid Synthases; Forkhead Box Protein O1; Gluconeogenesis; Glucose Tolerance Test; Glucosides; Glycogen; Hyperglycemia; Insulin Resistance; Kidney; Lipid Metabolism; Liver; Male; Mice, Inbred C57BL; Obesity; RNA, Messenger; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Thiophenes; Triglycerides; Up-Regulation

This study was initiated to investigate the mechanism by which oat β-d-glucan (OBG) can control blood sugar levels and improve hepatogenic glycometabolism in streptozotocin-nicotinamide induced mice. After administration of different concentrations and molecular weights of β-d-glucan by oral gavage for 28 days, the body weight, fasting blood glucose, serum insulin, hepatic glycogen, glucose kinase and glucose-6-phosphatase activity of the diabetic mice were measured. In comparison with a negative control group (saline), β-d-glucan, especially medium or high doses of high-molecular-weight β-d-glucan, had a strong hypoglycaemic effect in streptozotocin-nicotinamide-induced mice. The mechanism of this effect may be associated with the high viscosity of the solution, an increase in insulin secretion, a decline in insulin resistance, and especially an improvement in hepatogenic glycometabolism. Moreover, β-d-glucan also markedly repaired and improved the integrity of pancreatic islet β-cell and tissue structures.

Topics: Animals; beta-Glucans; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Drinking; Fasting; Glucose Tolerance Test; Glycogen; Hypoglycemic Agents; Insulin; Insulin Resistance; Liver; Liver Glycogen; Male; Mice; Molecular Weight; Niacinamide; Pancreas

Dehydroepiandrosterone (DHEA) has a fat-reducing effect, while little information is available on whether DHEA regulates glucose metabolism, which would in turn affect fat deposition. To investigate the effects of DHEA on glucose metabolism, rats were administered a high-fat diet containing either 0 (HCG), 25 (HLG), 50 (HMG), or 100 (HHG) mg·kg-1 DHEA per day via gavage for 8 weeks. Results showed that long-term administration of DHEA inhibited body weight gain in rats on a high-fat diet. No statistical differences in serum glucose levels were observed, whereas hepatic glycogen content in HMG and HHG groups and muscle glycogen content in HLG and HMG groups were higher than those in HCG group. Glucokinase, malate dehydrogenase and phosphofructokinase-2 activities in HMG and HHG groups, pyruvate kinase and succinate dehydrogenase activities in HMG group, and pyruvate dehydrogenase activity in all DHEA treatment groups were increased compared with those in HCG group. Phosphoenolpyruvate carboxykinase and glycogen phosphorylase mRNA levels were decreased in HMG and HHG groups, whereas glycogen synthase-2 mRNA level was increased in HMG group compared with those in HCG. The abundance of Glut2 mRNA in HMG and HHG groups and Glut4 mRNA in HMG group was higher than that in HCG group. DHEA treatment increased serum leptin content in HMG and HHG groups compared with that in HCG group. Serum insulin content and insulin receptor mRNA level in HMG group and insulin receptor substrate-2 mRNA level in HMG and HHG group were increased compared with those in HCG group. Furthermore, Pi3k mRNA level in HMG and Akt mRNA level in HMG and HHG groups were significantly increased than those in HCG group. These data showed that DHEA treatment could enhance glycogen storage and accelerate glucose catabolism in rats fed a high-fat diet, and this effect may be associated with the activation of PI3K/Akt-PFK-2 signaling pathway.

Topics: Animals; Blood Glucose; Body Mass Index; Body Weight; Dehydroepiandrosterone; Diet, High-Fat; Gluconeogenesis; Glucose Transport Proteins, Facilitative; Glycogen; Hormones; Liver; Phosphatidylinositol 3-Kinases; Phosphofructokinase-2; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Receptor, Insulin; RNA, Messenger; Signal Transduction; Time Factors

Modern lifestyle has resulted in an increase in the prevalence of obesity and its comorbidities in pregnant women and the young population. It has been well established that the consumption of a high-fat diet (HFD) has many direct effects on glucose metabolism. However, it is important to assess whether maternal consumption of a HFD during critical periods of development can lead to metabolic changes in the offspring metabolism. This study evaluated the potential effects of metabolic programming on the impairment of insulin signalling in recently weaned offspring from obese dams. Additionally, we investigated if early exposure to an obesogenic environment could exacerbate the impairment of glucose metabolism in adult life in response to a HFD. Swiss female mice were fed with Standard Chow (SC) or a HFD during gestation and lactation and tissues from male offspring were analysed at d28 and d82. Offspring from obese dams had greater weight gain and higher adiposity and food intake than offspring from control dams. Furthermore, they showed impairment in insulin signalling in central and peripheral tissues, which was associated with the activation of inflammatory pathways. Adipose tissue was ultimately the most affected in adult offspring after HFD rechallenge; this may have contributed to the metabolic deregulation observed. Overall, our results suggest that diet-induced maternal obesity leads to increased susceptibility to obesity and impairment of insulin signalling in offspring in early and late life that cannot be reversed by SC consumption, but can be aggravated by HFD re-exposure.

Topics: Adiposity; Animals; Blood Glucose; Body Weight; Diet, High-Fat; Female; Glucose Tolerance Test; Glycogen; Hypothalamus; Insulin; Leptin; Liver; Male; Mice; Muscle, Skeletal; Obesity; Pregnancy; Prenatal Exposure Delayed Effects; Signal Transduction

Therapeutic drugs must be developed to treat hyperglycaemia and hyperlipidaemia, which are major risk factors for developing coronary artery diseases and atherosclerosis. Pleurotus eryngii is a well-known food resource with functional properties in China. In this study, P. eryngii polysaccharide (PEP) was extracted with hot water, and its hypolipidaemic and hypoglycaemic activities were investigated. KKAy mice were divided into control and PEP groups, which were fed with high fat and PEP+high fat, respectively, for 6 weeks. Oral administration of PEP decreased body weight gain, the levels of plasma insulin, serum triglyceride, cholesterol low-density lipoprotein cholesterol and blasting blood glucose in mice. Moreover, PEP diet increased the level of high-density lipoprotein cholesterol and liver glycogen. Results indicate that PEP exhibited hypolipidaemic and hypoglycaemic activities and could be explored as possible therapeutic agents for hyperlipidaemia and hyperglycaemia.

Topics: Animals; Blood Glucose; Body Weight; Eating; Fasting; Fungal Polysaccharides; Glycogen; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Lipids; Liver; Mice; Pleurotus

Dietary Se has been shown to adversely affect adult fish by altering growth rates and metabolism. To determine the underlying mechanisms associated with these observations, we measured biochemical and transcriptomic endpoints in rainbow trout following dietary Se exposures. Treatment groups of juvenile rainbow trout were fed either control Lumbriculus variegatus worms or worms cultured on selenized yeast. Selenized yeast was cultured at four nominal doses of 5, 10, 20 or 40mg/kg Se dry weight (measured dose in the worms of 7.1, 10.7, 19.5, and 31.8mg/kgSedw respectively) and fish were fed for 60days. At 60 d, hepatic triglycerides, glycogen, total glutathione, 8-isoprostane and the transcriptome response in the liver (n=8/group) were measured. Fish fed the nominal dose of 20 and 40mg/kg Se dry weight had lower body weight and a shorter length, as well as lower triglyceride in the liver compared to controls. Evidence was lacking for an oxidative stress response and there was no change in total glutathione, 8-isoprostane levels, nor relative mRNA levels for glutathione peroxidase isoforms among groups. Microarray analysis revealed that molecular networks for long-chain fatty acid transport, lipid transport, and low density lipid oxidation were increased in the liver of fish fed 40mg/kg, and this is hypothesized to be associated with the lower triglyceride levels in these fish. In addition, up-regulated gene networks in the liver of 40mg/kg Se treated fish included epidermal growth factor receptor signaling, growth hormone receptor, and insulin growth factor receptor 1 signaling pathways. These molecular changes are hypothesized to be compensatory and related to impaired growth. A gene network related to Notch signaling, which is involved in cell-cell communication and gene transcription regulation, was also increased in the liver following dietary treatments with both 20 and 40mg/kg Se. Transcriptomic data support the hypothesis that dietary Se increases the expression of networks for growth-related signaling cascades in addition to those related to fatty acid synthesis and metabolism. We propose that the disruption of metabolites related to triglyceride processing and storage, as well as gene networks for epidermal growth factor and Notch signaling in the liver, represent key molecular initiating events for adverse outcomes related to growth and Se toxicity in fish.

Topics: Animals; Body Weight; Dietary Supplements; Gene Regulatory Networks; Glutathione; Glycogen; Liver; Oncorhynchus mykiss; Oxidative Stress; Real-Time Polymerase Chain Reaction; Receptors, Notch; Selenium; Signal Transduction; Triglycerides; Water Pollutants, Chemical

Obesity is one of the dramatic health issues affecting developed and developing nations, and exercise is a well-established intervention strategy. While exercise-by-genotype interactions have been shown in humans, overall little is known. Using the natural negative geotaxis of Drosophila melanogaster, an important model organism for the study of genetic interactions, a novel exercise machine, the TreadWheel, can be used to shed light on this interaction. The mechanism for inducing exercise with the TreadWheel is inherently gentle, thus minimizing possible confounding effects of other stressors. Using this machine, we were able to assess large cohorts of adult flies from eight genetic lines for their response to exercise after one week of training. We measured their triglyceride, glycerol, protein, glycogen, glucose content, and body weight, as well as their climbing ability and feeding behavior in response to exercise. Exercised flies showed decreased stored triglycerides, glycogen, and body weight, and increased stored protein and climbing ability. In addition to demonstrating an overall effect of TreadWheel exercise on flies, we found significant interactions of exercise with genotype, sex, or genotype-by-sex effects for most of the measured phenotypes. We also observed interaction effects between exercise, genotype, and tissue (abdomen or thorax) for metabolite profiles, and those differences can be partially linked to innate differences in the flies' persistence in maintaining activity during exercise bouts. In addition, we assessed gene expression levels for a panel of 13 genes known to be associated with respiratory fitness and found that many responded to exercise. With this study, we have established the TreadWheel as a useful tool to study the effect of exercise in flies, shown significant genotype-specific and sex-specific impacts of exercise, and have laid the ground work for more extensive studies of how genetics, sex, environment, and aging interact with exercise to influence metabolic fitness in Drosophila.

Topics: Animals; Body Weight; Drosophila; Drosophila Proteins; Feeding Behavior; Female; Gene Expression; Genetic Variation; Genotype; Glucose; Glycogen; Male; Phenotype; Physical Conditioning, Animal; Sex Factors; Triglycerides

The effect of germinated Superhongmi, a reddish brown pigmented rice cultivar, on the glucose profile and bone turnover in the postmenopausal-like model of ovariectomized rats was determined. The ovariectomized Sprague-Dawley rats were randomly divided into three dietary groups (

Topics: Adipokines; Animals; Biomarkers; Blood Glucose; Body Weight; Bone and Bones; Bone Resorption; Dietary Supplements; Estradiol; Female; Germination; Glycogen; Hyperglycemia; Hypoglycemic Agents; Insulin; Oryza; Ovariectomy; Postmenopause; Random Allocation; Rats, Sprague-Dawley

To ascertain anti-fatigue constituents and mechanisms of Herpetospermum caudigerum.. The 80% ethanol extracts of Herpetospermum caudigerum were partitioned with chloroform, ethyl acetate and n-butanol, respectively. Male Kunming mice were divided into 13 groups with 16 mice in each group: a control group fed with water, 9 groups treated with 3 fractions of Herpetospermum caudigerum (chloroform fraction, ethyl acetate fraction and n-butanol fraction) at dose of 80, 160 and 320 mg/kg for the low-dose group, medium-dose group and high-dose group, 3 herpetrione (HPE) treated groups fed with HPE at dose of 15, 30, and 60 mg/kg for the low-dose group, medium-dose group and high-dose group. All animals were treated once per day for 30 days. Anti-fatigue activity was assessed through the forced swimming test and serum biochemical parameters including blood lactic acid (BLA), blood urea nitrogen (BUN), malondialdehyde (MDA), hepatic glycogen (HG), lactic dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GPx) determined following the recommended procedures provided by the commercial kits.. Compared with the control group, the lignans extract (ethyl acetate fraction) of Herpetospermum caudigerum and HPE could signifificantly prolonged the exhaustive swimming time (P<0.05 or P<0.01), and also increased the HG levels (P<0.05 or P<0.01) and the activities of antioxidant enzymes (SOD, GPx and LDH, P<0.05 or P<0.01); BLA and MDA levels were decreased considerably in lignans extract and HPE treated groups (P<0.05 or P<0.01). HPE also could significantly decrease the BUN contents compared with the control group (P<0.05). The chloroform and n-butanol fraction showed no effect on swimming time and biochemical parameters.. The lignans extract had antifatigue activities and HPE may be partly responsible for the anti-fatigue effects of Herpetospermum caudigerum. The possible mechanisms of anti-fatigue activity were related to the decrease of BUN and BLA, the increase of the HG storage and protecting corpuscular membrane by preventing lipid oxidation via modifying several enzyme activities.

Topics: Animals; Body Weight; Cucurbitaceae; Fatigue; Glycogen; Lignans; Liver; Male; Mice; Plant Extracts; Swimming; Time Factors

The purpose of this study was to investigate the effects of leaf extract from Lithocarpus polystachyus Rehd. on type II diabetes mellitus (T2DM) and the active ingredients of this effect. In addition, this study determined, for the first time, the underlying molecular and pharmacological mechanisms of the extracts on hyperglycemia using long-term double high diet-fed and streptozotocin (STZ) induced type II diabetic mice. In the present study, leaf extract, phloridzin and trilobatin were assessed in vivo (gavage) and in vitro (non-invasive micro-test technique, NMT) in experimental T2DM mice. The biochemical parameters were measured including blood glucose and blood lipid level, liver biochemical indexes, and hepatic glycogen. The relative expression of glycometabolism-related genes was detected. The effect of leaf extracts on physiological glucose flux in liver tissue from control and T2DM mice was also investigated. Body weight of experimental T2DM mice increased significantly after the first week, but stabilized over the subsequent three weeks; body weight of all other groups did not change during the four weeks' study. After four weeks, all treatment groups decreased blood glucose, and treatment with leaf extract had numerous positive effects: a) promoted in glucose uptake in liver, b) increased synthesis of liver glycogen, c) reduced oxidative stress, d) up-regulation of glucokinase (GK), glucose transporter 2 (GLUT2), insulin receptor (IR) and insulin receptor substrate (IRS) expression in liver, e) down-regulation of glucose-6-phosphatase (G-6-P) expression, and f) ameliorated blood lipid levels. Both treatment with trilobatin or phloridzin accelerated liver glycogen synthesis, decreased oxidative stress and increased expression of GK. IRS and phosphoenolpyruvate carboxykinase (PEPCK) were both up-regulated after treatment with trilobatin. Expression of GLUT2, PEPCK and G-6-P were also increased in liver tissue after treatment with phloridzin. Our data indicate that leaf extract from L. polystachyus Rehd. has a preferable hypoglycemic effects than trilobatin or phloridzin alone. Leaf extract significantly increased glucose uptake and hepatic glycogen synthesis while also inducing a decline of hepatic gluconeogenesis and oxidative stress in T2DM mice. From this study, we draw conclusions that L. polystachyus promoted glycogen synthesis in T2DM mice, and that the active compounds were not only the trilobatin or phloridzin.

Topics: Amino Acid Isomerases; Animals; Blood Glucose; Body Weight; Cells, Cultured; Diabetes Mellitus, Experimental; Down-Regulation; Fagaceae; Glucose Tolerance Test; Glutathione; Glycogen; Hypoglycemic Agents; Insulin; Liver; Male; Malondialdehyde; Mice; Plant Extracts; Plant Leaves; Streptozocin; Superoxide Dismutase; Up-Regulation

Salvianolic acid B (Sal B), a major polyphenolic compound of Salvia miltiorrhiza Bunge, has been shown to possess potential antidiabetic activities. However, the action mechanism of SalB in type 2 diabetes has not been investigated extensively. The present study was designed to investigate the effects of Sal B on diabetes-related metabolic changes in a spontaneous model of type 2 diabetes, as well as its potential molecular mechanism.. Male C57BL/KsJ-db/db mice were orally treated with Sal B (50 and 100 mg/kg) or metformin (positive drug, 300 mg/kg) for 6 weeks.. Both doses of Sal B significantly decreased fasting blood glucose, serum insulin, triglyceride and free fatty acid levels, reduced hepatic gluconeogenic gene expression and improved insulin intolerance in db/db mice. High dose Sal B also significantly improved glucose intolerance, increased hepatic glycolytic gene expression and muscle glycogen content, and ameliorated histopathological alterations of pancreas, similar to metformin. Sal B treatment resulted in increased phosphorylated AMP-activated protein kinase (p-AMPK) protein expression in skeletal muscle and liver, increased glucose transporter 4 (GLUT4) and glycogen synthase protein expressions in skeletal muscle, and increased peroxisome proliferator-activated receptor alpha (PPARα) and phosphorylated acetyl CoA carboxylase (p-ACC) protein expressions in liver.. Our data suggest that Sal B displays beneficial effects in the prevention and treatment of type 2 diabetes at least in part via modulation of the AMPK pathway.

Topics: AMP-Activated Protein Kinases; Animals; Benzofurans; Body Weight; Dyslipidemias; Gene Expression Regulation; Gluconeogenesis; Glucose; Glucose Intolerance; Glucose Transporter Type 4; Glycogen; Glycogen Synthase; Glycolysis; Hyperglycemia; Hyperinsulinism; Lipids; Liver; Male; Mice, Inbred C57BL; Muscle, Skeletal; Pancreas; Phosphorylation; PPAR alpha; RNA, Messenger; Signal Transduction

The hypoglycemic activity of chromium methionine (CrMet) in alloxan-induced diabetic (AID) mice was investigated and compared with those of chromium trichloride hexahydrate (CrCl3·6H2O) and chromium nicotinate (CrNic) through a 15-day feeding experiment. The acute oral toxicity of CrMet was also investigated in ICR (Institute for Cancer Research) mice by a single oral gavage. The anti-diabetic activity of CrMet was explored in detail from the aspects of body weight (BW), blood glucose, triglyceride, total cholesterol, liver glycogen levels, aspartate transaminase (AST) and alanine transaminase (ALT) levels. The obtained results showed that CrMet had beneficial effects on glucose and lipid metabolism, and might possess hepatoprotective efficacy for diabetes. Daily treatment with 500 and 1000μg Cr/kg BW of CrMet in AID mice for 15 days indicated that this low-molecular-weight organic chromium complex had better bioavailability and more beneficial effects on diabetics than CrCl3·6H2O. CrMet also had advantage over CrNic in the control of AST and ALT activities. Acute toxicity studies revealed that CrMet had low toxicity potential and relatively high safety margins in mice with the LD50 value higher than 10.0g/kg BW. These findings suggest that CrMet might be of potential value in the therapy and protection of diabetes.

Topics: Administration, Oral; Alanine Transaminase; Animals; Aspartate Aminotransferases; Blood Glucose; Body Weight; Cholesterol; Chromium; Diabetes Mellitus, Experimental; Glycogen; Hypoglycemic Agents; Liver; Methionine; Mice, Inbred ICR; Organ Size; Toxicity Tests, Acute; Triglycerides

Peripheral insulin resistance (IR) is one of the main side effects caused by glucocorticoid (GC)-based therapies, and the molecular mechanisms of GC-induced IR are not yet fully elucidated. Thus, we aimed to investigate the effects of dexamethasone treatment on the main components of insulin and inflammatory signaling in the adipose tissue of rats.. Male Wistar rats received daily injections of dexamethasone (1mg/kg body weight (b.w.), intraperitoneally (i.p.)) for 5 days (DEX), whereas control rats received saline (CTL). The metabolic status was investigated, and the epididymal fat fragments were collected for lipolysis and western blot analyses.. The DEX rats became hyperglycemic, hyperinsulinemic, insulin resistant and glucose intolerant, compared with the CTL rats (P<0.05). The basal glycerol release in the fat fragments was 1.5-fold higher in the DEX rats (P<0.05). The phosphorylation of protein kinase B (PKB) at ser(473) decreased by 44%, whereas, the phosphorylation of insulin receptor substrate (IRS)-1 at ser(307) increased by 93% in the adipose tissue of the DEX rats after an oral bolus of glucose (P<0.05). The basal phosphorylation of c-jun-N-terminal kinase (JNK) and inhibitor of nuclear factor kappa-B (IKKβ) proteins was reduced by 46% and 58%, respectively, in the adipose tissue of the DEX rats (P<0.05). This was paralleled with a significant reduction (47%) in the glucocorticoid receptor (GR) protein content in the adipose tissue of the DEX rats (P<0.05).. The insulin-resistant status of rats induced by dexamethasone administration have PKB and IRS-1 activity attenuated in epididymal fat without increases in the phosphorylation of the proinflammatory signals JNK and IKKβ.

Topics: Adipose Tissue; Animals; Body Weight; Cytokines; Dexamethasone; Epididymis; Glucocorticoids; Glycogen; I-kappa B Kinase; Inflammation; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Male; MAP Kinase Kinase 4; Phosphorylation; Proto-Oncogene Proteins c-akt; Pyruvic Acid; Rats; Rats, Wistar; Signal Transduction; Toll-Like Receptor 4

The interval model training has been more recommended to promote aerobic adaptations due to recovery period that enables the execution of elevated intensity and as consequence, higher workload in relation to continuous training. However, the physiological and aerobic capacity adaptations in interval training with identical workload to continuous are still uncertain. The purpose was to characterize the effects of chronic and acute biomarkers adaptations and aerobic capacity in interval and continuous protocols with equivalent load. Fifty Wistar rats were divided in three groups: Continuous training (GTC), interval training (GTI) and control (CG). The running training lasted 8 weeks (wk) and was based at Anaerobic Threshold (AT) velocity. GTI showed glycogen super-compensation (mg/100 mg) 48 h after training session in relation to CG and GTC (GTI red gastrocnemius (RG)=1.41+/-0.16; GTI white gastrocnemius (WG)=1.78+/-0.20; GTI soleus (S)=0.26+/-0.01; GTI liver (L)=2.72+/-0.36; GTC RG=0.42+/-0.17; GTC WG=0.54+/-0.22; GTC S=0.100+/-0.01; GTC L=1.12+/-0.24; CG RG=0.32+/-0.05; CG WG=0.65+/-0.17; CG S=0.14+/-0.01; CG L=2.28+/-0.33). The volume performed by GTI was higher than GTC. The aerobic capacity reduced 11 % after experimental period in GTC when compared to GTI, but this change was insignificant (19.6+/-5.4 m/min; 17.7+/-2.5 m/min, effect size = 0.59). Free fatty acids and glucose concentration did not show statistical differences among the groups. Corticosterone concentration increased in acute condition for GTI and GTC. Testosterone concentration reduced 71 % in GTC immediately after the exercise in comparison to CG. The GTI allowed positive adaptations when compared to GTC in relation to: glycogen super-compensation, training volume performed and anabolic condition. However, the GTI not improved the aerobic performance.

Topics: Adaptation, Physiological; Aerobiosis; Anaerobic Threshold; Animals; Body Weight; Corticosterone; Fatty Acids, Nonesterified; Glucose; Glycogen; Liver; Male; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Wistar; Running; Testosterone

The water-soluble polysaccharides (EPS) were isolated from culture broth of Enterobacter cloacae Z0206, and the hypoglycemic and hypolipidemic effects of EPS were investigated. In this study, KKAy mice were gavaged once daily with either distilled water or EPS (200 mg/kg body weight) for 6 weeks. Results showed that EPS possessed significant hypoglycemic effects. Improved oral glucose tolerance, reduced serum insulin levels as well as decreased serum triglycerides (TG), cholesterol (TC) and low density lipoprotein cholesterol (LDL-c) were observed after treatment with EPS. Furthermore, EPS upregulated the expression of glucokinase (GK), HSL (Hormone Sensitive Lipase), adipose triglyceride lipase (ATGL), carnitine palmitoyl transferase 1-α (CPT1-α), glucose transporter 2 (Glut2), adenosine monophosphate activated protein kinase (AMPK) and silent information regulator 1 (Sirt1), but downregulated the gene expression of glucose-6-phosphatase (G6P) and fatty acid synthase (FAS) in the liver. These results suggest that EPS exhibits hypoglycemic and hypolipidemic effects possibly through regulating AMPK- and SirT1-mediated effects on carbohydrate and lipid metabolism.

Topics: Animals; Blood Glucose; Body Weight; Enterobacter cloacae; Fasting; Glucose Tolerance Test; Glycogen; Hexokinase; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Lipids; Liver; Male; Mice; Polysaccharides

Nymphaea stellata (Willd.) has been used in traditional medicine for centuries to treat several illnesses, including diabetes. However, scientific evidence supporting its mechanism of action is lacking. Here, we showed that an N. stellata flower chloroform extract (NSFCExt) has significant plasma glucose lowering ability. Furthermore, an active compound was identified and purified by column chromatography, and the structure of this compound, nymphayol, was determined by X-ray crystallographic analysis. Nymphayol was tested for its effects on insulin secretion by RIN-5F cells cultured in low or high glucose medium; we found that nymphayol treatment improved glucose-stimulated insulin secretion in vitro. Additionally, insulin sensitization and glucose uptake were increased in L6 myotubes. Nymphayol was administered to type 2 diabetic male Wistar rats at several doses (5, 10 or 20 mg/kg/day) for 45 days. After nymphayol administration, the plasma glucose concentration was significantly (p⩽0.05) lower (60.33%) than in control diabetic rats, and the plasma insulin level increased in a dose-dependent manner. In addition, the cellular insulin response was analyzed in type 2 diabetic rats; oral administration of nymphayol increased IRS1 phosphorylation and GLUT4 protein expression in liver and muscle. Nymphayol significantly (p⩽0.05) restored the levels of HbA1c, hepatic glycogen and hepatic glucose-metabolizing enzyme (hexokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, fructose-1, 6-bisphosphatase, glycogen synthase and glycogen phosphorylase) activity in diabetic rats. The administration of glibenclamide, a reference drug (600 μg/kg), also produced a significant (p⩽0.05) reduction in blood glucose in STZ-nicotinamide induced diabetic rats. The results suggest that nymphayol may be a useful therapy for diabetes because it stimulates insulin secretion and promotes glucose absorption.

Topics: Animals; Biological Transport; Blood Glucose; Body Weight; Cell Line; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drinking; Gene Expression Regulation; Glucose; Glucose Transporter Type 4; Glycated Hemoglobin; Glycogen; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Liver; Male; Muscle Fibers, Skeletal; Phytosterols; Rats; Rats, Wistar; Reactive Oxygen Species

Insulin and exercise stimulate glucose uptake into skeletal muscle via different pathways. Both stimuli converge on the translocation of the glucose transporter GLUT4 from intracellular vesicles to the cell surface. Two Rab guanosine triphosphatases-activating proteins (GAPs) have been implicated in this process: AS160 for insulin stimulation and its homolog, TBC1D1, are suggested to regulate exercise-mediated glucose uptake into muscle. TBC1D1 has also been implicated in obesity in humans and mice. We investigated the role of TBC1D1 in glucose metabolism by generating TBC1D1(-/-) mice and analyzing body weight, insulin action, and exercise. TBC1D1(-/-) mice showed normal glucose and insulin tolerance, with no difference in body weight compared with wild-type littermates. GLUT4 protein levels were reduced by ∼40% in white TBC1D1(-/-) muscle, and TBC1D1(-/-) mice showed impaired exercise endurance together with impaired exercise-mediated 2-deoxyglucose uptake into white but not red muscles. These findings indicate that the RabGAP TBC1D1 plays a key role in regulating GLUT4 protein levels and in exercise-mediated glucose uptake in nonoxidative muscle fibers.

Topics: Animals; Body Weight; Electrophoresis, Polyacrylamide Gel; Electroporation; Glucose Transporter Type 4; Glycogen; GTPase-Activating Proteins; Insulin; Male; Mice; Mice, Knockout; Muscle, Skeletal; Nuclear Proteins; Physical Conditioning, Animal; Real-Time Polymerase Chain Reaction

Anoectochilus roxburghii is a traditional Chinese herb used for treatment of diabetes and some other diseases. Anoectochilus roxburghii polysaccharose (ARP) is the main constituent of Anoectochilus roxburghii. The present study aimed to investigate the antidiabetic effects of ARP in diabetic mice induced by high-fat diet and streptozotocin.. Two doses of ARP (100 or 300 mg/kg) were administered once daily for 25 days to diabetic mice. To evaluate the antidiabetic effects of ARP, the fasting glucose levels, aspartate aminotransferase (AST), alanine transaminase (ALT) and superoxide dismutase (SOD) activities, malondialdehyde (MDA) content, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and liver glycogen were examined. Furthermore, histological examinations were carried out on the separated pancreas and liver of mice.. Compared with untreated diabetic mice, ARP (100 or 300 mg/kg) caused a significant decrease in blood glucose levels, activities of AST and ALT, and MDA contents, and a significant increase in liver glycogen contents, SOD activities, thymus index and spleen index. Simultaneously, the alteration in lipid metabolism was partially attenuated as evidenced by decreased serum TC, TG and LDL-C concentrations in diabetic mice. In addition, histological examinations showed that administration of ARP (100 or 300 mg/kg) significantly attenuated the pathologic lesions in pancreas and liver of diabetic mice, and improved pancreas and liver function.. The antidiabetic activity of ARP may be attributed to the improvement of glucose and lipid metabolism, increase of immune protection and reduction of oxidative stress.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Blood Glucose; Body Weight; Cholesterol; Diabetes Mellitus, Experimental; Diet, High-Fat; Eating; Glycogen; Hypoglycemic Agents; Liver; Male; Malondialdehyde; Mice, Inbred ICR; Orchidaceae; Pancreas; Plant Extracts; Streptozocin; Superoxide Dismutase; Toxicity Tests, Acute; Triglycerides

In the present study, we have tried to unravel the role of Selenium supplementation in containing hyperglycemia by regulating enzymes activities involved in carbohydrate metabolism in liver of diabetic animals. Male wistar rats were divided into four groups: normal control, diabetic, Selenium treated control and Selenium treated diabetic group. Diabetes was induced in the animals by injecting alloxan intraperitoneally at a dose level of 150 mg/kg body weight. Selenium in the form of sodium selenite was supplemented to rats at a dose level of 1 PPM in drinking water, ad libitum for two time durations of 2 and 4 weeks. Animals were sacrificed and livers were excised for the analyses of enzymes involved in carbohydrate metabolism as well as the levels of glycogen. In-vitro (14)C-d glucose uptake and its turnover were also assessed in liver slices of all the treatment groups using radiorespirometry. Selenium supplementation to the diabetic rats normalized the enzyme activities of glucose-6-phosphatase, lactate dehydrogenase and glycogen phosphorylase as well as restored the glycogen levels to within the normal limits which were altered during diabetes. Interestingly, when Selenium was supplemented to diabetic rats, (14)C-d glucose uptake and its turnover showed a statistically significant increase in their values which however, were decreased in diabetic rats. In conclusion, Selenium mediates insulin-like role during diabetes by tending to normalize the altered activities of glucose metabolizing enzymes and also improves the glucose uptake and its metabolism by the liver.

Topics: Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Cytokines; Diabetes Mellitus, Experimental; Dietary Supplements; Glucose-6-Phosphatase; Glucose-6-Phosphate Isomerase; Glycated Hemoglobin; Glycogen; Glycogen Phosphorylase; Hexokinase; L-Lactate Dehydrogenase; Liver; Male; Rats, Wistar; Selenium; Succinate Dehydrogenase

Major aims were to determine whether exposure to the commonly used food additive carrageenan could induce fasting hyperglycemia and could increase the effects of a high fat diet on glucose intolerance and dyslipidemia.. C57BL/6J mice were exposed to either carrageenan, high fat diet, or the combination of high fat diet and carrageenan, or untreated, for one year. Effects on fasting blood glucose, glucose tolerance, lipid parameters, weight, glycogen stores, and inflammation were compared.. Exposure to carrageenan led to glucose intolerance by six days and produced elevated fasting blood glucose by 23 weeks. Effects of carrageenan on glucose tolerance were more severe than from high fat alone. Carrageenan in combination with high fat produced earlier onset of fasting hyperglycemia and higher glucose levels in glucose tolerance tests and exacerbated dyslipidemia. In contrast to high fat, carrageenan did not lead to weight gain. In hyperinsulinemic, euglycemic clamp studies, the carrageenan-exposed mice had higher early glucose levels and lower glucose infusion rate and longer interval to achieve the steady-state.. Carrageenan in the Western diet may contribute to the development of diabetes and the effects of high fat consumption. Carrageenan may be useful as a nonobese model of diabetes in the mouse.

Topics: Animals; Blood Glucose; Body Weight; Carrageenan; Diet; Diet, High-Fat; Disease Models, Animal; Dyslipidemias; Food Additives; Food Deprivation; Glucose; Glucose Tolerance Test; Glycated Hemoglobin; Glycogen; Hyperglycemia; Hyperlipidemias; Inflammation; Lipids; Male; Mice; Mice, Inbred C57BL; Risk Factors

Glucose homeostasis is distorted by defects of the PI3K/AKT and AMPK pathways in insulin-sensitive tissues, allowing the accumulation of glucose in the blood. The purpose of this study was to assess the effects and mechanisms by which ethanol extract of Caulerpa lentillifera (CLE) regulates glucose metabolism in C57BL/KsJ-db/db (db/db) mice.. Mice were administered CLE (250 or 500 mg/kg BW) or rosiglitazone (RSG, 10 mg/kg BW) for 6 weeks. Then, oral glucose tolerance test (OGTT) and intraperitoneal insulin tolerance test (IPITT) were performed, and blood glucose was measured in db/db mice. Levels of insulin and insulin resistance factors in plasma, glycogen content in the liver, and IRS, PI3K, AKT, and GLUT4 expressions in skeletal muscles were measured in db/db mice. Glucose uptake and insulin signaling molecules were measured in L6 myocytes, using fluorometry and Western blotting.. CLE significantly decreased fasting blood glucose, glucose level in OGTT and IPITT, plasma insulin, homeostatic model assessment-insulin resistant (HOMA-IR), TNF-α, IL-6, FFA, TG and TC levels, and hepatic glycogen content in db/db mice. CLE significantly increased the activation of IRS, AKT, PI3K, and GLUT4, which are the key effector molecules of the PI3K/AKT pathway in L6 myocytes and the skeletal muscles of db/db mice. The enhanced glucose uptake by CLE was abolished by treatment with a PI3K inhibitor (LY294002), but not by an AMPK inhibitor (compound C) in L6 myocytes. CLE regulated glucose uptake and homeostasis via the PI3K/AKT pathway in myocytes and db/db mice, respectively.. Our results suggest that CLE could be a potential candidate for the prevention of diabetes.

Topics: Adenylate Kinase; Adipose Tissue; Animals; Blood Glucose; Body Weight; Caulerpa; Cell Line; Diet; Epididymis; Glucose Tolerance Test; Glycogen; Insulin; Insulin Resistance; Liver; Male; Mice, Inbred C57BL; Muscle Cells; Muscles; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats; RNA, Messenger; Signal Transduction

Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the effect of chromium malate on glycometabolism, glycometabolism-related enzymes and lipid metabolism in type 2 diabetic rats. Our results showed that fasting blood glucose, serum insulin level, insulin resistance index and C-peptide level in the high dose group had a significant downward trend when compared with the model group, chromium picolinate group and chromium trichloride group. The hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, Glut4, phosphor-AMPKβ1 and Akt levels in the high dose group were significantly higher than those of the model, chromium picolinate and chromium trichloride groups. Chromium malate in a high dose group can significantly increase high density lipoprotein cholesterol level while decreasing the total cholesterol, low density lipoprotein cholesterol and triglyceride levels when compared with chromium picolinate and chromium trichloride. The serum chromium content in chromium malate and chromium picolinate group is significantly higher than that of the chromium trichloride group. The results indicated that the curative effects of chromium malate on glycometabolism, glycometabolism-related enzymes and lipid metabolism changes are better than those of chromium picolinate and chromium trichloride. Chromium malate contributes to glucose uptake and transport in order to improved glycometabolism and glycometabolism-related enzymes.

Topics: Animals; Biological Transport; Blood Glucose; Body Weight; Chromium; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dietary Supplements; Disease Models, Animal; Fasting; Gastrointestinal Microbiome; Glucose; Glycogen; Insulin; Lipid Metabolism; Liver; Malates; Male; Maze Learning; Rats

Dietary energy source can influence muscle glycogen storage at slaughter. However, few studies have demonstrated whether the diet-induced change of muscle glycogen is achieved by the transformation of muscle fibre type. This study investigated the effects of dietary energy sources on meat quality, post mortem glycolysis and muscle fibre type transformation of finishing pigs. Seventy-two barrows with an average body weight of 65.0 ± 2.0 kg were selected and were allotted to three iso-energetic and iso-nitrogenous diets A, B or C, and each treatment consisted of three replicates (pens) of eight pigs each. Diet A contained 44.1% starch, 5.9% crude fat and 12.6% neutral detergent fiber (NDF); diet B contained 37.6% starch, 9.5% crude fat and 15.4% NDF; and diet C contained 30.9% starch, 14.3% crude fat and 17.8% NDF. The duration of the experiment was 28 days. After feed withdrawal 12 h, 24 pigs (eight per treatment) were slaughtered, samples from M. longissimus lumborum (LL) were collected for subsequent analysis. The results showed that pigs fed diet C had lesser average daily gain, average daily feed intake and back fat depth than those fed diet A (P<0.05). Diet C increased pH45min (P<0.05) and decreased drip loss (P<0.05) in LL muscles compared with diet A. Meat from pigs fed diet A showed increased contents of lactate and greater glycolytic potential (GP) compared with those fed diet C (P<0.05). Greater mRNA expression of myosin heavy-chain (MyHC)-I and IIa and lesser expression of MyHC-IIx and IIb (P<0.05) in LL muscles were found in pigs fed diet C, than in pigs fed diet A. In addition, pigs fed diet C resulted in downregulation of miR23a and upregulation of miR409 and miR208b (P<0.05), associated with conserved changes of their corresponding targets. These findings indicated that diets containing low starch and high fibre were beneficial in reducing muscle glycolysis, improving meat quality of finishing pigs. This reduction of GP may be partially associated with the improvement of oxidative fibre composition in LL muscle, and the change in myofibre type may be correlated with the change in the miRNA expression.

Topics: Animal Feed; Animals; Body Composition; Body Weight; Diet; Dietary Fiber; Dietary Supplements; Glycogen; Glycolysis; Meat; Muscle Fibers, Skeletal; Swine

Flaxseed (Linum usitatissimum L.) has been a focus of interest in the field of functional foods because of its potential health benefits. However, we hypothesised that maternal flaxseed intake during lactation could induce several metabolic dysfunctions in adult offspring. In the present study, we aimed to characterise the adrenal function of adult offspring whose dams were supplemented with whole flaxseed during lactation. At birth, lactating Wistar rats were divided into two groups: rats from dams fed the flaxseed diet (FLAX) with 25% of flaxseed and controls dams. Pups received standard diet after weaning and male offspring were killed at age 180 days old to collect blood and tissues. We evaluated body weight and food intake during development, corticosteronaemia, adrenal catecholamine content, hepatic cholesterol, TAG and glycogen contents, and the protein expression of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), 11-β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) and adrenaline β2 receptor at postnatal day 180 (PN180). After weaning, pups from the FLAX group had a higher body weight (+10 %) and food intake (+10%). At PN180, the FLAX offspring exhibited higher serum corticosterone (+48%) and lower adrenal catecholamine ( - 23%) contents, lower glycogen ( - 30%), higher cholesterol (4-fold increase) and TAG (3-fold-increase) contents in the liver, and higher 11β-HSD1 (+62%) protein expression. Although the protein expression of hypothalamic CRH was unaffected, the FLAX offspring had lower protein expression of pituitary ACTH ( - 34%). Therefore, induction of hypercorticosteronaemia by dietary flaxseed during lactation may be due to an increased hepatic activation of 11β-HSD1 and suppression of ACTH. The changes in the liver fat content of the FLAX group are suggestive of steatosis, in which hypercorticosteronaemia may play an important role. Thus, it is recommended that lactating women restrict the intake of flaxseed during lactation.

Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Adrenal Glands; Adrenocorticotropic Hormone; Animals; Body Weight; Catecholamines; Cholesterol; Corticosterone; Diet; Female; Flax; Glycogen; Lactation; Liver; Male; Maternal Nutritional Physiological Phenomena; Models, Animal; Nutritional Status; Rats; Rats, Wistar; Triglycerides; Weaning

Salvia libanotica (S. Libanotica) is a commonly used herb in folk medicine in Lebanon and the Middle East. The present study aimed to assess the scientific basis for the therapeutic use of S. libanotica in glycemia and to evaluate its effects on lipemia and abdominal fat.. Animals were fed a high-fat diet and allocated into a control and three experimental groups (GI, GII and GIII) receiving incremental doses of the plant water extract in drinking water (50, 150 and 450 mg/Kg body weight respectively) for six weeks.. The intake of S. libanotica extract was associated with a significant decrease in fasting serum glucose (102.9 ± 10.8 in GII and 87.5 ± 6.4 in GIII vs. 152.1 ± 7.9 mg/dl in controls) and a two fold increase in fasting serum insulin (GIII) and liver glycogen content (GII and GIII). Group III also had better glucose tolerance following intraperitoneal glucose challenges. Additionally, the plant extract intake produced a significant improvement in serum HDL (34.4 ± 2.4 in GIII vs. 27.2 ± 1.9 mg/dl in controls) and HDL/LDL cholesterol ratio (2.79 ± 0.32 in GII and 3.02 ± 0.31 in GIII vs. 1.74 ± 0.18 in controls), as well as a decrease in abdominal fat.. The current study is the first to demonstrate that the chronic intake of S. libanotica infusion helps in the prevention of high fat-induced hyperglycemia and dyslipidemia. This supports the plant use as a remedy for the prevention of type 2 diabetes and cardiovascular diseases.

Topics: Abdominal Fat; Alanine Transaminase; Alkaline Phosphatase; Animals; Blood Glucose; Body Weight; Diet, High-Fat; Disease Models, Animal; Glucose Tolerance Test; Glycogen; Insulin; Lipids; Liver; Male; Plant Extracts; Rats; Rats, Sprague-Dawley; Salvia

Fructose consumption is associated with altered hepatic function and metabolic compromise and not surprisingly has become a focus for perinatal studies. We have previously shown that maternal fructose intake results in sex specific changes in fetal, placental and neonatal outcomes. In this follow-up study we investigated effects on maternal, fetal and neonatal hepatic fatty acid metabolism and immune modulation.. Pregnant rats were randomised to either control (CON) or high-fructose (FR) diets. Fructose was given in solution and comprised 20% of total caloric intake. Blood and liver samples were collected at embryonic day 21 (E21) and postnatal day (P)10. Maternal liver samples were also collected at E21 and P10. Liver triglyceride and glycogen content was measured with standard assays. Hepatic gene expression was measured with qPCR.. Maternal fructose intake during pregnancy resulted in maternal hepatic ER stress, hepatocellular injury and increased levels of genes that favour lipogenesis. These changes were associated with a reduction in the NLRP3 inflammasome. Fetuses of mothers fed a high fructose diet displayed increased hepatic fructose transporter and reduced fructokinase mRNA levels and by 10 days of postnatal age, also have hepatic ER stress, and elevated IL1β mRNA levels. At P10, FR neonates demonstrated increased hepatic triglyceride content and particularly in males, associated changes in the expression of genes regulating beta oxidation and the NLRP3 inflammasome. Further, prenatal fructose results in sex-dependant changes in levels of key clock genes.. Maternal fructose intake results in age and sex-specific alterations in maternal fetal and neonatal free fatty acid metabolism, which may be associated in disruptions in core clock gene machinery. How these changes are associated with hepatic inflammatory processes is still unclear, although suppression of the hepatic inflammasome, as least in mothers and male neonates may point to impaired immune sensing.

Topics: Animals; Animals, Newborn; Body Weight; Circadian Rhythm Signaling Peptides and Proteins; Endoplasmic Reticulum Stress; Fatty Acids, Nonesterified; Female; Follow-Up Studies; Fructose; Gene Expression Regulation, Developmental; Glycogen; Lipid Metabolism; Liver; Male; Maternal Nutritional Physiological Phenomena; Pregnancy; Prenatal Exposure Delayed Effects; Random Allocation; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Sex Factors; Time Factors

The study was designed to investigate the anti-hyperglycemic activity of selenium nanoparticles (SeNPs) in streptozotocin-induced diabetic rats. Fifty-five mg/kg of streptozotocin was injected in rats to induce diabetes. Animals either treated with SeNPs alone or with insulin (6 U/kg) showed significantly decreased fasting blood glucose levels after 28 days of treatment. The serum insulin concentration in untreated diabetic animals was also enhanced by SeNPs. The results demonstrated that SeNPs could significantly decrease hepatic and renal function markers, total lipid, total cholesterol, triglyceride and low-density lipoprotein cholesterol levels, and glucose-6-phosphatase activity. At the same time, SeNPs increased malic enzyme, hexokinase and glucose-6-phosphate dehydrogenase activity, liver and kidney glycogen contents, and high-density lipoprotein cholesterol levels. In addition, SeNPs were able to prevent the histological injury in the hepatic and renal tissues of rats. However, insulin injection also exhibited a significant improvement in diabetic animals after 28 days of treatment. This study suggests that SeNPs can alleviate hyperglycemia and hyperlipidemia in streptozotocin-induced diabetic rats, possibly by eliciting insulin-mimetic activity.

Topics: Animals; Biomarkers; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Dynamic Light Scattering; Fasting; Gene Expression Regulation; Glutathione Peroxidase; Glycogen; Hyperglycemia; Hypoglycemic Agents; Insulin; Kidney; Lipids; Liver; Male; Nanoparticles; Rats, Wistar; Selenium; Streptozocin

Thiazolidinediones constitute a family of antidiabetic drugs, and rosiglitasone (RSG) has an extensive usage in treating the complications of type 2 diabetes mellitus. Carvacrol (CVL), a monoterpenic phenol that occurs in many essential oils of the family Labiatae including Origanum, Satureja, Thymbra, Thymus, and Corydothymus species, possess a wide variety of pharmacological properties including antioxidant potential. We hypothesized that carvacrol in combination with RSG would prove beneficial to ameliorate the dysregulated carbohydrate metabolism in high-fat diet (HFD)-induced type 2 diabetic C57BL/6J mice. Mice were divided into six groups and fed HFD, for 10 weeks. CVL (20 mg/kg BW) and RSG (4 mg/kg BW) were administered post-orally, daily for 35 days. HFD mice showed an elevation in plasma glucose, insulin, glycosylated hemoglobin and a decrease in hemoglobin. The activities of carbohydrate metabolic enzymes such as glucose-6-phosphatase and fructose-1,6-bisphosphatase increased whereas glucokinase and glucose-6-phosphate dehydrogenase activities decreased in the liver of HFD mice. The activities of hepatic marker enzymes such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gamma-glutamyl transpeptidase increased in HFD mice. Combination of CVL and RSG prevented the above changes toward normalcy. Histopathological analysis of H&E stained pancreas was also in agreement with the biochemical findings. These major findings provide evidence that combination of CVL with RSG has better antidiabetic properties.

Topics: Animals; Biomarkers; Blood Glucose; Body Weight; Cymenes; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Dose-Response Relationship, Drug; Drug Therapy, Combination; Glycated Hemoglobin; Glycogen; Hypoglycemic Agents; Liver; Male; Mice; Mice, Inbred C57BL; Monoterpenes; Rosiglitazone; Thiazolidinediones

Epidemiological studies have demonstrated that diabetes mellitus is a serious health burden for both governments and healthcare providers. This study was hypothesized to evaluate the antihyperglycemic potential of eugenol by determine the activities of key enzymes of glucose metabolism in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced into male albino Wistar rats by intraperitoneal administration of STZ (40 mg/kg body weight (b.w.)). Eugenol was administered to diabetic rats intragastrically at 2.5, 5, and 10 mg/kg b.w. for 30 days. The dose 10 mg/kg b.w. significantly reduced the levels of blood glucose and glycosylated hemoglobin (HbA1c) and increased plasma insulin level. The altered activities of the key enzymes of carbohydrate metabolism such as hexokinase, pyruvate kinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, and liver marker enzymes (AST, ALT, and ALP), creatine kinase and blood urea nitrogen in serum and blood of diabetic rats were significantly reverted to near normal levels by the administration of eugenol. Further, eugenol administration to diabetic rats improved body weight and hepatic glycogen content demonstrated the antihyperglycemic potential of eugenol in diabetic rats. The present findings suggest that eugenol can potentially ameliorate key enzymes of glucose metabolism in experimental diabetes, and it is sensible to broaden the scale of use of eugenol in a trial to alleviate the adverse effects of diabetes.

Topics: Animals; Blood Glucose; Blood Urea Nitrogen; Body Weight; Carbohydrates; Diabetes Mellitus, Experimental; Drinking Behavior; Eugenol; Feeding Behavior; Fructose-Bisphosphatase; Glucose; Glucose Tolerance Test; Glucose-6-Phosphatase; Glucosephosphate Dehydrogenase; Glycated Hemoglobin; Glycogen; Hexokinase; Hyperglycemia; Insulin; Kidney; Liver; Male; Pancreas; Pyruvate Kinase; Rats; Streptozocin

Studies indicate that hyperglycemia-induced oxidative stress triggers the development of microvascular and macrovascular complications in diabetes. Accordingly, we hypothesized that maslinic acid (MA) prevents these complications due to its antioxidant properties. We, therefore, investigated the effects of 5-week MA treatment of streptozotocin (STZ)-induced diabetic rats on anti-oxidative status of cardiac, hepatic and renal tissues as well as on kidney function. Proximal tubular effects of MA were studied in anesthetized rats challenged with hypotonic saline after a 3.5 h equilibration for 4 h of 1 h control, 1.5 h treatment and 1.5 h recovery periods using lithium clearance. MA was added to the infusate during the treatment period. Oral glucose tolerance responses to MA were monitored in rats given a glucose load after an 18 h fast. Compared with untreated diabetic rats, MA-treated diabetic animals exhibited significantly low malondialdehyde (MDA, a marker of lipid peroxidation) and increased the activity of antioxidant enzymes; superoxide dismutase and glutathione peroxidase in hepatic, cardiac and renal tissues. The expressions of gastrocnemius muscle GLUT4 and kidney GLUT1 and GLUT2 were assessed to elucidate the mechanism of the hypoglycemic effects of MA. MA-treatment diminished the expression of GLUT1 and GLUT2 in diabetic kidney and reduced glycemia values of diabetic rats. MA administration increased urinary Na+ outputs and additionally the FENa indicating that at least part of the overall reduction in Na+ reabsorption occurred in the proximal tubules. These results suggest antioxidant effects of MA can ameliorate oxidative stress and improve kidney function in diabetes mellitus.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Drinking; Glucose Transport Proteins, Facilitative; Glycogen; Heart; Insulin; Insulin Secretion; Kidney Tubules, Proximal; Lipid Peroxidation; Liver; Malondialdehyde; Myocardium; Oxidative Stress; Rats; Rats, Wistar; Sodium; Triterpenes; Water-Electrolyte Balance

We evaluated effects of chronic intracerebroventricular infusion of angiotensin (Ang)-(1-7) on cardiovascular and metabolic parameters in fructose-fed (FF) rats. After 6 weeks of fructose intake (10% in drinking water), Sprague-Dawley rats were subjected to intracerebroventricular infusion of Ang-(1-7) (200 ng/h; FF+A7 group) or 0.9% sterile saline (FF group) for 4 weeks with continued access to fructose. Compared with control rats, FF rats had increased mean arterial pressure and cardiac sympathetic tone with impaired baroreflex sensitivity. FF rats also presented increased circulating triglycerides, leptin, insulin, and glucose with impaired glucose tolerance. Furthermore, relative weights of liver and retroperitoneal adipose tissue were increased in FF rats. Glycogen content was reduced in liver, but increased in muscle. In contrast, fructose-fed rats subjected to chronic intracerebroventricular infusion of Ang-(1-7) presented reduced cardiac sympathetic tone with normalized mean arterial pressure, baroreflex sensitivity, glucose and insulin levels, and improved glucose tolerance. Relative weight of liver, and hepatic and muscle glycogen contents were also normalized in FF+A7 rats. In addition, FF+A7 rats had reduced mRNA expression for neuronal nitric oxide synthase and NR1 subunit of N-methyl-d-aspartate receptor in hypothalamus and dorsomedial medulla. Ang-(1-7) infusion did not alter fructose-induced hyperleptinemia and increased relative weight of retroperitoneal adipose tissue. There were no differences in body weights, neither in liver mRNA expression of phosphoenolpyruvate carboxykinase or glucose-6-phosphatase among the groups. These data indicate that chronic increase in Ang-(1-7) levels in the brain may have a beneficial role in fructose-fed rats by ameliorating cardiovascular and metabolic disorders.

Topics: Angiotensin I; Animals; Baroreflex; Blood Glucose; Blood Pressure; Body Weight; Brain; Dietary Carbohydrates; Disease Models, Animal; Fructose; Glycogen; Infusions, Intraventricular; Insulin; Metabolic Syndrome; Peptide Fragments; Rats; Rats, Sprague-Dawley; Risk Factors

Astragalus membranaceus (AM) is a popular "Qi-tonifying" herb with a long history of use as a Traditional Chinese Medicine with multiple biological functions. However, evidence for the effects of AM on exercise performance and physical fatigue is limited. We evaluated the potential beneficial effects of AM on ergogenic and anti-fatigue functions following physiological challenge. Male ICR strain mice were randomly assigned to four groups (n = 10 per group) for treatment: (1) sedentary control and vehicle treatment (vehicle control); (2) exercise training with vehicle treatment (exercise control); and (3) exercise training with AM treatment at 0.615 g/kg/day (Ex-AM1) or (4) 3.075 g/kg/day (Ex-AM5). Both the vehicle and AM were orally administered for 6 weeks. Exercise performance and anti-fatigue function were evaluated by forelimb grip strength, exhaustive swimming time, and levels of serum lactate, ammonia, glucose, and creatine kinase after 15-min swimming exercise. Exercise training combined with AM supplementation increased endurance exercise capacity and increased hepatic and muscle glycogen content. AM reduced exercise-induced accumulation of the byproducts blood lactate and ammonia with acute exercise challenge. Moreover, we found no deleterious effects from AM treatment. Therefore, AM supplementation improved exercise performance and had anti-fatigue effects in mice. It may be an effective ergogenic aid in exercise training.

Topics: Animals; Astragalus propinquus; Blood Glucose; Body Weight; Creatine Kinase; Dietary Supplements; Fatigue; Glycogen; Lactic Acid; Liver; Male; Medicine, Chinese Traditional; Mice; Muscle Strength; Muscle, Skeletal; Organ Size; Performance-Enhancing Substances; Physical Conditioning, Animal

ENA-actimineral resource A (ENA-A) is an alkaline mineral water and has a few biological activities such as antioxidant activity. The aim of this study was to examine the effects of ENA-A on lifespan in mice using senescence marker protein-30 knockout mice. The present study had groups of 18-week-old mice (n = 24), 26-week-old mice (n = 12), and 46-week-old mice (n = 20). Each differently aged mice group was divided into three subgroups: a control group, a 5 % ENA-A-treated group, and a 10 % ENA-A-treated group. Mice in the 18-week-old group were treated with vitamin C drinking water 1.5 g/L. However, the mice in the 26-week-old and 46-week-old groups were not treated with vitamin C. The experiments were done for 18 weeks. All vitamin C-treated mice were alive at week 18 (100% survival rate). In the non-vitamin C group, the 10% ENA-A-treated mice were alive at week 18. The control and 5% ENA-A-treated mice died by week 15. As expected, vitamin C was not detected in the non-vitamin C-treated group. However, vitamin C levels were increased in an ENA-A dose-dependent manner in the vitamin C-treated group. In the TUNEL assay, a number of positive hepatocytes significantly decreased in an ENA-A dose-dependent manner. Periodic acid Schiff positive hepatocytes were significantly increased in an ENA-A dose-dependent manner. In addition, the expression level of CuZnSOD was increased by the ENA-A treatment. These data suggest that the intake of ENA-A has a critical role in the anti-aging mechanism and could be applied toward the lifespans of humans.

Topics: Animals; Antioxidants; Apoptosis; Ascorbic Acid; Ascorbic Acid Deficiency; Body Weight; Bone and Bones; Calcium-Binding Proteins; Glycogen; Hepatocytes; Immunoblotting; Intracellular Signaling Peptides and Proteins; Liver; Longevity; Mice, Knockout; Minerals; Plant Preparations; Staining and Labeling; Superoxide Dismutase; Survival Analysis

The aim of this study was to investigate the mechanisms underlying the involvement of gut microbes in body weight gain of high-fat diet-fed obesity-prone (obese) and obesity-resistant (lean) mice. C57BL/6 mice were grouped into an obese group, a lean group and a normal control group. Both obese and lean mice were fed a high-fat diet while normal control mice were fed a normal diet; they were observed for six weeks. The results showed that lean mice had lower serum lipid levels, body fat and weight gain than obese mice. The ATPase, succinate dehydrogenase and malate dehydrogenase activities in liver as well as oxygen expenditure and rectal temperature of lean mice were significantly lower than in obese mice. As compared with obese mice, the absorption of intestinal carbohydrates but not of fats or proteins was significantly attenuated in lean mice. Furthermore, 16S rRNA abundances of faecal Firmicutes and Bacteroidetes were significantly reduced in lean mice. In addition, faecal β-D-galactosidase activity and short chain fatty acid levels were significantly decreased in lean mice. Expressions of peroxisome proliferator-activated receptor gamma 2 and CCAAT/enhancer binding protein-β in visceral adipose tissues were significantly downregulated in lean mice as compared with obese mice. Resistance to dyslipidaemia and high-fat diet-induced obesity was mediated by ineffective absorption of intestinal carbohydrates but not of fats or proteins, probably through reducing gut Bacteroidetes and Firmicutes contents and lowering of gut carbohydrate metabolism. The regulation of intestinal carbohydrates instead of fat absorption by gut microbes might be a potential treatment strategy for high-fat diet-induced obesity.

Topics: Adenosine Triphosphatases; Adipose Tissue; Animals; Bacteroidetes; beta-Galactosidase; Body Weight; Carbohydrate Metabolism; CCAAT-Enhancer-Binding Protein-beta; Diet, High-Fat; Dyslipidemias; Fatty Acids, Volatile; Feces; Glucose Tolerance Test; Glycogen; Insulin Resistance; Intestinal Mucosa; Intestines; Lipid Metabolism; Lipids; Liver; Malate Dehydrogenase; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Oxygen Consumption; PPAR gamma; Random Allocation; RNA, Ribosomal, 16S; Succinate Dehydrogenase; Weight Gain

Male BALB/c mice fed with either a regular or high fat diet were exposed to 0, 5 or 20 mg/kg perfluorooctane sulfonate (PFOS) for 14 days. Increased body weight, serum glucose, cholesterol and lipoprotein levels were observed in mice given a high fat diet. However, all PFOS-treated mice got reduced levels of serum lipid and lipoprotein. Decreasing liver glycogen content was also observed, accompanied by reduced serum glucose levels. Histological and ultrastructural examination detected more lipid droplets accumulated in hepatocytes after PFOS exposure. Moreover, transcripitonal activity of lipid metabolism related genes suggests that PFOS toxicity is probably unrelevant to PPARα's transcription. The present study demonstrates a lipid disturbance caused by PFOS and thus point to its role in inhibiting the secretion and normal function of low density lipoproteins.

Topics: Alkanesulfonic Acids; Animals; Body Weight; Diet, High-Fat; Estradiol; Fluorocarbons; Glycogen; Lipid Metabolism; Lipoproteins, LDL; Liver; Male; Mice; Mice, Inbred BALB C; Organ Size; PPAR alpha; Testosterone; Time Factors

While evaluating the toxicity of the tuberous root extracts of Hemidesmus indicus, a traditional medicinal plant, the glucose lowering property of the root was observed by the investigators. Therefore, it was thought of interest to isolate the anti-hyperglycemic principle from the root and determine its utility to develop an anti-diabetes mellitus medicine. The active principle was isolated from H. indicus root extract by anti-hyperglycemic activity guided chromatographic techniques. Glucose tolerance test in rats was used to evaluate the anti-hyperglycenic property. Anti-diabetes mellitus property was evaluated in alloxan-induced diabetic rats as well as streptozotocin-induced (type-2 model) diabetic rats. The active principle was isolated and identified with spectral data as β-amyrin palmitate. Although it is a known compound, its presence in H. indicus is not known previously. It was observed for the first time that β-amyrin palmitate has remarkable anti-hyperglycemic activity in orally glucose loaded rats. Further, interestingly, it exhibited excellent anti-diabetes mellitus activity in both alloxan-diabetic and streptozotocin-diabetic rats at a very low concentration (50µg/kg body weight). One of the mechanisms of action of β-amyrin palmitate appears to be blocking the entry of glucose from the intestine. β-Amyrin palmitate is very promising to develop a medicine for diabetes for combination therapy and/or mono-therapy.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Glucose Tolerance Test; Glycogen; Hemidesmus; Hypoglycemic Agents; Liver; Male; Oleanolic Acid; Organ Size; Plant Roots; Rats; Rats, Wistar

Changes in the maternal nutritional environment during fetal development can influence offspring's metabolic risk in later life. Animal models have demonstrated that offspring of diet-induced obese dams develop metabolic complications, including nonalcoholic fatty liver disease. In this study we investigated the mechanisms in young offspring that lead to the development of nonalcoholic fatty liver disease (NAFLD). Female offspring of C57BL/6J dams fed either a control or obesogenic diet were studied at 8 wk of age. We investigated the roles of oxidative stress and lipid metabolism in contributing to fatty liver in offspring. There were no differences in body weight or adiposity at 8 wk of age; however, offspring of obese dams were hyperinsulinemic. Oxidative damage markers were significantly increased in their livers, with reduced levels of the antioxidant enzyme glutathione peroxidase-1. Mitochondrial complex I and II activities were elevated, while levels of mitochondrial cytochrome c were significantly reduced and glutamate dehydrogenase was significantly increased, suggesting mitochondrial dysfunction. Offspring of obese dams also had significantly greater hepatic lipid content, associated with increased levels of PPARγ and reduced triglyceride lipase. Liver glycogen and protein content were concomitantly reduced in offspring of obese dams. In conclusion, offspring of diet-induced obese dams have disrupted liver metabolism and develop NAFLD prior to any differences in body weight or body composition. Oxidative stress may play a mechanistic role in the progression of fatty liver in these offspring.

Topics: Adiposity; Age Factors; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cytochromes c; Electron Transport Complex I; Electron Transport Complex II; Fatty Liver; Female; Glutamate Dehydrogenase; Glutathione Peroxidase; Glutathione Peroxidase GPX1; Glycogen; Homeostasis; Insulin; Lipase; Lipid Metabolism; Liver; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Oxidative Stress; Phenotype; PPAR gamma; Pregnancy; Prenatal Exposure Delayed Effects; Prenatal Nutritional Physiological Phenomena; Risk Factors; Signal Transduction

Red ginseng (RG) has been reported to improve the blood and organ lipid profile when combined with exercise. However, the effect of RG on energy metabolism during exercise is poorly understood. Therefore, this study was designed to investigate whether RG treatment alters fat utilization during exercise;. We used seven-week-old ICR mice (n = 42). RG (1 g/kg) was administered orally daily during two weeks of endurance training. All mice were randomized into two groups: training only group (CON group) and training with RG group (RG group). Endurance training consisted of 20~25 m/min on a slope of 8° for one hour five times a week. After a two-week experimental period, we measured substrate utilization during exercise at the same intensity and duration of training using a respiratory calorimetry chamber. Mice were dissected for glycogen measurement of muscles and liver before, immediately after, and one hour after the exercise;. Fat oxidation during the initial 20 min of the one-hour exercise significantly increased in the RG group compared to the CON group. In addition, the liver glycogen stores significantly decreased immediately after the one-hour exercise compared to at rest in the RG group, but did not differ between immediately after the one-hour exercise and at rest in the RG group. The glycogen concentration in white and red gastrocnemius muscle did not differ between the groups immediately after the one-hour exercise;. These results suggest that RG treatment for two weeks promotes fat oxidation and a glycogen-sparing effect during exercise. This might lead to a delay in peripheral fatigue during endurance exercise performance.

Topics: Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Energy Metabolism; Fatty Acids, Nonesterified; Glycogen; Insulin; Lipid Metabolism; Male; Mice; Mice, Inbred ICR; Muscle, Skeletal; Panax; Physical Conditioning, Animal; Plant Extracts

2,4-dinitrotoluene (2,4-DNT) is a nitroaromatic used in industrial dyes and explosives manufacturing processes that is found as a contaminant in the environment. Previous studies have implicated antagonism of PPARα signaling as a principal process affected by 2,4-DNT. Here, we test the hypothesis that 2,4-DNT-induced perturbations in PPARα signaling and resultant downstream deficits in energy metabolism, especially from lipids, cause organism-level impacts on exercise endurance. PPAR nuclear activation bioassays demonstrated inhibition of PPARα signaling by 2,4-DNT whereas PPARγ signaling increased. PPARα (-/-) and wild-type (WT) female mice were exposed for 14 days to vehicle or 2,4-DNT (134 mg/kg/day) and performed a forced swim to exhaustion 1 day after the last dose. 2,4-DNT significantly decreased body weights and swim times in WTs, but effects were significantly mitigated in PPARα (-/-) mice. 2,4-DNT decreased transcript expression for genes downstream in the PPARα signaling pathway, principally genes involved in fatty acid transport. Results indicate that PPARγ signaling increased resulting in enhanced cycling of lipid and carbohydrate substrates into glycolytic/gluconeogenic pathways favoring energy production versus storage in 2,4-DNT-exposed WT and PPARα (-/-) mice. PPARα (-/-) mice appear to have compensated for the loss of PPARα by shifting energy metabolism to PPARα-independent pathways resulting in lower sensitivity to 2,4-DNT when compared with WT mice. Our results validate 2,4-DNT-induced perturbation of PPARα signaling as the molecular initiating event for impaired energy metabolism, weight loss, and decreased exercise performance.

Topics: Animals; Body Weight; Dinitrobenzenes; Dose-Response Relationship, Drug; Energy Metabolism; Environmental Pollutants; Genomics; Glycogen; Liver; Mice, Inbred C57BL; Mice, Knockout; Physical Endurance; PPAR alpha; PPAR gamma; Signal Transduction; Swimming

Consequences of gestational protein restriction (GPR) on liver metabolism in rat offspring were investigated. Pregnant dams were divided into groups: normal (NP, 17% casein) or low-protein diet (LP, 6% casein). Livers were collected from 30-day-old offspring (d30) for analysis or isolation of mitochondria. At d30, hepatic and muscle glycogen was increased in LP group. Mitochondrial swelling and oxygen uptake (recorded with a Clark-type electrode) were significantly reduced in NP female and LP pups. Thiobarbituric acid reactive substances production was lower in females (NP or LP), suggesting significant inhibition of lipid peroxidation. Measurement of mitochondrial respiration (states 3 and 4 stimulated by succinate) showed a higher ADP/O ratio in LP pups, particularly females, suggesting higher phosphorylation efficiency. In the 1st month of life, under our experimental conditions, GPR protects liver mitochondria against oxidative stress and females seem to be more resistant or more suitable for survival.

Topics: Animals; Animals, Newborn; Body Weight; Cell Respiration; Diet, Protein-Restricted; Female; Glycogen; Lipid Peroxidation; Liver; Mitochondria; Oxidative Stress; Oxygen; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Thiobarbituric Acid Reactive Substances

Loss of muscle mass related to anti-cancer therapy is a major concern in cancer patients, being associated with important clinical endpoints including survival, treatment toxicity and patient-related outcomes. We investigated effects of voluntary exercise during cisplatin treatment on body weight, food intake as well as muscle mass, strength and signalling. Mice were treated weekly with 4 mg/kg cisplatin or saline for 6 weeks, and randomized to voluntary wheel running or not. Cisplatin treatment induced loss of body weight (29.8%, P < 0.001), lean body mass (20.6%, P = 0.001), as well as anorexia, impaired muscle strength (22.5% decrease, P < 0.001) and decreased glucose tolerance. In addition, cisplatin impaired Akt-signalling, induced genes related to protein degradation and inflammation, and reduced muscle glycogen content. Voluntary wheel running during treatment attenuated body weight loss by 50% (P < 0.001), maintained lean body mass (P < 0.001) and muscle strength (P < 0.001), reversed anorexia and impairments in Akt and protein degradation signalling. Cisplatin-induced muscular inflammation was not prevented by voluntary wheel running, nor was glucose tolerance improved. Exercise training may preserve muscle mass in cancer patients receiving cisplatin treatment, potentially improving physical capacity, quality of life and overall survival.

Topics: Animals; Anorexia; Body Weight; Cisplatin; Female; Gene Expression; Glucose Intolerance; Glycogen; Mice; Muscle Strength; Muscle, Skeletal; Muscular Atrophy; Physical Conditioning, Animal; Proto-Oncogene Proteins c-akt; Running; Signal Transduction

There is an age-long claim that the Musa paradisiaca root is used to manage reproductive dysfunction, most especially sexual dysfunction (as an aphrodisiac), but there are no data in the open scientific literature that have refuted or supported this claim and the effects of M. paradisiaca root on the testes. Therefore, this study was aimed at investigating the effect of oral administration of the aqueous extract of M. paradisiaca root on the testicular function parameters of male rat testes.. Sexually matured male albino rats (138.67±5.29 g) were randomly assigned into four groups, A, B, C, and D, that respectively received 0.5 mL (3.6 mL/kg body weight) of distilled water and 25, 50, and 100 mg/kg body weight of the extract, orally, once daily, for 14 days.. The extract significantly increased (p<0.05) the testes-body weight ratio, total protein, sialic acid, glycogen, cholesterol, activities of alkaline phosphatase, γ-glutamyltransferase, acid phosphatase, and the concentration of testicular testosterone. In contrast, the extract decreased the concentrations of both luteinizing and follicle-stimulating hormones in the serum of the animals. The results revealed that oral administration of M. paradisiaca root extract at doses of 25, 50, and 100 mg/kg body weight enhanced the testosterone-dependent normal functioning of the testes.. Overall, the aqueous extract of M. paradisiaca stimulated the normal functioning of the testes and exhibited both androgenic and anabolic properties. The results may explain the rationale behind the folkloric beneficial effect of the plant in the management of reproductive dysfunction.

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Body Weight; Cholesterol; Dose-Response Relationship, Drug; Follicle Stimulating Hormone; gamma-Glutamyltransferase; Glycogen; In Vitro Techniques; Indicators and Reagents; Luteinizing Hormone; Male; Musa; Organ Size; Plant Extracts; Plant Roots; Rats; Sialic Acids; Testis; Testosterone

The study was undertaken to evaluate the antidiabetic effect of green tea extract on carbohydrate metabolic key enzymes in control and streptozotocin high fat diet -induced diabetic rats. The daily oral treatment of green tea extract (300 mg/kg body weight) to diabetic rats for 30 days resulted in a significant reduction in the levels of plasma glucose, glycosylated hemoglobin (HbA1c) and increase in the levels of insulin and hemoglobin. The altered activities of the key enzymes of carbohydrate metabolism such as hexokinase, pyruvate kinase, lactate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, glucose-6-phosphate dehydrogenase, glycogen synthase and glycogen phosphorylase in liver of diabetic rats were significantly reverted to near normal levels by the administration of green tea extract. Further, green tea extract administration to diabetic rats improved muscle and hepatic glycogen content suggesting the antihyperglycemic potential of green tea extract in diabetic rats. The obtained results were compared with metformin, a standard oral hypoglycemic drug. Thus, this study indicates that the administration of green tea extract to diabetic rats resulted in alterations in the metabolism of glucose with subsequent reduction in plasma glucose levels.

Topics: Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Diet, High-Fat; Dose-Response Relationship, Drug; Eating; Enzymes; Glucose; Glycated Hemoglobin; Glycogen; Hypoglycemic Agents; Insulin; Liver; Male; Muscle, Skeletal; Plant Extracts; Rats; Rats, Wistar; Streptozocin; Tea

Several biological activities of total saponins of Radix notoginseng (TSRN), a traditional Chinese medicine, have been reported. The present study was carried out to investigate anti-fatigue activity of TSRN in male Kunming mice.. Mice were divided into four groups. The first group designated as control group was administered with distilled water by gavage every day. The second, third and fourth groups designated as TSRN treatment groups were administered with TSRN of 20, 40 and 80 mg/kg body weight/day, respectively. The treatment continued for 28 days. Exhaustive swimming time, blood lactate and tissue glycogen contents of mice after swimming were determined.. TSRN extended exhaustive swimming time of mice, effectively delayed the increase of lactate in the blood, as well as increased the tissue glycogen contents.. TSRN showed promising anti-fatigue activity in animal model. However, further study is needed to elucidate the mechanism of the effect of TSRN on fatigue.

Topics: Animals; Body Weight; Drugs, Chinese Herbal; Fatigue; Glycogen; Humans; Mice; Panax notoginseng; Plant Roots; Saponins

Lysophosphatidic acid (LPA) is a lipid mediator produced by adipocytes that acts via specific G-protein-coupled receptors; its synthesis is modulated in obesity. We previously reported that reducing adipocyte LPA production in high-fat diet (HFD)-fed obese mice is associated with improved glucose tolerance, suggesting a negative impact of LPA on glucose homeostasis. Here, our aim was to test this hypothesis.. First, glucose tolerance and plasma insulin were assessed after acute (30 min) injection of LPA (50 mg/kg) or of the LPA1/LPA3 receptor antagonist Ki16425 (5 mg kg(-1) day(-1), i.p.) in non-obese mice fed a normal diet (ND) and in obese/prediabetic (defined as glucose-intolerant) HFD mice. Glucose and insulin tolerance, pancreas morphology, glycogen storage, glucose oxidation and glucose transport were then studied after chronic treatment (3 weeks) of HFD mice with Ki16425.. In ND and HFD mice, LPA acutely impaired glucose tolerance by inhibiting glucose-induced insulin secretion. These effects were blocked by pre-injection of Ki16425 (5 mg/kg, i.p.). Inhibition of glucose-induced insulin secretion by LPA also occurred in isolated mouse islets. Plasma LPA was higher in HFD mice than in ND mice and Ki16425 transiently improved glucose tolerance. The beneficial effect of Ki16425 became permanent after chronic treatment and was associated with increased pancreatic islet mass and higher fasting insulinaemia. Chronic treatment with Ki16425 also improved insulin tolerance and increased liver glycogen storage and basal glucose use in skeletal muscle.. Exogenous and endogenous LPA exerts a deleterious effect on glucose disposal through a reduction of plasma insulin; pharmacological blockade of LPA receptors improves glucose homeostasis in obese/prediabetic mice.

Topics: Adipocytes; Animals; Body Weight; Diet, High-Fat; Gene Expression Regulation; Glucose; Glycogen; Homeostasis; Insulin; Insulin Secretion; Isoxazoles; Lipids; Lysophospholipids; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Muscle, Skeletal; Oxygen; Propionates; Time Factors

The contribution of liver glycogen catabolism to hyperglycemia and glucose intolerance induced by pharmacological hypercortisolism were investigated.. For this purpose, adult male Wistar rats that received 1.0 mg/kg dexamethasone (DEX) ip at 8:00 a.m. (DEX group) or saline (CON group) once a day for 5 consecutive days were compared.. Experimental hypercortisolism was confirmed by higher (p<0.05) glycemia, lower (p<0.05) body weight and glucose intolerance. In the fed state, the basal glycogen catabolism and the glucagon (1 nM) and epinephrine (2 μM) induced glycogen catabolism were similar between the groups. The activation of glycogen catabolism induced by phenylephrine (2 μM) and isoproterenol (20 μM) were increased (p<0.05) and decreased (p<0.05), respectively, in DEX rats. Furthermore, DEX rats exhibited higher (p<0.05) glycogen catabolism during the infusion of cAMP (3 μM). However, during the infusion of cAMP (15 μM), 6MB-cAMP (3 μM) or cyanide (0.5 mM), the intensification of glycogen breakdown was similar. Thus, in general, hypercortisolism does not influence the basal glycogen catabolism and the liver responsiveness to glycogenolytic agents in the fed state. In contrast with fed state, fasted rats (DEX group) showed a more intense (p<0.05) basal glycogen catabolism.. The contribution of glycogen catabolism to hyperglycemia during hypercortisolism depends of the nutritional status, starting from a negligible participation in the fed state up to a significant contribution in the fasted state.

Topics: Animals; Body Weight; Cushing Syndrome; Cyclic AMP; Dexamethasone; Epinephrine; Fasting; Glucagon; Glucose Intolerance; Glycogen; Hyperglycemia; Liver; Male; Rats; Rats, Wistar

Resveratrol (RES) is a well-known phytocompound and food component which has antioxidative and multifunctional bioactivities. However, there is limited evidence for the effects of RES on physical fatigue and exercise performance. The purpose of this study was to evaluate the potential beneficial effects of trans-RES on fatigue and ergogenic functions following physiological challenge. Male ICR mice from four groups (n = 8 per group) were orally administered RES for 21 days at 0, 25, 50, and 125 mg/kg/day, which were respectively designated the vehicle, RES-25, RES-50, and RES-125 groups. The anti-fatigue activity and exercise performance were evaluated using forelimb grip strength, exhaustive swimming time, and levels of serum lactate, ammonia, glucose, and creatine kinase (CK) after a 15-min swimming exercise. The exhaustive swimming time of the RES-25 group (24.72 ± 7.35 min) was significantly (p = 0.0179) longer than that of vehicle group (10.83 ± 1.15 min). A trend analysis revealed that RES treatments increased the grip strength. RES supplementation also produced dose-dependent decreases in serum lactate and ammonia levels and CK activity and also an increase in glucose levels in dose-dependent manners after the 15-min swimming test. The mechanism was related to the increased energy utilization (as blood glucose), and decreased serum levels of lactate, ammonia, and CK. Therefore, RES could be a potential agent with an anti-fatigue pharmacological effect.

Topics: Ammonia; Animals; Antioxidants; Blood Glucose; Body Weight; Creatine Kinase; Dietary Supplements; Fatigue; Glycogen; Kidney; Lactic Acid; Liver; Male; Mice; Muscle, Skeletal; Physical Conditioning, Animal; Resveratrol; Stilbenes; Swimming

The codling moth (Cydia pomonella) is a major insect pest of apples worldwide. Fully grown last instar larvae overwinter in diapause state. Their overwintering strategies and physiological principles of cold tolerance have been insufficiently studied. No elaborate analysis of overwintering physiology is available for European populations.. We observed that codling moth larvae of a Central European population prefer to overwinter in the microhabitat of litter layer near the base of trees. Reliance on extensive supercooling, or freeze-avoidance, appears as their major strategy for survival of the winter cold. The supercooling point decreases from approximately -15.3 °C during summer to -26.3 °C during winter. Seasonal extension of supercooling capacity is assisted by partial dehydration, increasing osmolality of body fluids, and the accumulation of a complex mixture of winter specific metabolites. Glycogen and glutamine reserves are depleted, while fructose, alanine and some other sugars, polyols and free amino acids are accumulated during winter. The concentrations of trehalose and proline remain high and relatively constant throughout the season, and may contribute to the stabilization of proteins and membranes at subzero temperatures. In addition to supercooling, overwintering larvae acquire considerable capacity to survive at subzero temperatures, down to -15 °C, even in partially frozen state.. Our detailed laboratory analysis of cold tolerance, and whole-winter survival assays in semi-natural conditions, suggest that the average winter cold does not represent a major threat for codling moth populations. More than 83% of larvae survived over winter in the field and pupated in spring irrespective of the overwintering microhabitat (cold-exposed tree trunk or temperature-buffered litter layer).

Topics: Adaptation, Physiological; Amino Acids; Animals; Body Weight; Carbohydrate Metabolism; Cold Temperature; Energy Metabolism; Freezing; Glutamine; Glycogen; Hemolymph; Larva; Lipid Metabolism; Metabolome; Moths; Osmolar Concentration; Polymers; Seasons; Survival Analysis; Water

Epidemiological studies have demonstrated that the diabetes mellitus is a serious health burden for both governments and healthcare providers. The present study was hypothesized to evaluate the antihyperglycemic potential of fraxetin by determining the activities of key enzymes of carbohydrate metabolism in streptozotocin (STZ) - induced diabetic rats. Diabetes was induced in male albino Wistar rats by intraperitoneal administration of STZ (40 mg/kg b.w). Fraxetin was administered to diabetic rats intra gastrically at 20, 40, 80 mg/kg b.w for 30 days. The dose 80 mg/kg b.w, significantly reduced the levels of blood glucose and glycosylated hemoglobin (HbA1c) and increased plasma insulin level. The altered activities of the key enzymes of carbohydrate metabolism such as glucokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase and hepatic enzymes (aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP)) in the liver tissues of diabetic rats were significantly reverted to near normal levels by the administration of fraxetin. Further, fraxetin administration to diabetic rats improved body weight and hepatic glycogen content demonstrated its antihyperglycemic potential. The present findings suggest that fraxetin may be useful in the treatment of diabetes even though clinical studies to evaluate this possibility may be warranted.

Topics: Alanine Transaminase; Alkaline Phosphatase; Animals; Aspartate Aminotransferases; Blood Glucose; Body Weight; Carbohydrate Metabolism; Coumarins; Diabetes Mellitus, Experimental; Drug Administration Schedule; Fructose-Bisphosphatase; Glucokinase; Glucose-6-Phosphatase; Glucosephosphate Dehydrogenase; Glycated Hemoglobin; Glycogen; Hypoglycemic Agents; Insulin; Liver; Male; Rats; Rats, Wistar; Streptozocin

The glucokinase activators improve the fasting as well as postprandial glucose control and are important investigational drugs for the treatment of diabetes. However, recent studies have implicated that continuous activation of glucokinase with a small molecule activator can increase hepatic triglycerides and the long term glucose control is not achieved. In this study, we investigated the effect of combination of glucokinase activator (GKA, Piragliatin) with GLP-1 receptor agonist exendin-4 (Ex-4) in male db/db mice. Twelve weeks combination treatment in the db/db mice resulted in a significant decrease in body weight gain, food consumption, random glucose and %HbA1c. The decrease in serum glucose and %HbA1c in combination group was more profound and significantly different than that of individual treatment (GKA or Ex-4) group. GKA treatment increased hepatic triglycerides, whereas combination of Ex-4 with GKA attenuated hepatic steatosis. The combination of GKA with Ex-4 reduced the hepatic lipid accumulation, improved the insulin sensitivity, and reduced hepatic glucose production in db/db mice. Overall, our data indicate that combination of GKA and GLP-1 receptor agonist Ex-4 improves glucose homeostasis, shows antiobesity activity, without causing harmful side effects like fatty liver.

Topics: Animals; Benzeneacetamides; Body Weight; Drug Synergism; Eating; Enzyme Activation; Exenatide; Fatty Liver; Glucokinase; Glucose; Glycogen; Homeostasis; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Liver; Male; Mice; Mice, Inbred C57BL; Peptides; Venoms

Se-polysaccharide from Catathelasma ventricosum (SPC-2) was purified by DEAE-52 and Sephadex G-100 column chromatography. The average size of SPC-2 was 1.6×10(5) Da, and it was mainly composed of glucose (87.4%) with the conformation of β-pyran ring. The branched structure of SPC-2 was proved intuitively by atomic force microscope (AFM). The antidiabetic potential of SPC-2 was tested in STZ-induced diabetic mice. After STZ-induced diabetic mice being administered of SPC-2 for 30 days, SPC-2 treatment significantly reduced the levels of malondialdehyde (MDA) and low-density lipoprotein cholesterol (LDL-C) that were increased by the STZ treatment. Further, the SPC-2 treatment led to increased activity of antioxidant enzymes in liver and kidney and high-density lipoprotein cholesterol (HDL-C) that were decreased by the STZ. The results of histopathology also showed SPC-2 protected tissues (pancreas, liver and kidney) against peroxidation damage and maintained tissue integrity.

Topics: Agaricales; Animals; Antioxidants; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Enzymes; Glycogen; Hypoglycemic Agents; Insulin; Kidney; Lipids; Liver; Male; Mice, Inbred ICR; Monosaccharides; Mycelium; Pancreas; Polysaccharides; Protective Agents; Selenium; Streptozocin

Based on a recent study indicating that enzymatically synthesized glycogen (ESG) possesses a dietary, fiber-like action, we hypothesized that ESG can reduce the risk of obesity. In this study, the antiobesity effects of ESG were investigated in a model of diet-induced obesity. Male Sprague-Dawley rats were divided into 4 groups and fed a normal or high-fat diet, with or without 20% ESG, for 4 weeks. Body weight, food intake, lipid deposition in the white adipose tissues and liver, fecal lipid excretion, and plasma lipid profiles were measured. At week 3, the body fat mass was measured using an x-ray computed tomography system, which showed that ESG significantly suppressed the high-fat diet-induced lipid accumulation. Similar results were observed in the weight of the adipose tissue after the experiment. Moreover, ESG significantly suppressed the lipid accumulation in the liver but increased fecal lipid excretion. The plasma concentrations of triacylglycerol and nonesterified fatty acid were lowered after a high-fat diet, whereas the total bile acid concentration was increased by ESG. However, the hepatic messenger RNA (mRNA) levels of enzymes related to lipid metabolism were not affected by ESG. Conversely, the mRNA levels of long-chain acyl-CoA dehydrogenase and medium-chain acyl-CoA dehydrogenase were up-regulated by ESG in the muscle. These results suggest that the combined effects of increased fecal lipid excretion, increased mRNA levels of enzymes that oxidize fatty acids in the muscle, and increased total bile acid concentration in the plasma mediate the inhibitory effect of ESG on lipid accumulation.

Topics: Acyl-CoA Dehydrogenase; Acyl-CoA Dehydrogenase, Long-Chain; Adipose Tissue; Animals; Anti-Obesity Agents; Bile Acids and Salts; Blood Glucose; Body Weight; Diet, High-Fat; Dietary Fats; Fatty Acids, Nonesterified; Glycogen; Lipid Metabolism; Liver; Male; Obesity; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tomography Scanners, X-Ray Computed; Triglycerides; Up-Regulation

This study investigated the effects of a combination of fucosylated chondroitin sulfate (CHS) and rosiglitazone (RSG) on glucose metabolism in the liver of insulin-resistant C57BL/6J mice fed a high-fat high-sucrose diet for 19 weeks. The results showed that the combination (CHS/RSG) synergistically improved body weight gain, liver weight, fasting blood glucose levels, glucose tolerance on an oral glucose tolerance test, serum insulin levels, homeostasis model assessment indexes, and hepatic glycogen content. In liver tissue, CHS/RSG significantly normalized the activities of hexokinase, pyruvate kinase, and glucose-6-phosphatase. In additionally, it increased the mRNA expression of insulin receptors, insulin receptor substrate 2, phosphatidylinositol 3 kinase (PI3K), protein kinase B (PKB), and glycogen synthase, and inhibited glycogen synthase kinase 3β(GSK-3β) mRNA expression in the liver. This suggests that CHS/RSG treatment improves glucose metabolism by modulating metabolic enzymes and strengthening the PI3K/PKB/GSK-3β signal pathway mediated by insulin at the transcriptional level.

Topics: Animals; Blood Glucose; Body Weight; Chondroitin Sulfates; Diet, High-Fat; Drug Synergism; Drug Therapy, Combination; Gene Expression Regulation; Glucose Tolerance Test; Glucose-6-Phosphatase; Glycogen; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hexokinase; Hyperglycemia; Hypoglycemic Agents; Insulin Resistance; Liver; Male; Mice; Mice, Inbred C57BL; Organ Size; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; Pyruvate Kinase; Receptor, Insulin; Rosiglitazone; Sea Cucumbers; Signal Transduction; Thiazolidinediones

The in vivo anti-fatigue activity of the total flavonoids from sweet potato [Ipomoea batatas (L.) Lam.] leaf was investigated in male Kunming mice. The total flavonoids from sweet potato leaf (TFSL) were orally administered at doses of 50, 100 and 200 mg/kg for 4 weeks and the anti-fatigue effect was studied using a weight-loaded swimming test, along with the determination of serum urea nitrogen (SUN), blood lactic acid (BLA) and hepatic and muscle glycogen contents. The results showed that TFSL had significant anti-fatigue effects. TFSL extended the exhaustive swimming time, effectively inhibited the increase of BLA, decreased the level of SUN and increased the hepatic and muscle glycogen content of mice. Thus, TFSL may have potential as an anti-fatigue agent.

Topics: Animals; Blood Urea Nitrogen; Body Weight; Fatigue; Flavonoids; Glycogen; Ipomoea batatas; Lactic Acid; Liver; Male; Mice; Muscles; Plant Leaves; Swimming

Chronic exercise training results in numerous skeletal muscle adaptations, including increases in insulin sensitivity and glycogen content. To understand the mechanism leading to increased muscle glycogen, we studied the effects of exercise training on glycogen regulatory proteins in rat skeletal muscle. Female Sprague Dawley rats performed voluntary wheel running for 1, 4 or 7 weeks. After 7 weeks of training, insulin-stimulated glucose uptake was increased in epitrochlearis muscle. As compared with sedentary control rats, muscle glycogen did not change after 1 week of training, but increased significantly after 4 and 7 weeks. The increases in muscle glycogen were accompanied by elevated glycogen synthase activity and protein expression. To assess the regulation of glycogen synthase, we examined its major activator, protein phosphatase 1 (PP1), and its major deactivator, glycogen synthase kinase (GSK)-3. Consistent with glycogen synthase activity, PP1 activity was unchanged after 1 week of training but significantly increased after 4 and 7 weeks of training. Protein expression of R(GL)(G(M)), another regulatory PP1 subunit, significantly decreased after 4 and 7 weeks of training. Unlike PP1 activity, GSK-3 phosphorylation did not follow the pattern of glycogen synthase activity. The ~ 40% decrease in GSK-3α phosphorylation after 1 week of exercise training persisted until 7 weeks, and may function as a negative feedback mechanism in response to elevated glycogen. Our findings suggest that exercise training-induced increases in muscle glycogen content could be regulated by multiple mechanisms, including enhanced insulin sensitivity, glycogen synthase expression, allosteric activation of glycogen synthase, and PP1 activity.

Topics: Adaptation, Physiological; Animals; Blood Glucose; Body Weight; Female; Glucose; Glucose Transporter Type 4; Glycogen; Glycogen Phosphorylase; Glycogen Synthase; Glycogen Synthase Kinase 3; Immunoblotting; Insulin; Muscle, Skeletal; Physical Conditioning, Animal; Protein Phosphatase 1; Rats; Rats, Sprague-Dawley; Time Factors

The pea aphid, Acyrthosiphon pisum (Hem: Aphididae), has been repeatedly used as a model species in a wide range of biological studies including genetics, ecology, physiology, and behavior. When red pea aphids feed on low quality plants in crowded conditions, some individuals lose their color shade and become pale yellowish, while other individuals on the same host plants remain changeless. The pale aphids have been shown to walk significantly faster and migrate more frequently to neighboring plants compared to the original red ones. We hypothesized that the color change and higher activity of pale aphids are directly associated with their suboptimal nutritional status. We showed that the pale aphids have significantly lower wet and dry weights than red ones. Analyses of energy reserves in individual aphids revealed that the pale aphids suffer a significant loss in their lipid and soluble carbohydrate contents. Our results provide a strong link between host quality, body color, dispersal rate, and energy reserves of pea aphids. Apparently, utilization of energy reserves resulted from an imbalance in food sources received by the aphids stimulates them to walk more actively to find new hosts and restore their lost energy. This reversible shift enables aphids to quickly respond to deprived host plants much earlier than the appearance of winged morph and restore their original status when they find appropriate host.

Topics: Animals; Aphids; Behavior, Animal; Body Weight; Carbohydrate Metabolism; Data Interpretation, Statistical; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Energy Metabolism; Environment; Food; Glycogen; Pigmentation; Pisum sativum; Stress, Psychological

Resveratrol (trans-3,4',5-trihydroxystilbene) is a naturally occurring phytoalexin produced by plants in response to various stresses. Several studies have shown that resveratrol is present in significant amounts in a variety of human diets, including wines, grapes, berries, and peanuts, and it possesses several beneficial health properties, such as atheroprotective, anti-obesity, anti-cancer, anti-inflammatory and antioxidant activities. In this study, we evaluated the effect of resveratrol on the pathogenesis of obesity and the metabolic profile of nutrients in non-high fat-fed obese OLETF rats.. Although lipid parameters in the serum and liver were not changed, the accumulation of abdominal white adipose tissues was markedly prevented in resveratrol diet-fed OLETF rats after 4 weeks of feeding. The results of the respiratory gas analysis indicated that dietary resveratrol induced the partial enhancement of fat metabolism and sparing actions for carbohydrate and protein at 1 week and 3 weeks of feeding in OLETF rats. Additionally, the adipose mRNA level of carnitine palmitoyltransferase in the resveratrol diet-fed OLETF rats was higher than the control rats after 4 weeks of feeding.. Our study demonstrated that dietary resveratrol can prevent obesity through a change in the metabolic profile of nutrients in obese OLETF rats.

Topics: Adipose Tissue, White; Animals; Body Weight; Carnitine O-Palmitoyltransferase; Cholesterol; Food, Formulated; Gene Expression; Glycogen; Lipid Metabolism; Liver; Male; Metabolome; Obesity; Rats; Rats, Inbred OLETF; Resveratrol; RNA, Messenger; Stilbenes; Triglycerides; Up-Regulation

Oat β-glucan was purified from oat bran and its effects on running performance and related biochemical parameters were investigated. Four-week-old male Sparsgue-Dawley rats, fed with/without oat β-glucan (312.5 mg kg(-1) d(-1)) for 7 weeks, were subjected to run on a treadmill system to make them exhausted. All rats were immediately sacrificed after prolonged exercise, and the major metabolic substrates were measured in serum and liver. The results showed feeding dietary oat β-glucan to rats could significantly reduce the body weight and increase the maximum running time compared with normal control (P<0.05). Furthermore, dietary oat β-glucan decreased the levels of blood urea nitrogen, lactate acid, and creatine kinase activity in serum, and increased the levels of non-esterified fatty acids, lactic dehydrogenase activity in serum, and the content of liver glycogen. Therefore, the present study demonstrated that dietary oat β-glucan can enhance the endurance capacity of rats while facilitating their recovery from fatigue.

Topics: Animals; Avena; Behavior, Animal; beta-Glucans; Blood Urea Nitrogen; Body Weight; Chemical Phenomena; Creatine Kinase; Eating; Exercise Test; Fatigue; Fatty Acids, Nonesterified; Glycogen; L-Lactate Dehydrogenase; Lactic Acid; Liver; Male; Muscle, Skeletal; Physical Conditioning, Animal; Physical Endurance; Rats; Rats, Sprague-Dawley; Running

The present investigation aimed to study the protective effect of intermittent normothermic cardioplegia in rabbit's hypertrophic hearts.. The parameters chosen were 1) the ratio heart weight / body weight, 2) the myocardial glycogen levels, 3) ultrastructural changes of light and electron microscopy, and 4) mitochondrial respiration.. 1) The experimental model, coarctation of the aorta induced left ventricular hypertrophy; 2) the temporal evolution of the glycogen levels in hypertrophic myocardium demonstrates that there is a significant decrease; 3) It was observed a time-dependent trend of higher oxygen consumption values in the hypertrophic group; 4) there was a significant time-dependent decrease in the respiratory coefficient rate in the hypertrophic group; 5) the stoichiometries values of the ADP: O2 revealed the downward trend of the values of the hypertrophic group; 6) It was possible to observe damaged mitochondria from hypertrophic myocardium emphasizing the large heterogeneity of data.. The acquisition of biochemical data, especially the increase in speed of glycogen breakdown, when anatomical changes are not detected, represents an important result even when considering all the difficulties inherent in the process of translating experimental results into clinical practice. With regard to the adopted methods, it is clear that morphometric methods are less specific. Otherwise, the biochemical data allow detecting alterations of glycogen concentrations and mitochondria respiration before the morphometric alterations should be detected.

Topics: Animals; Body Weight; Cardiomyopathy, Hypertrophic; Disease Models, Animal; Glycogen; Heart; Heart Arrest, Induced; Mitochondria, Heart; Myocardial Reperfusion Injury; Myocardium; Organ Size; Oxygen Consumption; Rabbits; Random Allocation; Statistics, Nonparametric

The argan tree plays an important socioeconomic and ecologic role in South Morocco. Moreover, there is much evidence for the beneficial effects of virgin argan oil (VAO) on human health. Thus, this study investigated whether administering VAO to rats can prevent the development of diabetes. VAO extracted by a traditional method from the almonds of Argania spinosa (2 mL/kg) was administered orally (for 7 consecutive days) to rats before and during intraperitoneal alloxan administration (75 mg/kg for 5 consecutive days). An alloxan diabetic-induced untreated group and treated by table oil were used as control groups. Body mass, blood glucose and hepatic glycogen were evaluated. In the present study, subchronic treatment with VAO at a dose of 2 mL/kg, before the experimental induction of diabetes, prevented the body mass loss, induced a significant reduction of blood glucose and a significant increase of hepatic glycogen level (p < 0.001) compared with the untreated diabetic group. In conclusion, the present study shows that argan oil should be further investigated in a human study to clarify its possible role in reducing weight loss in diabetics, and even in inhibiting the development or progression of diabetes. This antidiabetic effect could be due to the richness of VAO in tocopherols, phenolic compounds and unsaturated fatty acids.

Topics: Alloxan; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Glycogen; Hypoglycemic Agents; Plant Oils; Rats; Rats, Wistar; Sapotaceae

Perilipin 1 is involved in the control of adipose tissue triacylglycerol hydrolysis. Its ablation in mice decreases fat mass and induces a partial resistance to diet-induced and genetic obesity. However, the consequences of perilipin 1 invalidation on energy balance are not fully defined. Moreover, the impact of perilipin 1 ablation on exercise performance and on fatty acids mobilization and utilization during exercise has not been studied. We compared energy balance (food intake, energy expenditure, spontaneous physical activity) and response to exercise of Plin1(-/-) and wild-type mice receiving a chow diet. The Plin1(-/-) mice had less fat, comparable food intake, comparable or slightly decreased energy expenditure, and no change in spontaneous physical activity. Mean 24-hour respiratory quotient was slightly lower, suggesting enhanced fatty acid oxidation. Exercise performance (both acute and endurance) was not impaired. Changes in nonesterified fatty acid levels during exercise were comparable, showing that triacylglycerol mobilization was unimpaired. Oxygen consumption increased faster (both tests) and to higher values (acute exercise) in Plin1(-/-) mice. Respiratory quotient increased during both types of exercise in Plin1(-/-) and control mice, but less in Plin1(-/-) mice. These lower respiratory quotient values show that Plin1(-/-) mice rely more on fatty acid oxidation during exercise. This is probably related to an overexpression in liver and muscle of genes for fatty acids oxidation. Perilipin 1 ablation has limited consequences on energy balance. It does not impair exercise performance; fatty acids mobilization during exercise is not impaired, whereas their oxidation is enhanced.

Topics: Animals; Blood Glucose; Body Weight; Carrier Proteins; Energy Metabolism; Fasting; Glycogen; Lipid Metabolism; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Skeletal; Oxidation-Reduction; Perilipin-1; Phosphoproteins; Physical Endurance; Physical Exertion; RNA, Messenger; Running; Triglycerides

The antifatigue effect of bacoside extract (BME) from Bacopa monniera (L.) Wettst. was investigated. Rats were subjected to weight-loaded forced swim test (WFST) every alternate day for 3 weeks. The BME at a dosage of 10 mg/kg body weight was administered orally to rats for 2 weeks in order to evaluate the following biomarkers of physical fatigue: swimming time, change in body weight, lipid peroxidation, lactic acid (LA), glycogen, antioxidant enzyme activities such as superoxide dismutase (SOD) and catalase (CAT) and blood parameters, namely blood urea nitrogen (BUN) and creatine kinase (CK). The exhaustive swimming time was increased by 3-fold in the BME supplemented group compared with that of the control group on day 13. The BME treatment lowered malondialdehyde (MDA) levels in brain, liver and muscle tissues by 11.2%, 16.2% and 37.7%, respectively, compared with the control exercised group (p < 0.05). The BME also reduced the LA, serum BUN and CK activities significantly compared with that of the control. Administration of BME significantly protected the depletion of SOD and CAT activities. The HSP-70 expression studies by western blot also confirmed the antifatigue property of BME. The present study thus indicates that BME ameliorates the various impairments associated with physical fatigue.

Topics: Animals; Bacopa; Biomarkers; Blood Urea Nitrogen; Blotting, Western; Body Weight; Brain; Catalase; Drug Evaluation, Preclinical; Enzyme Activation; Fatigue; Glycogen; HSP70 Heat-Shock Proteins; Lactic Acid; Lipid Peroxidation; Liver; Male; Malondialdehyde; Muscles; Plant Extracts; Rats; Rats, Wistar; Superoxide Dismutase; Swimming; Time Factors

The aim of the study was to evaluate the impact of 2 isoenergetic growing diets with different CP (17 vs. 23%) on the performance and breast meat quality of 2 lines of chicken divergently selected for abdominal fatness [i.e., fat and lean (LL) lines]. Growth performance, breast and abdominal fat yields, breast meat quality parameters (pH, color, drip loss), and muscle glycogen storage at death were measured. Increased dietary CP resulted in increased BW, increased breast meat yield, and reduced abdominal fatness at slaughter regardless of genotype (P < 0.001). By contrast, dietary CP affected glycogen storage and the related meat quality parameters only in the LL chickens. Giving LL chickens the low-CP diet led to reduced concentration of muscle glycogen (P < 0.01), and as a result, breast meat with a higher (P < 0.001) ultimate pH, decreased (P < 0.001) lightness, and reduced (P < 0.001) drip loss during storage. The decreased muscle glycogen content observed in LL receiving the low-CP diet compared with the high-CP diet occurred concomitantly with greater phosphorylation amount for the α-catalytic subunit of adenosine monophosphate-activated protein kinase and glycogen synthase. This was consistent with the reduced muscle glycogen content observed in LL fed the low-CP diet because adenosine monophosphate-activated protein kinase inhibits glycogen synthesis through its action on glycogen synthase. Our results demonstrated that nutrition is an effective means of modulating breast meat properties in the chicken. The results also highlighted the need to take into account interaction with the genetic background of the animal to select nutritional strategies to improve meat quality traits in poultry.

Topics: Adenylate Kinase; Adipose Tissue; Animals; Blotting, Western; Body Weight; Chickens; Dietary Proteins; Female; Genotype; Glycogen; Glycogen Synthase; Male; Meat; Muscle, Skeletal; Selection, Genetic; Statistics, Nonparametric

The present study tested the hypothesis that long-term repeated exposure to stressors results in irreversible changes in carbohydrate metabolism. Groups of adult male rats (five per group) were restrained for 1 h and 4 h later were forced to swim for 15 min everyday for 2, 4, or 24 weeks; five rats were autopsied after each interval. Groups of five rats exposed to stress for 2 or 4 weeks were maintained without further treatment (recovery groups) for up to 24 weeks. The fasting blood glucose concentration, measured at weekly intervals, was significantly higher in the stressed rats than in controls throughout the experiment, except in the 24th week, whereas that of the recovery groups was significantly higher than controls only up to the 8th week after the end of stress exposure and then reached normalcy. The blood concentrations of glucose, lactate, and pyruvate were significantly higher in the 2 and 4 weeks stress groups than in controls, whereas, except for lactate, in rats stressed for 24 weeks these values did not significantly differ from those in controls. These changes were accompanied by increased gluconeogenesis and glycogenolysis as shown by alterations in activities of hepatic carbohydrate metabolizing enzymes and unaltered blood insulin concentrations in rats stressed for 2, 4, and 24 weeks. Furthermore, the blood insulin levels did not significantly vary among controls and the 2, 4, and 24 weeks stress groups. The results reveal that though hyperglycemia induced by long-term stress exposure is reversible, it persists for a prolonged period, even after the termination of stress exposure, before reaching normalcy. Prevalence of hyperglycemia for a prolonged period through increased activities of hepatic enzymes in stressed rats exemplifies allostasis.

Topics: 3-Hydroxysteroid Dehydrogenases; Adrenal Glands; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Chronic Disease; Gluconeogenesis; Glucose-6-Phosphatase; Glycogen; Insulin; Lactic Acid; Liver; Liver Glycogen; Male; Organ Size; Pyruvic Acid; Rats; Rats, Wistar; Recovery of Function; Restraint, Physical; Stress, Psychological; Transaminases

Zingiber officinale (ZO), commonly known as ginger, has been traditionally used in the treatment of diabetes mellitus. Several studies have reported the hypoglycaemic properties of ginger in animal models. The present study evaluated the antihyperglycaemic effect of its aqueous extract administered orally (daily) in three different doses (100, 300, 500 mg/kg body weight) for a period of 30 d to streptozotocin (STZ)-induced diabetic rats. A dose-dependent antihyperglycaemic effect revealed a decrease of plasma glucose levels by 38 and 68 % on the 15th and 30th day, respectively, after the rats were given 500 mg/kg. The 500 mg/kg ZO significantly (P<0·05) decreased kidney weight (% body weight) in ZO-treated diabetic rats v. control rats, although the decrease in liver weight (% body weight) was not statistically significant. Kidney glycogen content increased significantly (P<0·05) while liver and skeletal muscle glycogen content decreased significantly (P<0·05) in diabetic controls v. normal controls. ZO (500 mg/kg) also significantly decreased kidney glycogen (P<0·05) and increased liver and skeletal muscle glycogen in STZ-diabetic rats when compared to diabetic controls. Activities of glucokinase, phosphofructokinase and pyruvate kinase in diabetic controls were decreased by 94, 53 and 61 %, respectively, when compared to normal controls; and ZO significantly increased (P<0·05) those enzymes' activities in STZ-diabetic rats. Therefore, the present study showed that ginger is a potential phytomedicine for the treatment of diabetes through its effects on the activities of glycolytic enzymes.

Topics: Animals; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Type 1; Gluconeogenesis; Glycogen; Glycolysis; Hyperglycemia; Hypoglycemic Agents; Kidney; Lethal Dose 50; Liver; Male; Muscle, Skeletal; Organ Size; Phytotherapy; Plant Extracts; Rats; Rats, Sprague-Dawley; Rhizome; Streptozocin; Zingiber officinale

Combination therapy had become very popular currently for the diabetes mellitus and its complications, because of long term unreasonable drug use and adverse reaction to human body. In this study, a polysaccharide (ASP) from the roots of Acanthopanax senticosus was evaluated as an adjuvant with metformin for antidiabetic therapy in alloxan-induced diabetic rats. The result identified ASP plus metformin had a more beneficial promotion for relieving the symptoms of diabetes and reversing liver and kidney damage to normal level than only metfomin administration to diabetic rats. The blood glucose, blood lipid (TC and TG), thiobarbituric acid reactive substances (TBARS), AST, ALT, ALP, total bilirubin, creatinine and urea levels in diabetic rats were decreased by combination of ASP and metformin. Furthermore, the body weight, liver glycogen formation, antioxidant substance (GSH) and antioxidant enzyme (SOD and GPX) levels increased evidently in diabetic mice treated with both ASP and metformin. In particular, sometimes ASP plus metformin could significantly reverse the pathophysiologic parameters of diabetic rats to normal level than only metformin administration. Therefore ASP could be developed to a new adjuvant combined with metformin for diabetes mellitus therapy in the future.

Topics: Animals; Bilirubin; Blood Glucose; Body Weight; Creatinine; Diabetes Mellitus, Experimental; Drug Interactions; Eleutherococcus; Glutathione; Glycogen; Humans; Hypoglycemic Agents; Kidney; Lipids; Liver; Male; Metformin; Polysaccharides; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances; Urea

Activated carbon (AC) amendments to sediments were tested for nontoxic, secondary effects on survival, weight change, and energetic biomarkers of the deposit feeder Neanthes arenaceodentata. The tests employed silica sand, reference sediments, and contaminated sediments. Survival was not affected by the sediment type, the AC dose (20% versus 5%), or the AC particle size. Without additional food supply, exposure to untreated and AC-amended sediments resulted in similar reduction of weight and lipid content, with no difference between ingestible and noningestible AC. Overall, whether with or without AC, the organisms showed signs of starvation, as the organisms would most likely rely on organic surface deposits for their diet in the environments from which the sediments were collected. When additional food was supplied, the organisms grew significantly and maintained higher lipid and glycogen contents. However, when feeding on fish food, organisms grew less in AC amendments with slightly lower lipid and glycogen contents relative to organisms exposed to untreated sediment. Batch tests show that AC did not sorb sediment-associated nitrogen but sorbed nitrogen from fish food. Despite some effects of AC on these deposit feeders, absolute effects of AC amendments on growth and energy reserves were not significant.

Topics: Adsorption; Animals; Biological Assay; Biomarkers; Body Weight; Charcoal; Energy Metabolism; Environmental Restoration and Remediation; Feeding Behavior; Geologic Sediments; Glycogen; Lipid Metabolism; Polychaeta; Proteins; Survival Analysis

The aim of the present investigation was to evaluate the anti-diabetic activity of 20-OH-ecdysone on glucose metabolic key enzymes in control and streptozotocin induced diabetic rats. On oral administration of 20-OH-ecdysone at a dose of 5mg/kg body weight per day to diabetic rats for 30 days resulted in a significant decrease in the levels of plasma glucose, glycosylated hemoglobin (HbA1c) and an increase in the levels of insulin and hemoglobin. Administration of 20-OH-ecdysone showed significant increase in the levels of glycolytic enzyme (hexokinase) and hepatic shunt enzyme (glucose-6-phosphate dehydrogenase) whereas significant decrease in the levels of gluconeogenic enzymes (glucose-6-phosphatase and fructose-1,6-bisphosphatase) in diabetic treated rats. Furthermore, protection against body weight loss of diabetic animals also observed. This study indicates that the administration of 20-OH-ecdysone to diabetic rats resulted in alterations in the metabolism of glucose with subsequent reduction in plasma glucose levels. A comparison was made between the action of 20-OH-ecdysone and antidiabetic drug-glibenclamide. The effects produced by the 20-OH-ecdysone were comparable to that of glibenclamide.

Topics: Administration, Oral; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Drinking; Eating; Ecdysterone; Enzymes; Fructose-Bisphosphatase; Glucose-6-Phosphatase; Glucosephosphate Dehydrogenase; Glycated Hemoglobin; Glycogen; Hexokinase; Hypoglycemic Agents; Rats; Streptozocin; Vitex

This study investigated the effects of resveratrol (RV) on diabetes-related metabolic changes in a spontaneous model of type 2 diabetes, as well as activation of AMP-activated protein kinase (AMPK) and downstream targets.. C57BL/KsJ-db/db mice were fed a normal diet with RV (0.005% and 0.02%, w/w) or rosiglitazone (RG, 0.001%, w/w) for 6 weeks. Both doses of RV significantly decreased blood glucose, plasma free fatty acid, triglyceride, apo B/apo AІ levels and increased plasma adiponectin levels. RV activated AMPK and downstream targets leading to decreased blood HbA1c levels, hepatic gluconeogenic enzyme activity, and hepatic glycogen, while plasma insulin levels, pancreatic insulin protein, and skeletal muscle GLUT4 protein were higher after RV supplementation. The high RV dose also significantly increased hepatic glycolytic gene expression and enzyme activity, along with skeletal muscle glycogen synthase protein expression, similar to RG. Furthermore, RV dose dependently decreased hepatic triglyceride content and phosphorylated I kappa B kinase (p-IKK) protein expression, while hepatic uncoupling protein (UCP) and skeletal muscle UCP expression were increased.. RV potentiates improving glycemic control, glucose uptake, and dyslipidemia, as well as protecting against pancreatic β-cell failure in a spontaneous type 2 diabetes model. Dietary RV has potential as an antidiabetic agent via activation of AMPK and its downstream targets.

Topics: Adiponectin; AMP-Activated Protein Kinases; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dietary Supplements; Dyslipidemias; Glucose Transporter Type 4; Glycated Hemoglobin; Glycogen; Insulin; Insulin Secretion; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Muscle, Skeletal; Resveratrol; Rosiglitazone; Stilbenes; Thiazolidinediones; Triglycerides

This study evaluated the effect of eye muscle area (EMA), ossification, carcass weight, marbling and rib fat depth on the incidence of dark cutting (pH(u)>5.7) using routinely collected Meat Standards Australia (MSA) data. Data was obtained from 204,072 carcasses at a Western Australian processor between 2002 and 2008. Binomial data of pH(u) compliance was analysed using a logit model in a Bayesian framework. Increasing eye muscle area from 40 to 80 cm², increased pH(u) compliance by around 14% (P<0.001) in carcasses less than 350 kg. As carcass weight increased from 150 kg to 220 kg, compliance increased by 13% (P<0.001) and younger cattle with lower ossification were also 7% more compliant (P<0.001). As rib fat depth increased from 0 to 20mm, pH(u) compliance increased by around 10% (P<0.001) yet marbling had no effect on dark cutting. Increasing musculature and growth combined with good nutrition will minimise dark cutting beef in Australia.

Topics: Adiposity; Animals; Australia; Body Composition; Body Weight; Calcification, Physiologic; Cattle; Dietary Fats; Female; Food Inspection; Food Quality; Glycogen; Hydrogen-Ion Concentration; Legislation, Food; Male; Meat; Models, Biological; Muscle, Skeletal; Musculoskeletal Development; Spine; Subcutaneous Fat, Abdominal; Western Australia

In this paper, the composition and biological activities of polysaccharides from Inula britannica flower IBP obtained by water extraction were investigated. The properties and chemical compositions of IBP were analyzed with HPLC and IR methods. The results showed that IBP consisted of two kinds of polysaccharides with the molecular weight of 3500 Da, 700 Da. IBP consisted of mannose, glucuronic acid, rhamnose, galacturonic acid, glucose, galactose, arabinose with a molar ratio of 4.1:1:1.4:2.7:14.6:6.3:7.9. The IR spectrum of IBP revealed the typical characteristics of polysaccharides and protein. IBP was administered orally at three doses [100, 200 and 400 mg/kg body weight] for 14 days to the diabetic mice induced by alloxan. The body weight, plasma glucose, serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and liver glycogen were evaluated in normal and alloxan-induced diabetic mice. IBP could dose-dependently significantly increase the body weight of diabetic mice, and reverse the decrease of plasma glucose, glycogen and the decrease of blood lipid of diabetic mice as compared to those in control group. These results indicated that IBP could be developed to a potential anti-diabetic drug in the future.

Topics: Animals; Blood Glucose; Body Weight; Cholesterol; Diabetes Mellitus, Experimental; Flowers; Glycogen; Hypoglycemic Agents; Inula; Male; Mice; Mice, Inbred ICR; Molecular Weight; Monosaccharides; Polysaccharides; Triglycerides

We have investigated molecular mechanisms for muscle mass accretion in a non-inbred mouse model (DU6P mice) characterized by extreme muscle mass. This extreme muscle mass was developed during 138 generations of phenotype selection for high protein content. Due to the repeated trait selection a complex setting of different mechanisms was expected to be enriched during the selection experiment. In muscle from 29-week female DU6P mice we have identified robust increases of protein kinase B activation (AKT, Ser-473, up to 2-fold) if compared to 11- and 54-week DU6P mice or controls. While a number of accepted effectors of AKT activation, including IGF-I, IGF-II, insulin/IGF-receptor, myostatin or integrin-linked kinase (ILK), were not correlated with this increase, phosphatase and tensin homologue deleted on chromosome 10 (PTEN) was down-regulated in 29-week female DU6P mice. In addition, higher levels of PTEN phosphorylation were found identifying a second mechanism of PTEN inhibition. Inhibition of PTEN and activation of AKT correlated with specific activation of p70S6 kinase and ribosomal protein S6, reduced phosphorylation of eukaryotic initiation factor 2α (eIF2α) and higher rates of protein synthesis in 29-week female DU6P mice. On the other hand, AKT activation also translated into specific inactivation of glycogen synthase kinase 3ß (GSK3ß) and an increase of muscular glycogen. In muscles from 29-week female DU6P mice a significant increase of protein/DNA was identified, which was not due to a reduction of protein breakdown or to specific increases of translation initiation. Instead our data support the conclusion that a higher rate of protein translation is contributing to the higher muscle mass in mid-aged female DU6P mice. Our results further reveal coevolution of high protein and high glycogen content during the selection experiment and identify PTEN as gate keeper for muscle mass in mid-aged female DU6P mice.

Topics: Animals; Body Weight; Enzyme Activation; Evolution, Molecular; Female; Glycogen; Immunohistochemistry; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Mice; Models, Biological; Muscles; Organ Size; Phenotype; Protein Biosynthesis; Proteolysis; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Substrate Specificity; Tissue Extracts

The aim of the present study is to investigate the antidiabetic properties of oligosaccharides of Ophiopogonis japonicus (OOJ) in experimental type 2 diabetic rats. OOJ was administered orally in doses of 225 and 450 mg/kg body weight to high-fat diet and low-dose streptozotocin (STZ)-induced type 2 diabetic rats for 3 weeks. The results showed that OOJ treatment could increase body weight, decrease organ related weights of liver and kidney, reduce fasting blood glucose level, and improve oral glucose tolerance in diabetic rats. Moreover, increased glycogen content in liver and skeletal muscle, reduced urinary protein excretion, higher hepatic GCK enzyme activity, lower hepatic PEPCK enzyme activity, enhanced GLP-1 level, decreased glucagon level and alleviated histopathological changes of pancreas occurred in OOJ-treated diabetic rats by comparison with untreated diabetic rats. This study demonstrates, for the first time to our knowledge, that OOJ exerts remarkable antidiabetic effect in experimental type 2 diabetes mellitus, thus justifying its traditional usage.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Fasting; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycogen; Hypoglycemic Agents; Liver; Male; Muscle, Skeletal; Oligosaccharides; Ophiopogon; Organ Size; Proteinuria; Rats; Rats, Sprague-Dawley

This work investigated the effects of copper as preventive treatment against mercury-induced alterations in young rats. Wistar rats were treated (subcutaneous) with saline or CuCl(2) · 2H(2) O (6.9 mg/kg/day) from 3 to 7 days old and with saline or HgCl(2) (5.0 mg/kg/day) from 8 to 12 days old. Rats were sacrificed 24 h after the last dose. Mercury-exposed rats presented inhibition of liver (43%) and kidney (52%) porphobilinogen (PBG)-synthase activity and serum lactic dehydrogenase activity (50%). Also, an increase of the serum creatinine and urea levels around threefold and fivefold was observed, respectively. Pre-exposure to copper partially prevented the mercury effect on liver but not on kidney PBG synthase, and prevented the increase of the creatinine levels. Blood and brain PBG synthase and serum alanineaminotransferase activities, as well as glycemia, and liver glycogen content were not altered by treatments. These results show that copper, although being an essential metal, is inefficient as a preventive agent against mercury poisoning in parameters investigated after the end of mercury exposure.

Topics: Animals; Animals, Newborn; Anoctamins; Blood Glucose; Blood Urea Nitrogen; Body Weight; Brain; Chloride Channels; Copper; Creatinine; Dose-Response Relationship, Drug; Glycogen; Kidney; Liver; Mercuric Chloride; Organ Size; Porphobilinogen Synthase; Protective Agents; Rats, Wistar

Climate change is causing winters to become milder (less cold and shorter). Recent studies of overwintering ectotherms have suggested that warmer winters increase metabolism and decrease winter survival and subsequent fecundity. Energetic constraints (insufficient energy stores) have been hypothesized as the cause of winter mortality but have not been tested explicitly. Thus, alternative sources of mortality, such as winter dehydration, cannot be ruled out. By employing an experimental design that compared the energetics and water content of lizards that died naturally during laboratory winter with those that survived up to the same point but were then sacrificed, we attempt to distinguish among multiple possible causes of mortality. We test the hypothesis that mortality is caused by insufficient energy stores in the liver, abdominal fat bodies, tail or carcass or through excessive water loss. We found that lizards that died naturally had marginally greater mass loss, lower water content, and less liver glycogen remaining than living animals sampled at the same time. Periodically moistening air during winter reduced water loss, but this did not affect survival, calling into question dehydration as a cause of death. Rather, our results implicate energy limitations in the form of liver glycogen, but not lipids, as the primary cause of mortality in overwintering lizards. When viewed through a lens of changing climates, our results suggest that if milder winters increase the metabolic rate of overwintering ectotherms, individuals may experience greater energetic demands. Increased energy use during winter may subsequently limit individual survival and possibly even impact population persistence.

Topics: Animals; Body Weight; Cold Temperature; Dehydration; Energy Metabolism; Female; Glycogen; Lipid Metabolism; Liver; Lizards; Male; Models, Biological; Seasons; Survival Analysis

Genomic imprinting refers to parent-of-origin dependent gene expression caused by differential DNA methylation of the paternally and maternally derived alleles. Imprinting is increasingly recognized as an important source of variation in complex traits, however, its role in explaining variation in muscle and physiological traits, especially those of commercial value, is largely unknown compared with genetic effects.. We investigated both genetic and genomic imprinting effects on key muscle traits in mice from the Berlin Muscle Mouse population, a key model system to study muscle traits. Using a genome scan, we first identified loci with either imprinting or genetic effects on phenotypic variation. Next, we established the proportion of phenotypic variation explained by additive, dominance and imprinted QTL and characterized the patterns of effects. In total, we identified nine QTL, two of which show large imprinting effects on glycogen content and potential, and body weight. Surprisingly, all imprinting patterns were of the bipolar type, in which the two heterozygotes are different from each other but the homozygotes are not. Most QTL had pleiotropic effects and explained up to 40% of phenotypic variance, with individual imprinted loci accounting for 4-5% of variation alone.. Surprisingly, variation in glycogen content and potential was only modulated by imprinting effects. Further, in contrast to general assumptions, our results show that genomic imprinting can impact physiological traits measured at adult stages and that the expression does not have to follow the patterns of paternal or maternal expression commonly ascribed to imprinting effects.

Topics: Animals; Body Weight; Genomic Imprinting; Glycogen; Mice; Muscles; Quantitative Trait Loci

There is a strong inverse relationship between a females own birth weight and her subsequent risk for gestational diabetes with increased risk of developing diabetes later in life. We have shown that growth restricted females develop loss of glucose tolerance during late pregnancy with normal pancreatic function. The aim of this study was to determine whether growth restricted females develop long-term impairment of metabolic control after an adverse pregnancy adaptation. Uteroplacental insufficiency was induced by bilateral uterine vessel ligation (Restricted) or sham surgery (Control) in late pregnancy (E18) in F0 female rats. F1 Control and Restricted female offspring were mated with normal males and allowed to deliver (termed Ex-Pregnant). Age-matched Control and Restricted Virgins were also studied and glucose tolerance and insulin secretion were determined. Pancreatic morphology and hepatic glycogen and triacylglycerol content were quantified respectively. Restricted females were born lighter than Control and remained lighter at all time points studied (p<0.05). Glucose tolerance, first phase insulin secretion and liver glycogen and triacylglycerol content were not different across groups, with no changes in β-cell mass. Second phase insulin secretion was reduced in Restricted Virgins (-34%, p<0.05) compared to Control Virgins, suggestive of enhanced peripheral insulin sensitivity but this was lost after pregnancy. Growth restriction was associated with enhanced basal hepatic insulin sensitivity, which may provide compensatory benefits to prevent adverse metabolic outcomes often associated with being born small. A prior pregnancy was associated with reduced hepatic insulin sensitivity with effects more pronounced in Controls than Restricted. Our data suggests that pregnancy ameliorates the enhanced peripheral insulin sensitivity in growth restricted females and has deleterious effects for hepatic insulin sensitivity, regardless of maternal birth weight.

Topics: Adult; Animals; Animals, Newborn; Blood Glucose; Body Weight; Diabetes, Gestational; Female; Glucose Tolerance Test; Glycogen; Humans; Infant, Low Birth Weight; Infant, Newborn; Insulin; Insulin Resistance; Insulin-Secreting Cells; Liver; Male; Models, Biological; Placental Insufficiency; Pregnancy; Pregnancy, Animal; Rats; Risk; Triglycerides

Pumpkin (Cucurbita moschata) is a popular and nutritious vegetable consumed worldwide. The overall purpose of this study was to evaluate the effects of C. moschata fruit extract (CME) on anti-fatigue and ergogenic functions following physiological challenges. Male ICR mice from four groups designated vehicle, CME-50, CME-100 and CME-250, respectively (n = 8 per group in each test) were orally administered CME for 14 days at 0, 50, 100 and 250 mg/kg/day. The anti-fatigue activity and exercise performance were evaluated using exhaustive swimming time, forelimb grip strength, as well as levels of plasma lactate, ammonia, glucose, and creatine kinase after an acute swimming exercise. The resting muscular and hepatic glycogen was also analyzed after 14-day supplementation with CME. Trend analysis revealed that CME treatments increased grip strength. CME dose-dependently increased 5% body weight loaded swimming time, blood glucose, and muscular and hepatic glycogen levels. CME dose-dependently decreased plasma lactate and ammonia levels and creatine kinase activity after a 15-min swimming test. The mechanism was relevant to the increase in energy storage (as glycogen) and release (as blood glucose), and the decrease of plasma levels of lactate, ammonia, and creatine kinase. Therefore, CME may be potential for the pharmacological effect of anti-fatigue.

Topics: Animals; Body Weight; Cucurbita; Fatigue; Fruit; Glycogen; Hand Strength; Liver; Male; Mice; Muscle, Skeletal; Organ Size; Physical Conditioning, Animal; Plant Extracts

A series of Pd(II) and Pt(II) complexes with two N(∩)S donor ligands, 5-chloro-3-(indolin-2-one)benzothiazoline and 6-nitro-3-(indolin-2-one)benzothiazoline, have been synthesized by the reaction of metal chlorides (PdCl2 and PtCl2) with ligands in 1:2 molar ratios. All the synthesized compounds were characterized by elemental analyses, melting point determinations and a combination of electronic, IR, 1H NMR and 13C NMR spectroscopic techniques for structure elucidation. In order to evaluate the effect of metal ions upon chelation, both the ligands and their complexes have been screened for their antimicrobial activity against the various pathogenic bacterial and fungal strains. The metal complexes have shown to be more antimicrobial against the microbial species as compared to free ligands. One of the ligands, 5-chloro-3-(indolin-2-one)benzothiazoline and its corresponding palladium and platinum complexes have been tested for their antifertility activity in male albino rats. The marked reduction in sperm motility and density resulted in infertility by 62-90%. Significant alterations were found in biochemical parameters of reproductive organs in treated animals as compared to control group. It is concluded that all these effects may finally impair the fertility of male rats.

Topics: Animals; Anti-Infective Agents; Antispermatogenic Agents; Bacteria; Benzothiazoles; Body Weight; Cholesterol; Electrons; Fertility; Fructose; Fungi; Glycogen; Ligands; Magnetic Resonance Spectroscopy; Male; Microbial Sensitivity Tests; N-Acetylneuraminic Acid; Organ Size; Palladium; Platinum; Rats; Rats, Wistar; Spectrophotometry, Infrared; Sperm Motility

People living at high altitude appear to have lower blood glucose levels and decreased incidence of diabetes. Faster glucose uptake and increased insulin sensitivity are likely explanations for these findings: skeletal muscle is the largest glucose sink in the body, and its adaptation to the hypoxia of altitude may influence glucose uptake and insulin sensitivity. This study tested the hypothesis that chronic normobaric hypoxia increases insulin-stimulated glucose uptake in soleus muscles and decreases plasma glucose levels. Adult male C57BL/6J mice were kept in normoxia [fraction of inspired O₂ = 21% (Control)] or normobaric hypoxia [fraction of inspired O₂ = 10% (Hypoxia)] for 4 wk. Then blood glucose and insulin levels, in vitro muscle glucose uptake, and indexes of insulin signaling were measured. Chronic hypoxia lowered blood glucose and plasma insulin [glucose: 14.3 ± 0.65 mM in Control vs. 9.9 ± 0.83 mM in Hypoxia (P < 0.001); insulin: 1.2 ± 0.2 ng/ml in Control vs. 0.7 ± 0.1 ng/ml in Hypoxia (P < 0.05)] and increased insulin sensitivity determined by homeostatic model assessment 2 [21.5 ± 3.8 in Control vs. 39.3 ± 5.7 in Hypoxia (P < 0.03)]. There was no significant difference in basal glucose uptake in vitro in soleus muscle (1.59 ± 0.24 and 1.71 ± 0.15 μmol·g⁻¹·h⁻¹ in Control and Hypoxia, respectively). However, insulin-stimulated glucose uptake was 30% higher in the soleus after 4 wk of hypoxia than Control (6.24 ± 0.23 vs. 4.87 ± 0.37 μmol·g⁻¹·h⁻¹, P < 0.02). Muscle glycogen content was not significantly different between the two groups. Levels of glucose transporters 4 and 1, phosphoinositide 3-kinase, glycogen synthase kinase 3, protein kinase B/Akt, and AMP-activated protein kinase were not affected by chronic hypoxia. Akt phosphorylation following insulin stimulation in soleus muscle was significantly (25%) higher in Hypoxia than Control (P < 0.05). Neither glycogen synthase kinase 3 nor AMP-activated protein kinase phosphorylation changed after 4 wk of hypoxia. These results demonstrate that the adaptation of skeletal muscles to chronic hypoxia includes increased insulin-stimulated glucose uptake.

Topics: Altitude; AMP-Activated Protein Kinase Kinases; Animals; Blood Glucose; Body Weight; Glucose; Glycogen; Hematocrit; Hypoglycemic Agents; Hypoxia; Insulin; Male; Mice; Mice, Inbred C57BL; Models, Animal; Muscle, Skeletal; Protein Kinases; Proto-Oncogene Proteins c-akt

Resistance exercise such as weight-lifting (WL) increases oxidation products in plasma, but less is known regarding the effect of WL on oxidative damage to tissues. Dietary compounds are known to improve antioxidant defences. Whey protein (WP) is a source of protein in a variety of sport supplements and can enhance physical performance.. To evaluate the effect of WL on biomarkers of lipid and protein oxidation, on liver antioxidants and on muscle growth in the absence or presence of WP in rats.. Thirty-two male Fisher rats were randomly assigned to sedentary or exercise-trained groups and were fed with control or WP diets. The WL programme consisted of inducing the animals to perform sets of jumps with weights attached to the chest. After 8 weeks, arteriovenous blood samples, abdominal fat, liver and gastrocnemius muscle were collected for analysis.. WP precludes WL-mediated increases in muscle protein carbonyl content and maintains low levels of TBARS in exercised and sedentary animals. WL reduced liver CAT activity, whereas WP increased hepatic glutathione content. In addition, WL plus WP generated higher body and muscle weight than exercise without WP.. These data suggest that WP improves antioxidant defences, which contribute to the reduction of lipid and protein oxidation as well as body and muscle weight gain in resistance-exercised rats.

Topics: Abdominal Fat; Animals; Antioxidants; Biomarkers; Body Weight; Catalase; Diet; Glutathione; Glycogen; Lipid Metabolism; Liver; Male; Milk Proteins; Muscle, Skeletal; Oxidation-Reduction; Physical Conditioning, Animal; Rats; Resistance Training; Thiobarbituric Acid Reactive Substances; Weight Gain; Whey Proteins

Regulation of energy homeostasis is mainly mediated by factors in the hypothalamus and the brainstem. Understanding these regulatory mechanisms is of great clinical relevance in the treatment of obesity and related diseases. The homeobox gene Sax2 is expressed predominantly in the brainstem, in the vicinity of serotonergic neurons, and in the ventral neural tube starting during early development. Previously, we have shown that the loss of function of the Sax2 gene in mouse causes growth retardation starting at birth and a high rate of postnatal lethality, as well as a dramatic metabolic phenotype. To further define the role of Sax2 in energy homeostasis, age-matched adult wild-type, Sax2 heterozygous and null mutant animals were exposed to a high-fat diet. Although food uptake among the different groups was comparable, Sax2 null mutants fed a high-fat diet exhibited a significantly lower weight gain compared to control animals. Unlike their counterparts, Sax2 null mutants did not develop insulin resistance and exhibited significantly lower leptin levels under both standard chow and high-fat diet conditions. Furthermore, neuropeptide Y, an important regulator of energy homeostasis, was significantly decreased in the forebrain of Sax2 null mutants on a high-fat diet. These data strongly suggest a critical role for Sax2 gene expression in diet-induced obesity. Sax2 gene expression may be required to allow the coordinated crosstalk of factors involved in the maintenance of energy homeostasis, possibly regulating the transcription of specific factors involved in energy balance.

Topics: Adipose Tissue, Brown; Adipose Tissue, White; Animals; Blood Glucose; Body Temperature; Body Weight; Brain; Dietary Fats; Eating; Energy Metabolism; Female; Gene Expression; Glycogen; Heterozygote; Homeodomain Proteins; Insulin; Leptin; Lipid Metabolism; Liver; Male; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Mice, Mutant Strains; Neuropeptide Y; Nuclear Proteins; Obesity; Pro-Opiomelanocortin; Serotonin; Sex Characteristics; Transcription Factors

In sheep, central leptin infusion reduces food intake and increases energy expenditure in adipose tissue and skeletal muscle. The mechanisms for these peripheral effects of central leptin in sheep are not known but, on the basis of rodent studies, may involve AMPK. In mice, central leptin acutely increases both skeletal muscle AMPK activation and glucose uptake. Thus, to investigate whether these effects exist in higher-order mammals, ovariectomized Corriedale ewes (n = 4 per group) received a continuous lateral ventricular infusion (60 μl/h) of either leptin (50 μg/h) or artificial cerebrospinal fluid (aCSF; CON) for 8 days. Tritiated glucose (3-(3)H-glucose) was infused intravenously for calculation of whole body glucose turnover during both acute (6 h) and chronic (7-8 days) leptin/aCSF infusion. Muscle biopsies were also obtained. Leptin infusion reduced (P < 0.05) food intake and body weight, and it also increased plasma epinephrine concentration at 6 h and 7 days, suggesting increased sympathetic nerve activity. Despite this, and in contrast to rodent studies, central leptin infusion did not increase skeletal muscle AMPKα Thr(172) phosphorylation or ACCβ Ser(221) phosphorylation. Surprisingly, the glucose rate of appearance (glucose Ra) and rate of disappearance (glucose Rd) were reduced by both acute and chronic leptin infusion. Direct infusion of the AMPK activator 5-aminoimidazole-4-carboxyamide-ribonucleoside (AICAR) into the femoral artery increased skeletal muscle AMPK phosphorylation. In conclusion, although central leptin infusion in sheep caused the predicted reduction in food intake and increases plasma epinephrine concentration, it had no effect on AMPK activation in skeletal muscle and actually reduced glucose disposal. This suggests that there are species differences in the peripheral responses to central leptin infusion.

Topics: Acetyl-CoA Carboxylase; Aminoimidazole Carboxamide; AMP-Activated Protein Kinases; Animal Structures; Animals; Blood Glucose; Body Weight; Catecholamines; Eating; Fatty Acids, Nonesterified; Female; Glycerol; Glycogen; Growth Hormone; Hydrocortisone; Hypoglycemic Agents; Infusions, Intra-Arterial; Infusions, Intraventricular; Insulin; Leptin; Liver; Muscle, Skeletal; Ovariectomy; Phosphorylation; Protein Subunits; Ribonucleotides; Sheep; Signal Transduction; Subcutaneous Fat

Advanced HF (heart failure) is associated with altered substrate metabolism. Whether modification of substrate use improves the course of HF remains unknown. The antihyperglycaemic drug MET (metformin) affects substrate metabolism, and its use might be associated with improved outcome in diabetic HF. The aim of the present study was to examine whether MET would improve cardiac function and survival also in non-diabetic HF. Volume-overload HF was induced in male Wistar rats by creating ACF (aortocaval fistula). Animals were randomized to placebo/MET (300 mg·kg(-1) of body weight·day(-1), 0.5% in food) groups and underwent assessment of metabolism, cardiovascular and mitochondrial functions (n=6-12/group) in advanced HF stage (week 21). A separate cohort served for survival analysis (n=10-90/group). The ACF group had marked cardiac hypertrophy, increased LVEDP (left ventricular end-diastolic pressure) and lung weight confirming decompensated HF, increased circulating NEFAs (non-esterified 'free' fatty acids), intra-abdominal fat depletion, lower glycogen synthesis in the skeletal muscle (diaphragm), lower myocardial triacylglycerol (triglyceride) content and attenuated myocardial (14)C-glucose and (14)C-palmitate oxidation, but preserved mitochondrial respiratory function, glucose tolerance and insulin sensitivity. MET therapy normalized serum NEFAs, decreased myocardial glucose oxidation, increased myocardial palmitate oxidation, but it had no effect on myocardial gene expression, AMPK (AMP-activated protein kinase) signalling, ATP level, mitochondrial respiration, cardiac morphology, function and long-term survival, despite reaching therapeutic serum levels (2.2±0.7 μg/ml). In conclusion, MET-induced enhancement of myocardial fatty acid oxidation had a neutral effect on cardiac function and survival. Recently reported cardioprotective effects of MET may not be universal to all forms of HF and may require AMPK activation or ATP depletion. No increase in mortality on MET supports its safe use in diabetic HF.

Topics: AMP-Activated Protein Kinase Kinases; Animals; Blood Glucose; Body Weight; Disease Models, Animal; Drug Evaluation, Preclinical; Glycogen; Heart Failure; Hemodynamics; Hypoglycemic Agents; Lipid Metabolism; Lung; Male; Metformin; Mitochondria, Heart; Myocardium; Organ Size; Protein Kinases; Rats; Rats, Wistar; Survival Analysis; Ultrasonography

Angelica acutiloba root (Japanese Dong Quai), used for treatment of gynecological disorders, is currently cultivated in Taiwan. The present study evaluated the preventative effect of Angelica acutiloba root (Japanese Dong Quai) on the induction of insulin resistance. Insulin resistance was induced in rats by feeding a high fructose diet for 6 weeks. Thereafter, the rats were maintained on the same diet and treated with oral A. acutiloba root extract or pioglitazone once daily for 8 weeks. At the end of treatment, the degree of basal insulin resistance was measured by homeostasis model assessment (HOMA-IR). Insulin sensitivity was calculated using the composite whole body insulin sensitivity index (ISIcomp). Protein expression was evaluated by immunoblotting. A. acutiloba (300 mg/kg/day) displayed similar characteristics to pioglitazone (20 mg/kg/day) in reducing HOMA-IR and elevating ISIcomp. Elevated glycosylated hemoglobin levels and hyperinsulinemia were ameliorated by A. acutiloba treatment without hepatotoxic or nephrotoxic effects. A. acutiloba treatment improved dyslipidemia, induced lipoprotein lipase activity and enhanced hepatic glycogen accumulation. Further, A. acutiloba treatment enhanced the action of insulin on muscle glucose transporter subtype 4 translocation and attenuated hepatic phosphoenolpyruvate carboxykinase expression. The findings suggest that A. acutiloba may be an effective ethnomedicine for improving insulin sensitivity.

Topics: Angelica; Animals; Body Weight; Fructose; Glucose Tolerance Test; Glucose Transporter Type 4; Glycogen; Homeostasis; Hypoglycemic Agents; Insulin Resistance; Intracellular Signaling Peptides and Proteins; Lipids; Liver; Male; Phosphoenolpyruvate Carboxykinase (GTP); Pioglitazone; Plant Extracts; Plant Roots; Rats, Wistar; Thiazolidinediones

Past studies have suggested that the stress-induced GLUT4 localization pathway is damaged in fast-twitch muscles (white muscles) of obese subjects. In this study, we used obese rodents in an attempt to determine whether the stress-induced GLUT4 localization pathway is abnormal in slow-twitch muscles (red muscles), which are responsible for most daily activities. Protein expression levels of the intracellular stress sensor AMP-activated protein kinase (AMPK), its upstream kinase LKB1, its downstream protein AS160 and the glucose transporter protein 4 (GLUT4) in the red gastrocnemius muscle were measured under either resting or stress conditions (1 h of swimming or 14% hypoxia) in both lean and obese Zucker rats (n = 7 for each group). At rest, obese rats displayed higher fasting plasma insulin levels and increased muscle AMPK and AS160 phosphorylation levels compared with lean controls. No significant difference was found in the protein levels of LKB1, total GLUT4, or membrane GLUT4 between the obese and lean control groups. After one hour of swimming, AMPK and AS160 phosphorylation levels and the amount of GLUT4 translocated to the plasma membrane were significantly elevated in lean rats but remained unchanged in obese rats relative to their resting conditions. One hour 14% hypoxia did not cause significant changes in the LKB1-AMPK-AS160-GLUT4 pathway in either lean or obese rats. This study demonstrated that the AMPK-AS160-GLUT4 pathway was altered at basal levels and after exercise stimulation in the slow-twitch muscle of obese Zucker rats.

Topics: Adenylate Kinase; AMP-Activated Protein Kinase Kinases; Animals; Blood Glucose; Body Weight; Glucose Transporter Type 4; Glycogen; GTPase-Activating Proteins; Hypoxia; Insulin; Male; Muscle Fibers, Slow-Twitch; Obesity; Phosphorylation; Physical Exertion; Protein Serine-Threonine Kinases; Protein Transport; Rats; Rats, Zucker; Stress, Physiological

Substrate imbalance is a well-recognized feature of diabetic cardiomyopathy. Insulin resistance effectively limits carbohydrate oxidation, resulting in abnormal cardiac glycogen accumulation. Aims of the present study were to 1) characterize the role of glycogen-associated proteins involved in excessive glycogen accumulation in type 2 diabetic hearts and 2) determine if exercise training can attenuate abnormal cardiac glycogen accumulation. Control (db(+)) and genetically diabetic (db/db) C57BL/KsJ-lepr(db)/lepr(db) mice were subjected to sedentary or treadmill exercise regimens. Exercise training consisted of high-intensity/short-duration (10 days) and low-intensity/long-duration (6 wk) protocols. Glycogen levels were elevated by 35-50% in db/db hearts. Exercise training further increased (2- to 3-fold) glycogen levels in db/db hearts. Analysis of soluble and insoluble glycogen pools revealed no differential accumulation of one glycogen subspecies. Phosphorylation (Ser(640)) of glycogen synthase, an indicator of enzymatic fractional activity, was greater in db/db mice subjected to sedentary and exercise regimens. Elevated glycogen levels were accompanied by decreased phosphorylation (Thr(172)) of 5'-AMP-activated kinase and phosphorylation (Ser(79)) of its downstream substrate acetyl-CoA carboxylase. Glycogen concentration was not associated with increases in other glycogen-associated proteins, including malin and laforin. Novel observations show that exercise training does not correct diabetes-induced elevations in cardiac glycogen but, rather, precipitates further accumulation.

Topics: Animals; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Exercise Therapy; Glycogen; Glycogen Storage Disease Type IIb; Mice; Mice, Inbred C57BL; Mice, Transgenic; Myocardium; Physical Conditioning, Animal; Receptors, Leptin

Potentilla alba L. (Rosaceae) rhizomes have anti-inflammatory, antioxidant, and adaptogenic effects and are used for the treatment of diarrhea and intestinal colic. However, the data concerning the adaptogenic and central nervous system activities of P. alba are fragmentary.. To determine the effect of oral administration of dried P. alba extract on the swimming endurance, light/dark exploration, and open-field tests for mice.. The mice were orally administered Rhodiola rosea extract (RR group); dry extract of P. alba at doses of 12, 36, or 72 mg/kg (groups: PA12, PA36, and PA72); or distilled water (control group) for 7 consecutive days.. The swimming times of the RR, PA36, and PA72 groups were significantly longer than those of the control group. The administration of P. alba significantly increased the light time, latency time, and the number of rearings in a dose-dependent manner. In the open-field test, the P. alba extract at a dose of 12 mg/kg produced a significant increase in the frequency of head dipping and the number of squares crossed and a significant decrease in grooming compared with the control treatment.. The current findings demonstrate that P. alba extracts significantly increased swimming endurance time and have anxiolytic-like action with a predominant locomotor component.

Topics: Adaptation, Psychological; Animals; Anti-Anxiety Agents; Behavior, Animal; Blood Glucose; Body Weight; Central Nervous System; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Evaluation, Preclinical; Glycogen; Lactic Acid; Male; Mice; Mice, Inbred BALB C; Photoperiod; Phytotherapy; Plant Extracts; Potentilla; Rhizome; Rhodiola; Swimming

Topics: Basal Metabolism; Body Mass Index; Body Weight; Dietary Carbohydrates; Dietary Fats; Energy Intake; Energy Metabolism; Exercise; Glycogen; Humans; Nutritional Physiological Phenomena; Obesity

We investigated the effect of Ishige okamurae extract on blood glucose level and insulin resistance in C57BL/-KsJ-db/db mice. We administered a standard AIN-93G diet with or without IOE to the animals for 6 weeks. After 6 weeks, blood glucose level was improved and blood glycosylated hemoglobin levels were lowered in sample group mice as compared to those in the diabetic control group mice. Hyperinsulinemia was reduced in the I. okamurae extract group mice with type 2 diabetes. With regard to hepatic glucose metabolic enzyme activities, glucokinase activity was enhanced in the IOE group mice, while glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities in the IOE group mice were significantly lowered than those in the diabetic control group mice. In addition, the hepatic glycogen content was elevated in the IOE group as compared to that in the diabetic control group. The homeostatic index of insulin resistance was lower in the I. okamurae extract group mice than in the diabetic control group mice. These results suggest that a dietary supplement of I. okamurae extract lowers the blood glucose level by altering the hepatic glucose metabolic enzyme activities and improves insulin resistance.

Topics: Animals; Blood Glucose; Body Weight; Eating; Glucose Tolerance Test; Glycated Hemoglobin; Glycogen; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Liver; Liver Function Tests; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Phaeophyceae; Plant Extracts

The effects of dietary energy source and feed withdrawal on muscle glycolytic potential (GP) and blood acid-base responses to handling were investigated in slaughter-weight pigs (initial BW 94.7 ± 1.01 kg). Crossbred pigs (n = 96; 48 barrows, 48 gilts) were used in a randomized complete block design with a 4 × 2 × 2 factorial arrangement of treatments: l) diet [control, high fat (10% supplemental fat), low-digestible carbohydrate (20% total starch), and high-fat/low-digestible carbohydrate (10% supplemental fat and 20% total starch)]; 2) feed withdrawal (0 and 36 h); and 3) sex (barrow and gilt). Diets were fed for 28 d before the feed withdrawal treatment was applied, at the end of which all pigs were individually moved through a 12.20-m-long × 0.91-m-wide passageway for 16 laps (195 m total distance), with the assistance of an electric goad (2 times per lap). Longissimus muscle biopsies were collected at the beginning of the feeding and feed withdrawal periods and immediately after and 4 h after the handling procedure. Venous blood was collected 2 h before and immediately after the handling procedure to measure acid-base responses. At the end of the feeding period, pigs fed the control and high-fat diets were heavier (P < 0.001) than those on the low-digestible carbohydrate and the high-fat/low-digestible carbohydrate diets (129.8, 130.9, 114.0, and 122.1 kg, respectively; SEM 1.91). Diet, feed withdrawal, and sex did not affect (P > 0.05) blood acid-base responses to handling. Muscle GP at the end of the feeding period and 4 h posthandling was least (P < 0.05) for pigs fed the high-fat diet and similar for the other 3 diet treatments. Pigs subjected to 36 h compared with 0 h of feed withdrawal had less GP (P < 0.05) immediately after and 4 h after the handling procedure. There was an interaction between diet and feed withdrawal treatments for changes in GP from the start of feed withdrawal to 4 h posthandling. The reduction in GP was greater (P < 0.05) for fasted than for fed pigs receiving the control and high-fat diets, but was similar (P > 0.05) for fasted and fed pigs receiving the 2 low-digestible carbohydrate diets. In conclusion, neither dietary energy source nor fasting affected blood acid-base responses to handling; however, fasting-induced changes in LM GP were diet dependent.

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Temperature; Body Weight; Energy Intake; Female; Food Deprivation; Glycogen; Hydrogen-Ion Concentration; Least-Squares Analysis; Male; Muscle, Skeletal; Random Allocation; Swine

We examined the effects of 3 diets differing in their relative levels of sugar and protein on development and metabolic pools (protein, TG, and glycogen) among sets of isofemale lines of 2 ecologically distinct Drosophila species, D. melanogaster and D. mojavensis. Our high protein:sugar ratio diet contained 7.1% protein and 17.9% carbohydrate, the EPS diet was 4.3% protein and 21.2% carbohydrate, and the LPS was only 2.5% protein and 24.6% carbohydrate. Larvae of D. melanogaster, a generalist fruit breeder, were able to survive on all 3 diets, although all 3 metabolic pools responded with significant diet and diet × line interactions. Development was delayed by the diet with the most sugar relative to protein. The other species, D. mojavensis, a cactus breeder ecologically unaccustomed to encountering simple sugars, completely failed to survive when fed the diet with the highest sugar and showed very poor survival even with the diet with equal parts of protein and sugar. Furthermore, the D. mojavensis adult metabolic pools of protein, TG, and glycogen significantly differed from those of D. melanogaster adults fed the identical diet. Thus, considerable within- and between-species differences exist in how diets are metabolized. Given that the genomes of both of these Drosophila species have been sequenced, these differences and their genetic underpinnings hold promise for understanding human responses to nutrition and for developing strategies for dealing with metabolic disease.

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Weight; Dietary Carbohydrates; Dietary Proteins; Drosophila; Drosophila melanogaster; Drosophila Proteins; Ecosystem; Female; Glycogen; Longevity; Species Specificity; Triglycerides

This study was performed to investigate the involvement of nitric oxide (NO) in corticosterone, endpoint product of hypothalamo-pituitary-adrenal (HPA) axis activation, and metabolic responses to 3 days of food deprivation. To investigate this aim, we used a nonspecific inhibitor of nitric oxide synthases, N-nitro- L-arginine methyl ester (L-NAME). In food deprived group we have noted a significant increase in plasma corticosterone concentration accompanied by a significant depletion in hepatic glycogen content with concomitant increase in glycogen phosphorylase (GP) activity by 63.72%, key enzyme of glycogenolysis and decrease in hexokinase (HK) activity by 25.16%, leading to significant decrease in glucose concentration. However, L-NAME administration in food deprived rats decreased slightly corticosterone level and GP activity (16.39%) and increased HK activity (11.26%) as compared to food deprived group. Considering these results, we can deduce that in food deprivation nitric oxide is involved in the regulation of corticosterone release and in glucose metabolic responses via glycogenolysis activation by the stimulation of GP activity and the inhibition of HK activity. However, more studies are necessary to further clarify the mechanisms by which NO induces these responses.

Topics: Animals; Blood Glucose; Body Weight; Corticosterone; Food Deprivation; Glycogen; Glycogen Phosphorylase; Hexokinase; Liver; Male; NG-Nitroarginine Methyl Ester; Nitrates; Nitric Oxide; Nitrites; Rats; Rats, Wistar

Lippia nodiflora L. (Verbenaceae) is a creeping perennial herb widely used in traditional system of medicine to treat ulcers, bronchitis and heart diseases; it also possesses antidiabetic property. In the present study, γ-sitosterol isolated from Lippia nodiflora was screened for its antidiabetic property in streptozotocin (STZ) induced diabetic rats. Insulin secretion in response to glucose was evaluated in isolated rat islets. Oral administration of γ-sitosterol (20 mg/kg body weight) once daily for 21 days in STZ-induced diabetic rats resulted in a significant decrease in blood glucose and glycosylated hemoglobin with a significant increase in plasma insulin level, body weight and food intake. Furthermore γ-sitosterol showed antihyperlipidemic activity as evidenced by significant decrease in serum total cholesterol, triglycerides and very low density lipoprotein-cholesterol levels coupled with elevation of high density lipoprotein-cholesterol levels in treated rats. A significant decrease in the activities of alanine aminotransaminase, aspartate aminotransaminase, alkaline phosphatase and acid phosphatase in γ-sitosterol treated rats when compared to diabetic control rats indicated its protective role against liver damage. γ-Sitosterol increased insulin secretion in response to glucose. Immunohistochemical study of pancreas also confirmed the biochemical findings. These results indicated that γ-sitosterol, the compound isolated from L. nodiflora, possessed antihyperglycemic activity.

Topics: Animals; Biomarkers; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Fasting; Glycated Hemoglobin; Glycogen; Hypoglycemic Agents; Insulin; Insulin Secretion; Lipid Metabolism; Lippia; Liver; Male; Muscles; Rats; Rats, Wistar; Sitosterols

Chicks are commonly fasted for the first 36 to 72 h posthatch because of the logistics of commercial production. Fasting for 48 to 72 h posthatch results in retarded BW, delayed intestinal development, and lower pectoral muscle weight. This study is focused on the first 36 h of fasting and its interaction with feeding before hatch. Four treatment groups, differing in time of first feed, 6 h [early feeding (EF)] or 36 h [standard feeding procedure (SP)] posthatch, with or without in ovo feeding (IOF) with dextrin and β-hydroxy-β-methylbutyrate-calcium salt in a saline solution, were examined for glycogen status in the liver and pectoral muscle, myogenic cell proliferation, and myofiber diameter in embryos and chickens on various days posthatch. In addition, chicken BW, ADG, pectoral muscle weight, and pectoral muscle percentage of BW until 35 d of age were recorded. Results showed that delaying the first feed for 36 h posthatch (SP group) led to an irreversibly reduced growth rate compared with the EF group. However, IOF affected the growth of chickens in the SP group, whereas the control embryos had depleted glycogen reserves in the liver; IOF-treated embryos had elevated hepatic glycogen contents on embryonic day (E) 19, E20, and the day of hatch. In addition, on d 2 posthatch, although hatchlings in the SP group showed the predicted low levels of glycogen in their livers, birds in the EF group exhibited more than 30-fold and 3-fold increases in liver and muscle glycogen, respectively. In ovo-fed birds in the SP group also exhibited higher glycogen reserves, BW, pectoral muscle weight, and BW gain than control birds in the SP group. In ovo feeding had an immediate effect on promoting myoblast proliferation on E19, whereas on d 3 posthatch, the effect was pronounced only in the EF groups. On d 5, although myoblast proliferation in all groups declined, it remained higher in both IOF groups. These effects were expressed on d 3 and 35 by myofiber diameter. Together, IOF had a long-term supportive effect on BW and posthatch muscle growth when first feed was delayed by 36 h.

Topics: Animal Husbandry; Animals; Body Weight; Chick Embryo; Chickens; Dextrins; Eating; Feeding Methods; Female; Glycogen; Least-Squares Analysis; Liver; Male; Muscle, Skeletal; Myoblasts; Organ Size; Valerates

To evaluate the efficacy and safety of 2 analogs of L-carnitine on rats made insulin resistant by a high-fructose diet.. Using rats made insulin resistant by a high-fructose diet, we investigated the impact of 2 analogs of L-carnitine (25 mg/kg) and L-carnitine (250 mg/kg) on glucose, triglycerides and cholesterol blood levels, and liver glycogen. We also evaluated the safety of both analogs by the assessment of some biochemical and hematological parameters, a histological analysis and a study of embryotoxicity.. Both analogs reduced the levels of triglycerides in the liver and plasma, but only analog 2 reduced the cholesterol levels in insulin-resistant rats. No changes were observed in glycogen content. Safety evaluations revealed alterations in blood lymphocytes and embryotoxicity data.. This study demonstrated that the 2 analogs maintain the pharmacological properties of L-carnitine but have a different efficacy, potency and toxicity.

Topics: Animals; Blood Glucose; Body Weight; Carnitine; Chick Embryo; Cholesterol; Diet; Disease Models, Animal; Drug Evaluation, Preclinical; Embryo, Nonmammalian; Fructose; Glycogen; Insulin; Insulin Resistance; Liver; Male; Rats; Rats, Wistar; Sweetening Agents; Teratogens; Triglycerides; Vitamin B Complex

Examine whether normalizing net hepatic glycogenesis restores endogenous glucose production and hepatic glucose phosphorylation in response to diabetic levels of plasma glucose and insulin in Zucker diabetic fatty rats (ZDF).. Hepatic glucose and intermediate fluxes (µmol · kg(-1) · min(-1)) were measured with and without a glycogen phosphorylase inhibitor (GPI) using [2-(3)H]glucose, [3-(3)H]glucose, and [U-(14)C]alanine in 20 h-fasted conscious ZDF and their lean littermates (ZCL) under clamp conditions designed to maintain diabetic levels of plasma glucose and insulin.. With infusion of GPI into ZDF (ZDF-GPI+G), compared with vehicle infused ZDF (ZDF-V), high glycogen phosphorylase a activity was decreased and low synthase I activity was increased to that of ZCL. Low net glycogenesis from plasma glucose rose to 75% of ZCL levels (4 ± 1 in ZDF-V, 18 ± 1 in ZDF-GPI+G, and 24 ± 2 in ZCL) and phosphoenolpyruvate 260% (4 ± 2 in ZDF-V, 16 ± 1 in ZDF+GPI-G, and 6 ± 2 in ZCL). High endogenous glucose production was suppressed with GPI infusion but not to that of ZCL (46 ± 4 in ZDF-V, 18 ± 4 in ZDF-GPI+G, and -8 ± 3 in ZCL). This was accompanied by reduction of the higher glucose-6-phosphatase flux (75 ± 4 in ZDF-V, 41 ± 4 in ZDF-GPI+G, and 86 ± 12 in ZCL) and no change in low glucose phosphorylation or total gluconeogenesis.. In the presence of hyperglycemic-hyperinsulinemia in ZDF, reduced glycogenic flux partially contributes to a lack of suppression of hepatic glucose production by failing to redirect glucose-6-phosphate flux from production of glucose to glycogen but is not responsible for a lower rate of glucose phosphorylation.

Topics: Animals; Body Weight; Gluconeogenesis; Glucose; Glucose-6-Phosphatase; Glycogen; Hyperglycemia; Hyperinsulinism; Insulin; Liver; Male; Obesity; Rats; Rats, Zucker

This study aims to examine the effects of polysaccharide levan on oxidative stress and hyperglycemia in alloxan-induced diabetic rats. Levan, used in this study, was a microbial levan synthetisized by a non pathogenic bacteria recently isolated and identified as Bacillus licheniformis. Animals were allocated into four groups of six rats each: a control group (Control), diabetic group (Diab.), normal rats received levan (L) and diabetic rats fed with levan (DL). Treated diabetic rats were administrated with levan in drinking water through oral gavage for 60 days. The administration of polysaccharide levan in diabetic rats caused a significant increase in glycogen level by 52% and a decrease in glucose level in plasma by 52%. Similarly, the administration of polysaccharide levan in diabetic rats caused a decrease in the thiobarbituric acid-reactive substances (TBARS) by 31%, 41%, 39% and 25%, an increase in superoxide dismutase (SOD) by 40%, 50%, 44% and 34%, and in catalase (CAT) by 18%, 20%, 12% and 18% in liver, kidney, pancreas and heart, respectively. Furthermore, a significant decrease in hepatic and renal indices toxicity was observed, i.e. alkalines phosphatases (ALP), aspartate and lactate transaminases (AST and ALT) activities, total bilirubin, creatinine and urea levels by 19%, 31%, 32%, 36%, 37% and 23%, respectively. The results show that administration of polysaccharide levan can restore abnormal oxidative indice near normal levels. This study demonstrates, for the first time, that polysaccharide levan is efficient in inhibiting hyperglycemia and oxidative stress induced by diabetes and suggests that levan supplemented to diet may be helpful in preventing diabetic complications in adult rats.

Topics: Animals; Blood Glucose; Body Weight; Creatinine; Diabetes Mellitus, Experimental; Fructans; Glycogen; Hypoglycemic Agents; Kidney Function Tests; Liver; Liver Function Tests; Male; Organ Size; Organ Specificity; Polysaccharides; Rats; Rats, Wistar; Urea

Implementation of a nutrition programme for team sports involves application of scientific research together with the social skills necessary to work with a sports medicine and coaching staff. Both field and court team sports are characterized by intermittent activity requiring a heavy reliance on dietary carbohydrate sources to maintain and replenish glycogen. Energy and substrate demands are high during pre-season training and matches, and moderate during training in the competitive season. Dietary planning must include enough carbohydrate on a moderate energy budget, while also meeting protein needs. Strength and power team sports require muscle-building programmes that must be accompanied by adequate nutrition, and simple anthropometric measurements can help the nutrition practitioner monitor and assess body composition periodically. Use of a body mass scale and a urine specific gravity refractometer can help identify athletes prone to dehydration. Sports beverages and caffeine are the most common supplements, while opinion on the practical effectiveness of creatine is divided. Late-maturing adolescent athletes become concerned about gaining size and muscle, and assessment of maturity status can be carried out with anthropometric procedures. An overriding consideration is that an individual approach is needed to meet each athlete's nutritional needs.

Topics: Athletic Performance; Body Composition; Body Weight; Dehydration; Diet; Dietary Carbohydrates; Dietary Proteins; Dietary Supplements; Energy Intake; Energy Metabolism; Exercise; Glycogen; Guidelines as Topic; Humans; Nutritional Requirements; Nutritional Status; Physical Education and Training; Sports

The chromium citrate complex [CrCIT] was synthesized and its structure was determined by infrared, UV-visible and atomic absorption spectroscopy, elemental and thermodynamic analysis. Anti-diabetic activity, oxidative DNA damage capacity and acute oral toxicity of [CrCIT] were investigated and compared with that of chromium trichloride hexahydrate. [CrCIT] was synthesized in a single step reaction by chelating chromium(III) with citric acid in aqueous solution. The molecular formula of [CrCIT] was inferred as CrC(6)H(5)O(7)·4H(2)O. The anti-diabetic activity of the complex [CrCIT] was assessed in alloxan-diabetic rats by daily oral gavage for 3 weeks. The biological activity results showed that the complex at the dose of 0.25-0.75 mg Cr/kg body weight could decrease the blood glucose level and increase liver glycogen level in alloxan-diabetic rats. [CrCIT] had more beneficial influences on the improvement of controlling blood glucose, serum lipid and liver glycogen levels compared with CrCl(3)·6H(2)O. Furthermore, [CrCIT] did not cause oxidative DNA damage under physiologically relevant conditions, and [CrCIT] did not produce any hazardous symptoms or deaths in acute oral toxicity test, showing the LD(50) value for female and male rats were higher than 15.1 g/kg body weight. The results suggested that [CrCIT] might represent a novel and proper chromium supplement with potential therapeutic value to control blood glucose in diabetes.

Topics: Animals; Blood Glucose; Body Weight; Cholesterol; Chromium; Citrates; Coordination Complexes; Diabetes Mellitus, Experimental; DNA Damage; Female; Glycogen; Hypoglycemic Agents; Liver; Male; Oxidative Stress; Rats; Toxicity Tests; Triglycerides

Shiitake mushrooms (SMs) have been used in Asia for treatment and/or prevention of chronic diseases and hypercholesterolemia. Previously, we observed a diet supplemented with 5% SM resulted in a twofold increase in plasma IL-6 levels in DBA arthritic mice. An elevation in plasma IL-6 has also been implicated in the pathogenesis fatty liver disease. Thus, the aim of this study was to investigate the effect of SM supplemented-diet on hepatic steatosis. In study 1, eight-week old female C57BL/6 mice were randomly assigned to the following groups for 6 weeks: the AIN-93 diet; 5% SM, and 5% white button mushroom (WBM) supplemented diets (12/group). In study 2, mice were fed either the AIN-93 diet or SM (20/group). After 6 weeks, 13 mice fed SM diet were given the AIN93 diet for 8 or 15 days. Unlike other groups, all mice fed the SM diet developed fatty liver (mean histopathology score 4.5 vs <1 in the other groups; p<0.001) without fibrosis and inflammation. Fifteen days post withdrawal of SM completely normalized liver histology. To the best of our knowledge, this is the first report that chronic consumption of SM is associated with the development of fatty liver. The mechanism by which SM causes hepatic steatosis warrants further investigation.

Topics: Aflatoxins; Agaricus; Animals; Asia; Body Weight; Diet; Dietary Supplements; Endotoxins; Fatty Liver; Female; Glycogen; Interleukin-6; Liver; Mice; Mice, Inbred C57BL; Organ Size; Shiitake Mushrooms

Natural remedies from medicinal plants are considered to be effective and safe alternatives to treat diabetes mellitus. Solanum torvum Swartz. fruit is widely used in the traditional system of medicine to treat diabetes. In the present study methyl caffeate, isolated from S. torvum fruit, was screened for its efficacy in controlling diabetes in animal models. Antihyperglycemic effect of methyl caffeate was studied in normal glucose-fed rats. The effects of oral administration of methyl caffeate (10, 20 and 40 mg/kg) for 28 days on body weight, fasting blood glucose, plasma insulin, hemoglobin, glycated hemoglobin, total protein, hepatic glycogen and carbohydrate metabolism enzymes in streptozotocin induced diabetic rats were investigated. Histological observations in the pancreas and GLUT4 expression in skeletal muscles were also studied. Methyl caffeate at 40 mg/kg significantly prevented the increase in blood glucose level after glucose administration at 60 min in comparison to the hyperglycemic control group. In streptozotocin induced diabetic rats, methyl caffeate produced significant reduction in blood glucose and increased body weight. The levels and/or activities of other biochemical parameters were near normal due to treatment with methyl caffeate. Methyl caffeate treated diabetic rats showed upregulation of GLUT4 and regeneration of β-cells in the pancreas. These results substantiated that methyl caffeate possessed hypoglycemic effect, and it could be developed into a potent oral antidiabetic drug.

Topics: Animals; Blood Glucose; Body Weight; Caffeic Acids; Chromatography, High Pressure Liquid; Diabetes Mellitus, Experimental; Fasting; Fructose-Bisphosphatase; Fruit; Gene Expression Regulation; Glucose Tolerance Test; Glucose Transporter Type 4; Glucose-6-Phosphatase; Glycated Hemoglobin; Glycogen; Hexokinase; Hypoglycemic Agents; Insulin; Liver; Male; Rats; RNA, Messenger; Solanum; Spectrum Analysis

The present study evaluates the effects of chitooligosaccharides (COS) for the management of alloxan induced diabetes in mice. For the management of the carbohydrate metabolism in diabetes by the COS, the amount of glucose in blood along with quantification of glycogen in liver were measured and noted a significant recovery in respect to diabetic control group. As hyperlipidemia and oxidative stress are the disorders of diabetes so, we have also assessed the serum levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDLc), very low density lipoprotein cholesterol (VLDLc) and high density lipoprotein cholesterol (HDLc). For the recovery of oxidative stress the SOD MDA catalase in liver and GOT and GPT activities in serum were measured. The COS results a significant recovery in the levels of above mentioned biosensors of lipid profile when treated to experimentally induce diabetic mice. The effect of COS at the dose of 10mg/kg body weight was found to be a potent agent for diabetes and complication associated with this disease. The COS has no toxic effect in general which has been focused here by the monitoring of COS dose in normal healthy mice. The results of this study enlighted that the COS has antidiabetic, antihyperlipidemic and antioxidative activities.

Topics: Alanine Transaminase; Animals; Antioxidants; Aspartate Aminotransferases; Blood Glucose; Body Weight; Catalase; Chitin; Chitosan; Cholesterol; Creatinine; Diabetes Mellitus, Experimental; Glycogen; Hypolipidemic Agents; Lipoproteins; Liver; Male; Mice; Mice, Inbred Strains; Oligosaccharides; Papain; Spectroscopy, Fourier Transform Infrared; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Triglycerides; Urea

To develop an easy-energy-supply agent, medium-chain fatty acids (MCFAs) liposomes were prepared by thin-layer dispersion, freeze-thawing and dynamic high pressure microfluidization (DHPM)-freeze-thawing methods. Results showed that MCFAs nanoliposomes obtained by the novel method (DHPM-freeze-thawing) exhibited a smaller size (72.6 ± 4.9 nm), narrower size distribution (PDI = 0.175 ± 0.005), higher zeta potential (-41.27 ± 1.16 mV) and entrapment efficiency (45.9 ± 6.0%) compared to the other two methods. In the weight-loaded swimming test of the mice, the high-dose group of MCFAs nanoliposomes indicated a significantly longer swimming time (105 ± 31 min, p < 0.05), a lower serum urea nitrogen (839.5 ± 111.9 mg/L, p < 0.05) and blood lactic acid (5.7 ± 1.0 mmol/L, p ≤ 0.001), and a higher hepatic glycogen (15.0 ± 3.6 mg/g, p ≤ 0.001) than those of the control group (53 ± 13 min, 1153.6 ± 102.5 mg/L, 12.5 ± 1.9 mmol/L and 8.8 ± 3.3 mg/g, respectively). However, no significant difference was found between the high-dose group and MCFAs group. The results suggested that MCFAs nanoliposomes could be used as a potential easy-energy-supply agent.

Topics: Animals; Blood Urea Nitrogen; Body Weight; Energy Metabolism; Fatty Acids; Freezing; Glycogen; Lactic Acid; Liposomes; Liver; Male; Mice; Mice, Inbred BALB C; Swimming

To test the hypothesis that free fatty acid (FFA) and muscle glycogen modify exercise-induced regulation of PDH (pyruvate dehydrogenase) in human skeletal muscle through regulation of PDK4 expression.. On two occasions, healthy male subjects lowered (by exercise) muscle glycogen in one leg (LOW) relative to the contra-lateral leg (CON) the day before the experimental day. On the experimental days, plasma FFA was ensured normal or remained elevated by consuming breakfast rich (low FFA) or poor (high FFA) in carbohydrate, 2 h before performing 20 min of two-legged knee extensor exercise. Vastus lateralis biopsies were obtained before and after exercise.. PDK4 protein content was approximately 2.2- and approximately 1.5-fold higher in LOW than CON leg in high FFA and low FFA, respectively, and the PDK4 protein content in the CON leg was approximately twofold higher in high FFA than in low FFA. In all conditions, exercise increased PDHa (PDH in the active form) activity, resulting in similar levels in LOW leg in both trials and CON leg in high FFA, but higher level in CON leg in low FFA. PDHa activity was closely associated with the PDH-E1alpha phosphorylation level.. Muscle glycogen and plasma FFA attenuate exercise-induced PDH regulation in human skeletal muscle in a nonadditive manner. This might be through regulation of PDK4 expression. The activation of PDH by exercise independent of changes in muscle glycogen or plasma FFA suggests that exercise overrules FFA-mediated inhibition of PDH (i.e., carbohydrate oxidation), and this may thus be one mechanism behind the health-promoting effects of exercise.

Topics: Adult; Body Height; Body Weight; Exercise; Fatty Acids, Nonesterified; Glycogen; Humans; Insulin; Leg; Male; Muscle, Skeletal; Oxygen Consumption; Protein Serine-Threonine Kinases; Pyruvate Dehydrogenase Acetyl-Transferring Kinase; Pyruvate Dehydrogenase Complex; Reference Values; Weight-Bearing; Young Adult

Exposure to maternal undernutrition during development increases the risk for neurological and cognitive defects. However, little is known about the underlying mechanisms involved. Peripheral responses to insulin are increased following food-restriction, thus the possibility arises that brain insulin actions are affected by undernutrition, causing damages to the higher cerebral functions. In this study, we examined the effects of early undernutriton on molecular targets of insulin actions such as glucose transporters, glycogen, glycogen synthase kinase-3 (GSK3) and mitogen-activated protein kinases, as well as proteins involved in apoptosis in the cortex from 10-day-old rats. We show that undernutrition results in an enhanced glycogen content which is confined to astrocytes, according to our histochemical approaches. Cortical phospho-GSK3 is also increased. In addition to glycogen synthesis, GSK3 regulates crucial cellular processes. Therefore, its elevated degree of phosphorylation may have an impact on these processes and, consequently, on the cortical development. Phospho-p38 and both total JNK and phospho-JNK, which regulate apoptosis, are reduced following undernutrition. However, cleaved caspase 3 is not altered, which suggests that this condition does not induce extensive modifications to the cortical apoptosis. Thus, our results indicate that undernutrition gives rise to molecular alterations that may have repercussions on cerebral cortex development and functions.

Topics: Age Factors; AMP-Activated Protein Kinases; Animals; Animals, Newborn; Animals, Suckling; Body Weight; Cerebral Cortex; Enzyme Activation; Female; Glycogen; Glycogen Synthase Kinase 3; JNK Mitogen-Activated Protein Kinases; Malnutrition; Organ Size; p38 Mitogen-Activated Protein Kinases; Pregnancy; Prenatal Nutritional Physiological Phenomena; Rats; Rats, Wistar

Expression of an activated form of calcineurin in skeletal muscle selectively up-regulates slow-fiber-specific gene expression. Here, we tested the hypothesis that expression of activated calcineurin in skeletal muscle influences body composition, energy homeostasis, and exercise performance. Using transgenic mice expressing activated calcineurin (CnA*) in skeletal muscle (MCK-CnA* transgenic mice), we determined whether skeletal muscle reprogramming by calcineurin activation affects exercise performance and skeletal muscle mitochondrial function. Body weight and extensor digitorum longus (EDL) skeletal muscle weight were reduced 10% in MCK-CnA* mice compared with wild-type littermates. Basal oxygen consumption, food intake, and voluntary exercise behavior were unchanged between MCK-CnA* and wild-type mice. However, when total energy expenditure was normalized by fat-free mass, energy expenditure was increased in MCK-CnA* mice. An endurance performance treadmill running test revealed MCK-CnA* mice are fatigue resistant and run 50% farther before exhaustion. After a standardized exercise bout, glycogen and triglyceride content in EDL muscle was higher in MCK-CnA* vs. wild-type mice. Mitochondrial respiratory capacity was increased 35% in EDL muscle from resting MCK-CnA* mice. In conclusion, our results provide evidence to support the hypothesis that calcineurin activation in skeletal muscle increases mitochondrial oxidative function and energy substrate storage, which contributes to enhanced endurance exercise performance. These adaptive changes occur as a consequence of a lifelong expression of a constitutively active calcineurin and mimic the response to chronic endurance training.

Topics: Acyltransferases; Animals; Body Weight; Calcineurin; Diacylglycerol O-Acyltransferase; Electron Transport; Energy Metabolism; Fatty Acid Transport Proteins; Gene Expression Regulation, Enzymologic; Glycogen; Mice; Mice, Transgenic; Mitochondria; Muscle Contraction; Muscle, Skeletal; Organ Size; Oxygen Consumption; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Physical Conditioning, Animal; Physical Endurance; Trans-Activators; Transcription Factors; Triglycerides

We investigated if alterations in the insulin-signaling pathway could contribute to reduced hepatic glycogen levels in adult rats subjected to a protein deficiency during intrauterine life and lactation and reared through to recovery on a soybean diet.. Rats from mothers fed with 17% or 6% protein (casein) during pregnancy and lactation were maintained with a 17% casein diet (offspring born to and suckled by mothers fed a control diet and subsequently fed the same diet after weaning [CC group] and offspring born to and suckled by mothers fed a control diet and subsequently fed a soybean flour diet with 17% protein after weaning [CS group]), a soybean diet (offspring of mothers fed a low-protein diet and a control diet after weaning [LC group] and offspring of mothers fed a low-protein diet and fed a soybean flour diet containing 17% protein after weaning [LS group]), or a 6% casein diet (offspring of mothers fed a low-protein diet and subsequently fed the same diet after weaning [LL group]) from weaning until 90 d of life.. A soybean diet did not modify basal serum glucose and glucagon concentrations, but raised basal serum insulin and consequently increased the serum insulin/glucose ratio. Insulin receptor and insulin receptor substrate-1 levels were lower in rats fed a soybean diet compared with those maintained with a casein diet. In the LS group, the p85 levels were higher than in the LC group, whereas in CS rats its expression was lower than in CC rats. The expression of p110 was lower in the CS group compared with the CC group and similar in the LS and LC groups. Insulin receptor substrate-1 phosphorylation was similar in the LS, LC, and CS groups and lower compared with the CC group. The insulin receptor substrate-1-p85/phosphatidylinositol 3-kinase association was lower in LS than in LC rats and in CS than in CC rats. Akt phosphorylation was lower in the CS and LS groups than in the CC and LC groups.. Adult rats maintained with a soybean diet exhibited insulin resistance due, at least in part, to alterations in the early steps of the insulin signal transduction pathway.

Topics: Analysis of Variance; Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Blotting, Western; Body Weight; Caseins; Diet; Disease Models, Animal; Female; Glycine max; Glycogen; Insulin; Insulin Resistance; Lactation; Liver; Male; Pregnancy; Prenatal Nutritional Physiological Phenomena; Protein-Energy Malnutrition; Rats; Rats, Wistar

The influence of feeding on swimming performance and exercise recovery in fish is poorly understood. Examining swimming behavior and physiological status following periods of feeding and fasting is important because wild fish often face periods of starvation. In the current study, researchers force fed and fasted groups of largemouth bass (Micropterus salmoides) of similar sizes for a period of 16 days. Following this feeding and fasting period, fish were exercised for 60 s and monitored for swimming performance and physiological recovery. Resting metabolic rates were also determined. Fasted fish lost an average of 16 g (nearly 12%) of body mass, while force fed fish maintained body mass. Force fed fish swam 28% further and required nearly 14 s longer to tire during exercise. However, only some physiological conditions differed between feeding groups. Resting muscle glycogen concentrations was twofold greater in force fed fish, at rest and throughout recovery, although it decreased in both feeding treatments following exercise. Liver mass was nearly three times greater in force fed fish, and fasted fish had an average of 65% more cortisol throughout recovery. Similar recovery rates of most physiological responses were observed despite force fed fish having a metabolic rate 75% greater than fasted fish. Results are discussed as they relate to largemouth bass starvation in wild systems and how these physiological differences might be important in an evolutionary context.

Topics: Adenosine Triphosphate; Animals; Basal Metabolism; Bass; Blood Glucose; Body Weight; Chlorides; Citrate (si)-Synthase; Fasting; Fresh Water; Glycogen; Hematocrit; Hemoglobins; Hydrocortisone; L-Lactate Dehydrogenase; Lactic Acid; Liver; Muscle Fibers, Fast-Twitch; Nutritional Status; Organ Size; Phosphocreatine; Physical Conditioning, Animal; Potassium

This study investigated whether exercise training could prevent the negative side effects of dexamethasone. Rats underwent a training period and were either submitted to a running protocol (60% physical capacity, 5 days/week for 8 weeks) or kept sedentary. After this training period, the animals underwent dexamethasone treatment (1 mg/kg per day, i.p., 10 days). Glycemia, insulinemia, muscular weight and muscular glycogen were measured from blood and skeletal muscle. Vascular endothelial growth factor (VEGF) protein was analyzed in skeletal muscles. Dexamethasone treatment evoked body weight loss (-24%), followed by muscular atrophy in the tibialis anterior (-25%) and the extensor digitorum longus (EDL, -15%). Dexamethasone also increased serum insulin levels by 5.7-fold and glucose levels by 2.5-fold compared to control. The exercise protocol prevented atrophy of the EDL and insulin resistance. Also, dexamethasone-treated rats showed decreased muscular glycogen (-41%), which was further attenuated by the exercise protocol. The VEGF protein expression decreased in the skeletal muscles of dexamethasone-treated rats and was unaltered by the exercise protocol. These data suggest that exercise attenuates hyperglycemia and may also prevent insulin resistance, muscular glycogen loss and muscular atrophy, thus suggesting that exercise may have some benefits during glucocorticoid treatment.

Topics: Animals; Blood Glucose; Body Weight; Dexamethasone; Exercise Test; Glucocorticoids; Glycogen; Hyperinsulinism; Insulin; Insulin Resistance; Male; Muscle, Skeletal; Muscular Atrophy; Physical Conditioning, Animal; Rats; Rats, Wistar; Time Factors

Calorie restriction (CR), the purposeful reduction of energy intake with maintenance of adequate micronutrient intake, is well known to extend the lifespan of laboratory animals. Compounds like 2-deoxy-D-glucose (2DG) that can recapitulate the metabolic effects of CR are of great interest for their potential to extend lifespan. 2DG treatment has been shown to have potential therapeutic benefits for treating cancer and seizures. 2DG has also recapitulated some hallmarks of the CR phenotype including reduced body temperature and circulating insulin in short-term rodent trials, but one chronic feeding study in rats found toxic effects. The present studies were performed to further explore the long-term effects of 2DG in vivo. First we demonstrate that 2DG increases mortality of male Fischer-344 rats. Increased incidence of pheochromocytoma in the adrenal medulla was also noted in the 2DG treated rats. We reconfirm the cardiotoxicity of 2DG in a 6-week follow-up study evaluating male Brown Norway rats and a natural form of 2DG in addition to again examining effects in Fischer-344 rats and the original synthetic 2DG. High levels of both 2DG sources reduced weight gain secondary to reduced food intake in both strains. Histopathological analysis of the hearts revealed increasing vacuolization of cardiac myocytes with dose, and tissue staining revealed the vacuoles were free of both glycogen and lipid. We did, however, observe higher expression of both cathepsin D and LC3 in the hearts of 2DG-treated rats which indicates an increase in autophagic flux. Although a remarkable CR-like phenotype can be reproduced with 2DG treatment, the ultimate toxicity of 2DG seriously challenges 2DG as a potential CR mimetic in mammals and also raises concerns about other therapeutic applications of the compound.

Topics: Adrenal Glands; Animals; Autophagy; Blotting, Western; Body Temperature; Body Weight; Deoxyglucose; Glucose; Glycogen; Heart; Insulin; Lipid Metabolism; Male; Myocardium; Rats; Rats, Inbred BN; Rats, Inbred F344; Survival Analysis; Vacuoles

The role for melatonin in glucose homeostasis and insulin resistance is not very clear and has recently been an active area of investigation. The present study investigated the role of melatonin in seasonal accumulation of adipose tissue in Scotophilus heathi, with particular reference to its role in glucose homeostasis and development of insulin resistance. The circulating melatonin levels correlated positively (p<0.05) with the changes in body mass due to fat accumulation and circulating insulin level, but correlated negatively with the blood glucose level in S. heathi. The bats showed high circulating blood glucose levels and impaired glucose tolerance during the period of fat deposition suggesting insulin resistance condition which improves after winter when most of the fat has been utilized as a metabolic fuel. The high circulating melatonin levels during the period of maximum body fat at the beginning of winter prepare the bats for winter dormancy by modulating the glucose homeostasis through affecting blood glucose levels, muscle and liver glycogen stores, insulin receptor and glucose transporter 4 (GLUT 4) expression. This is also confirmed by in vivo study in which melatonin injection improves the glucose tolerance, increases muscle insulin receptor and GLUT 4 expression, and enhances glucose clearance from the blood. The results of present study further showed that the effect of melatonin injection on the blood glucose levels is determined by the metabolic state of the bats and may protect from decrease in blood glucose level during extreme starvation, however, melatonin when injected during fed state increases glucose clearance from the blood. In summary, the present study suggested that melatonin interferes with the glucose homeostasis through modulating intracellular glucose transport and may protect bats from hypoglycemia during winter dormancy.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Chiroptera; Glucose; Glucose Tolerance Test; Glucose Transporter Type 4; Glucose-6-Phosphate; Glycogen; Hibernation; Homeostasis; Insulin; Lipids; Liver; Melatonin; Muscle, Skeletal; Receptor, Insulin; Seasons

In Indian traditional system of medicine, Ficus religiosa (Family Moraceae) is prescribed for the treatment of diabetes mellitus. In the present study, the antidiabetic effect of aqueous extract of Ficus religiosa bark (FRAE) was investigated in normal, glucose-loaded hyperglycemic and streptozotocin (STZ)-induced diabetic rats.. Oral administration of FRAE at the doses of 25, 50 and 100mg/kg was studied in normal, glucose-loaded and STZ-diabetic rats.. The three doses caused significant reduction in blood glucose levels in all the models. The effect was more pronounced in 50 and 100mg/kg than 25mg/kg. FRAE also showed significant increase in serum insulin, body weight and glycogen content in liver and skeletal muscle of STZ-induced diabetic rats while there was significant reduction in the levels of serum triglyceride and total cholesterol. FRAE also showed significant antilipidperoxidative effect in the pancreas of STZ-induced diabetic rats. The antidiabetic effect of Ficus religiosa was compared with glibenclamide, a well-known hypoglycemic drug.. The results indicate that aqueous extract of Ficus religiosa bark possesses significant antidiabetic activity.

Topics: Administration, Oral; Animals; Body Weight; Cholesterol; Diabetes Mellitus; Ficus; Glyburide; Glycogen; Hypoglycemic Agents; Insulin; Liver; Male; Pancreas; Rats; Rats, Wistar; Streptozocin; Triglycerides

The antifatigue effects of the hot-water extract of longan (Dimocarpus longan Lour.) seeds were studied in mice. Longan seed polysaccharides were administered at doses of 50, 100, 200 and 400 mg/kg and antifatigue activity was evaluated using a swimming test, along with the determination of serum urea nitrogen, hepatic glycogen and blood lactic acid content. The results show that longan seed polysaccharides, in doses ranging from 50 to 100 mg/kg, extended swimming time, increased hepatic glycogen (p < 0.01, n = 10), reduced blood urea nitrogen (p < 0.01, n = 10) and decreased blood lactic acid (p < 0.01, n = 10) in the mice. Therefore longan seed polysaccharides may have potential as an antifatigue agent.

Topics: Animals; Blood Urea Nitrogen; Body Weight; Drug Evaluation, Preclinical; Fatigue; Glycogen; Lactic Acid; Liver; Male; Mice; Mice, Inbred ICR; Phytotherapy; Plant Extracts; Polysaccharides; Sapindaceae; Seeds; Swimming

Endothelial nitric oxide synthase (eNOS) is associated with a number of physiological functions involved in the regulation of metabolism; however, the functional role of eNOS is poorly understood. We tested the hypothesis that eNOS is critical to muscle cell signaling and fuel usage during exercise in vivo, using 16-wk-old catheterized (carotid artery and jugular vein) C57BL/6J mice with wild-type (WT), partial (+/-), or no expression (-/-) of eNOS. Quantitative reductions in eNOS expression ( approximately 40%) elicited many of the phenotypic effects observed in enos(-/-) mice under fasted, sedentary conditions, with expression of oxidative phosphorylation complexes I to V and ATP levels being decreased, and total NOS activity and Ca(2+)/CaM kinase II Thr(286) phosphorylation being increased in skeletal muscle. Despite these alterations, exercise tolerance was markedly impaired in enos(-/-) mice during an acute 30-min bout of exercise. An eNOS-dependent effect was observed with regard to AMP-activated protein kinase signaling and muscle perfusion. Muscle glucose and long-chain fatty acid uptake, and hepatic and skeletal muscle glycogenolysis during the exercise bout was markedly accelerated in enos(-/-) mice compared with enos(+/-) and WT mice. Correspondingly, enos(-/-) mice exhibited hypoglycemia during exercise. Thus, the ablation of eNOS alters a number of physiological processes that result in impaired exercise capacity in vivo. The finding that a partial reduction in eNOS expression is sufficient to induce many of the changes associated with ablation of eNOS has implications for chronic metabolic diseases, such as obesity and insulin resistance, which are associated with reduced eNOS expression.

Topics: AMP-Activated Protein Kinases; Animals; Body Composition; Body Weight; Calorimetry, Indirect; Energy Metabolism; Female; Gluconeogenesis; Glycogen; Hypoglycemia; Insulin; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Mitochondria; Muscle, Skeletal; Nitric Oxide Synthase Type III; Oxidative Phosphorylation; Photoperiod; Physical Conditioning, Animal; Physical Exertion; Pregnancy; Regional Blood Flow; Signal Transduction

Diabetes mellitus is a chronic metabolic disorder affecting about 6% of population worldwide with its complications and is rapidly reaching epidemic scale. Cinnamomum zeylanicum is widely used in alternative system of medicine for treatment of diabetes. In the present study, we have performed bioassay guided fractionation of chloroform extract of C. zeylaniucm and identified cinnamaldehyde (CND) as an active principle against diabetes. In continuation to it, a detailed study was undertaken to elucidate its mode of antidiabetic action in STZ induced diabetic rats. Oral administration of CND (20 mg/kg bw) to diabetic rats for 2 months showed significant improvement (p<0.001) in muscle and hepatic glycogen content. In vitro incubation of pancreatic islets with CND enhanced the insulin release compared to glibenclamide. The insulinotropic effect of CND was found to increase the glucose uptake through glucose transporter (GLUT4) translocation in peripheral tissues. The treatment also showed a significant improvement in altered enzyme activities of pyruvate kinase (PK) and phosphoenolpyruvate carboxykinase (PEPCK) and their mRNA expression levels. Furthermore, the median lethal dose (LD(50)) of CND could not be obtained even at 20 times (0.4 g/kg bw) of its effective dose. With the high margin of safety of CND, it can be developed as a potential therapeutic candidate for the treatment of diabetes.

Topics: Acrolein; Animals; Body Weight; Cinnamomum zeylanicum; Diabetes Mellitus, Experimental; Drinking; Glucose Transporter Type 4; Glycogen; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Kidney; Lethal Dose 50; Liver; Male; Organ Size; Phosphoenolpyruvate Carboxykinase (ATP); Phosphoenolpyruvate Carboxykinase (GTP); Pyruvate Kinase; Rats; Rats, Wistar

The relative proportions and relationships of pipping muscle and liver nutrients in broiler embryos on d 15 and 19 of incubation were determined. Ninety hatching eggs obtained from a 30-wk-old broiler breeder flock were incubated on 3 replicate tray levels (30 eggs per tray) for 19 d. On 15 and 19 d of incubation, 10 live embryos per tray level were necropsied to collect pipping muscle and liver samples. As the broiler embryo developed between d 15 and 19 of incubation, the glycogen and protein concentrations of the pipping muscle increased, whereas those of the liver decreased, and the fat concentration of the pipping muscle decreased, whereas that of the liver increased. Across d 15 and 19, pipping muscle glycogen was negatively correlated with liver fat, whereas on d 15, pipping muscle glucose was negatively correlated with liver fat, and pipping muscle glycogen was negatively correlated with liver glucose and glycogen. Pipping muscle fat was negatively correlated with liver glucose on d 15 but positively correlated with liver glycogen on d 19. In conclusion, in preparation for hatch between d 15 and 19 of incubation, weights of the liver and pipping muscle of broiler embryos increased relative to their BW. This occurred in association with the accumulation of glucose, glycogen, and protein and with the loss of fat in the pipping muscle. The carbohydrate stores in the pipping muscle were supported by the active metabolism of the liver before 19 d of incubation, which included the transfer of glucose and fatty acids to the pipping muscle via the circulation. Despite the liver's active supply of these nutrient subunits for assimilation and oxidation by the pipping muscle, there was an overall accumulation of hepatic fat between d 15 and 19 of incubation. These data suggest that the integrated changes in the energy profiles of pipping muscle and liver between 15 and 19 d of embryogenesis are integral to the broiler embryo's preparation for hatch.

Topics: Animals; Body Weight; Chick Embryo; Chickens; Egg Yolk; Glucose; Glycogen; Liver; Muscle, Skeletal; Proteins

1. Eggs from a meat-type breeder flock (Ross) were used in two trials to study the effects of in ovo administration of L-carnitine (carnitine) on hatchability traits (hatchability percentage, embryo deaths, pipped with live or dead embryo), chick weight at hatch as an absolute value (CWT) or expressed as a percentage of egg weight (CWT%), hatching period, glycogen status (liver and pectoral muscle) and plasma insulin-like growth factor-1 (IGF-1) of hatched chicks were investigated. There were 9 treatments with three replicates of each. Treatments were non-injected control (negative control), or injection with sterilised saline (09%, positive control), or sterilised saline with carnitine at 25, 50, 100, 200, 300, 400, and 500 microg/egg. 2. In ovo carnitine treatment increased CWT, CWT%, glycogen in the liver and pectoral muscle, glycogen index and plasma IGF-1 of hatched chicks, and did not influence hatchability traits and hatching period. The glycogen index of hatched chicks of the in ovo carnitine treatments with values (500 > 400 = 300 > 200) was higher than that of the control and in ovo carnitine at 25, 50, and 100 microg/egg treatments. The nature of response to carnitine was cubic for CWT and CWT%, and linear for glycogen in the liver and pectoral muscle, glycogen index of hatched chicks when the negative control or positive control treatment was used as base line. 3. It was concluded that in ovo administration of carnitine at 25-500 microg/egg increased chick weight at hatch and IGF-1, and did not influence hatchability traits and hatching period of eggs. The linear relationship between in ovo administration of carnitine and glycogen status of hatched chicks indicated that increasing in ovo doses improved glycogen status of hatched chicks.

Topics: Animals; Body Weight; Carnitine; Chick Embryo; Chickens; Glycogen; Insulin-Like Growth Factor I; Liver; Muscle, Skeletal; Random Allocation

Adipose tissue is a primary site for lipid storage containing trace amounts of glycogen. However, refeeding after a prolonged partial fast produces a marked transient spike in adipose glycogen, which dissipates in coordination with the initiation of lipid resynthesis. To further study the potential interplay between glycogen and lipid metabolism in adipose tissue, the aP2-PTG transgenic mouse line was utilized since it contains a 100- to 400-fold elevation of adipocyte glycogen levels that are mobilized upon fasting. To determine the fate of the released glucose 1-phosphate, a series of metabolic measurements were made. Basal and isoproterenol-stimulated lactate production in vitro was significantly increased in adipose tissue from transgenic animals. In parallel, basal and isoproterenol-induced release of nonesterified fatty acids (NEFAs) was significantly reduced in transgenic adipose tissue vs. control. Interestingly, glycerol release was unchanged between the genotypes, suggesting that enhanced triglyceride resynthesis was occurring in the transgenic tissue. Qualitatively similar results for NEFA and glycerol levels between wild-type and transgenic animals were obtained in vivo during fasting. Additionally, the physiological upregulation of the phosphoenolpyruvate carboxykinase cytosolic isoform (PEPCK-C) expression in adipose upon fasting was significantly blunted in transgenic mice. No changes in whole body metabolism were detected through indirect calorimetry. Yet weight loss following a weight gain/loss protocol was significantly impeded in the transgenic animals, indicating a further impairment in triglyceride mobilization. Cumulatively, these results support the notion that the adipocyte possesses a set point for glycogen, which is altered in response to nutritional cues, enabling the coordination of adipose glycogen turnover with lipid metabolism.

Topics: Adipocytes; Adipose Tissue; Animals; Body Weight; Calorimetry, Indirect; Fasting; Fatty Acids, Nonesterified; Glycogen; Lactic Acid; Male; Mice; Mice, Transgenic; Phosphoenolpyruvate Carboxykinase (ATP); Reverse Transcriptase Polymerase Chain Reaction; RNA; Specific Pathogen-Free Organisms; Triglycerides

Life history theory hypothesizes that genetically based variation in life history traits results from alleles that alter age-specific patterns of energy allocation among the competing demands of reproduction, storage, and maintenance. Despite the important role that alleles with age-specific effects must play in life history evolution, few naturally occurring alleles with age-specific effects on life history traits have been identified. A recent mapping study identified S6 kinase (S6k) as a candidate gene affecting lipid storage in Drosophila. S6k is in the target of rapamycin pathway, which regulates cell growth in response to nutrient availability and has also been implicated to influence many life history traits from fecundity to life span. In this article, we used quantitative complementation tests to examine the effect of allelic variation at S6k on a range of phenotypes associated with metabolism and fitness in an age-, diet-, and sex-specific manner. We found that alleles of S6k have pleiotropic effects on total protein levels, glycogen storage, life span, and the immune response and demonstrate that these allelic effects are age, diet, and sex specific. As many of the genes in the target of rapamycin pathway are evolutionarily conserved, our data suggest that genes in this pathway could play a pivotal role in life history evolution in a wide range of taxa.

Topics: Aging; Alleles; Animals; Bacteria; Body Weight; Diet; Dietary Proteins; Drosophila melanogaster; Energy Metabolism; Female; Fertility; Genetic Complementation Test; Genetic Variation; Glycogen; Longevity; Male; Mutation; Phagocytosis; Phenotype; Proteome; Ribosomal Protein S6 Kinases; Sex Characteristics; Sexual Abstinence; Triglycerides

A methanol extract of Gymnema sylvestre leaf and callus showed anti-diabetic activities through regenerating β-cells. Optimum callus was developed under stress conditions of blue light with 2,4-D (1.5 mg/l) and KN (0.5 mg/l), which induced maximum biomass of green compact callus at 45 days, as determined by growth curve analysis. Leaf and optimum callus extracts contains gymnemic acid, which was analyzed using TLC, HPTLC and HPLC methods. The research reported here deals with leaf and callus extracts of G. sylvestre, which significantly increase the weight of the whole body, liver, pancreas and liver glycogen content in alloxan-induced diabetic rats (Wistar rats). The gymnemic acid of leaf and callus extracts significantly increases the regeneration of β-cells in treated rats, when compared with the standard diabetic rats. It could have potential as a pharmaceutical drug for insulin-dependent diabetes mellitus (IDDM).

Topics: Animals; Body Weight; Diabetes Mellitus, Experimental; Female; Glycogen; Gymnema sylvestre; Hypoglycemic Agents; Insulin-Secreting Cells; Liver; Male; Organ Size; Plant Extracts; Plant Leaves; Plant Somatic Embryogenesis Techniques; Rats; Rats, Wistar; Regeneration

Two F(2) Charolais x German Holstein families comprising full and half sibs share identical but reciprocal paternal and maternal Charolais grandfathers differ in milk production. We hypothesized that differences in milk production were related to differences in nutritional partitioning revealed by glucose metabolism and carcass composition. In 18F(2) cows originating from mating Charolais bulls to German Holstein cows and a following intercross of the F(1) individuals (n=9 each for family Ab and Ba; capital letters indicate the paternal and lowercase letter the maternal grandsire), glucose tolerance tests were performed at 10 d before calving and 30 and 93 d in milk (DIM) during second lactation. Glucose half-time as well as areas under the concentration curve for plasma glucose and insulin were calculated. At 94 DIM cows were infused intravenously with 18.3 micromol of d-[U-(13)C(6)]glucose/kg(0.75) of BW, and blood samples were taken to measure rate of glucose appearance and glucose oxidation as well as plasma concentrations of metabolites and hormones. Cows were slaughtered at 100 DIM and carcass size and composition was evaluated. Liver samples were taken to measure glycogen and fat content, gene expression levels, and enzyme activities of pyruvate carboxylase, phosphoenolpyruvate carboxykinase, and glucose 6-phosphatase as well as gene expression of glucose transporter 2. Milk yield was higher and milk protein content at 30 DIM was lower in Ba than in Ab cows. Glucose half-life was higher but insulin secretion after glucose challenge was lower in Ba than in Ab cows. Cows of Ab showed higher glucose oxidation, and plasma concentrations at 94 DIM were lower for glucose and insulin, whereas beta-hydroxybutyrate was higher in Ba cows. Hepatic gene expression of pyruvate carboxylase, glucose 6-phosphatase, and glucose transporter 2 were higher whereas phosphoenolpyruvate carboxykinase activities were lower in Ba than in Ab cows. Carcass weight as well as fat content of the carcass were higher in Ab than in Ba cows, whereas mammary gland mass was lower in Ab than in Ba cows. Fat classification indicated leaner carcass composition in Ba than in Ab cows. In conclusion, the 2 families showed remarkable differences in milk production that were accompanied by changes in glucose metabolism and body composition, indicating capacity for milk production as main metabolic driving force. Sex chromosomal effects provide an important regulatory mechanism for milk perfo

Topics: Adipose Tissue; Animals; Blood Glucose; Body Composition; Body Weight; Breeding; Cattle; Female; Glucose; Glucose Transporter Type 2; Glycogen; Insulin; Lactation; Liver; Male; Milk

The influences of salinity and body size on biochemical (activities of glutathione-S-transferase, lactate dehydrogenase (LDH), acetylcholinesterase and digestive enzymes amylase and CMCase), physiological (feeding and egestion rates, energy reserves) and behavioural (burrowing speed) biomarkers were examined in the infaunal polychaete Nereis diversicolor. Only a few biomarkers were affected, including increased egestion rate and activities of CMCase and LDH at higher salinity, and higher egestion rate in larger worms. These findings reinforce the status of N. diversicolor as a robust sentinel species for estuaries which are environments that are particularly productive but also particularly at risk.

Topics: Acetylcholinesterase; Amylases; Animals; Behavior, Animal; Biomarkers; Body Weight; Ecosystem; Environmental Monitoring; Feeding Behavior; Glutathione Transferase; Glycogen; L-Lactate Dehydrogenase; Lipids; Polychaeta; Proteins; Salinity; Water Pollution

Maternal protein restriction during pregnancy and lactation reduces whole body lipid stores and alters lipid homeostasis in the adult offspring. Lipid homeostasis in the body is regulated, in part, by the liver via the metabolic processes of synthesis and utilization of lipids. The present study tested the hypothesis that maternal protein restriction will imprint changes in hepatic lipid metabolism and thereby alter the hepatic lipid content of the adult offspring. Pregnant rats were fed purified diets containing 19% protein (control group) or 8% protein (low-protein group) throughout pregnancy and lactation. On day 28, pups from both groups were weaned onto regular laboratory chow. On days 65 and 150, male and female pups from each litter in both groups were killed and blood and liver collected. Maternal protein restriction was found to reduce birth weight and produce long-term reduction in the body weight of the offspring. On day 65, liver triglyceride content was decreased by 40% in the male offspring that were fed a low-protein diet. The reduction in liver triglyceride content persisted until day 150, at which time it was accompanied by decreases in hepatic cholesterol content. No such changes were observed in the female offspring. To determine if the alterations in liver lipid content resulted in compensatory changes in liver carbohydrate stores, hepatic glycogen content was measured in male offspring. Hepatic glycogen content was similar between the 2 groups on days 65 and 150. In conclusion, the present study in rats showed that maternal protein restriction during pregnancy and lactation imprints long-term changes in hepatic lipid content selectively in the male offspring.

Topics: Animals; Birth Weight; Body Weight; Cholesterol; Diet, Protein-Restricted; Dietary Proteins; Female; Glycogen; Lactation; Liver; Male; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley; Sex Factors; Triglycerides

Fatty acids, which are the major cardiac fuel, are derived from lipid droplets stored in cardiomyocytes, among other sources. The heart expresses hormone-sensitive lipase (HSL), which regulates triglycerides (TG) breakdown, and the enzyme is under hormonal control. Evidence obtained from adipose tissue suggests that testosterone regulates HSL activity. To test whether this is also true in the heart, we measured HSL activity in the left ventricle of sedentary male rats that had been treated with testosterone supplementation or orchidectomy with or without testosterone substitution. Left ventricle HSL activity against TG was significantly elevated in intact rats supplemented with testosterone. HSL activity against both TG and diacylglyceride was reduced by orchidectomy, whereas testosterone replacement fully reversed this effect. Moreover, testosterone increased left ventricle free fatty acid levels, caused an inhibitory effect on carbohydrate metabolism in the heart, and elevated left ventricular phosphocreatine and ATP levels as compared to control rats. These data indicate that testosterone is involved in cardiac HSL activity regulation which, in turn, may affect cardiac lipid and carbohydrate metabolism.

Topics: Adenine; Animals; Body Weight; Fatty Acids; Glycogen; Heart Ventricles; Lactic Acid; Lipid Metabolism; Male; Organ Size; Phosphates; Pyruvic Acid; Rats; Rats, Wistar; Sterol Esterase; Testosterone

Recent studies showed that germ-free (GF) mice are resistant to obesity when consuming a high-fat, high-carbohydrate Western diet. However, it remains unclear what mechanisms are involved in the antiobesity phenotype and whether GF mice develop insulin resistance and dyslipidemia with high-fat (HF) feeding. In the present study, we compared the metabolic consequences of HF feeding on GF and conventional (conv) C57BL/6J mice. GF mice consumed fewer calories, excreted more fecal lipids, and weighed significantly less than conv mice. GF/HF animals also showed enhanced insulin sensitivity with improved glucose tolerance, reduced fasting and nonfasting insulinemia, and increased phospho-Akt((Ser-473)) in adipose tissue. In association with enhanced insulin sensitivity, GF/HF mice had reduced plasma TNF-α and total serum amyloid A concentrations. Reduced hypercholesterolemia, a moderate accretion of hepatic cholesterol, and an increase in fecal cholesterol excretion suggest an altered cholesterol metabolism in GF/HF mice. Pronounced nucleus SREBP2 proteins and up-regulation of cholesterol biosynthesis genes indicate that enhanced cholesterol biosynthesis contributed to the cholesterol homeostasis in GF/HF mice. Our results demonstrate that fewer calorie consumption and increased lipid excretion contributed to the obesity-resistant phenotype of GF/HF mice and reveal that insulin sensitivity and cholesterol metabolism are metabolic targets influenced by the gut microbiota.

Topics: Animals; Blotting, Western; Body Weight; Cholesterol; Dietary Fats; Germ-Free Life; Glucose Tolerance Test; Glycogen; Insulin Resistance; Lipids; Liver; Male; Mice; Mice, Inbred C57BL; Obesity; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction

The objective of this study was to analyze the aerobic capacity, through the maximal lactate steady-state (MLSS) protocol, of rats subjected to fetal protein malnutrition and recovered with a fructose-rich diet. Pregnant adult Wistar rats that were fed a balanced (17% protein) diet or a low-protein (6% protein) diet were used. After birth, the offspring were distributed into groups according to diet until 60 days of age: balanced (B), balanced diet during the whole experimental period; balanced-fructose (BF), balanced diet until birth and fructose-rich diet (60% fructose) until 60 days; low protein-balanced (LB), low-protein diet until birth and balanced diet until 60 days; and low protein-fructose (LF), low protein diet until birth and fructose-rich diet until 60 days. It was verified that the fructose-rich diet reduced body growth, mainly in the BF group. There was no difference among the groups in the load corresponding to the MLSS (B, 7.5+/-0.5%; BF, 7.4+/-0.6%; LB, 7.7+/-0.4%; and LF, 7.7+/-0.6% relative to body weight). However, the BF group presented higher blood lactate concentrations (4.8+/-0.9 mmol.L(-1)) at 25 min in the load corresponding to the MLSS (B, 3.2+/-0.9 mmol.L(-1); LB, 3.4+/-0.9 mmol.L(-1); and LF, 3.2+/-1.0 mmol.L(-1)). Taken together, these results indicate that the ability of young rats to perform exercise was not altered by intrauterine malnutrition or a fructose-rich diet, although the high fructose intake after the balanced diet in utero increased blood lactate during swimming exercises in rats.

Topics: Age Factors; Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Weight; Diet, Protein-Restricted; Dietary Proteins; Dietary Sucrose; Disease Models, Animal; Exercise Tolerance; Female; Fetal Nutrition Disorders; Glycogen; Kinetics; Lactic Acid; Liver; Male; Maternal Nutritional Physiological Phenomena; Pregnancy; Prenatal Exposure Delayed Effects; Protein-Energy Malnutrition; Rats; Rats, Wistar; Recovery of Function; Serum Albumin; Swimming

Arginine methylation by protein N-arginine methyltransferases (PRMTs) is an important posttranslational modification in the regulation of protein signaling. PRMT2 contains a highly conserved catalytic Ado-Met binding domain, but the enzymatic function of PRMT2 with respect to methylation is unknown. The JAK-STAT pathway is proposed to be regulated through direct arginine methylation of STAT transcription factors, and STAT3 signaling is known to be required for leptin regulation of energy balance.. To identify the potential role of STAT3 arginine methylation by PRMT2 in the regulation of leptin signaling and energy homeostasis.. We identified that PRMT2(-/-) mice are hypophagic, lean, and have significantly reduced serum leptin levels. This lean phenotype is accompanied by resistance to food-dependent obesity and an increased sensitivity to exogenous leptin administration. PRMT2 colocalizes with STAT3 in hypothalamic nuclei, where it binds and methylates STAT3 through its Ado-Met binding domain. In vitro studies further clarified that the Ado-Met binding domain of PRMT2 induces STAT3 methylation at the Arg31 residue. Absence of PRMT2 results in decreased methylation and prolonged tyrosine phosphorylation of hypothalamic STAT3, which was associated with increased expression of hypothalamic proopiomelanocortin following leptin stimulation.. These data elucidate a molecular pathway that directly links arginine methylation of STAT3 by PRMT2 to the regulation of leptin signaling, suggesting a potential role for PRMT2 antagonism in the treatment of obesity and obesity-related syndromes.

Topics: Animals; Arcuate Nucleus of Hypothalamus; Body Weight; Eating; Energy Metabolism; Glycogen; Leptin; Liver; Methylation; Methyltransferases; Mice; Mice, Mutant Strains; Obesity; Phosphorylation; Protein Structure, Tertiary; Protein-Arginine N-Methyltransferases; Signal Transduction; STAT3 Transcription Factor

Increasing environmental pollution may participate in the growing incidence of metabolic disorders. Static magnetic fields (SMFs) are an emerging environmental health issue due to increased exposure in residential and commercial areas; however, their metabolic effects in serum and skeletal muscle are largely unknown. The aim of this study was to investigate the effect of SMF exposure on glucose and lipid metabolism in serum and skeletal muscles of rats.. Twelve 6- to 7-week-old male Wistar rats were randomly divided into two groups: rats exposed to 128 mT SMF and sham-exposed rats. This moderate-intensity exposure was performed for 1 h/day for 15 consecutive days.. Animals exposed to 128 mT SMF displayed significant changes in both glucose (i.e., increases in plasma glucose and lactate and decrease in plasma insulin levels) and lipid (i.e., increases in plasma glycerol, cholesterol and phospholipids but not triglyceride levels) metabolism. During intraperitoneal glucose tolerance tests, SMF-exposed rats displayed significantly higher hyperglycemia compared to sham-exposed rats despite similar insulin levels in both groups. In tissues, SMF exposure induced significant alterations in enzyme activities only in glycolytic muscles and caused a significant decrease in quadriceps and liver glycogen content together with increased phospholipid levels.. This study provides evidence that subacute SMF exposure of moderate intensity induces important alterations of glucose and lipid metabolisms, which deserve further investigations to evaluate long-term consequences.

Topics: Animals; Body Weight; Glucose; Glycogen; Lipid Metabolism; Liver; Magnetics; Male; Muscle, Skeletal; Oxidation-Reduction; Rats; Rats, Wistar

1. The objective of this study was to test the hypothesis that in ovo feeding of carbohydrates and arginine into the duck amnion may improve the glycogen store and perinatal growth. At 23 d of incubation, fertile eggs were injected with 1·2 ml of sodium chloride (NaCl), sucrose + maltose (CHO), arginine (Arg) or sucrose + maltose + arginine (CHO + Arg), with controls not injected. Body weight, liver and muscle glycogen levels, and hepatic glucose-6-phosphatase activity were determined at 25 d of incubation, at hatch, and at 3 and 7 d posthatch. 2. At hatch and 7 d of age, the body weights were greater in the in ovo-feeding treatments than the controls. Arg and CHO + Arg significantly enhanced liver glycogen level at hatch compared with controls. CHO and CHO + Arg significantly increased muscle glycogen level at 25 d of incubation over controls. CHO and Arg decreased glucose-6-phosphatase at 25 d of incubation, whereas NaCl and CHO + Arg increased glucose-6-phosphatase at hatch relative to controls. 3. In ovo feeding of carbohydrates and arginine at 23 d of incubation may improve glycogen reserves, which may, in turn, provide the energy needed for perinatal growth.

Topics: Animals; Arginine; Body Weight; Ducks; Embryo, Nonmammalian; Embryonic Development; Energy Metabolism; Glucose-6-Phosphatase; Glycogen; Liver; Maltose; Muscles; Organ Size; Ovum; Sucrose

The purpose of this study was to determine the metabolic profile during the 2006 Ironman World Championship in Kailua-Kona, Hawaii.. One recreational male triathlete completed the race in 10:40:16. Before the race, linear regression models were established from both laboratory and field measures to estimate energy expenditure and substrate utilization. The subject was provided with an oral dose of ²H2(18)O approximately 64 h before the race to calculate total energy expenditure (TEE) and water turnover with the doubly labeled water (DLW) technique. Body weight, blood sodium and hematocrit, and muscle glycogen (via muscle biopsy) were analyzed pre-and postrace.. The TEE from DLW and indirect calorimetry was similar: 37.3 MJ (8,926 kcal) and 37.8 MJ (9,029 kcal), respectively. Total body water turnover was 16.6 L, and body weight decreased 5.9 kg. Hematocrit increased from 46 to 51% PCV. Muscle glycogen decreased from 152 to 48 mmoL/kg wet weight pre- to postrace.. These data demonstrate the unique physiological demands of the Ironman World Championship and should be considered by athletes and coaches to prepare sufficient nutritional and hydration plans.

Topics: Adult; Body Water; Body Weight; Calorimetry, Indirect; Energy Metabolism; Glycogen; Hematocrit; Humans; Linear Models; Male; Muscle, Skeletal; Sports

Sixty-four market-weight (130.0 +/- 0.65 kg) barrows (n = 16) and gilts (n = 48) were used in a split-plot design with a 2 x 2 x 2 factorial arrangement of treatments: 1) handling intensity (gentle vs. aggressive), 2) transport floor space (0.39 vs. 0.49 m(2)/pig), and 3) distance moved during handling (25 vs. 125 m) to determine the effects of multiple concurrent stressors on metabolic responses. For the handling intensity treatment, pigs were moved individually approximately 50 m through a handling course with either 0 (gentle) or 8 (aggressive) shocks from an electric goad. Pigs were loaded onto a trailer and transported for approximately 1 h at floor spaces of either 0.39 or 0.49 m(2)/pig. After transport, pigs were unloaded, and the distance moved treatment was applied; pigs were moved 25 or 125 m through a handling course using livestock paddles. Rectal temperature was measured, and blood samples (to measure blood acid-base status) were collected 2 h before the handling intensity treatment was applied and immediately after the distance moved treatment was applied. A LM sample to measure glycolytic potential was collected after the distance moved treatments on a subset of 32 pigs. There were handling intensity x distance moved interactions (P < 0.05) for several blood acid-base measurements. In general, there was no effect of distance moved on these traits when pigs were previously handled gently. However, when pigs were previously handled aggressively, pigs moved 125 compared with 25 m had greater (P < 0.05) blood lactate and less (P < 0.05) blood pH, bicarbonate, and base-excess. Pigs transported at 0.39 compared with 0.49 m(2)/pig had a greater (P < 0.01) increase in creatine kinase values; however, transport floor space did not affect any other measurements. Data were analyzed by the number of stressors (the aggressive handling, restricted transport floor space, and 125-m distance moved treatments) experienced by each pig (0, 1, 2, or 3). As the number of stressors experienced by the pig increased, rectal temperature, blood lactate, and LM lactate increased linearly (P

Topics: Acid-Base Equilibrium; Animal Husbandry; Animals; Bicarbonates; Body Temperature; Body Weight; Confined Spaces; Female; Floors and Floorcoverings; Glycogen; Glycolysis; Handling, Psychological; Hydrogen-Ion Concentration; Lactic Acid; Least-Squares Analysis; Male; Muscle, Skeletal; Stress, Physiological; Swine; Transportation

Diabetes mellitus is the most common and serious metabolic disorder among people all over the world. Many plants have successfully been used to overcome this problem. Costus speciosus is widely used in Indian medicine to treat various diseases including diabetes. Bioassay guided fractionation was followed to isolate costunolide from the hexane extract of C. speciosus root. The structure was elucidated using X-ray crystallography. Costunolide was administered to streptozotocin (STZ) (50 mg/kg bw)-induced diabetic male wistar rats at different doses (5, 10, 20 mg/kg bw) for 30 days to assess its effect on fasting plasma glucose and cholesterol levels. It was found that plasma glucose was significantly (p<0.05) reduced in a dose-dependent manner when compared to the control. In addition, oral administration of costunolide (20 mg/kg bw) significantly decreased glycosylated hemoglobin (HbA(1c)), serum total cholesterol, triglyceride, LDL cholesterol and at the same time markedly increased plasma insulin, tissue glycogen, HDL cholesterol and serum protein. Also costunolide restored the altered plasma enzyme (aspartate aminotransferase, alanine aminotrasferase, lactate dehydrogenase, alkaline phosphatase and acid phosphatase) levels to near normal. Costunolide might have stimulated the beta islets to secrete insulin by inhibiting the expression of nitric oxide synthase. The results of this experimental study indicated that costunolide possessed normo-glycemic and hypolipidemic activity and hence it could be used as a drug for treating diabetes.

Topics: Animals; Blood Glucose; Blood Proteins; Body Weight; Cholesterol; Costus; Diabetes Mellitus, Experimental; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Glycated Hemoglobin; Glycogen; Hypoglycemic Agents; Insulin; Lipids; Male; Plant Extracts; Plant Roots; Rats; Rats, Wistar; Sesquiterpenes; Streptozocin

Integrin receptor plays key roles in mediating both inside-out and outside-in signaling between cells and the extracellular matrix. We have observed that the tissue-specific loss of the integrin beta1 subunit in striated muscle results in a near complete loss of integrin beta1 subunit protein expression concomitant with a loss of talin and to a lesser extent, a reduction in F-actin content. Muscle-specific integrin beta1-deficient mice had no significant difference in food intake, weight gain, fasting glucose, and insulin levels with their littermate controls. However, dynamic analysis of glucose homeostasis using euglycemichyperinsulinemic clamps demonstrated a 44 and 48% reduction of insulin-stimulated glucose infusion rate and glucose clearance, respectively. The whole body insulin resistance resulted from a specific inhibition of skeletal muscle glucose uptake and glycogen synthesis without any significant effect on the insulin suppression of hepatic glucose output or insulin-stimulated glucose uptake in adipose tissue. The reduction in skeletal muscle insulin responsiveness occurred without any change in GLUT4 protein expression levels but was associated with an impairment of the insulin-stimulated protein kinase B/Akt serine 473 phosphorylation but not threonine 308. The inhibition of insulin-stimulated serine 473 phosphorylation occurred concomitantly with a decrease in integrin-linked kinase expression but with no change in the mTOR.Rictor.LST8 complex (mTORC2). These data demonstrate an in vivo crucial role of integrin beta1 signaling events in mediating cross-talk to that of insulin action.

Topics: Actins; Adipose Tissue; Animals; Body Weight; Carrier Proteins; Eating; Fasting; Glucose; Glucose Transporter Type 4; Glycogen; Insulin; Insulin Resistance; Integrin beta1; Liver; Mice; Mice, Knockout; Muscle, Striated; Organ Specificity; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor); Proto-Oncogene Proteins c-akt; Rapamycin-Insensitive Companion of mTOR Protein; Signal Transduction; Talin; TOR Serine-Threonine Kinases

Three polysaccharides MP-1, MP-2, and MP-3 were isolated from hot water extract of Chinese medicine Morinda officinalis through 95% ethanol precipitation and gel-filtration chromatography (DEAE-Sepharose CL-6B column and Sephadex G-75 or G-100 column). MP-1 was identified as an inulin-type fructan with simple linear (2-->1)-linked structure. Both MP-2 and MP-3 were acidic polysaccharides which consisted predominantly of galacturonic acid, arabinose and galactose. Partial structure characterization of MP-3 was carried out by partial acid hydrolysis and periodate oxidation. The total polysaccharides of the herb were tested in mice weight-loaded swimming model and were found to have anti-fatigue activity.

Topics: Animals; Body Weight; Drug Evaluation, Preclinical; Fatigue; Glycogen; Lactic Acid; Liver; Magnetic Resonance Spectroscopy; Male; Mice; Morinda; Phytotherapy; Plant Roots; Polysaccharides; Swimming; Time Factors; Urea

Obesity is a risk factor for type 2 diabetes in cats. The risk of developing diabetes is severalfold greater for male cats than for females, even after having been neutered early in life. The purpose of this study was to investigate the role of different metabolic pathways in the regulation of endogenous glucose production (EGP) during the fasted state considering these risk factors. A triple tracer protocol using (2)H(2)O, [U-(13)C(3)]propionate, and [3,4-(13)C(2)]glucose was applied in overnight-fasted cats (12 lean and 12 obese; equal sex distribution) fed three different diets. Compared with lean cats, obese cats had higher insulin (P < 0.001) but similar blood glucose concentrations. EGP was lower in obese cats (P < 0.001) due to lower glycogenolysis and gluconeogenesis (GNG; P < 0.03). Insulin, body mass index, and girth correlated negatively with EGP (P < 0.003). Female obese cats had approximately 1.5 times higher fluxes through phosphoenolpyruvate carboxykinase (P < 0.02) and citrate synthase (P < 0.05) than male obese cats. However, GNG was not higher because pyruvate cycling was increased 1.5-fold (P < 0.03). These results support the notion that fasted obese cats have lower hepatic EGP compared with lean cats and are still capable of maintaining fasting euglycemia, despite the well-documented existence of peripheral insulin resistance in obese cats. Our data further suggest that sex-related differences exist in the regulation of hepatic glucose metabolism in obese cats, suggesting that pyruvate cycling acts as a controlling mechanism to modulate EGP. Increased pyruvate cycling could therefore be an important factor in modulating the diabetes risk in female cats.

Topics: Animals; Blood Glucose; Body Mass Index; Body Weight; Carbon Isotopes; Cats; Citrate (si)-Synthase; Citric Acid Cycle; Diabetes Mellitus, Type 2; Diet; Disease Models, Animal; Eating; Fasting; Female; Gluconeogenesis; Glycerol; Glycogen; Glycogenolysis; Indicator Dilution Techniques; Insulin; Liver; Magnetic Resonance Spectroscopy; Male; Obesity; Phosphoenolpyruvate Carboxykinase (GTP); Pyruvic Acid; Sex Factors

We investigated the mechanisms whereby peroxisome proliferator-activated receptor-gamma (PPARgamma) agonism affects glucose and lipid metabolism in brown adipose tissue (BAT) by studying the impact of PPARgamma activation on BAT glucose uptake and metabolism, lipogenesis, and mRNA levels plus activities of enzymes involved in triacylglycerol (TAG) synthesis. Interscapular BAT of rats treated or not with rosiglitazone (15 mg*kg(-1).day(-1), 7 days) was evaluated in vivo for glucose uptake and lipogenesis and in vitro for glucose metabolism, gene expression, and activities of glycerolphosphate acyltransferase (GPAT), phosphatidate phosphatase-1 (PAP or lipin-1), and diacylglycerol acyltransferase (DGAT). Rosiglitazone increased BAT mass without affecting whole tissue glucose uptake. BAT glycogen content (-80%), its synthesis from glucose (-50%), and mRNA levels of UDP-glucose pyrophosphorylase (-40%), which generates UDP-linked glucose for glycogen synthesis, were all reduced by rosiglitazone. In contrast, BAT TAG-glycerol synthesis in vivo and glucose incorporation into TAG-glycerol in vitro were stimulated by the agonist along with the activities and mRNA levels of glycerol 3-phosphate-generating phosphoenolpyruvate carboxykinase and glycerokinase. Furthermore, rosiglitazone markedly increased the activities of GPAT and DGAT but not those of lipin-1-mediated PAP-1, enzymes involved in the sequential acylation of glycerol 3-phosphate and TAG synthesis. Because an adequate supply of fatty acids is essential for BAT nonshivering thermogenesis, the enhanced ability of BAT to synthesize TAG under PPARgamma activation may constitute an important mechanism by which lipid substrates are stored in preparation for an eventual thermogenic activation.

Topics: Adipose Tissue, Brown; Animals; Blood Glucose; Body Weight; Diacylglycerol O-Acyltransferase; Energy Metabolism; Glucose; Glycogen; Hypoglycemic Agents; Insulin; Lactates; Lipogenesis; Male; Models, Animal; Pancreatitis-Associated Proteins; PPAR gamma; Rats; Rats, Sprague-Dawley; RNA, Messenger; Rosiglitazone; Thiazolidinediones; Triglycerides

The present study was performed to investigate the involvement of SNARK in physical activity levels in mice. To examine the acute effect of SNARK deficiency on voluntary running, Snark-deficient mice (Snark(+/-): n = 16) and their wild-type counterparts (Snark(+/+): n = 16) were assigned to sedentary or exercise (1 wk voluntary wheel running) groups. In addition, to clarify the differences in voluntary running activity and its effect between genotypes, mice (Snark(+/+): n = 16; Snark(+/-): n = 16) were also kept in individual cages with/without a running wheel for 5 mo. Unexpectedly, in both voluntary running experiments, running distances were increased in Snark(+/-) mice compared with Snark(+/+) mice. Under sedentary conditions, body and white adipose tissue weights were increased significantly in Snark(+/-) mice. However, no significant differences were observed between the two genotypes under exercise conditions, and the values were significantly less than those under sedentary conditions in the long-term experiment. In the short-term experiment, serum interleukin-6 level in exercised Snark(+/+) mice was the same as that in sedentary Snark(+/+) mice, whereas that in sedentary Snark(+/-) mice was significantly lower than in the other groups. In contrast, serum leptin level was reduced significantly in exercised Snark(+/-) mice compared with sedentary Snark(+/-) mice. The results of this study demonstrated that exposure to an environment that allows voluntary exercise promotes increased running activity and prevents obesity in Snark-deficient mice.

Topics: Adenylate Kinase; Animals; Body Temperature; Body Weight; Eating; Female; Glycogen; Histocytochemistry; Interleukin-6; Leptin; Male; Mice; Mice, Knockout; Obesity; Organ Size; Physical Conditioning, Animal; Protein Serine-Threonine Kinases; Running

Corticosterone and insulin play complex roles in the amount and composition of calories ingested, and the utilization and deposition of this energy. Understanding the interplay of these two hormones is complicated because increasing concentrations of corticosterone dose-dependently increase circulating insulin levels. We addressed individual contributions of each hormone by controlling, at steady-state levels, corticosterone (by adrenalectomy and exogenous replacement) and insulin (by streptozotocin-induced destruction of pancreatic beta-cells and exogenous replacement) across a spectrum of concentrations in rats, creating 8 hormonal combinations. For 5 days after surgery, all rats received chow. At day 5, they were subdivided into those that continued to receive chow and those that had a choice between chow, lard, and 32% sucrose for a further 5 days. During the choice/chow period, total calories ingested were stimulated by corticosterone and choice diet, and subject to a corticosterone-insulin interaction. Sucrose, but not lard, intake was stimulated by insulin. Body weight was increased by insulin, decreased by high corticosterone, and unaffected by diet. White adipose tissue depot weights were stimulated by insulin, corticosterone, and diet. Plasma triglycerides, free fatty acids, total ketone bodies, glucose, and glycerol were all significantly increased by corticosterone and the choice diet but inhibited by insulin. In contrast, plasma leptin was only increased by insulin and diet, plasma glucagon and liver glycogen was only affected by insulin and liver triglycerides, and arcuate nucleus proopiomelanocortin mRNA was only influenced by diet. Collectively, these data show that corticosterone and insulin determine the intake, form, and compartmentalization of energy both independently and interactively.

Topics: Adrenalectomy; Animals; Arcuate Nucleus of Hypothalamus; Body Weight; Corticosterone; Diabetes Mellitus, Experimental; Disease Models, Animal; Energy Intake; Energy Metabolism; Glycogen; Insulin; Leptin; Liver; Male; Neuropeptide Y; Pro-Opiomelanocortin; Rats; Rats, Sprague-Dawley; Streptozocin; Triglycerides

The possible protective effect of ethanolic extract of B. monosperma leaves (BMEE) on diabetes and diabetes-induced oxidative stress was evaluated in alloxan (ALXN)-induced diabetic male adult mice. Experimental animals were divided into three groups viz., I, II, and III. Diabetes mellitus (DM) was induced in groups II and III mice by a single intraperitoneal injection of alloxan (150 mg/kg body wt). Group I (control mice) received an equal volume of normal saline. Group III mice were further treated with BMEE (300 mg/kg body wt, p.o.) for a period of 45 days. Body weight and fasting blood glucose (FBG) levels were measured at periodic intervals during the test period. At the end of treatment period, blood was collected by cardiac puncture under mild ether anesthesia and serum was isolated to analyze its lipid profile i.e. serum total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL) and very low density lipoprotein (VLDL). The homogenates of hepatic, pancreatic and renal tissues were also analyzed for both enzymatic and non-enzymatic antioxidants, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), reduced glutathione (GSH), thiobarbituric acid reactive substances (TBARS) and total protein (TP). Alloxan injection resulted in a significantly (P < 0.05) increased concentration of FBG level. Besides, the levels of enzymatic and nonenzymatic antioxidants were decreased and TBARS level increased significantly (P < 0.05) in hepatic, pancreatic and renal tissues. Also, serum TC, TG, LDL and VLDL-cholesterol level elevated significantly (P < 0.05), whereas HDL-cholesterol reduced significantly (P < 0.05) in group II (alloxan-treated diabetic control). The FBG level decreased significantly (P < 0.05) after 45 days treatment of BMEE from 172 to 117.143 mg/dl, as compared to normal control (79.286 mg/dl). The activities of antioxidant enzymes (CAT and GSH-Px) and GSH level in hepatic, pancreatic and renal tissues also increased significantly (P < 0.05) in BMEE-treated mice, but the activity of SOD was not improved significantly. BMEE treatment also reduced the TBARS levels and lowered serum lipid profile significantly (P < 0.05). The findings of the present study indicated significant hypoglycemic and anti-oxidant activity in B. monosperma leaves, thus lends credence to its folklore use in the management and/or control of type-2 DM.

Topics: Alloxan; Analysis of Variance; Animals; Antioxidants; Blood Chemical Analysis; Blood Glucose; Body Weight; Butea; Diabetes Mellitus, Experimental; Glycogen; Hypoglycemic Agents; Kidney; Liver; Male; Mice; Pancreas; Phytotherapy; Plant Extracts

To evaluate the antidiabetic and antioxidant effects of various fractions of Phyllanthus simplex on alloxan induced diabetes in rats.. Hypoglycemic effect of Phyllanthus simplex fractions was evaluated in normal and diabetic rats. Diabetes was induced by intraperitoneal injection of alloxan monohydrate (120 mg/kg). Normal and diabetic rats were divided into different groups (six rats each group) and orally administered with petroleum ether (P.E.) (200 and 400 mg/kg), ethyl acetate (EtOAc) (100 and 200 mg/kg), methanol (125 and 250 mg/kg), water fraction (150 and 300 mg/kg) and glibenclamide (10 mg/kg) for 21 days. Blood samples were collected from overnight fasted normal rats on day 21, from overnight fasted diabetic rats at 7, 14 and 21 days of treatment and analyzed for blood glucose level. On day 22 blood samples were collected from diabetic rats to estimate biochemical parameters, rats were sacrificed by single stunning and tissues were excised to measure their antioxidant and glycogen status.. In the normoglycemic rats, MeOH (125 and 250 mg/kg) and aqueous fractions (150 and 300 mg/kg) showed a significant (P<0.05) hypoglycemic effect on day 21. In diabetic control rats, MeOH (125 and 250 mg/kg) and aqueous fractions (150 and 300 mg/kg) showed significant antihyperglycemic effect (P<0.001). The active fractions (MeOH and aqueous) of Phyllanthus simplex also increased the body weight of diabetic rats significantly compared to the control group. The active fractions were able to normalize the marked alterations in antioxidant enzymes and antioxidant parameters levels in liver and kidney. Treatment with the active fractions also normalized the diabetic induced hyperlipidemia and liver glycogen.. These results demonstrate the antidiabetic and antioxidant potential of fractions of Phyllanthus simplex and suggests that the plant may have therapeutic value in diabetes and related complications.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Glycogen; Hyperlipidemias; Hypoglycemic Agents; Kidney; Liver; Male; Phyllanthus; Phytotherapy; Plant Extracts; Rats

We evaluated the effects of partly substituting lard with marine n-3 fatty acids (FA) on body composition and weight, adipose tissue distribution and gene expression in five adipose depots of male Wistar rats fed a high-fat diet. Rats were fed diets including lard (19.5 % lard) or n-3 FA (9.1 % lard and 10.4 % Triomar) for 7 weeks. Feed consumption and weight gain were similar, whereas plasma lipid concentrations were lower in the n-3 FA group. Magnetic resonance imaging revealed smaller visceral (mesenteric, perirenal and epididymal) adipose depots in the n-3 FA-fed animals (35, 44 and 32 % reductions, respectively). n-3 FA feeding increased mRNA expression of cytokines as well as chemokines in several adipose depots. Expression of Adipoq and Pparg was enhanced in the mesenteric adipose depots of the n-3 FA-fed rats, and fasting plasma insulin levels were lowered. Expression of the lipogenic enzymes Acaca and Fasn was increased in the visceral adipose depots, whereas Dgat1 was reduced in the perirenal and epididymal depots. Cpt2 mRNA expression was almost doubled in the mesenteric depot and liver. Carcass analyses showed similar body fat (%) in the two feeding groups, indicating that n-3 FA feeding led to redistribution of fat away from the visceral compartment.

Topics: Adipokines; Adipose Tissue; Adiposity; Animals; Body Composition; Body Weight; Cytokines; Diet; Dietary Fats; Fatty Acids, Omega-3; Fish Oils; Gene Expression Regulation; Glucose; Glycogen; Lipid Metabolism; Lipids; Liver; Magnetic Resonance Imaging; Male; Muscle, Skeletal; Rats; Rats, Wistar; RNA, Messenger

We investigated cardiac hypertrophy elicited by rosiglitazone treatment at the level of protein synthesis/degradation, mTOR, MAPK and AMPK signalling pathways, cardiac function and aspects of carbohydrate/lipid metabolism. Hearts of rats treated or not with rosiglitazone (15 mg/kg day) for 21 days were evaluated for gene expression, protein synthesis, proteasome and calpain activities, signalling pathways, and function by echocardiography. Rosiglitazone induced eccentric heart hypertrophy associated with increased expression of ANP, BNP, collagen I and III and fibronectin, reduced heart rate and increased stroke volume. Rosiglitazone robustly increased heart glycogen content ( approximately 400%), an effect associated with increases in glycogenin and UDPG-PPL mRNA levels and glucose uptake, and a reduction in glycogen phosphorylase expression and activity. Cardiac triglyceride content, lipoprotein lipase activity and mRNA levels of enzymes involved in fatty acid oxidation were also reduced by the agonist. Rosiglitazone-induced cardiac hypertrophy was associated with an increase in myofibrillar protein content and turnover (increased synthesis and an enhancement of calpain-mediated myofibrillar degradation). In contrast, 26S beta5 chymotryptic proteasome activity and mRNA levels of 20S beta2 and beta5 and 19S RPN 2 proteasome subunits along with the ubiquitin ligases atrogin and CHIP were all reduced by rosiglitazone. These morphological and biochemical changes were associated with marked activation of the key growth-promoting mTOR signalling pathway, whose pharmacological inhibition with rapamycin completely blocked cardiac hypertrophy induced by rosiglitazone. The study demonstrates that both arms of protein balance are involved in rosiglitazone-induced cardiac hypertrophy, and establishes the mTOR pathway as a novel important mediator therein.

Topics: Animals; Atrial Natriuretic Factor; Blotting, Western; Body Weight; Cardiomegaly; Eating; Echocardiography; Glucosyltransferases; Glycogen; Glycogen Phosphorylase; Glycogen Synthase; Glycoproteins; Hemodynamics; Hypoglycemic Agents; Lipoprotein Lipase; Male; Myofibrils; Natriuretic Peptide, Brain; Proteasome Endopeptidase Complex; Protein Kinases; Rats; Rats, Sprague-Dawley; Rosiglitazone; Thiazolidinediones; TOR Serine-Threonine Kinases; UTP-Glucose-1-Phosphate Uridylyltransferase

The present study investigated whether or not muscle triacylglycerol (MTG) contributed as a main energy source and MTG level and utilized fatty acid (FA) composition decreased during a 4-hour swimming exercise in rats fed a normal diet or a high-fat diet (HFD). Sixty male Wistar rats aged 5 weeks were fed a normal diet (CE-2, n = 25, experiment A) or HFD (n = 35, experiment B) for 22 days. On the final day, rats in both experiments were killed either without exercise or 1, 2, 3, or 4 hours after beginning the swimming exercise. MTG accumulation was higher in rats fed the HFD than those fed the CE-2 in both slow- and fast-typed muscles. Serum concentrations of free fatty acids (FFA) and glucose were increased and muscle glycogen contents were decreased with the continuance of swimming exercise, especially in rats fed the CE-2. The prolonged swimming did not influence MTG contents and FA compositions of MTG in either the experiment. These results might indicate that specific FA of MTG was not oxidized and MTG did not contribute as a main energy source during the prolonged swimming exercise in rats; instead, serum FFA, glucose, and muscle glycogen were mainly used.

Topics: Animals; Blood Glucose; Body Weight; Dietary Fats; Fatty Acids, Nonesterified; Glycogen; Male; Muscles; Organ Size; Organ Specificity; Physical Conditioning, Animal; Rats; Rats, Wistar; Swimming; Triglycerides

The stem of Begonia malabarica was used traditionally by the Malasar tribe to treat diabetes. To validate the hypoglycemic and antihyperglycemic effects of the hexane, ethylacetate and methanol extracts obtained from an ethnomedicinal plant, Begonia malabarica.. The doses for the study were fixed based on Irwin test. The hypoglycemic effect of hexane, ethylacetate and methanol extracts of Begonia malabarica stems were studied in normal animals. The antihyperglycemic effect of the methanol extract was studied in streptozotocin induced diabetic rats.. In normal rats the treatment with the methanol extract of Begonia malabarica had shown a highly significant reduction (16.54 and 34.47%) in plasma glucose levels from the 0 h values at the dose of 100 and 200 mg/kg respectively. In streptozotocin induced diabetic rats the body weight of the Begonia malabarica methanol extract treated animals had shown a significant increase (13.38% at 200 mg/kg) after 4 weeks treatment. The plasma glucose levels were reduced significantly by 46.57 and 50.20% after 4 weeks treatment at 100 and 200mg/kg respectively. Likewise the absolute kidney weight was also reduced in a significant manner. After 25 days treatment the Begonia malabarica methanol extract treated animals had shown low fasting plasma glucose levels (54.29, 61.34% in 100 and 200 mg/kg) and reduced postprandial plasma glucose levels (54.23, 65.96% in 100 and 200 mg/kg) when compared with diabetic control values. Serum insulin levels and liver glycogen levels were increased to 40.04 and 42.18% in 200 mg/kg Begonia malabarica methanol extract treated animals respectively. The treatment with Begonia malabarica methanol extract did not change the triglycerides and total cholesterol levels. The urea and creatinine levels were also reduced significantly by this treatment. The reduction in SGPT levels indicated the absence of toxicity of Begonia malabarica extract at this dose level.. This study supports the use of Begonia malabarica by the Malasar tribe for the treatment of diabetes. Fractionation of this extract may yield novel prototypes to manage diabetes mellitus.

Topics: Analysis of Variance; Animals; Begoniaceae; Blood Glucose; Blood Urea Nitrogen; Body Weight; Cholesterol; Creatinine; Diabetes Mellitus, Experimental; Glycogen; Hypoglycemic Agents; Insulin; Kidney; Liver; Male; Organ Size; Phytotherapy; Plant Bark; Plant Extracts; Rats; Rats, Wistar; Streptozocin; Triglycerides

The European polecat (Mustela putorius) is a naturally lean carnivore prone to excessive weight gain in captivity. This study assessed its suitability to investigate the natural history of the obese phenotype displayed in overweight humans, domestic animals, and seasonally obese wild mammals. Ten farm-bred polecats were subjected to a 5-day fast with 10 controls. Obesity (40% body fat) was associated with an unfavorable plasma lipid profile and high glucose and insulin concentrations. The polecats were in phase II of fasting with normoglycemia, low liver carbohydrate stores, and decreased plasma concentrations of urea and most amino acids. Although the plasma nonesterified fatty acid (NEFA) levels were elevated, the adipose tissue lipase activities suggested a blunted lipolytic response. Lipid mobilization was more efficient from intraabdominal fat. The animals developed hepatic lipidosis with elevated NEFA influx into the liver and losses of n-3 polyunsaturated fatty acids and arginine as hypothetical etiological factors. The plasma leptin, insulin, and triiodothyronine levels decreased but were not accompanied by reduced sex steroid or increased stress hormone concentrations. The blunted lipolytic response often encountered in obesity suggests that the organism is trying to defend the obese phenotype. Liver lipidosis and decreased insulin and triiodothyronine levels seem to be among the most consistent responses to fasting manifested in diverse mammalian orders and different levels of body fatness. The polecat could be recommended as an easily accessible carnivorean model to study the natural history of the obese phenotype and its comorbidities.

Topics: Animals; Blood Cell Count; Body Temperature; Body Weight; Cholesterol; Europe; Fasting; Female; Ferrets; Food Deprivation; Glycogen; Hormones; Lipase; Liver; Male; Nitrogen Compounds; Obesity; Organ Size; Time Factors; Triglycerides; Weight Loss

The present study was undertaken to assess the effect of Helicteres isora L. on four important enzymes of carbohydrate metabolism (glucokinase [GK], hexokinase [HK] phosphofructokinase [PFK] and fructose-1, 6-bisphosphatase [FBP]) along with glycogen content of insulin-dependent (skeletal muscle and liver) and insulin-independent tissues (kidneys and brain) in streptozotocin (STZ; 60 mg/kg)-induced model of diabetes for 30 days. Administration of bark extracts (100, 200 mg/kg) for 30 days led to decrease in plasma glucose levels by approximately 9.60% and 22.04% and 19.18% and 33.93% on 15th and 30th day, respectively, of the experiment. Liver and two-kidney weight expressed as percentage of body weight significantly increased in diabetics (P < 0.05) versus normal controls. Renal glycogen content increased by 10 folds while hepatic and skeletal muscle glycogen content decreased by 75% and 68% in diabetic controls versus controls. H. isora did not affect glycogen content in any tissue. The decreased activities of PFK, GK, FBP and HK in diabetic controls were 40%, 50%, 50% and 60% and bark extract of H. isora partially corrected this alteration. The efficacy of the bark extract was comparable with Tolbutamide, a well-known hypoglycemic drug.

Topics: Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Glycogen; Kidney; Liver; Malvaceae; Organ Size; Plant Bark; Plant Extracts; Rats; Rats, Wistar; Streptozocin

During diabetes mellitus, endogenous hepatic glucose production is increased as a result of impaired activities of the key enzymes of carbohydrate metabolism, which leads to the condition known as hyperglycemia. D-pinitol, a bioactive constituent isolated from soybeans, has been shown to reduce hyperglycemia in experimental diabetes. We therefore designed this study to investigate the effect of oral administration of D-pinitol (50 mg/kg b. w. for 30 days) on the activities of key enzymes in carbohydrate and glycogen metabolism in the liver tissues of streptozotocin-induced diabetic rats. The efficacy was compared with glyclazide, a standard hypoglycemic drug. Oral administration of D-pinitol to diabetic group of rats showed a marked decrease in the levels of blood glucose, glycosylated hemoglobin and an increase in plasma insulin and body weight. The activities of the hepatic enzymes such as hexokinase, pyruvate kinase, glucose-6-phosphate dehydrogenase, glycogen synthase and hepatic glycogen content were significantly (p < 0.05) increased whereas the activities of glucose-6-phosphatase, fructose-1,6-bisphosphatase, lactate dehydrogenase and glycogen phosphorylase were significantly (p < 0.05) decreased in diabetic rats treated with D-pinitol. The results suggest that alterations in the activities of key metabolic enzymes of carbohydrate metabolism could be one of the biochemical rationale by which D-pinitol attenuates the hyperglycemic effect in diabetic rats.

Topics: Animals; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Gliclazide; Glucose Tolerance Test; Glycogen; Glycogen Phosphorylase; Glycogen Synthase; Hypoglycemic Agents; Inositol; Liver; Male; Rats; Rats, Wistar

The effects of Cu and Cd at their at their low concentrations (80microg/g diet) on the morphology and ultrastructure of the midgut and Malpighian tubules of Boettcherisca peregrina larvae were observed by light and transmission electron microscopy. After exposure to both metals, the midgut got darker, shorter, and thicker than in control, and many strumae occurred on the surface of the midgut. Similarly, Malpighian tubules got shorter and thinner. Ultrastructural alterations in the midgut included mitochondrial condensation, swelling, and lysis. The rough endoplasmic reticulum (rER) showed dilation and vesiculation. The microvilli were shortened and disorganized. The stored glycogens increased and many mineral spherites appeared along with lipid droplets decreased. Ultrastructural alterations observed in the Malpighian tubules included rER vesiculation and mitochondria swelling with loss of cristae. Shortened and disordered microvilli, increased numbers of large hydropic vacuoles, and mineral spherites were also observed.

Topics: Animals; Biomarkers; Body Weight; Cadmium; Copper; Digestive System; Diptera; Endoplasmic Reticulum; Glycogen; Growth; Larva; Malpighian Tubules; Microscopy, Electron, Transmission; Tissue Distribution

The hypothalamic AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) pathway is known to play an important role in the control of food intake and energy expenditure. Here, we hypothesize that citrate, an intermediate metabolite, activates hypothalamic ACC and is involved in the control of energy mobilization. Initially, we showed that ICV citrate injection decreased food intake and diminished weight gain significantly when compared to control and pair-fed group results. In addition, we showed that intracerebroventricular (ICV) injection of citrate diminished (80% of control) the phosphorylation of ACC, an important AMPK substrate. Furthermore, citrate treatment inhibited (75% of control) hypothalamic AMPK phosphorylation during fasting. In addition to its central effect, ICV citrate injection led to low blood glucose levels during glucose tolerance test (GTT) and high glucose uptake during hyperglycemic-euglycemic clamp. Accordingly, liver glycogen content was higher in animals given citrate (ICV) than in the control group (23.3+/-2.5 vs. 2.7+/-0.5 microg mL(-1) mg(-1), respectively). Interestingly, liver AMPK phosphorylation was reduced (80%) by the citrate treatment. The pharmacological blockade of beta3-adrenergic receptor (SR 59230A) blocked the effect of ICV citrate and citrate plus insulin on liver AMPK phosphorylation. Consistently with these results, rats treated with citrate (ICV) presented improved insulin signal transduction in liver, skeletal muscle, and epididymal fat pad. Similar results were obtained by hypothalamic administration of ARA-A, a competitive inhibitor of AMPK. Our results suggest that the citrate produced by mitochondria may modulate ACC phosphorylation in the hypothalamus, controlling food intake and coordinating a multiorgan network that controls glucose homeostasis and energy uptake through the adrenergic system.

Topics: Acetyl-CoA Carboxylase; AMP-Activated Protein Kinases; Animals; Body Weight; Citric Acid; Corticosterone; Feeding Behavior; Glucose; Glucose Tolerance Test; Glycogen; Homeostasis; Hypothalamus; Injections, Intraventricular; Insulin; Liver; Male; Multienzyme Complexes; Phosphorylation; Propanolamines; Protein Serine-Threonine Kinases; Rats; Rats, Wistar; Satiety Response; Signal Transduction

Type 2 diabetes is preceded by the presence of skeletal muscle insulin resistance, and drugs that increase insulin sensitivity in skeletal muscle prevent the disease. S15511 is an original compound with demonstrated effects on insulin sensitivity in animal models of insulin resistance. However, the mechanisms behind the insulin-sensitizing effect of S15511 are unknown. The aim of our study was to explore whether S15511 improves insulin sensitivity in skeletal muscles. Insulin sensitivity was assessed in skeletal muscles from S15511-treated rats by measuring intracellular insulin-signaling activity and insulin-stimulated glucose transport in isolated muscles. In addition, GLUT4 expression and glycogen levels were assessed after treatment. S15511 treatment was associated with an increase in insulin-stimulated glucose transport in type IIb fibers, while type I fibers were unaffected. The enhanced glucose transport was mirrored by a fiber type-specific increase in GLUT4 expression, while no improvement in insulin-signaling activity was observed. S15511 is a novel insulin sensitizer that is capable of improving glucose homeostasis in nondiabetic rats. The compound enhances skeletal muscle insulin sensitivity and specifically targets type IIb muscle fibers by increasing GLUT4 expression. Together these data show S15511 to be a potentially promising new drug in the treatment and prevention of type 2 diabetes.

Topics: 3-O-Methylglucose; Adaptor Proteins, Signal Transducing; Adipose Tissue; Animals; Biological Transport, Active; Body Weight; Fluorenes; Glucose; Glucose Transporter Type 4; Glycogen; Hypoglycemic Agents; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Male; Muscle, Skeletal; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Signal Transduction

The present study was aimed at evaluating the molecular mechanisms associated with the differences in muscle glycogen content and breast meat quality between 2 experimental lines of chicken divergently selected on abdominal fatness. The glycogen at death (estimated through the glycolytic potential) of the pectoralis major muscle and the quality of the resulting meat were estimated in the 2 lines. The fat chickens exhibited greater glycolytic potential, and in turn lower ultimate pH than the lean chickens. Consequently, the breast meat of fat birds was paler and less colored (i.e., less red and yellow), and exhibited greater drip loss compared with that of lean birds. In relation to these variations, transcription and activation levels of adenosine monophosphate-activated protein kinase (AMPK) were investigated. The main difference observed between lines was a 3-fold greater level of AMPK activation, evaluated through phosphorylation of AMPKalpha-(Thr(172)), in the muscle of lean birds. At the transcriptional level, data indicated concomitant down- and upregulation for the gamma1 and gamma2 AMPK subunit isoforms, respectively, in the muscle of lean chickens. Transcriptional levels of enzymes directly involved in glycogen turnover were also investigated. Data showed greater gene expression for glycogen synthase, glycogen phosphorylase, and the gamma subunit of phosphorylase kinase in lean birds. Together, these data indicate that selection on body fatness in chicken alters the muscle glycogen turnover and content and consequently the quality traits of the resulting meat. Alterations of AMPK activity could play a key role in these changes.

Topics: Adipose Tissue; AMP-Activated Protein Kinases; Animals; Blotting, Western; Body Weight; Chickens; Fluorescence; Gene Expression Regulation; Glycogen; Glycogen Phosphorylase; Glycogen Synthase; Meat; Pectoralis Muscles; RNA, Messenger

The use of medicinal plants in the management of several ailments is gaining popularity nowadays. Massularia acuminata, one of such plants is commonly used as chewing sticks due to its antimicrobial activity and the aqueous extract of its stem as an aphrodisiac. Aphrodisiac activity in some plants may be due to androgen increasing property of its phytochemicals.. This study therefore sought to assess the androgenic potentials of aqueous extract of Massularia acuminata stem in male rats for 21 days.. Male rats weighing between 220 and 260 g were completely randomized into four groups: A, B, C and D. Group A, the control received orally 1 ml of distilled water (the vehicle) while groups B, C and D were orally administered with 1 ml each corresponding to 250, 500 and 1000 mg/kg body weight of the plant extract, respectively for 21 days. Rats were sacrificed 24h after 1, 7 and 21 days.. Compared with the control, extract administration at all the doses produced significant increase (P<0.05) in testes-body weight ratio, testicular protein, glycogen, sialic acid, cholesterol, testosterone, luteinizing and follicle stimulating hormone concentrations throughout the period of administration. Testicular gamma glutamyl transferase activities were decreased significantly (P<0.05) after the first dose and was sustained throughout the experimental period.. The available evidence in this study suggests that aqueous extract of Massularia acuminata stem has androgenic potential which may stimulate male sexual maturation and enhance normal testicular function.

Topics: Androgens; Animals; Body Weight; Dose-Response Relationship, Drug; Follicle Stimulating Hormone; Glycogen; Luteinizing Hormone; Male; Nigeria; Plant Extracts; Plant Stems; Plants, Medicinal; Rats; Rats, Wistar; Rubiaceae; Testis; Testosterone

Insufficient maternal protein intake has been postulated to cause impaired fuel metabolism and diabetes mellitus in adult mammalian progeny, but the mechanism remains unclear.. To investigate the effect of a maternal low protein whey-based diet during pregnancy and lactation on pancreatic function and skeletal muscle glucose metabolism in the offspring.. Sprague-Dawley rats: 8 mothers and 46 offspring.. Female rats were fed throughout pregnancy and lactation with otherwise-complete isoenergetic diets sufficient (20% whey protein; control: n=3) or insufficient (5% whey protein; low-protein: n=5) in whey protein. From weaning all offspring ate control diet.. Food intake and weight gain were measured for both mothers and offspring, and in vitro functional studies of endocrine pancreas and skeletal muscle were performed on offspring at 40 and 50 days of age, respectively.. Food intake (P=0.004) and weight gain (P=0.006) were lower in low protein than control mothers during early gestation. Offspring of low protein mothers had significant lower body weight from 5 to 15 days of age, although there was no significant difference in food consumption. Glucose, arginine- and glucose/arginine-stimulated insulin secretion from perfused pancreases isolated from low protein offspring were decreased by between 55 and 65% compared with control values. Studies in skeletal muscle demonstrated no difference in insulin sensitivity between the two groups.. Dietary whey protein insufficiency in female rats during pregnancy and lactation can evoke major changes in insulin secretion in progeny, and these changes represent a persistent functional abnormality in the endocrine pancreas.

Topics: Animals; Animals, Newborn; Blood Glucose; Body Weight; Diet, Protein-Restricted; Eating; Female; Glucose; Glycogen; Insulin; Insulin Secretion; Lactation; Male; Milk Proteins; Mothers; Muscle, Skeletal; Organ Culture Techniques; Pancreas; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley; Weight Gain; Whey Proteins

The objective of the present study was to describe plasma hormonal and metabolite profile and mRNA expression levels and activities of the enzymes pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), and acetyl-coenzyme A (CoA) carboxylase in the liver of male Holstein calves before (1 and 3 wk of age) and after (8, 13, and 19 wk of age) weaning at 6 wk of age. The mean plasma concentration of acetate and beta-hydroxybutyrate increased, and that of plasma lactate and nonesterified fatty acids decreased with week, particularly after weaning. Plasma glucose concentration was lowest at 8 wk of age. The mean plasma concentration of insulin and glucagon did not change with time, and that of cortisol was greatest at 1 wk of age. In the liver, enzyme activity of PC was greatest at 1 wk of age and decreased with time. There was a significant relationship between the activity and the mRNA level for PC. Activity of PEPCK also decreased with week. Acetyl-CoA carboxylase activity tended to decrease with week, and activity at 13 wk of age was lower than that at other times. Expression of PC mRNA, but not that of PEPCK and acetyl-CoA carboxylase alpha, decreased with week. We conclude that the hepatic gluconeogenic enzymes and acetyl-CoA carboxylase activities tend to decrease with age, reflecting changes in plasma metabolites in early weaning production systems.

Topics: Acetyl-CoA Carboxylase; Animals; Animals, Newborn; Blood Chemical Analysis; Body Weight; Cattle; Dairying; Enzymes; Gene Expression Regulation, Enzymologic; Glycogen; Hormones; Liver; Male; Phosphoenolpyruvate Carboxykinase (GTP); Pyruvate Carboxylase; RNA, Messenger; Time Factors; Triglycerides; Weaning

Here, we investigated the effect of jump exercise on tumor growth, cancer cachexia, lymphocyte proliferation and macrophage function in Walker 256 tumor-bearing rats. Male Wistar rats (60 days) were divided into sedentary (C) and exercised (E) groups. Jump training consisted of six sets of 10 jumps in water with overload of 50% of body mass with 1 min of resting, four times per week for 8 weeks. After 6 weeks of training, half of each group was inoculated with 2 x 10(7) cells of Walker 256 tumor. Sedentary tumor-bearing and exercised tumor-bearing are referred to as T and TE, respectively. Tumor weight in the T group was 25 g. These animals display loss of weight, hypertriacylglycerolemia, hyperlacticidemia, depletion of glycogen stores and increase in PIF expression. Jump exercise (TE) induced a significant lower tumor weight, preserves liver glycogen stores, partly prevented the hypertriacylglycerolemia, hyperlacticidemia and, prevented the fall in body weight and reduced PIF expression. Lymphocyte was increased by tumor burden (T) and was higher by including exercise (TE). The same was observed regarding phagocytosis and lysosomal volume. Anaerobic exercise decreases tumor growth, cancer cachexia and increases innate and adaptative immune function.

Topics: Animals; Body Weight; Cachexia; Carcinoma 256, Walker; Cell Proliferation; Disease Models, Animal; Glycogen; Lactates; Lymphocytes; Macrophages; Male; Phagocytosis; Physical Conditioning, Animal; Rats; Rats, Wistar; Triglycerides; Weight Loss

Short-term exercise training in humans attenuates AMP-activated protein kinase (AMPK) activation during subsequent exercise conducted at the same absolute workload. Short-term 5-aminoimidazole-4-carboxyamide-ribonucleoside (AICAR) administration in rats mimics exercise training on skeletal muscle in terms of increasing insulin sensitivity, mitochondrial enzymes, and GLUT4 content, but it is not known whether these adaptations are accompanied by reduced AMPK activation during subsequent exercise. We compared the effect of 10 days of treadmill training (60 min/day) with 10 days of AICAR administration (0.5 mg/g body weight ip) on subsequent AMPK activation during 45 min of treadmill exercise in male Sprague-Dawley rats. Compared with nonexercised control rats, acute exercise significantly (P < 0.05) increased AMPKalpha Thr172 phosphorylation (p-AMPKalpha; 1.6-fold) and ACCbeta Ser218 phosphorylation (p-ACCbeta; 4.9-fold) in the soleus and p-ACCbeta 2.2-fold in the extensor digitorum longus. Ten days of exercise training abolished the increase in soleus p-AMPKalpha and attenuated the increase in p-ACCbeta (nonsignificant 2-fold increase). Ten days of AICAR administration also attenuated the exercise-induced increases in AMPK signaling in the soleus although not as effectively as 10 days of exercise training (nonsignificant 1.3-fold increase in p-AMPKalpha; significant 3-fold increase in p-ACCbeta). The increase in skeletal muscle 2-deoxyglucose uptake during exercise was greater after either 10 days of exercise training or AICAR administration. In conclusion, 10 days of AICAR administration substantially mimics the effect of 10 days training on attenuating skeletal muscle AMPK activation in response to subsequent exercise.

Topics: Acetyl-CoA Carboxylase; Aminoimidazole Carboxamide; AMP-Activated Protein Kinase Kinases; Animals; Body Weight; Eating; Enzyme Activators; Glucose; Glycogen; Male; Muscle, Skeletal; Phosphorylation; Physical Exertion; Protein Kinases; Rats; Rats, Sprague-Dawley; Ribonucleotides; Signal Transduction; Time Factors

The present study was undertaken to determine the effect of Yi-Qi-Yang-Yin-Ye (Y-Q-Y-Y-Y), a compound of Traditional Chinese Herbal Medicine, on insulin resistance (IR) in the diet-induced obese rat model induced by intravenous injection with a low dose of streptozotocin and fed a high fat and high caloric diet. Y-Q-Y-Y-Y (2, 4, 8 g/kg) was administered via gavage daily for 4 weeks. The results showed that Y-Q-Y-Y-Y treatment decreased the levels of body weight, total cholesterol (TC), triglycerides (TG), low density lipoprotein-cholesterol (LDL-C), free fatty acid (FFA), insulin (INS) and fast blood glucose (FBG) and increased the level of high density lipoprotein-cholesterol (HDL-C) in the diet-induced obese rats. Glucose tolerance was improved in the diet-induced obese rats treated with Y-Q-Y-Y-Y as well as GIR (glucose infusion rate) in the hyperinsulinemic euglycemic clamp experiment compared to the model control rats (p < 0.01). Moreover, treatment with Y-Q-Y-Y-Y up-regulated glycogen contents in both liver and skeletal muscle and increased insulin receptor amounts on the erythrocytes surface as assessed by using (125)I-labeled auto-antibodies against insulin receptors. Taken together, our data suggested that Yi-Qi-Yang-Yin-Ye ameliorates insulin resistance in the diet-induced obese rats.

Topics: Animals; Blood Glucose; Body Weight; Disease Models, Animal; Drugs, Chinese Herbal; Energy Intake; Glycogen; Insulin; Insulin Resistance; Lipid Metabolism; Liver; Medicine, Chinese Traditional; Muscle, Skeletal; Obesity; Rats; Rats, Wistar; Receptor, Insulin

We determined whether muscle AMP-activated protein kinase (AMPK) has a role in the development of insulin resistance.. Muscle-specific transgenic mice expressing an inactive form of the AMPK alpha2 catalytic subunit (alpha2i TG) and their wild-type littermates were fed either a high-fat (60% kcal fat) or a control (10% kcal fat) diet for 30 weeks.. Compared with wild-type mice, glucose tolerance in alpha2i TG mice was slightly impaired on the control diet and significantly impaired on the high-fat diet. To determine whether the whole-body glucose intolerance was associated with impaired insulin sensitivity in skeletal muscle, glucose transport in response to submaximal insulin (450 microU/ml) was measured in isolated soleus muscles. On the control diet, insulin-stimulated glucose transport was reduced by approximately 50% in alpha2i TG mice compared with wild-type mice. High-fat feeding partially decreased insulin-stimulated glucose transport in wild-type mice, while high-fat feeding resulted in a full blunting of insulin-stimulated glucose transport in the alpha2i TG mice. High-fat feeding in alpha2i TG mice was accompanied by decreased expression of insulin signaling proteins in gastrocnemius muscle.. The lack of skeletal muscle AMPK alpha2 activity exacerbates the development of glucose intolerance and insulin resistance caused by high-fat feeding and supports the thesis that AMPK alpha2 is an important target for the prevention/amelioration of skeletal muscle insulin resistance through lifestyle (exercise) and pharmacologic (e.g., metformin) treatments.

Topics: AMP-Activated Protein Kinases; Animals; Blood Glucose; Body Weight; Dietary Fats; Fatty Acids, Nonesterified; Glucose; Glucose Tolerance Test; Glycogen; Immunoblotting; Insulin; Insulin Resistance; Mice; Mice, Transgenic; Muscles; Triglycerides

Diabetes is a major public health problem. The development of new therapies that are able to improve glycemia management and even to cure diabetes is of great interest. In this study, protective effects of sodium tungstate against STZ-induced beta-cell damages were investigated.. Sixty rats were divided into six groups: control, diabetic, sodium tungstate treated diabetic rats from one week before STZ injection (TDB), food-restricted diabetic (FRD), tungstate treated control, sodium tungstate treated diabetic rats from one week after STZ administration (TDA). We evaluated serum insulin, glucose and glucose tolerance; liver glycogen content, glucokinase (GK) activity; blood and pancreas antioxidant power, lipid peroxidation; and fuchsin-aldehyde histochemical staining of beta-cells.. Blood glucose levels of TDB group were lower than other diabetic groups (P<0.01). Blood insulin levels of all diabetic groups were lower than controls (P<0.01). Glucose intolerance improved in TDB animals. Blood and pancreas antioxidant power, liver glycogen contents and GK activities and granulated beta cells increased in TDB rats in comparison with other diabetic groups (P<0.01). Likewise, lipid peroxidation decreased significantly in TDB rats (P<0.01).. Results suggested that sodium tungstate if administrated before STZ injection improves glycemic state by a direct effect on pancreatic beta-cells and preserves them by reducing the activity of these cells at the time of STZ injection, reducing STZ-induced oxidative stress, reducing insulin secretion, or all of the above mentioned.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Blood Glucose; Body Weight; Cytoprotection; Diabetes Mellitus, Experimental; Feeding Behavior; Glucokinase; Glucose; Glycogen; Immunohistochemistry; Insulin; Insulin-Secreting Cells; Liver; Male; Oxidative Stress; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances; Tungsten Compounds

Very-low-density lipoprotein (VLDL) and chylomicrons (CM) are major sources of fatty acid supply to the heart, but little is known about their metabolism in diabetic myocardium. To investigate this, working hearts isolated from control rats and diabetic rats 2 wk following streptozotocin (STZ) injection were perfused with control and diabetic lipoproteins. Analysis of the diabetic lipoproteins showed that both VLDL and CM were altered compared with control lipoproteins; both were smaller and had different apolipoprotein composition. Heparin-releasable lipoprotein lipase (HR-LPL) activity was increased in STZ-induced diabetic hearts, but tissue residual LPL activity was decreased; moreover, diabetic lipoproteins stimulated HR-LPL activity in both diabetic and control hearts. Diabetic hearts oxidized lipoprotein-triacylglycerol (TAG) to a significantly greater extent than controls (>80% compared with deposition as tissue lipid), and the oxidation rate of exogenous lipoprotein-TAG was increased significantly in diabetic hearts regardless of TAG source. Significantly increased intracardiomyocyte TAG accumulation was found in diabetic hearts, although cardiac mechanical function was not inhibited, suggesting that lipotoxicity precedes impaired cardiac performance. Glucose oxidation was significantly decreased in diabetic hearts; additionally, however, diabetic lipoproteins decreased glucose oxidation in diabetic and control hearts. These results demonstrate increased TAG-rich lipoprotein metabolism concomitant with decreased glucose oxidation in type 1 diabetic hearts, and the alterations in cardiac lipoprotein metabolism may be due to the properties of diabetic TAG-rich lipoproteins as well as the diabetic state of the myocardium. These changes were not related to cardiomyopathy at this early stage of diabetes.

Topics: Animals; Apolipoproteins; Blood Glucose; Body Weight; Chylomicrons; Coronary Circulation; Diabetes Mellitus, Experimental; Esterification; Fatty Acids; Glycogen; Heart; In Vitro Techniques; Lipoprotein Lipase; Lipoproteins, VLDL; Male; Myocardium; Organ Size; Oxidation-Reduction; Perfusion; Phospholipids; Rats; Rats, Wistar; Triglycerides

This study investigated the effect of vitamin B6 deficiency on the utilization and recuperation of stored fuel in physically trained rats. 48 rats were given either vitamin B6-deficient (B6-) diet or control (B6) diet for 4 weeks and were trained on treadmill for 30 minutes daily. All animals were then subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). The DE group was exercised on treadmill for 1 hour just before being sacrificed. Animals in the AE group were allowed to take a rest for 2 hours after being exercised like the DE group. Glucose and free fatty acids were compared in plasma. Glycogen and triglyceride were compared in liver and skeletal muscle. Protein levels were compared in plasma, liver, and skeletal muscle. Compared with the B6+ group, plasma glucose levels of the B6- group were significantly lower before and after exercise. Muscle glycogen levels of the B6- group were significantly lower than those of the B6+ group regardless of exercise. The liver glycogen level of the B6- group was also significantly lower than that of B6+ group during and after exercise. Before exercise, plasma free fatty acid levels were not significantly different between the B6+ and B6- groups, and plasma free fatty acid levels of the B6- group were significantly lower during and after exercise. The muscle triglyceride level of the B6- group was significantly lower than that of the B6+ group before exercise, and there were no differences between B6+ and B6- groups during and after exercise. Liver triglyceride levels were not significantly different between B6+ and B6- groups. Plasma protein levels of the B6- group were lower than those of B6+ before and after exercise. Muscle protein levels of the B6- group were not significantly different from those of the B6 group. Liver protein levels of the B6- group were significantly lower than that of the B6+ group after exercise. Liver protein levels of both B6+ and B6- groups were not significantly changed, regardless of exercise. Thus, it is suggested that vitamin B6 deficiency may reduce fuel storage and utilization with exercise in physically trained rats.

Topics: Animals; Blood Glucose; Body Weight; Fatty Acids, Nonesterified; Glycogen; Liver; Male; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; Triglycerides; Vitamin B 6 Deficiency

Malnutrition during gestation and lactation modifies metabolic strategies and leads to metabolic disease in adult life. Studies in human populations suggest that malnutrition during infancy may also induce long term metabolic disorders.The present study investigated if post-weaning and a late period of development might be sensitive for long term metabolic impairment. Hereto male Wistar rats were malnourished with a low protein diet (6%), during gestation and lactation (MGL), from weaning to 55 days (MPW) or during adulthood from 90 to 120 days (MA). Control rats (C) were fed with a regular diet (23% protein). We determine plasma concentrations of insulin, glucagon, triacylglycerols (TAG), free fatty acids (FFA), and liver glycogen after a Glucose Tolerance Test (GTT).Independent of the age of onset, malnutrition induced low body weight. Early and post-weaning malnutrition produced impaired glucose tolerance and low values of TAG, also in MPW induced low values of insulin and glucagon. At 90 days, after balanced diet rehabilitation, the MGL group showed a similar glucose tolerance test as the controls but display low values of insulin, while the MPW group exhibited high levels of glucose and TAG, and low values of insulin, glucagon, FFA and hepatic glycogen. At 180 days, after balanced rehabilitation only MPW rats showed metabolic alterations. Malnutrition during adult life (MA) did not produce metabolic disturbances. Surprisingly the results uncover the post-weaning stage as a vulnerable period to malnutrition that induces long lasting metabolic alterations and deficiency in pancreatic function.

Topics: Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Weight; Fatty Acids; Female; Glucagon; Glucose Tolerance Test; Glycogen; Insulin; Liver; Male; Protein-Energy Malnutrition; Rats; Rats, Wistar; Time Factors; Triglycerides; Weaning

Taurine had the hypoglycemic effect during experimental insulin-dependent diabetes mellitus and decreased the concentrations of glucose and fructosamine, and increased the contents of insulin, C-peptide, and glycogen in the liver. Studying the dynamics of structural changes in pancreatic tissue confirmed a positive effect of taurine on beta-cell function. The protective effect of taurine manifested in the absence of morphological signs for alloxan-induced diabetes: decrease in the number and size of pancreatic islets, change in their distribution, reduction of beta-cell count, and accumulation of homogeneous deposits in islets.

Topics: Animals; Body Weight; C-Peptide; Cell Count; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diuresis; Drinking; Fructosamine; Glucose; Glycogen; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liver; Male; Pancreas; Rats; Taurine

Common carp (Cyprinus carpio) were fed two different rations, 0.5% body weight (low ration; LR) and 5% body weight (high ration; HR), throughout acclimation, sublethal (64 microg/L) Cu exposure for 28 days, and a subsequent 2-week recovery period. Growth, liver water content, and liver energy stores were assessed during this period. Growth rates were elevated in HR fish compared to LR fish, as was the hepatic lipid content. This was associated with a higher water content in the livers of LR fish. Liver glycogen levels were similar in both feeding treatments and remained relatively stable during Cu exposure. Cu exposure caused a significant reduction in growth in both HR and LR fish. Reduction in growth coincided with significant changes in liver and blood composition. Liver lipid levels dropped significantly during the first days of the exposure in both feeding treatments, and the difference between LR and HR lipid levels disappeared during Cu exposure. During the first week of Cu exposure, the difference in liver water content disappeared as well, with a significant reduction of the water levels in the LR fish. A rise of hepatic protein was observed after 2 and 4 weeks of Cu exposure in the LR carp and after 4 weeks of exposure in the HR fish. Cu exposure led to pronounced increases in plasma ammonia concentrations in HR carp. Growth and energy stores recuperated during the 2-week recovery period in both feeding treatments. The observed changes during Cu exposure are probably related to physiological disturbances like hypoxia and stress, as well as an inhibition of ammonia excretion.

Topics: Ammonia; Animals; Body Weight; Carps; Copper; Energy Metabolism; Food; Glycogen; Lipid Metabolism; Liver; Nutritional Status; Proteins; Water; Water Pollutants, Chemical

The effects of administration of aqueous extract of Fadogia agrestis (Schweinf. Ex Hiern) stem on some testicular function indices of male rats (Rattus norvegicus) and their recovery potentials for 10 days were investigated.. Rats were grouped into four: A, B, C and D where A (the control) received orally 1 ml of distilled water (the vehicle), B, C and D (the test groups) received orally on daily basis graded doses of 18, 50 and 100mg/kg body weight of the plant extract, respectively, for 28 days.. Compared with the control, extract administration for 28 days at all the doses resulted in significant increase (P<0.05) in percentage testes-body weight ratio, testicular cholesterol, sialic acid, glycogen, acid phosphatase and gamma-glutamyl transferase activities while there was significant decrease (P<0.05) in the activities of testicular alkaline phosphatase, acid phosphatase, glutamate dehydrogenase and concentrations of protein. Recoveries were made by the animals on some of the testicular function indices mainly at 18 mg/kg body weight.. The alterations brought about by the aqueous extract of Fadogia agrestis stem are indications of adverse effects on the male rat testicular function and this may adversely affect the functional capacities of the testes. The recovery made at the dose of 18 mg/kg body weight as used in folklore medicine suggests that it does not exhibit permanent toxicity at this dose.

Topics: Acid Phosphatase; Administration, Oral; Alkaline Phosphatase; Animals; Body Weight; Cholesterol; Dose-Response Relationship, Drug; gamma-Glutamyltransferase; Glutamate Dehydrogenase; Glycogen; Male; N-Acetylneuraminic Acid; Nigeria; Plant Extracts; Proteins; Rats; Rubiaceae; Testis

SH2-containing inositol 5'-phosphatase 2 (SHIP2) is a 5'-lipid phosphatase hydrolyzing the phosphatidylinositol (PI) 3-kinase product PI(3,4,5)P(3) to PI(3,4)P(2) in the regulation of insulin signaling, and is shown to be increased in peripheral tissues of diabetic C57BL/KSJ-db/db mice. To clarify the impact of SHIP2 in the pathogenesis of insulin resistance with type 2 diabetes, we generated transgenic mice overexpressing SHIP2. The body weight of transgenic mice increased by 5.0% (P < 0.05) compared with control wild-type littermates on a normal chow diet, but not on a high-fat diet. Glucose tolerance and insulin sensitivity were mildly but significantly impaired in the transgenic mice only when maintained on the normal chow diet, as shown by 1.2-fold increase in glucose area under the curve over control levels at 9 months old. Insulin-induced phosphorylation of Akt was decreased in the SHIP2-overexpressing fat, skeletal muscle, and liver. In addition, the expression of hepatic mRNAs for glucose-6-phosphatase and phosphoenolpyruvate carboxykinase was increased, that for sterol regulatory element-binding protein 1 was unchanged, and that for glucokinase was decreased. Consistently, hepatic glycogen content was reduced in the 9-month-old transgenic mice. Structure and insulin content were histologically normal in the pancreatic islets of transgenic mice. These results indicate that increased abundance of SHIP2 in vivo contributes, at least in part, to the impairment of glucose metabolism and insulin sensitivity on a normal chow diet, possibly by attenuating peripheral insulin signaling and by altering hepatic gene expression for glucose homeostasis.

Topics: Adipocytes; Animals; Blood Glucose; Body Weight; Energy Metabolism; Female; Glycogen; Homeostasis; Inositol Polyphosphate 5-Phosphatases; Insulin; Ion Channels; Lipogenesis; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mitochondrial Proteins; Pancreas; Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; Phosphoric Monoester Hydrolases; RNA, Messenger; Signal Transduction; Transgenes; Uncoupling Protein 1; Uncoupling Protein 2; Uncoupling Protein 3

The aim of the present study was to test the hypothesis that peroxisome proliferator activated receptor-gamma coactivator (PGC) 1alpha is required for exercise-induced adaptive gene responses in skeletal muscle. Whole body PGC-1alpha knockout (KO) and littermate wild-type (WT) mice performed a single treadmill-running exercise bout. Soleus and white gastrocnemius (WG) were obtained immediately, 2 h, or 6 h after exercise. Another group of PGC-1alpha KO and WT mice performed 5-wk exercise training. Soleus, WG, and quadriceps were obtained approximately 37 h after the last training session. Resting muscles of the PGC-1alpha KO mice had lower ( approximately 20%) cytochrome c (cyt c), cytochrome oxidase (COX) I, and aminolevulinate synthase (ALAS) 1 mRNA and protein levels than WT, but similar levels of AMP-activated protein kinase (AMPK) alpha1, AMPKalpha2, and hexokinase (HK) II compared with WT mice. A single exercise bout increased phosphorylation of AMPK and acetyl-CoA carboxylase-beta and the level of HKII mRNA similarly in WG of KO and WT. In contrast, cyt c mRNA in soleus was upregulated in WT muscles only. Exercise training increased cyt c, COXI, ALAS1, and HKII mRNA and protein levels equally in WT and KO animals, but cyt c, COXI, and ALAS1 expression remained approximately 20% lower in KO animals. In conclusion, lack of PGC-1alpha reduced resting expression of cyt c, COXI, and ALAS1 and exercise-induced cyt c mRNA expression. However, PGC-1alpha is not mandatory for training-induced increases in ALAS1, COXI, and cyt c expression, showing that factors other than PGC-1alpha can exert these adaptations.

Topics: 5-Aminolevulinate Synthetase; Adaptation, Physiological; Animals; Blotting, Western; Body Weight; Cyclic AMP-Dependent Protein Kinases; Cyclooxygenase 1; Cytochromes c; Electrophoresis, Polyacrylamide Gel; Gene Expression Regulation; Glycogen; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria, Muscle; Muscle Proteins; Muscle, Skeletal; Myoglobin; Nucleotides; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Physical Conditioning, Animal; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Trans-Activators; Transcription Factors

Intracellular redox balance may affect nutrient metabolism in skeletal muscle. Astaxanthin, a carotenoid contained in various natural foods, exerts high antioxidative capacity in the skeletal muscles. The present study investigated the effect of astaxanthin on muscle lipid metabolism in exercise. ICR mice (8 weeks old) were divided into four different groups: sedentary, sedentary treated with astaxanthin, running exercise, and exercise treated with astaxanthin. After 4 weeks of treatment, exercise groups performed treadmill running. Astaxanthin increased fat utilization during exercise compared with mice on a normal diet with prolongation of the running time to exhaustion. Colocalization of fatty acid translocase with carnitine palmitoyltransferase I (CPT I) in skeletal muscle was increased by astaxanthin. We also found that hexanoyl-lysine modification of CPT I was increased by exercise, while astaxanthin prevented this increase. In additional experiment, we found that astaxanthin treatment accelerated the decrease of body fat accumulation with exercise training. Our results suggested that astaxanthin promoted lipid metabolism rather than glucose utilization during exercise via CPT I activation, which led to improvement of endurance and efficient reduction of adipose tissue with training.

Topics: Animals; Body Composition; Body Weight; Carnitine O-Palmitoyltransferase; CD36 Antigens; Energy Metabolism; Fatty Acids, Nonesterified; Glycogen; Lactic Acid; Lipid Metabolism; Mice; Mice, Inbred ICR; Muscle, Skeletal; Organ Size; Oxidation-Reduction; Physical Conditioning, Animal; Physical Endurance; Substrate Specificity; Xanthophylls

The aim of this study was to determine the effect of changes in body mass, fat reserves and feeding activity on circulating levels of lipids, glucose, protein and metabolic hormones in a vespertilionid bat, Scotophilus heathi. Furthermore, the relationship between changes in metabolic factors and hormones with the unique reproductive features of female S. heathi was also examined. The results of this study showed annual variation in body mass, fat reserve and feeding activity, which correlated significantly with circulating levels of lipids, protein and metabolic hormones. Increased corticosterone level during September-October in S. heathi promotes increased feeding activity, which in turn induces hyperinsulinemia in S. heathi during November. Hyperinsulinemia together with low body temperature in November facilitates fat accumulation in bat. Coinciding with the period of fat accumulation raises serum leptin level, which has been demonstrated to suppress ovarian activities thus causing delayed ovulation in S. heathi. Circulating levels of lipids were high during winter dormancy, which may provide energy to stored sperms. The study thus suggests that the unique reproductive features of female vespertilionid bat are strongly linked to fat deposition.

Topics: Adiposity; Animals; Blood Glucose; Blood Proteins; Body Temperature; Body Weight; Chiroptera; Energy Metabolism; Feeding Behavior; Female; Glycogen; Insecta; Insulin; Leptin; Lipids; Reproduction; Seasons; Thyroid Hormones; Urea

People of Asir region of Saudi Arabia chew Caralluma sinaica (CS) to lower glucose level. To establish its utility in diabetes mellitus we have under taken this study. The effect of CS on streptozotocin (STZ)-induced diabetic model as well as effect on oral glucose tolerance test were studied. The extract was shown to have positive test for possessing following chemical constituents like phenolic alkaloids, glycosides, flavonoids, coumarins, steroids and tannins. Administration of CS in different doses (50, 100, 150 and 200mg/kg, p.o.) to normal animals caused significant (P<0.01) decrease in glucose level. Prior administration of either CS (100mg/kg, p.o.) or glibenclamide (GB) (5mg/kg, p.o.) blocked the rise of glucose caused by the streptozotocin. Antidiabetic activity of CS was compared with clinically available drug GB. Administration of CS (100mg/kg, p.o.) to diabetic rabbits for 30 days has been shown to decrease plasma glucose level to almost normal level (P<0.001). Liver and kidney weight expressed as percentage of body weight significantly (P<0.05; P<0.01) increased in diabetic rabbits versus normal control (CNT). CS significantly (P<0.05) reversed the increasing weight of liver caused by STZ but not GB. STZ induced lowering of glycogen content of liver and muscle was reversed by both CS and GB. STZ induced a significant (P<0.001) increase in renal glycogen content this was almost normalized by CS (P<0.001) whereas GB significantly decreased (P<0.002) glycogen content. In oral glucose tolerance test administration of glucose increased plasma glucose level significantly in the diabetic control over the 2-h period. Compared to diabetic control plasma glucose levels in rabbits given CS or GB were significantly lower at all the time points that blood was sampled after oral glucose load. Comparing with the GB treatment blood glucose lowering effect was more pronounced for diabetic rabbits given CS. All these effects could explain the basis for use of this plant extract to manage diabetes mellitus.

Topics: Animals; Apocynaceae; Body Weight; Diabetes Mellitus, Experimental; Glucose Tolerance Test; Glyburide; Glycogen; Hypoglycemic Agents; Kidney; Liver; Male; Organ Size; Plant Extracts; Rabbits

The aim of this work was to evaluate the effect of prolonged melatonin administration on chosen metabolic and hormonal variables in male and female Sprague-Dawley rats. Melatonin was administered in tap water (4 microg/ml) daily from the 6th month of age. Rats were fed a standard type of diet ad libitum and were kept in a light regimen L:D--12:12h. The experiment was terminated after 12 weeks of melatonin administration. Melatonin decreased body mass during the whole experiment in females and from the 42nd day of the experiment in males. Relative heart muscle weight in females and absolute/relative thymus weight in males were increased after melatonin administration. Melatonin decreased glycaemia, heart muscle glycogen concentration in females and liver glycogen concentration in both sexes. Serum insulin concentration in males was decreased; serum corticosterone concentration was increased in both males and females. Serum triacylglycerol and heart muscle cholesterol concentration in females were decreased, however in males serum and heart muscle cholesterol concentration was increased. Liver phospholipid concentration in females was decreased and heart muscle phospholipid concentration in males was increased. Melatonin increased malondialdehyde concentration in heart muscle in males and in liver in both sexes. Melatonin induced prominent sex-dependent changes in both carbohydrate and lipid metabolism.

Topics: Animals; Body Weight; Cholesterol; Circadian Rhythm; Corticosterone; Female; Glycemic Index; Glycogen; Insulin; Lipid Metabolism; Liver; Male; Malondialdehyde; Melatonin; Myocardium; Organ Size; Phospholipids; Rats; Rats, Sprague-Dawley; Sex Factors; Thymus Gland; Triglycerides

ASP-deficient mice (C3 KO) have delayed postprandial TG clearance, are hyperphagic, and display increased energy expenditure. Markers of carbohydrate and fatty acid metabolism in the skeletal muscle and heart were examined to evaluate the mechanism. On a high-fat diet, compared with wild-type mice, C3 KO mice have increased energy expenditure, decreased RQ, lower ex vivo glucose oxidation (-39%, P = 0.018), and higher ex vivo fatty acid oxidation (+68%, P = 0.019). They have lower muscle glycogen content (-25%, P < 0.05) and lower activities for the glycolytic enzymes glycogen phosphorylase (-31%, P = 0.005), hexokinase (-43%, P = 0.007), phosphofructokinase (-51%, P < 0.0001), and GAPDH (-15%, P = 0.04). Analysis of mitochondrial enzyme activities revealed that hydroxyacyl-coenzyme A dehydrogenase was higher (+25%, P = 0.004) in C3 KO mice. Furthermore, Western blot analysis of muscle revealed significantly higher fatty acid transporter CD36 (+40%, P = 0.006) and cytochrome c (a marker of mitochondrial content; +69%, P = 0.034) levels in C3 KO mice, whereas the activity of AMP kinase was lower (-48%, P = 0.003). Overall, these results demonstrate a shift in the metabolic potential of skeletal muscle toward increased fatty acid utilization. Whether this is 1) a consequence of decreased adipose tissue storage with repartitioning toward muscle or 2) a direct result of the absence of ASP interaction with the receptor C5L2 in muscle remains to be determined. However, these in vivo data suggest that ASP inhibition could be a potentially viable approach in correcting muscle metabolic dysfunction in obesity.

Topics: 3-Hydroxyacyl CoA Dehydrogenases; Adipose Tissue, Brown; AMP-Activated Protein Kinases; Animals; Body Weight; Complement C3; Dietary Fats; Eating; Energy Metabolism; Glucose; Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+); Glycogen; Glycogen Phosphorylase; Hexokinase; Mice; Mice, Inbred C57BL; Mice, Knockout; Multienzyme Complexes; Muscle, Skeletal; Myocardium; Phosphofructokinases; Protein Serine-Threonine Kinases; Respiration

The aim of this study was to determine the modulatory effect of Lycium barbarum polysaccharides (LBP) on the oxidative stress induced by an exhaustive exercise. 32 male Wistar rats were taken in the study. The experiment was a 30-day exhaustive exercise program. We determined the lipid peroxidation, glycogen levels, and anti-oxidant enzyme activities in skeletal muscle. The results demonstrated that L. barbarum polysaccharides administration significantly increases glycogen level and anti-oxidant enzyme activities, and decreased malondialdehyde (MDA) level and creatine kinase activities. In conclusion, L. barbarum polysaccharides administration can significantly decrease the oxidative stress induced by the exhaustive exercise.

Topics: Animals; Antioxidants; Body Weight; Drugs, Chinese Herbal; Glycogen; Lycium; Male; Malondialdehyde; Muscle, Skeletal; Oxidative Stress; Physical Conditioning, Animal; Rats; Rats, Wistar

Juvenile visceral steatosis (jvs-/-) mice lack the activity of the carnitine transporter OCTN2 and are dependent on carnitine substitution. The effects of carnitine deprivation on carnitine homeostasis and energy metabolism are not known in jvs-/- mice.. jvs-/- mice were studied 3, 6 and 10 days after carnitine deprivation, and compared to jvs-/- mice substituted with carnitine, wild-type (jvs+/+) and jvs+/- mice. Carnitine concentrations were assessed radioenzymatically.. Compared to wild-type mice, carnitine-treated jvs-/- mice had decreased plasma beta-hydroxybutyrate levels and showed hepatic fat accumulation. The carnitine levels in plasma, liver and skeletal muscle were decreased by 58, 16 and 17%, respectively. After ten days of carnitine deprivation, the plasma carnitine concentration had fallen by 87% (to 2.3 mumol/l) and the tissue carnitine levels by approximately 50% compared to carnitine-treated jvs-/- mice. Carnitine deprivation was associated with a further drop in plasma beta-hydroxybutyrate and increased hepatic fat. Skeletal muscle glycogen stores decreased and lactate levels increased with carnitine deprivation, whereas tissue ATP levels were maintained.. In jvs-/- mice, tissue carnitine stores are more resistant than carnitine plasma concentrations to carnitine deprivation. Metabolic changes (liver steatosis and loss of muscle glycogen stores) appear also early after carnitine deprivation.

Topics: 3-Hydroxybutyric Acid; Adenosine Triphosphate; Animals; Body Weight; Carnitine; Energy Metabolism; Fatty Liver; Genotype; Glycogen; Homeostasis; Lactates; Lipid Metabolism, Inborn Errors; Liver; Mice; Mice, Knockout; Muscle, Skeletal; Organ Size; Organic Cation Transport Proteins; Solute Carrier Family 22 Member 5

Turkey experimental lines E (selected 44 yr for increased total egg production) and F (selected 38 yr for increased 16-wk BW) were mated reciprocally with the randombred control lines from which they were derived (RBC1 and RBC2, respectively), and the pureline and reciprocal cross poults were compared for their BW, heart weight, heart rates, myocardial glycogen and lactate concentrations, and plasma creatine kinase (CK) and lactate dehydrogenase (LDH) activities. The CK and LDH were used as indicators of cardiac insufficiency. Orthogonal contrasts of the data from the pureline and reciprocal cross data were used to estimate additive genetic effects, reciprocal effects (confounded maternal and sex-linked effects), and heterosis for each of the traits measured. Long-term selection for increased egg production in the E line has reduced embryo heart weight and has altered the energy metabolism of the myocardium. The differences in energy metabolism may be due to the more rapid heart rates. Conversely, long-term selection for increased 16-wk BW has significantly decreased the heart rate of F line embryos and has not changed the weight of the heart relative to the BW until the embryo has passed through the plateau stage. The F line embryos show a different energy metabolism that relies much more on gluconeogenesis. Embryo deaths occur more frequently in turkey embryos when the energy metabolism of the myocardium shows elevated glycogen to lactate ratios as it did in the pure E and F lines.

Topics: Animals; Blood Glucose; Body Weight; Creatine Kinase; Female; Glycogen; Heart; Heart Rate; L-Lactate Dehydrogenase; Lactic Acid; Liver; Male; Myocardium; Organ Size; Oviposition; Turkeys

Hyperglycemia, abnormal lipid and antioxidant profiles are the most usual complications in diabetes mellitus. In the present study, the antihyperglycemic, antihyperlipemic and antioxidant potency of an ethanol extract of Costus speciosus root was investigated in alloxan-induced diabetic male (Charles Foster) rats. Four groups of alloxan diabetic rats (n = 6) were administered orally with different doses of Costus speciosus root extract (150, 300 and 450 mg/kg BW) and a standard drug, glibenclamide (600 microg/kg BW), for 4 weeks. Two groups of rats (n = 6) served as normal and diabetic controls. While the diabetic controls showed significant abnormal carbohydrate, lipid and antioxidant profiles, administration of 150 mg/kg BW dose neither improved glucose nor lipid metabolism and antioxidant levels. Administration of 300 and 450 mg/kg BW doses, however, resulted in a reversal of diabetes and its complications. Both doses significantly brought down blood glucose concentration (26.76%, 34.68%), increased glycogenesis and decreased glyconeogenesis bringing the glucose metabolism toward normalcy. These doses also reversed the hyperlipidemia by reducing plasma total lipid (12.87%, 178.24%), cholesterol (21.92%, 30.77%) and triglyceride (25.32%, 33.99%) and improved hepatic antioxidant enzyme activities. The high dose (450 mg/kg BW) was found to have more potential antioxidant activities compared with glibenclamide. It is concluded that Costus speciosus root extract possesses anti-hyperglycemic, antihyperlipemic and antioxidative effects, which may prove to be of clinical importance in the management of diabetes and its complications.

Topics: Alloxan; Animals; Blood Glucose; Body Weight; Costus; Creatinine; Diabetes Mellitus, Experimental; Eating; Glucose-6-Phosphatase; Glycogen; Hexokinase; Hypoglycemic Agents; Hypolipidemic Agents; Lipid Metabolism; Lipids; Liver; Male; Phytotherapy; Plant Extracts; Rats; Triglycerides

The aim of this study was to provide a sequential analysis of the expression patterns of key genes involved in lipid metabolism in white adipose tissue (WAT) and liver and their relationship with blood parameters in response to fasting. Adult male rats were studied under different feeding conditions: feeding state, after 4, 8, or 24 h fasting, and after 3 h refeeding after 8 h fasting. Blood parameters and the expression of genes involved in lipogenesis and lipolysis in WAT and liver were analyzed. mRNA levels of genes involved in lipogenesis in liver (SREBP1c, FAS, and GPAT) had already decreased after 4 h fasting, as well as those of PPARgamma in WAT, whereas the decrease in SREBP1c, FAS, GPAT, and GLUT4 mRNA levels in WAT was observed after 8 h. Concerning lipolytic and fatty-acid-oxidation-related genes, liver PPARalpha, FGF21, CPT1, and PDK4 mRNA levels increased after 8 h fasting and those of ACOX1 after 24 h, and in WAT, ATGL, and CPT1 mRNA levels were greater after 24 h. Three hours refeeding increased the expression levels of PPARgamma in WAT, SREBP1c in both liver and WAT, and GPAT in liver, and decreased the expression levels of PPARalpha, CPT1, and PDK4 in liver. These results give new insight into the different adaptive time course response to fasting in the expression of genes involved in lipid metabolism, thus pointing out the very rapid response of lipogenic genes, particularly in liver, and the later response of lipolytic genes, particularly in WAT.

Topics: Adipose Tissue; Animals; Body Weight; Fasting; Gene Expression Profiling; Gene Expression Regulation; Glucose; Glycogen; Insulin; Lipid Metabolism; Liver; Male; Organ Size; Random Allocation; Rats; Rats, Wistar

Sutherlandia frutescens has been marked as a potential hypoglycaemic agent for the treatment of type 2 diabetes. We investigated the effects of Sutherlandia frutescens in bringing about hypoglycaemia and promoting glucose uptake in pre-diabetic rats. Crushed Sutherlandia frutescens leaves in drinking water were administered to rats fed a high fat diet. Positive control rats received only metformin. Glucose uptake experiments were undertaken using [(3)H] deoxy-glucose. Various physiological parameters were also measured. Rats receiving Sutherlandia frutescens displayed normoinsulinaemic levels, after 8 weeks medicational compliance, compared to the fatty controls. There was a significant increase in glucose uptake into muscle and adipose tissue, and a significant decrease in intestinal glucose uptake (p<0.001 at 60min) in rats receiving the plant extract. The Sutherlandia frutescens plant extract shows promise as a type 2 anti-diabetes medication because of its ability to normalize insulin levels and glucose uptake in peripheral tissues and suppress intestinal glucose uptake, with no weight gain noted. The exact mechanism of action and the extract's efficacy in humans need further confirmation.

Topics: Anesthesia; Animals; Blood Glucose; Body Weight; Diet; Dietary Fats; Glucose; Glycogen; Hyperinsulinism; Hypoglycemic Agents; Insulin; Intestinal Mucosa; Male; Metformin; Plant Extracts; Plants, Medicinal; Prediabetic State; Rats; Rats, Wistar

The fruit fly Anastrepha fraterculus is a major pest of native and exotic fruit trees in South America. Changes in weight, water content and metabolism were observed during its ontogenetic development in standard conditions (25 degrees C, RH=60% and 14 h:10 h photoperiod). The metabolic variables glycogen, total proteins, triglycerides and total lipids were measured by means of spectrophotometric methods. The results were correlated with pupae metamorphosis, temporal pattern, and beginning of adult life. Pupae were observed daily, and a sub-sample of 10 individuals was collected and maintained at -20 degrees C. The same procedure was performed with adults at 4 days after adult eclosion. Levels of total lipids and triglycerides were constant during pupal development, peaking in 312-h-old pupae. In 0-h-old pupae, glycogen levels were high, and decreased progressively until the insects were 312 h old. The peak in total proteins coincides with the post-histolysis period of the larval tissue (96-120 h). These results indicated that glycogen and proteins may be the principal sources of energy for metamorphosis. Total lipid and triglyceride contents remained steady during metamorphosis, and these were consumed in the first 4 days of adult life.

Topics: Animals; Body Weight; Glycogen; Insect Proteins; Pupa; Tephritidae; Triglycerides

This study examined the effects of different oxygenation levels and substrate availability on cardiac performance, metabolism, and biochemistry in sexually immature male and female rainbow trout (Oncorhynchus mykiss). Ventricle strips were electrically paced (0.5 Hz, 14 degrees C) in hyperoxic or hypoxic Ringer solution. Our results demonstrate that 1) males sustain isometric force production (F) longer than females under hyperoxia (P O2 = 640 mmHg) with exogenous glucose present; 2) contractility is not maintained under moderate (P O2 = 130 mmHg) or severe hypoxia (P O2 = 10-20 mmHg) with glucose in either sex; however, following reoxygenation, F is higher in females compared with males; and 3) female tissue has higher lactate levels, net lactate efflux, and lactate dehydrogenase activity than males, whereas males have higher glycogen, citrate synthase, and beta-hydroxy acyl-CoA dehydrogenase activities, and greater inotropic responses to exogenous glucose and octanoate. No sex differences were detected in responsiveness to epinephrine and inhibitors of glucose transport or activities of hexokinase and pyruvate kinase. We conclude that sex differences exist in rainbow trout cardiac tissue: females appear to prefer glycolysis for ATP production, whereas males have a higher capacity for aerobic and lipid metabolism.

Topics: Animals; Body Weight; Electric Stimulation; Energy Metabolism; Epinephrine; Fatty Acids; Female; Glucose; Glycogen; Glycolysis; Heart; Heart Rate; Hyperoxia; Hypoxia; In Vitro Techniques; Lactic Acid; Male; Myocardial Contraction; Myocardium; Oncorhynchus mykiss; Organ Size; Oxygen; Sex Characteristics; Vasoconstrictor Agents; Ventricular Function

The effect of coconut fat (rich in medium saturated fatty acids) or fish oil (rich in omega-3 polyunsaturated fatty acids) supplementation for 2 generations on tumor growth, cancer cachexia, animal survival and macrophage function was investigated in Walker 256 tumor-bearing rats. Female Wistar rats were supplemented with coconut fat or fish oil prior to mating and then throughout pregnancy and gestation. Both supplementations were daily and orally given at 1 g per kg body weight as a single bolus. Same treatment was performed by the 2 following generations. At 90 days of age, male offspring (50%) from F2 generation were subcutaneously inoculated with 2 x 10(7) Walker 256 tumor cells. At 14 days after tumor implantation, rats not supplemented displayed cancer cachexia characterized by loss of body weight, hypoglycemia, hyperlacticidemia, hypertriglyceridemia, decreased food intake and depletion of glycogen stores in the liver and skeletal muscles. Supplementation with coconut fat did not affect these parameters. However, supplementation with fish oil decreased tumor growth (59%), prevented body weight loss and food intake reduction and attenuated cancer cachexia. In addition, fish oil increased animal survival up to 20 days (from 25% in rats not supplemented to 67% in rats supplemented with fish oil) and improved macrophage function characterized by increased phagocytosis capacity and production of hydrogen peroxide and nitric oxide. These results suggest that fish oil supplementation for 2 generations improves macrophage function in association to reduced tumor growth and attenuated cancer cachexia, maintaining food intake and increasing animal survival.

Topics: Animals; Blood Glucose; Body Weight; Cachexia; Carcinoma 256, Walker; Coconut Oil; Eating; Fatty Acids, Omega-3; Female; Fish Oils; Glycogen; Hypertriglyceridemia; Hypoglycemia; Lactic Acid; Liver Glycogen; Macrophages, Peritoneal; Muscle, Skeletal; Phagocytosis; Plant Oils; Rats; Rats, Wistar

Arginine-vasopressin (AVP) is known to be involved in maintaining glucose homeostasis, and AVP-resistance is observed in poorly controlled non-insulin-dependent diabetes mellitus subjects, resulting in a lowered plasma volume. Recently we reported that V1a vasopressin receptor-deficient (V1aR(-/-)) mice exhibited a decreased circulating blood volume and hypermetabolism of fat accompanied with impaired insulin-signaling. Here we further investigated the roles of the AVP/V1a receptor in regulating glucose homeostasis and plasma volume using V1aR(-/-) mice. The plasma glucose levels at the baseline or during a glucose tolerance test were higher in V1aR(-/-) than wild-type (WT) mice. Moreover, a hyperinsulinemic-euglycemic clamp revealed that the glucose infusion rate was significantly lower in V1aR(-/-) mice than in WT mice and that hepatic glucose production was higher in V1aR(-/-) mice than WT mice. In contrast to the increased hepatic glucose production, the liver glycogen content was decreased in the mutant mice. These results indicated that the mutant mice had impaired glucose tolerance. Furthermore, feeding V1aR(-/-) mice a high-fat diet accompanied by increased calorie intake resulted in significantly overt obesity in comparison with WT mice. In addition, we found that the circulating plasma volume and aldosterone level were decreased in V1aR(-/-) mice, although the plasma AVP level was increased. These results suggested that the effect of AVP on water recruitment was disturbed in V1aR(-/-) mice. Thus, we demonstrated that one of the AVP-resistance conditions resulting from deficiency of the V1a receptor leads to decreased plasma volume as well as impaired glucose homeostasis, which can progress to obesity under conditions of increased calorie intake.

Topics: Animals; Arginine Vasopressin; Blood Glucose; Body Weight; Dietary Fats; Energy Intake; Feeding Behavior; Glycogen; Homeostasis; Insulin; Leptin; Liver; Male; Metabolic Syndrome; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Obesity; Plasma Volume; Receptors, Vasopressin

The action of orally administered dexamethasone (0.2 mg kg(-1) day(-1)) on metabolic parameters of adjuvant-induced arthritic rats was investigated. The body weight gain and the progression of the disease were also monitored. Dexamethasone was very effective in suppressing the Freund's adjuvant-induced paw edema and the appearance of secondary lesions. In contrast, the body weight loss of dexamethasone-treated arthritic rats was more accentuated than that of untreated arthritic or normal rats treated with dexamethasone, indicating additive harmful effects. The perfused livers from dexamethasone-treated arthritic rats presented high content of glycogen in both fed and fasted conditions, as indicated by the higher rates of glucose release in the absence of exogenous substrate. The metabolization of exogenous L: -alanine was increased in livers from dexamethasone-treated arthritic rats in comparison with untreated arthritic rats, but there was a diversion of carbon flux from glucose to L: -lactate and pyruvate. Plasmatic levels of insulin and glucose were significantly higher in arthritic rats following dexamethasone administration. Most of these changes were also found in livers from normal rats treated with dexamethasone. The observed changes in L: -alanine metabolism and glycogen synthesis indicate that insulin was the dominant hormone in the regulation of the liver glucose metabolism even in the fasting condition. The prevalence of the metabolic effects of dexamethasone over those ones induced by the arthritis disease suggests that dexamethasone administration was able to suppress the mechanisms implicated in the development of the arthritis-induced hepatic metabolic changes. It seems thus plausible to assume that those factors responsible for the inflammatory responses in the paws and for the secondary lesions may be also implicated in the liver metabolic changes, but not in the body weight loss of arthritic rats.

Topics: Alanine; Ammonia; Animals; Arthritis, Experimental; Blood Glucose; Body Weight; Dexamethasone; Fasting; Feeding Behavior; Freund's Adjuvant; Glycogen; Inflammation; Insulin; Lactates; Male; Oxygen; Perfusion; Pyruvates; Rats; Urea; Weight Gain

Dendrobaena octaedra is a freeze tolerant earthworm widely distributed in boreal regions. Specimens collected in Sweden were cold acclimated and then frozen at -7 degrees C to examine the influence of body mass on survival of freezing. Results showed that survival was negatively correlated to body mass. Glycogen content of the worms was variable and seemed to decrease with increasing body mass consistent with the hypothesis that freeze survival is dependent on the ability to rapidly break down glycogen and accumulate high concentrations of glucose. The results suggest that large worms (subadults and adults) invest energy in production of cocoons at the expense of glycogen storage for cryoprotectant production, whereas juvenile worms increase their survival chances by investing energy in glycogen storage at the expense of growth as a preparation for winter.

Topics: Animals; Body Weight; Freezing; Glycogen; Oligochaeta

Although high insulin concentrations reduce food intake, low insulin concentrations promote lard intake over chow, possibly via an insulin-derived, liver-mediated signal. To investigate the role of the hepatic vagus in voluntary lard intake, streptozotocin-diabetic rats with insulin or vehicle replaced into either the superior mesenteric or jugular veins received a hepatic branch vagotomy (HV) or a sham operation. All rats received a pellet of corticosterone that clamped the circulating steroid at moderately high concentrations to enhance lard intake. After 5 d of recovery, rats were offered the choice of lard and chow for 5 d. In streptozotocin-diabetic rats, HV, like insulin replacement, restored lard intake to nondiabetic levels. Consequently, this reduced chow intake without affecting total caloric intake, and insulin site-specifically increased white adipose tissue weight. HV also ablated the effects of insulin on reducing circulating glucose levels and attenuated the streptozotocin-induced weight loss in most groups. Collectively, these data suggest that the hepatic vagus normally inhibits lard intake and can influence glucose homeostasis and the pattern of white adipose tissue deposition. These actions may be modulated by insulin acting both centrally and peripherally.

Topics: Adipose Tissue, White; Animals; Blood Glucose; Body Weight; Corticosterone; Diabetes Mellitus, Experimental; Dietary Fats; Energy Intake; Fatty Acids, Nonesterified; Glycogen; Hypoglycemic Agents; Insulin; Ketone Bodies; Male; Rats; Rats, Sprague-Dawley; Streptozocin; Time Factors; Triglycerides; Vagotomy; Vagus Nerve

The aim of this study was to investigate the effect of insulin resistance on glycogen concentration and glycogen synthase activity in the red and white gastrocnemius muscles and to determine whether the inverse relationship existing between glycogen concentration and enzyme activity is maintained in insulin resistant state. These questions were addressed using 3 models that induce various degrees of insulin resistance: sucrose feeding, dexamethasone administration, and a combination of both treatments (dex+sucrose). Sucrose feeding raised triglyceride levels without affecting plasma glucose or insulin concentrations whereas dexamethasone and dex+sucrose provoked severe hyperinsulinemia, hyperglycemia and hypertriglyceridemia. Sucrose feeding did not alter muscle glycogen concentration but provoked a small reduction in the glycogen synthase activity ratio (-/+ glucose-6-phosphate) in red but not in white gastrocnemius. Dexamethasone administration augmented glycogen concentration and reduced glycogen synthase activity ratio in both muscle fiber types. In contrast, dex+sucrose animals showed decreased muscle glycogen concentration compared to dexamethasone group, leading to levels similar to those of control animals. This was associated with lower glycogen synthase activity compared to control animals leading to levels comparable to those of dexamethasone-treated animals. Thus, in dex+sucrose animals, the inverse relationship observed between glycogen levels and glycogen synthase activity was not maintained, suggesting that factors other than the glycogen concentration modulate the enzyme's activity. In conclusion, while insulin resistance was associated with a reduced glycogen synthase activity ratio, we found no correlation between muscle glycogen concentration and insulin resistance. Furthermore, our results suggest that sucrose treatment may modulate dexamethasone action in skeletal muscle.

Topics: Animals; Body Weight; Dexamethasone; Gene Expression Regulation; Glucose; Glycogen; Glycogen Synthase; Insulin; Insulin Resistance; Male; Models, Biological; Muscle, Skeletal; Rats; Rats, Sprague-Dawley

The objectives of this study were to determine the effects of dietary L-carnitine supplementation on liver lipid accumulation, hepatic nutrient metabolism, and lactation in multiparous cows during the periparturient period. Cows were assigned to treatments at d -25 relative to expected calving date and remained on the experiment until 56 d in milk. Treatments were 4 amounts of supplemental dietary carnitine: control (0 g/d of L-carnitine; n = 14); low carnitine (LC, 6 g/d; n = 11); medium carnitine (MC, 50 g/d; n = 12); and high carnitine (HC, 100 g/d; n = 12). Carnitine was supplied by mixing a feed-grade carnitine supplement with 113.5 g of ground corn and 113.5 g of dried molasses, which was then fed twice daily as a topdress to achieve desired daily carnitine intakes. Carnitine supplementation began on d -14 relative to expected calving and continued until 21 d in milk. Liver and muscle carnitine concentrations were markedly increased by MC and HC treatments. Milk carnitine concentrations were elevated by all amounts of carnitine supplementation, but were greater for MC and HC than for LC during wk 2 of lactation. Dry matter intake and milk yield were decreased by the HC treatment. The MC and HC treatments increased milk fat concentration, although milk fat yield was unaffected. All carnitine treatments decreased liver total lipid and triacylglycerol accumulation on d 10 after calving. In addition, carnitine-supplemented cows had higher liver glycogen during early lactation. In general, carnitine supplementation increased in vitro palmitate beta-oxidation by liver slices, with MC and HC treatments affecting in vitro palmitate metabolism more potently than did LC. In vitro conversion of Ala to glucose by liver slices was increased by carnitine supplementation independent of dose. The concentration of nonesterified fatty acids in serum was not affected by carnitine. As a result of greater hepatic fatty acid beta-oxidation, plasma beta-hydroxybutyric acid was higher for the MC and HC treatments. Serum insulin was greater for all carnitine treatments, although plasma glucose was unaffected. Plasma urea N was lower and plasma total protein was higher for the MC and HC treatments. By decreasing liver lipid accumulation and stimulating hepatic glucose output, carnitine supplementation might improve glucose status and diminish the risk of developing metabolic disorders during early lactation.

Topics: Animal Feed; Animals; Body Constitution; Body Weight; Carnitine; Cattle; Diet; Dietary Supplements; Eating; Energy Metabolism; Female; Glycogen; Lactation; Lipids; Liver; Milk; Parturition; Pregnancy; Random Allocation; Time Factors

The common hepatic branch of the vagus nerve is a two-way highway of communication between the brain and the liver, duodenum, stomach and pancreas that regulates many aspects of food intake and metabolism. In this study, we utilized the afferent-specific neurotoxin capsaicin to examine if common hepatic vagal sensory afferents regulate lard intake. Rats implanted with a corticosterone pellet were made diabetic using streptozotocin (STZ) and a subset received steady-state exogenous insulin replacement into the superior mesenteric vein. These were compared with non-diabetic counterparts. Each group was then subdivided into those whose common hepatic branch of the vagus was treated with vehicle or capsaicin. Five days after surgery, the rats were offered the choice of chow and lard to consume for a further 5 days. The STZ-diabetic rats ate significantly less lard than the non-diabetic rats. Capsaicin treatment restored lard intake to that of the insulin-replaced, STZ-diabetic rats, but modified neither chow nor total caloric intake. This increased lard intake led to selective fat deposition into the mesenteric white adipose tissue depot, as opposed to an increase in all visceral fat pad depots evident after insulin replacement-induced lard intake. Capsaicin treatment also increased the levels of circulating glucose and triglycerides and negated the actions of insulin on these and free fatty acids and ketone bodies. Collectively, these data suggest that afferent signalling through the common hepatic branch of the vagus inhibits lard, but not chow, intake, directs fat deposition and regulates plasma metabolite levels.

Topics: Adipose Tissue, White; Adrenal Glands; Afferent Pathways; Animals; Biomarkers; Blood Glucose; Body Weight; Capsaicin; Corticosterone; Diabetes Mellitus, Experimental; Dietary Fats; Feeding Behavior; Food Preferences; Glucagon; Glycogen; Hypoglycemic Agents; Insulin; Leptin; Lipids; Liver; Male; Organ Size; Rats; Rats, Sprague-Dawley; Spleen; Thymus Gland; Time Factors; Vagus Nerve

Diet-induced obesity (DIO) is associated with insulin resistance in liver and muscle, but not in adipose tissue. Mice with fat-specific disruption of the gene encoding the insulin receptor are protected against DIO and glucose intolerance. In cell culture, glutamine induces insulin resistance in adipocytes, but has no effect in muscle cells. We investigated whether supplementation of a high-fat diet with glutamine induces insulin resistance in adipose tissue in the rat, improving insulin sensitivity in the whole animal.. Male Wistar rats received standard rodent chow or a high-fat diet (HF) or an HF supplemented with alanine or glutamine (HFGln) for 2 months. Light microscopy and morphometry, oxygen consumption, hyperinsulinaemic-euglycaemic clamp and immunoprecipitation/immunoblotting were performed.. HFGln rats showed reductions in adipose mass and adipocyte size, a decrease in the activity of the insulin-induced IRS-phosphatidylinositol 3-kinase (PI3-K)-protein kinase B-forkhead transcription factor box 01 pathway in adipose tissue, and an increase in adiponectin levels. These results were associated with increases in insulin-stimulated glucose uptake in skeletal muscle and insulin-induced suppression of hepatic glucose output, and were accompanied by an increase in the activity of the insulin-induced IRS-PI3-K-Akt pathway in these tissues. In parallel, there were decreases in TNFalpha and IL-6 levels and reductions in c-jun N-terminal kinase (JNK), IkappaB kinase subunit beta (IKKbeta) and mammalian target of rapamycin (mTOR) activity in the liver, muscle and adipose tissue. There was also an increase in oxygen consumption and a decrease in the respiratory exchange rate in HFGln rats.. Glutamine supplementation induces insulin resistance in adipose tissue, and this is accompanied by an increase in the activity of the hexosamine pathway. It also reduces adipose mass, consequently attenuating insulin resistance and activation of JNK and IKKbeta, while improving insulin signalling in liver and muscle.

Topics: Animals; Body Weight; Diet; Dietary Supplements; Glucose; Glutamine; Glycogen; Insulin; Lipids; Liver; Male; Muscle, Skeletal; Obesity; Rats; Rats, Wistar; Signal Transduction

1. The efficacy of coumarin (1,2-benzopyrone) was examined for the regulation of hyperthyroidism in female rats. 2. Coumarin was administered (10 mg/kg per day for 15 days) to l-thyroxine (L-T(4))-induced hyperthyroid as well as to euthyroid rats and changes in serum concentrations of thyroid hormones and in associated parameters, such as serum cholesterol, activity of hepatic 5'-monodeiodinase (5'DI) and glucose-6-phosphatase (G-6-Pase), glycogen content, bodyweight and daily food consumption, were analysed. Simultaneously, changes in hepatic lipid peroxidation (LPO), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were also investigated. 3. Although L-T(4) administration increased serum levels of thyroid hormones, the activity of hepatic 5'DI, G-6-Pase and LPO and daily food consumption, it decreased the level of serum cholesterol, hepatic glycogen content and the activities of anti-oxidant enzymes, such as SOD, CAT and GSH. 4. However, simultaneous administration of coumarin for 15 days to a group of hyperthyroid animals reversed most of the aforementioned changes, indicating its potential to ameliorate hyperthyroidism. Moreover, the drug did not increase, but rather decreased, hepatic LPO, suggesting its safe nature. 5. The present findings reveal a positive role for coumarin in the regulation of hyperthyroidism without any hepatotoxicity. It also appears that the test compound inhibits thyroid function at both a glandular level and at the level of peripheral conversion of T(4) to tri-iodothyronine.

Topics: Animals; Antithyroid Agents; Body Weight; Catalase; Cholesterol; Coumarins; Disease Models, Animal; Eating; Female; Glucose-6-Phosphatase; Glutathione; Glycogen; Hyperthyroidism; Iodide Peroxidase; Lipid Peroxidation; Liver; Rats; Rats, Wistar; Superoxide Dismutase; Thyroid Gland; Thyroid Hormones; Thyroxine; Time Factors

The antiandrogenic effect of oral administration of aqueous extract of Chromolaena odoratum leaves (250 and 500 mg kg(-1) body weight) for 14 days in male albino rats was investigated. Forty-two white albino rats were randomly divided into three groups: A, B and C. Group A which served as the control received 1 ml of distilled water (the vehicle) twice daily for 14 days, whereas groups B and C were treated in the same way like the control except that the animals received 250 and 500 mg kg(-1) body weight of the plant extract respectively. Compared with the control, extract administration at 250 and 500 mg kg(-1) body weight revealed a significant reduction (P<0.05) in testicular body weight ratio, acid phosphatase activities, protein, cholesterol, glycogen, sialic acid and testosterone concentrations with a significant increase (P<0.05) in lactate dehydrogenase and gamma-glutamyl transferase activities. There was no significant change (P>0.05) in serum concentrations of follicle stimulating and luteinising hormones. Histological examination revealed disruption in the arrangement of seminiferous tubules with no distinct basement membrane. These changes were accompanied by reduction in the number of spermatozoa. All these results indicated that aqueous extract of C. odoratum leaves possesses antiandrogenic property by interfering with steroidogenesis at the testicular level and this will adversely affect the functional capacity of the testes and the fertility of the animal.

Topics: Acid Phosphatase; Androgen Antagonists; Animals; Body Weight; Cholesterol; Chromolaena; gamma-Glutamyltransferase; Glycogen; L-Lactate Dehydrogenase; Male; Plant Extracts; Plant Leaves; Random Allocation; Rats; Rats, Wistar; Seminiferous Tubules; Spermatozoa; Testis; Testosterone

The effect of Erabu sea snake (Laticauda semifasciata) lipids on the swimming endurance was investigated in aged mice. Fifty three-week-old male Crlj:CD-1 (ICR) mice were fed one of three experimental diets containing either 6% lard, 6% fish oil, or 6% sea snake lipids for 16 wk. The swimming exercise was carried out in an acrylic plastic tank filled with 25 cm of water maintained at 23(o)C. Swimming times to exhaustion were measured with a load of 2% of their body weights attached to the tails of the mice. The swimming times to exhaustion of the group that were fed the sea snake lipid diet tended to be longer than those of the lard diet group, and were significantly improved compared with the fish oil diet group (p<0.05). The plasma and muscle lactate levels were significantly lower in the sea snake lipid diet group than in the lard and fish oil diet groups (p<0.05). The liver glycogen and plasma glucose levels of the sea snake lipid diet group did not differ markedly from those of the lard diet group (p>0.05), and were significantly higher than those of the fish oil diet group (p<0.05). These results suggest that an intake of sea snake lipids but not the fish oil, which is also rich in n-3 polyunsaturated fatty acids (n-3 PUFAs), is useful for improving the swimming endurance of aged mice by attenuating lactate production and/or enhancing lactate clearance during swimming exercise, and the n-3 PUFAs contained in the sea snake lipids did little or nothing for this improved endurance.

Topics: Adipose Tissue; Aging; Animals; Body Weight; Dietary Fats; Eating; Elapidae; Fish Oils; Glycogen; Humans; Lactates; Liver; Male; Mice; Mice, Inbred ICR; Muscle, Skeletal; Physical Conditioning, Animal; Physical Endurance; Swimming; Weight-Bearing

The aim of this study was to investigate, in situ, the temporal effects of urban effluent discharge on energy reserves and steroid hormone levels in the intrasedimentary worm Nereis diversicolor. Results have shown no differences in energy reserves (glycogen, lipids) in organisms originating from a contaminated site (Oued Souss) and a comparatively clean site (Oualidia). Both sites are located on the Moroccan Atlantic coast. In contrast, steroid hormone (progesterone, testosterone, and 17beta-estradiol) levels were significantly decreased in animals from Oued Souss. The differences in the responses suggest that organisms from the polluted site have been exposed to endocrine disruptors.

Topics: Animals; Body Weight; Endocrine Disruptors; Energy Metabolism; Environmental Monitoring; Glycogen; Gonadal Steroid Hormones; Lipid Metabolism; Morocco; Polychaeta; Seasons

The present study was conducted to evaluate the toxicity of the exposure to diphenyl diselenide [(PhSe)2] and diphenyl ditelluride [(PhTe)2] on reproductive system in Wistar rats. Adult male rats were exposed intraperitonealy (acute) or subcutaneously (sub-chronic, during 4 or 8 weeks) to (PhSe)2 or (PhTe)2 prior to mating. A number of biochemical parameters in rat testes were examined, such as delta-aminolevulinate dehydratase (delta-ALA-D) activity, lipid peroxidation, glycogen content and components of the antioxidant defenses (superoxide dismutase (SOD) activity and ascorbic acid concentration). Furthermore, a possible effect on fertility and reproductive performance in male rats were studied. Sperm counts of caudal epididymis were also evaluated. No lethality was noted in any group. Reduction on body weight in rats which received (PhTe)2 was only evidenced in acute exposure, while (PhSe)2-exposed rats presented significant loss of body weight in acute and 4 week-exposure. Mating and fertility indexes were not affected after acute and sub-chronic exposure. Regarding other parameters studied, except for a decrease in testes glycogen content in acutely (PhSe)2-treated group, no alterations were found in treated groups. Sperm counts of rats treated acutely and sub-chronically were unaffected by drugs exposure. Histological evaluation revealed no modification on testicular tissue in rats exposed to (PhSe)2 and (PhTe)2. The results suggest the absence of the male reproductive toxicity induced by (PhSe)2 and (PhTe)2 administered intraperitonealy (acute) or subcutaneously (sub-chronical) to adult rats Wistar.

Topics: Animals; Ascorbic Acid; Benzene Derivatives; Body Weight; Female; Fertility; Glycogen; Injections, Intraperitoneal; Injections, Subcutaneous; Lipid Peroxidation; Male; Organometallic Compounds; Organoselenium Compounds; Porphobilinogen Synthase; Pregnancy; Rats; Rats, Wistar; Reproduction; Sperm Count; Superoxide Dismutase; Testis; Thiobarbituric Acid Reactive Substances; Toxicity Tests, Acute; Toxicity Tests, Chronic

The present research was undertaken to evaluate some biological parameters in rats fed with a supplemented diet with Opuntia ficus indica powder seeds. Feed intake and body weight of rats were measured every two days during nine weeks of treatment. Digestibility, feed conversion efficiency and protein efficiency ratio were determined. No difference in digestibility was noticed between the different diets. The results indicated a significant decrease in body weight of rats receiving a diet partially substituted with O. ficus indica powder seeds, probably due to a significant decrease in serum-free thyroxin (FT(4)) compared to the control group. In the treated group, a decrease of glucose concentration in blood and an increase of glycogen in liver and skeletal muscle were noticed. A significant increase in HDL-cholesterol was noted in the group receiving the supplemented diet with O. ficus indica powder seeds. These results suggest that O. ficus indica seeds can be used as a healthy food.

Topics: Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Weight; Dietary Supplements; Digestive System Physiological Phenomena; Eating; Feces; Glycogen; Liver; Male; Muscle, Skeletal; Opuntia; Rats; Rats, Wistar; Seeds

The current study was undertaken to consider predictive methods for describing the vigor of Reticulitermes flavipes (Kollar) termites stored in a laboratory under conditions similar to control groups in bioassay. These novel methods were based on measurements for levels of biological molecules (uric acid, soluble proteins, lipid, and glycogen), percent water content, live weight, and running speed. Also considered were two established, non-predictive methods for determining vigor, survivorship and consumption rate. Of the novel measures tested, lipid and body water percentage show promise in distinguishing weak from vigorous groups of termites, with body water percentage a more practical means of measurement. Low body water percentage was concluded to be an indicator of weak groups of termites.

Topics: Animals; Body Water; Body Weight; Eating; Glycogen; Health; Insect Proteins; Isoptera; Lipid Metabolism; Running; Survival Rate; Uric Acid

AMPK is a key regulator of fat and carbohydrate metabolism. It has been postulated that defects in AMPK signaling could be responsible for some of the metabolic abnormalities of type 2 diabetes. In this study, we examined whether insulin-resistant obese Zucker rats have abnormalities in the AMPK pathway. We compared AMPK and ACC phosphorylation and the protein content of the upstream AMPK kinase LKB1 and the AMPK-regulated transcriptional coactivator PPARgamma coactivator-1 (PGC-1) in gastrocnemius of sedentary obese Zucker rats and sedentary lean Zucker rats. We also examined whether 7 wk of exercise training on a treadmill reversed abnormalities in the AMPK pathway in obese Zucker rats. In the obese rats, AMPK phosphorylation was reduced by 45% compared with lean rats. Protein expression of the AMPK kinase LKB1 was also reduced in the muscle from obese rats by 43%. In obese rats, phosphorylation of ACC and protein expression of PGC-1alpha, two AMPK-regulated proteins, tended to be reduced by 50 (P = 0.07) and 35% (P = 0.1), respectively. There were no differences in AMPKalpha1, -alpha2, -beta1, -beta2, and -gamma3 protein content between lean and obese rats. Training caused a 1.5-fold increase in AMPKalpha1 protein content in the obese rats, although there was no effect of training on AMPK phosphorylation and the other AMPK isoforms. Furthermore, training also significantly increased LKB1 and PGC-1alpha protein content 2.8- and 2.5-fold, respectively, in the obese rats. LKB1 protein strongly correlated with hexokinase II activity (r = 0.75, P = 0.001), citrate synthase activity (r = 0.54, P = 0.02), and PGC-1alpha protein content (r = 0.81, P < 0.001). In summary, obese insulin-resistant rodents have abnormalities in the LKB1-AMPK-PGC-1 pathway in muscle, and these abnormalities can be restored by training.

Topics: Acetyl-CoA Carboxylase; AMP-Activated Protein Kinase Kinases; AMP-Activated Protein Kinases; Animals; Body Weight; Glucose; Glycogen; Hexokinase; Insulin; Insulin Resistance; Lipids; Models, Biological; Multienzyme Complexes; Muscle, Skeletal; Obesity; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Phosphorylation; Physical Conditioning, Animal; Protein Kinases; Protein Serine-Threonine Kinases; Rats; Rats, Zucker; RNA-Binding Proteins; Signal Transduction; Transcription Factors

A series of polyphenols known as catechins are abundant in green tea, which is consumed mainly in Asian countries. The effects of catechin-rich green tea extract (GTE) on running endurance and energy metabolism during exercise in BALB/c mice were investigated. Mice were divided into four groups: nonexercise control, exercise control (Ex-cont), exercise+0.2% GTE, and exercise+0.5% GTE groups. Treadmill running time to exhaustion, plasma biochemical parameters, skeletal muscle glycogen content, beta-oxidation activity, and malonyl-CoA content immediately after exercise were measured at 8-10 wk after the initiation of the experiment. Oxygen consumption and respiratory exchange ratio were measured using indirect calorimetry. Running times to exhaustion in mice fed 0.5% GTE were 30% higher than in Ex-cont mice and were accompanied by a lower respiratory exchange ratio, higher muscle beta-oxidation activity, and lower malonyl-CoA content. In addition, muscle glycogen content was high in the GTE group compared with the Ex-cont group. Plasma lactate concentrations in mice fed GTE were significantly lower after exercise, concomitant with an increase in free fatty acid concentrations. Catechins, which are the main constituents of GTE, did not show significant effects on peroxisome proliferator-activated receptor-alpha or delta-dependent luciferase activities. These results suggest that the endurance-improving effects of GTE were mediated, at least partly, by increased metabolic capacity and utilization of fatty acid as a source of energy in skeletal muscle during exercise.

Topics: Animals; Blood Glucose; Body Weight; Camellia sinensis; Carbon Dioxide; Catechin; Fatty Acids, Nonesterified; Glycogen; Lactic Acid; Lipid Mobilization; Male; Malonyl Coenzyme A; Mice; Mice, Inbred BALB C; Muscle, Skeletal; Oxidation-Reduction; Oxygen Consumption; Peroxisome Proliferator-Activated Receptors; Physical Conditioning, Animal; Physical Endurance; Plant Extracts; Plant Leaves; Running; Triglycerides

Rainbow trout has a limited ability to utilize digestible carbohydrates efficiently. Trout feeds generally contain high levels of DHA, a fatty acid known to inhibit a number of glycolytic and lipogenic enzymes in animals. A study was conducted to determine whether carbohydrate utilization by rainbow trout might be affected by dietary DHA level. Two low-carbohydrate (<4 % digestible carbohydrate) basal diets were formulated to contain 1 (adequate) or 4 (excess) g/100 g DHA diet respectively. The two basal diets were diluted with increasing levels of digestible starch (0 %, 10 %, 20 % and 30 %, respectively) to produce eight diets. These diets were fed to fish for 12 weeks at 15 degrees C according to a pair-fed protocol that consisted of feeding the same amount of basal diet but different amounts of starch. Live weight, N and lipid gains, hepatic glycogen and plasma glucose values significantly increased, whereas feed efficiency (gain:feed) significantly decreased, with increasing starch intake (P<0.05). The retention efficiency of N (N gain/digestible N intake) improved with starch supplementation but was not affected by DHA level (P>0.05). Starch increased the activity of glucokinase, pyruvate kinase, glucose 6-phosphate dehydrogenase and fatty acid synthase (P<0.05) but did not affect hexokinase and malic enzyme activity. DHA had no effect on growth but increased plasma glucose and reduced carcass lipid and liver glycogen contents (P<0.05). Glycolytic and lipogenic enzymes were not affected by DHA level, except for pyruvate kinase, which was reduced by increasing DHA level. These results suggest only a marginal effect of dietary DHA on the ability of fish to utilize carbohydrate.

Topics: Animal Feed; Animals; Blood Glucose; Body Weight; Dietary Carbohydrates; Dietary Fats; Dietary Supplements; Digestion; Docosahexaenoic Acids; Fatty Acids; Glycogen; Liver; Oncorhynchus mykiss; Starch

Hemionitis arifolia, a folklore anti-diabetes fern, was evaluated for its hypoglycaemic and anti-diabetic properties using rats. Glucose lowering effect and anti-diabetes activity were studied using glucose tolerance test in normal rats and alloxan diabetic rats, respectively. When different extracts were tested, the ethanol and, to some extent, the water extracts were found to lower the levels of blood glucose in glucose fed rats. The ethanol extract showed optimum activity at 200 mg/kg. The extract exhibited only marginal hypoglycaemic activity in overnight fasted normal rats and it was devoid of conspicuous toxic symptoms in sub-acute toxicity evaluation in mice. When the alcohol extract was fractionated by sequential solvent extraction, the activity was found in ethyl acetate fraction (50 mg/kg). This fraction containing steroids and coumarins showed anti-diabetes activity in alloxan diabetic rats as judged from serum glucose levels, liver glycogen content and body weight. This fraction is an attractive material for further research vis-à-vis drug development.

Topics: Alloxan; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Ferns; Glucose Tolerance Test; Glycogen; Hypoglycemic Agents; India; Liver; Mice; Plant Extracts; Plants, Medicinal; Rats; Rats, Wistar

Changes in body weight and composition are the result of complex interactions among metabolic fluxes contributing to macronutrient balances. To better understand these interactions, a mathematical model was constructed that used the measured dietary macronutrient intake during semistarvation and refeeding as model inputs and computed whole body energy expenditure, de novo lipogenesis, and gluconeogenesis as well as turnover and oxidation of carbohydrate, fat, and protein. Published in vivo human data provided the basis for the model components that were integrated by fitting a few unknown parameters to the classic Minnesota human starvation experiment. The model simulated the measured body weight and fat mass changes during semistarvation and refeeding and predicted the unmeasured metabolic fluxes underlying the body composition changes. The resting metabolic rate matched the experimental measurements and required a model of adaptive thermogenesis. Refeeding caused an elevation of de novo lipogenesis that, along with increased fat intake, resulted in a rapid repletion and overshoot of body fat. By continuing the computer simulation with the prestarvation diet and physical activity, the original body weight and composition were eventually restored, but body fat mass was predicted to take more than one additional year to return to within 5% of its original value. The model was validated by simulating a recently published short-term caloric restriction experiment without changing the model parameters. The predicted changes in body weight, fat mass, resting metabolic rate, and nitrogen balance matched the experimental measurements, thereby providing support for the validity of the model.

Topics: Adipose Tissue; Basal Metabolism; Body Composition; Body Weight; Caloric Restriction; Eating; Energy Metabolism; Glycogen; Humans; Lipid Metabolism; Models, Biological; Nitrogen; Oxygen Consumption; Starvation; Triglycerides

The purpose of the present study was to elucidate the possible role of leptin in food intake and body weight regulation in goldfish. We examined the effects of i.c.v. or i.p. acute leptin administration on food intake in food-deprived goldfish at different time intervals post-injection (0-2, 2-8 and 0-8 h). Food intake was reduced by i.p. administered leptin (1 microg) at 8 h post-injection, without statistically significant differences after i.c.v. treatment. The present study shows for the first time in a teleost that chronic (10 days) leptin treatment (i.p.) reduces food intake, body weight gain, specific growth rate and food efficiency ratio. Moreover, lipid and carbohydrate metabolism seems to be regulated by leptin in fish. Chronic leptin treatment increased lipid mobilization and carbohydrate storage as hepatic and muscle glycogen. Finally, leptin could mediate its actions on energy homeostasis in fish, at least in part, through interactions with hypothalamic catecholamines, since chronic leptin treatment reduced both hypothalamic noradrenergic and dopaminergic turnover without significant modifications in hypothalamic serotoninergic and neuropeptide Y (NPY) systems. In summary, our results suggest that leptin can regulate feeding behaviour and body weight homeostasis in fish.

Topics: Animals; Body Weight; Carbohydrate Metabolism; Catecholamines; Eating; Energy Metabolism; Glycogen; Goldfish; Hypothalamus; Injections, Intraperitoneal; Injections, Intravenous; Leptin; Lipid Metabolism; Liver; Muscles; Neuropeptide Y; Serotonin; Starvation; Time Factors

The aim of this study was the evaluation of the effects of a subchronic exposure to malathion, an organophosphorus (OP) insecticide, on plasma glucose and hepatic enzymes of glycogenolysis and glycolysis in rats in vivo. Malathion was administered intragastrically by stomach tube in the amount of 1 ml corn oil containing 100mg/kg body weight (BW) daily for 32 days. At the end of the experiment, the liver was removed. The activities of glycogen phosphorylase (GP) and hexokinase (HK) were analysed in the homogenate. The methodology employed was a non-denaturing electrophoresis followed by activity-staining (native PAGE). Malathion decrease GP activity by 50% and increase HK activity by 10%. In addition, an hepatomegaly was recorded with a rise in the hepatic glycogen rate in malathion-treated rats. Moreover, subchronic administration of malathion has no effect on blood glucose concentration. The storage of glycogen in liver may be due to a stimulation of insulin secretion after the inhibition of acethylcholinesterase activity in pancreatic beta cells by malathion. These findings were in favour of an activation of glycogen storage by malathion.

Topics: Administration, Oral; Animals; Blood Glucose; Body Weight; Electrophoresis, Polyacrylamide Gel; Glycogen; Glycogen Phosphorylase; Hexokinase; Insecticides; Liver; Malathion; Male; Organ Size; Rats; Rats, Wistar

Developmental changes in ovine myocardial glucose transporters and insulin signaling following hyperthermia-induced intrauterine fetal growth restriction (IUGR) were the focus of our study. Our objective was to test the hypothesis that the fetal ovine myocardium adapts during an IUGR gestation by increasing glucose transporter protein expression, plasma membrane-bound glucose transporter protein concentrations, and insulin signal transduction protein concentrations. Growth measurements and whole heart tissue were obtained at 55 days gestational age (dGA), 90 dGA, and 135 dGA (term = 145 dGA) in fetuses from control (C) and hyperthermic (HT) pregnant sheep. Additionally, in 135 dGA animals, arterial blood was obtained and Doppler ultrasound was used to determine umbilical artery systolic (S) and diastolic (D) flow velocity waveform profiles to calculate pulsatility (S - D/mean) and resistance (S - D/S) indices. Myocardial Glut-1, Glut-4, insulin signal transduction proteins involved in Glut-4 translocation, and glycogen content were measured. Compared to age-matched controls, HT 90-dGA fetal body weights and HT 135-dGA fetal weights and gross heart weights were lower. Heart weights as a percent of body weights were similar between C and HT sheep at 135 dGA. HT 135-dGA animals had (i) lower fetal arterial plasma glucose and insulin concentrations, (ii) lower arterial blood oxygen content and higher plasma lactate concentrations, (iii) higher myocardial Glut-4 plasma membrane (PM) protein and insulin receptor beta protein (IRbeta ) concentrations, (iv) higher myocardial glycogen content, and (v) higher umbilical artery Doppler pulsatility and resistance indices. The HT ovine fetal myocardium adapts to reduced circulating glucose and insulin concentrations by increasing plasma membrane Glut-4 and IRbeta protein concentrations. The increased myocardial Glut-4 PM and IRbeta protein concentrations likely contribute to or increase the intracellular delivery of glucose and, together with the increased lactate concentrations, enhance glycogen synthesis, which allows for maintained myocardial growth commensurate with fetal body growth.

Topics: Animals; Body Weight; Female; Fetal Growth Retardation; Fever; Gestational Age; Glucose; Glucose Transporter Type 1; Glucose Transporter Type 4; Glycogen; Insulin; Insulin Receptor Substrate Proteins; Intracellular Signaling Peptides and Proteins; Myocardium; Organ Size; Phosphatidylinositol 3-Kinases; Phosphoproteins; Pregnancy; Proto-Oncogene Proteins c-akt; Receptor, Insulin; Sheep, Domestic; Signal Transduction

Creatine supplementation may exert beneficial effects on muscle performance and facilitate peripheral glucose disposal in both rats and human subjects. The present study was undertaken to explore the effects of creatine supplementation on the ATP, creatine, phosphocreatine and glycogen content of white and red gastrocnemius and soleus muscles and on blood D-glucose and plasma insulin concentrations before and during an intravenous glucose tolerance test in Goto-Kakizaki rats, a current animal model of inherited type 2 diabetes mellitus. Creatine supplementation increased muscle creatine content, especially in the soleus muscle of young rats (+35.5-/+15.8%; d.f.=10; p<0.05), and lowered the insulinogenic index, i.e. the paired ratio between plasma insulin and blood D-glucose concentrations. The latter change was mainly attributable to a lowering of plasma insulin concentration. It is proposed, therefore, that creatine supplementation may improve the sensitivity to insulin in extrapancreatic sites in the present animal model of type 2 diabetes.

Topics: Adenosine Triphosphate; Animals; Blood Glucose; Body Weight; Creatine; Diabetes Mellitus, Type 2; Disease Models, Animal; Eating; Glucose Tolerance Test; Glycogen; Insulin; Male; Muscle, Skeletal; Rats; Rats, Inbred Strains

Streptozotocin (STZ) is an agent used in creating experimental diabetes. Varying findings have been reported about the striated muscle glycogen levels in diabetes. In this study, it was planned to observe interaction of vitamin C (AA), of which deficiency has been shown in diabetics, with soleus muscle glycogen levels and oxidative events on STZ-diabetic subjects.. In the study, 38 male adult Wistar Albino rats with weights 200 +/- 20 g were used by separating them into four groups: Control, Vitamin C, Diabetes, Diabetes + Vitamin C. Body weights and fasting blood glucose were measured at the beginning and end of the experiment. AA, TBARS, GSH, NOx and glycogen levels of soleus muscles, and AA level of blood were measured. The results were compared using Anova variance and Mann-Whitney U tests. Results showed that AA levels in blood increased with vitamin C administration; AA, GSH and NOx levels in the muscle were low and MDA and glycogen levels were high in diabetics; and that vitamin C in the given dosage partially corrected these values. These results indicate that higher dosage than daily 20 mg/kg Vitamin C is required for being effective on metabolic and oxidizing events in diabetic rats.

Topics: Animals; Ascorbic Acid; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Glutathione; Glycogen; Male; Malondialdehyde; Muscle, Skeletal; Nitric Oxide; Organ Size; Oxidation-Reduction; Rats; Rats, Wistar

This study assessed whether liquid carbohydrate-protein (C+P) supplements, ingested early during recovery, enhance muscle glycogen resynthesis versus isoenergetic liquid carbohydrate (CHO) supplements, given early or an isoenergetic solid meal given later during recovery (PLB).. Two hours after breakfast (7.0 kcal.kg; 0.3 g.kg P, 1.2 g.kg C, 0.1 g.kg F), six male cyclists performed a 60-min time trial (AMex). Pre- and postexercise, vastus lateralis glycogen concentrations were determined using nMRS. Immediately, 1 h, and 2 h postexercise, participants ingested C+P (4.8 kcal.kg; 0.8 g.kg C, 0.4 g.kg P), CHO (4.8 kcal.kg; 1.2 g.kg C), or PLB (no energy). Four hours postexercise, a solid meal was ingested. At that time, C+P and CHO received a meal identical to breakfast, whereas PLB received 21 kcal.kg (1 g.kg P, 3.6 g.kg C, 0.3 g.kg F); energy intake during 6 h of recovery was identical among treatments. After 6 h of recovery, measurement and cycling protocols (PMex) were repeated.. Absolute muscle glycogen utilization was 18% greater (P

Topics: Adult; Bicycling; Body Weight; Dietary Carbohydrates; Dietary Proteins; Dietary Supplements; Energy Intake; Follow-Up Studies; Glycogen; Heart Rate; Humans; Magnetic Resonance Spectroscopy; Male; Muscle, Skeletal; Physical Endurance; Placebos; Recovery of Function

Previous studies from our laboratory have shown that vanadium stabilizes xenobiotic metabolizing enzymes and antioxidant status and suppresses DNA-protein crosslinks during chemically-induced hepatocarcinogenesis in rats. In the present study, we have further investigated the in vivo antitumor potential of this micronutrient by determining the effect of 0.5 ppm vanadium in drinking water on biomarkers for the early stages of hepatocarcinogenesis; the biomarkers included gamma-glutamyl transpeptidase (GGT)-positive foci and glycogen-storage foci, in situ expression of proliferating cell nuclear antigen (PCNA), and genotoxic DNA damage assessed by the alkaline Comet assay. Histomorphometry also was assessed during the study. Hepatocarcinogenesis was induced by treating 4-week-old male Sprague-Dawley rats with a single, necrogenic, intraperitoneal (i.p.) injection of 200 mg/kg body weight diethylnitrosamine (DEN). Compared to the carcinogen control, vanadium administration over the 32 weeks of the experiment reduced the relative liver weight by 30%, the incidence of nodules by 69.34%, the total number and multiplicity of nodules by 80.77%, and remodeled the hepatocellular premalignant architecture towards a normal phenotype. Moreover, long-term vanadium treatment reduced the development of GGT foci by 76.2% (P < 0.001), decreased periodic acid-Schiff's reactivity by 59.49% (P < 0.01), and decreased PCNA expression, with the concomitant reduction in PCNA immunolabeling index by 93.36% (P < 0.001). Finally, vanadium inhibited early DNA damage (DNA strand-breaks) in DEN-treated rat hepatocytes as expressed in the Comet assay by a 60.04% reduction in the length:width value of DNA mass (P < 0.01) and a 51.54% reduction in the tail length of the DNA comets (P < 0.001). Our results indicate that continuous supplementation with 0.5 ppm vanadium suppresses hepatocellular neoplastic transformation in rats.

Topics: Animals; Anticarcinogenic Agents; Body Weight; Diethylnitrosamine; DNA Damage; gamma-Glutamyltransferase; Glycogen; Liver; Liver Neoplasms; Male; Organ Size; Precancerous Conditions; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; Vanadium

Effects of amylin and pair feeding (PF) on body weight and metabolic parameters were characterized in diet-induced obesity-prone rats. Peripherally administered rat amylin (300 microg/kg.d, 22d) reduced food intake and slowed weight gain: approximately 10% (P<0.05), similar to PF. Fat loss was 3-fold greater in amylin-treated rats vs. PF (P<0.05). Whereas PF decreased lean tissue (P<0.05 vs. vehicle controls; VEH), amylin did not. During wk 1, amylin and PF reduced 24-h respiratory quotient (mean+/-se, 0.82+/-0.0, 0.81+/-0.0, respectively; P<0.05) similar to VEH (0.84+/-0.01). Energy expenditure (EE mean+/-se) tended to be reduced by PF (5.67+/-0.1 kcal/h.kg) and maintained by amylin (5.86+/-0.1 kcal/h.kg) relative to VEH (5.77+/-0.0 kcal/h.kg). By wk 3, respiratory quotient no longer differed; however, EE increased with amylin treatment (5.74+/-0.09 kcal/.kg; P<0.05) relative to VEH (5.49+/-0.06) and PF (5.38+/-0.07 kcal/h.kg). Differences in EE, attributed to differences in lean mass, argued against specific amylin-induced thermogenesis. Weight loss in amylin and pair-fed rats was accompanied by similar increases arcuate neuropeptide Y mRNA (P<0.05). Amylin treatment, but not PF, increased proopiomelanocortin mRNA levels (P<0.05 vs. VEH). In a rodent model of obesity, amylin reduced body weight and body fat, with relative preservation of lean tissue, through anorexigenic and specific metabolic effects.

Topics: Adipose Tissue; Agouti Signaling Protein; Amyloid; Animals; Anti-Obesity Agents; Body Composition; Body Weight; Calorimetry, Indirect; Diet, Atherogenic; Eating; Energy Metabolism; Gene Expression; Glycogen; Hypothalamic Hormones; In Situ Hybridization; Intercellular Signaling Peptides and Proteins; Islet Amyloid Polypeptide; Liver; Liver Glycogen; Male; Melanins; Mice; Muscle, Skeletal; Neuropeptide Y; Obesity; Pituitary Hormones; Pro-Opiomelanocortin; Rats; Thinness; Triglycerides

The effects of supplemental D-psicose in the diet on diurnal variation in plasma glucose and insulin concentrations were investigated in rats. Forty-eight male Wistar rats were divided into four groups. Each group except for the control group was fed a diet of 5% D-fructose, D-psicose, or psico-rare sugar (3:1 mixture of D-fructose and D-psicose) for 8 weeks. Plasma glucose levels were lower and plasma insulin levels were higher at all times of day in the psicose and psico-rare sugar groups than in the control and fructose groups. Weight gain was significantly lower in the psicose group than in the control and fructose groups. Liver glycogen content, both before and after meals was higher in the psicose group than in the control and fructose groups. These results suggest that supplemental D-psicose can lower plasma glucose levels and reduce body fat accumulation. Hence, D-psicose might be useful in preventing postprandial hyperglycemia in diabetic patients.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Circadian Rhythm; Dietary Carbohydrates; Energy Intake; Fructose; Glycogen; Insulin; Liver; Male; Muscle, Skeletal; Organ Size; Random Allocation; Rats; Rats, Wistar

Summer diapause in the cotton bollworm, Helicoverpa armigera (Hübner), which prolongs the pupal stage, particularly in males, is induced by high temperatures. In the laboratory, summer-diapausing pupae of H. armigera were induced at high temperatures (33-39 degrees C) with a photoperiod of LD8:16; winter-diapausing and non-diapausing pupae, cultured at 20 degrees C with a photoperiod of LD8:16 and at 27 degrees C, LD16:8, respectively, acted as a control. Retention time of eye spots, weight, and lipid and glycogen levels were compared. At high temperatures, both body weight and energy storage capacity were much higher in summer-diapausing pupae than in non-diapausing pupae reared at 33-39 degrees C. At temperatures (>33 degrees C) high enough to maintain summer diapause, the eye spots of summer-diapausing pupae did not move during the 30-day experiment. However, eye spots of summer-diapausing pupae placed at 30 degrees C began to move about 10 days after they were transferred, significantly later than in non-diapausing pupae reared at 33-39 degrees C or non-diapausing pupae reared at 27 degrees C, which initiated eye spot movement 2 days after pupation. The differences in retention time of eye spots between summer- and winter-diapausing pupae shows that winter diapause is more intense than summer diapause in this insect. The weight loss, and lipid and glycogen metabolism curves indicate that the summer-diapausing pupae's metabolism is very low. We conclude that summer diapause in the cotton bollworm is a true diapause and that the summer diapause enables the cotton bollworm to withstand the high temperatures of summer.

Topics: Analysis of Variance; Animals; Body Weight; Estivation; Glycogen; Lipid Metabolism; Moths; Photoperiod; Pigmentation; Seasons; Temperature

In the present study, the effect of skim milk and the fermented milk product named dahi (yogurt) on plasma glucose, insulin, and lipid levels as well as on liver glycogen and lipid contents in rats fed with high fructose diet has been investigated. Rats were fed with high fructose diet (21%) supplemented with skim milk, dahi (10 g/day each), or no milk product (control group) for 6 weeks. After 6 weeks of high fructose diet administration, the plasma glucose became significantly higher in control animals (246 mg/dL), whereas it was lower in skim milk (178 mg/dL)- and dahi (143 mg/dL)-fed rats. The glucose tolerance became impaired at the third week of feeding of high fructose diet in control animals, whereas in skim milk- and dahi-fed animals achievement of glucose intolerance was delayed until the fourth and fifth week, respectively. Blood glycosylated hemoglobin and plasma insulin were significantly lower in skim milk (10% and 34%, respectively)- and dahi (17%, and 48%, respectively)-fed animals than those of the control group. Plasma total cholesterol, triglycerides, low-density lipoprotein-cholesterol, and very-low-density lipoprotein-cholesterol and blood free fatty acids were significantly lower in skim milk (13%, 14%, 14%, 19%, and 14%, respectively)- and dahi (22%, 33%, 30%, 33%, and 29%, respectively)-fed animals as compared with control animals. Moreover, the total cholesterol, triglyceride, and glycogen contents in liver tissues were also lower in skim milk (55%, 50%, and 36%, respectively)- and dahi (64%, 27%, and 4%, respectively)-fed animals as compared with control animals. In contrast, high-density lipoprotein-cholesterol in plasma was higher in skim milk (14%)- and dahi (29%)-fed animals as compared with control animals. These results indicate that skim milk and its fermented milk product, dahi, delay the progression of fructose-induced diabetes and dyslipidemia in rats and that these may be useful as antidiabetic food supplements that can be included in daily meals of the diabetic as well as normal population.

Topics: Animals; Blood Glucose; Body Weight; Diet; Eating; Fats; Fermentation; Fructose; Glucose Tolerance Test; Glycated Hemoglobin; Glycogen; Insulin; Lipids; Liver; Male; Milk; Rats; Rats, Wistar; Yogurt

To examine cellular and biochemical features of skeletal muscle in response to dietary-induced obesity in a novel Yucatan minipig model of childhood obesity.. From 4 to 16 months of age, minipigs were fed either a recommended human-type diet (NF; n = 4) or were overfed a western-type diet with saturated fat and high-glycemic index carbohydrates (OF, n = 4). Muscle samples (biceps femoris) were histochemically stained for the identification of intramuscular adipocytes, intramyocellular lipid aggregates (oil red O), and myofiber types (myosin ATPase, succinate dehydrogenase). Gene expressions and/or activities of factors involved in lipogenesis, lipolysis, or energetic metabolism were quantified in muscle.. Cross-sectional areas of myofibers paralleled pig body weight (r = 0.86, p < 0.01). The size of intramuscular adipocytes, the relative proportion of oil red O-stained fibers, and total muscle lipid content tended (p < or = 0.10) to increase in response to OF diet. Hormone-sensitive lipase, carnitine palmityl transferase-I, and uncoupling protein 2 mRNA levels were lower (p < 0.05) in OF pigs than in NF pigs. Activities of beta-hydroxyacyl-coenzyme A dehydrogenase and citrate synthase assessing post-carnitine palmityl transferase I events and the proportion of oxidative myofibers were not altered by OF diet. Activity and gene expression of fatty acid synthase were lower (p < 0.02) in OF pigs than in NF pigs.. Overfeeding in Yucatan minipigs reduced the expression levels of three catabolic steps in skeletal muscle that are involved also in the etiology of human obesity.

Topics: Adipocytes; Animals; Body Weight; Dietary Carbohydrates; Dietary Fats; Fatty Acid Synthases; Gene Expression; Glycogen; Humans; L-Lactate Dehydrogenase; Lipids; Lipogenesis; Muscle Fibers, Skeletal; Muscle, Skeletal; Obesity; PPAR gamma; RNA, Messenger; Sterol Regulatory Element Binding Protein 1; Subcutaneous Fat; Swine; Swine, Miniature

Sibutramine has been described as an anti-obesity drug with the ability to inhibit serotonin (5-HT), noradrenaline, and dopamine re-uptake, but without affinity to histamine and muscarinic receptors. On the other hand, cyproheptadine antagonizes serotonin 5-HT(2A), 5-HT(2B), and 5-HT(2C), histamine H1, and muscarinic (M) receptors. There are many reports concerning the influence of sibutramine on central serotoninergic pathways. In this study, we suggest that peripheral pathways may also be involved in the serotoninergic effects of sibutramine. In vivo experiments were undertaken to investigate the serotoninergic effects of sibutramine on body mass, the glycogen concentration in the diaphragm of rats, and locomotor behaviour. Rats were submitted to oral treatment with sibutramine, cyproheptadine, or sibutramine applied in combination with cyproheptadine, for a period of 2 months to investigate the 5-HT2 effects of sibutramine on these parameters. As the results demonstrated, the lower increase in body mass and the increased glycogen levels in the diaphragm muscle of rats treated with sibutramine seem to be modulated by 5-HT2 receptors, since these effects were completely antagonized by cyproheptadine in the group treated with the 2 drugs co-applied. Furthermore, the behavioural results also suggest that mechanisms modulated by 5-HT2 receptors are involved in the increase of locomotion in the rats treated with sibutramine, since the effect did not occur in the rats treated with sibutramine co-applied with the 5-HT2 receptor antagonist, cyproheptadine. The results suggest that sibutramine modifies energy-related parameters such as body mass, diaphragm glycogen, and locomotor behaviour in rats via 5-HT2 serotoninergic pathways.

Topics: Animals; Appetite Depressants; Body Weight; Cyclobutanes; Cyproheptadine; Diaphragm; Eating; Energy Metabolism; Glycogen; Male; Motor Activity; Rats; Rats, Wistar; Receptors, Serotonin, 5-HT2; Selective Serotonin Reuptake Inhibitors; Serotonin Antagonists; Time Factors

Conjugated linoleic acids (CLAs) exert numerous effects in animal models as well as in humans. Among other things, CLAs decrease plasma lipid levels and bring about hepatic steatosis. The latter effects are attributed to an agonistic action of CLAs on the peroxisome-proliferator-activated receptor family primarily responsible for activating genes involved in lipid metabolism and are related to changes in mRNA levels. Such changes are not necessarily reflected in changes in activity of controlling enzymes.. To investigate the effects of CLAs treatment on lipid metabolism, we determined lipid concentrations in plasma, lipoproteins and liver and measured the activity of a number of key enzymes in hepatic lipid metabolism as differences in lipid concentrations should be related to changes in enzyme activities. These variables were determined with the rat as a model.. Rats were fed a control diet or a diet containing 1.15% trans-10, cis-12 isomer and 1.11% cis-9, trans-11 isomer as part of a commercial mixture of CLAs. After 2 w the animals were killed, and plasma and liver fractions isolated. Subsequently, lipid concentrations of cholesterol, triacylglycerols and phospholipids were determined in the isolated lipoproteins. In livers homogenates, the concentrations of glycogen, cholesterol, triacylglycerol and phospholipids and the activities of enzymes catalyzing pacesetting steps of metabolism were determined, i. e. acetyl-CoA carboxylase, fatty acid synthase, diacylglycerol acyltransferase, 3-hydroxy- acyl-CoA dehydrogenase, citrate synthase and phosphofructokinase.. CLAs induced a lowering of the cholesterol levels in total plasma and in LDL and HDL lipoproteins and of phospholipid concentrations in LDL and HDL. CLAs treatment decreased the hepatic activity of diacylglycerol acyltransferase and had no effect on any of the other enzyme activities.. In other studies enhanced specific activities of ACC and FAS were found in livers of mice using the same or similar methods and experimental protocol as in the present study. The lack of effect of CLAs treatment on hepatic key enzymes of fatty acid synthesis and oxidation in Wistar rats questions the use of this strain for studying the mechanism(s) underlying CLA's effects on these parameters. However, in the rat model we observed reduced levels of cholesterol in total plasma and in LDL and HDL. Therefore, some aspects like loss of body fat are better studied in mice; for other aspects like reduction in serum cholesterol level the rat may be the model of choice.

Topics: Acetyl-CoA Carboxylase; Animals; Biomarkers; Body Weight; Carbohydrate Metabolism; Carrier Proteins; Diacylglycerol O-Acyltransferase; Eating; Fatty Acid Synthases; Glycogen; Linoleic Acids, Conjugated; Lipid Metabolism; Lipids; Liver; Male; Models, Animal; Organ Size; Phosphofructokinases; Rats; Rats, Wistar

The cage systems commonly used for housing laboratory rats often result in sedentary and overweight animals, as a consequence of restricted opportunities for physical activity combined with ad libitum feeding. This can have implications both for animal well-being and for the experimental outcome. Physical activity has several known positive effects on health and lifespan, and physical fitness might therefore be incorporated into the animal welfare concept. The aim of this study was to investigate if and how pen housing affects the physical activity and fitness of rats. Thirty-two juvenile male Sprague-Dawley rats were randomly assigned to two different housing systems for a 4-week period. Sixteen rats were kept individually in standard Makrolon type III cages (42x26x18 cm) furnished with black plastic tubes (singly-housed, SI). The remaining rats were kept in groups of eight, housed in large floor pens (150x210 cm), which were furnished with various objects to increase environmental complexity (pen-housed, PH). The body weight gain, and food and water intake of the rats were measured. During weeks 3 or 4, home cage behaviour, urinary cortiosterone/creatinine ratios (CO/CR), and muscle strength on an inclined plane, were measured. Enzyme activities and glycogen content were measured in tissue samples from m. triceps brachii taken after euthanization at the end of the study. There were no significant differences between groups for food and water intake, but PH rats weighed 14% less than SI rats after 4 weeks, and PH rats also had a more diverse behavioural pattern than SI rats. PH rats had significantly higher oxidative capacity (28% more citrate synthase (CS)) and greater glycogen content (28%) in their muscle samples than SI rats. The PH rats performed significantly better on the inclined plane, both in the muscle strength test (mean angle 75+/-0.5 degrees for PH rats and 69+/-0.4 degrees for SI rats) and the endurance strength test (mean time 233+/-22 s for PH rats and 73+/-14 s for SI rats). There was a negative correlation between body weight and results on the inclined plane for the PH rats. There were no significant differences between housing types with respect to CO/CR ratios. In conclusion, the large pen represents an environment that stimulates physical activity and more varied behaviour, which should be beneficial for the welfare of the animal.

Topics: 3-Hydroxyacyl CoA Dehydrogenases; Animal Welfare; Animals; Body Weight; Citrate (si)-Synthase; Corticosterone; Creatinine; Drinking; Eating; Glycogen; Hexokinase; Housing, Animal; L-Lactate Dehydrogenase; Male; Motor Activity; Muscle, Skeletal; Organ Size; Physical Fitness; Rats; Rats, Sprague-Dawley

The glucose storage polymer glycogen is generally considered to be an important source of energy for skeletal muscle contraction and a factor in exercise endurance. A genetically modified mouse model lacking muscle glycogen was used to examine whether the absence of the polysaccharide affects the ability of mice to run on a treadmill. The MGSKO mouse has the GYS1 gene, encoding the muscle isoform of glycogen synthase, disrupted so that skeletal muscle totally lacks glycogen. The morphology of the soleus and quadriceps muscles from MGSKO mice appeared normal. MGSKO-null mice, along with wild type littermates, were exercised to exhaustion. There were no significant differences in the work performed by MGSKO mice as compared with their wild type littermates. The amount of liver glycogen consumed during exercise was similar for MGSKO and wild type animals. Fasting reduced exercise endurance, and after overnight fasting, there was a trend to reduced exercise endurance for the MGSKO mice. These studies provide genetic evidence that in mice muscle glycogen is not essential for strenuous exercise and has relatively little effect on endurance.

Topics: Animals; Blood Glucose; Body Weight; Female; Glycogen; Glycogen Synthase; Glycolysis; Heterozygote; Lactates; Liver; Liver Glycogen; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Skeletal; Muscles; Physical Conditioning, Animal; Polymers; Polysaccharides; Time Factors

Changes in dietary macronutrient composition and/or central nervous system neuronal activity can underlie obesity and disturbed fuel homeostasis. We examined whether switching rats from a diet with high carbohydrate content (HC; i.e., regular chow) to diets with either high fat (HF) or high fat/high protein content at the expense of carbohydrates (LC-HF-HP) causes differential effects on body weight and glucose homeostasis that depend on the integrity of brain melanocortin (MC) signaling. In vehicle-treated rats, switching from HC to either HF or LC-HF-HP feeding caused similar reductions in food intake without alterations in body weight. A reduced caloric intake (-16% in HF and LC-HF-HP groups) required to maintain or increase body weight underlay these effects. Chronic third cerebroventricular infusion of the MC receptor antagonist SHU9119 (0.5 nmol/day) produced obesity and hyperphagia with an increased food efficiency again observed during HF (+19%) and LC-HF-HP (+33%) feeding. In this case, however, HF feeding exaggerated SHU9119-induced hyperphagia and weight gain relative to HC and LC-HF-HP feeding. Relative to vehicle-treated controls, SHU9119 treatment increased plasma insulin (2.8-4 fold), leptin (7.7-15 fold), and adiponectin levels (2.4-3.7 fold), but diet effects were only observed on plasma adiponectin (HC and LC-HF-HP

Topics: Animals; Body Composition; Body Weight; Brain; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Dose-Response Relationship, Drug; Eating; Energy Metabolism; Glucose Tolerance Test; Glycogen; Homeostasis; Hormones; Hyperphagia; Liver; Male; Melanocyte-Stimulating Hormones; Rats; Rats, Wistar; Receptors, Corticotropin; Receptors, Melanocortin; Signal Transduction

This study deals with the effects of post (12 or 18 months) whole body continuous (2 years) exposure of rabbits to 650 MHz electromagnetic fields (EMF) that are characteristic of those produced by broadcasting stations, on body weight and body mass, on the morphology of liver, spleen and brain, and on apoptosis rates and glycogen distribution in the liver. Two groups of rabbits were continuously exposed for 2 years to EMF of 650 MHz followed by 12 months (group 1) or 18 months (group 2) of post-exposure; a third group (group 3) was sham exposed. It was shown that the changes in apoptosis rates were conditional during the time of exposure, but not on a specific organ and that the whole body continuous exposure gave rise to modifications whose types and intensities were related to the time of post-exposure (12 or 18 months, respectively), the type of organ, and the individual animal. A number of effects were observed only in group 1, and not in group 2, which suggests some kind of adaptive response or of long-term recovery in the rabbits following continuous exposure to 650 MHz EMF.

Topics: Animals; Apoptosis; Body Weight; Brain; Electromagnetic Fields; Female; Glycogen; Liver; Male; Microscopy, Electron, Transmission; Rabbits; Spleen; Time Factors; Whole-Body Irradiation

Moderate amounts of alcohol intake have been reported to have a protective effect on the cardiovascular system and this may involve enhanced insulin sensitivity. We established an animal model of increased insulin sensitivity by low ethanol consumption and here we investigated metabolic parameters and molecular mechanisms potentially involved in this phenomenon. For that, Wistar rats have received drinking water either without (control) or with 3% ethanol for four weeks. The effect of ethanol intake on insulin sensitivity was analyzed by insulin resistance index (HOMA-IR), intravenous insulin tolerance test (IVITT) and lipid profile. The role of liver was investigated by the analysis of insulin signaling pathway, GLUT2 gene expression and tissue glycogen content. Rats consuming 3% ethanol showed lower values of HOMA-IR and plasma free fatty acids (FFA) levels and higher hepatic glycogen content and glucose disappearance constant during the IVITT. Neither the phosphorylation of insulin receptor (IR) and insulin receptor substrate-1 (IRS-1), nor its association with phosphatidylinositol-3-kinase (PI3-kinase), was affected by ethanol. However, ethanol consumption enhanced liver IRS-2 and protein kinase B (Akt) phosphorylation (3 times, P<0.05), which can be involved in the 2-fold increased (P<0.05) hepatic glycogen content. The GLUT2 protein content was unchanged. Our findings point out that liver plays a role in enhanced insulin sensitivity induced by low ethanol consumption.

Topics: Alcohol Drinking; Animals; Blotting, Northern; Blotting, Western; Body Weight; Cholesterol; Eating; Ethanol; Fatty Acids, Nonesterified; Gene Expression; Glucose Transporter Type 2; Glycogen; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Intracellular Signaling Peptides and Proteins; Lipoproteins; Liver; Male; Monosaccharide Transport Proteins; Phosphatidylinositol 3-Kinases; Phosphoproteins; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Receptor, Insulin; Triglycerides

Effects of in vivo adrenaline infusion on subsequent insulin-stimulated glucose uptake and glycogen synthase activation was investigated in slow-twitch (soleus) and fast-twitch (epitrochlearis) muscles. Furthermore, role of glycogen content and Protein kinase B (PKB) phosphorylation for modulation insulin sensitivity was investigated.. Male Wistar rats received adrenaline from osmotic mini pumps ( approximately 150 microg kg(-1) h(-1)) for 1 or 12 days before muscles were removed for in vitro studies.. Glucose uptake at physiological insulin concentration was elevated in both muscles after 1 and 12 days of adrenaline infusion. Insulin-stimulated glycogen synthase activation was also improved in both muscles. This elevated insulin sensitivity occurred despite the muscles were exposed to hyperglycaemia in vivo. After 1 day of adrenaline infusion, glycogen content was reduced in both muscles; insulin-stimulated PKB ser(473) phosphorylation was increased in both muscles only at the highest insulin concentration. After 12 days of adrenaline infusion, glycogen remained low in epitrochlearis, but returned to normal level in soleus; insulin-stimulated PKB phosphorylation was normal in both muscles.. Insulin-stimulated glucose uptake and glycogen synthase activation were increased after adrenaline infusion. Increased insulin-stimulated glucose uptake and glycogen synthase activation after adrenaline infusion cannot be explained by a reduction in glycogen content or an increase in PKB phosphorylation. The mechanisms for the improved insulin sensitivity after adrenaline treatment deserve particular attention as they occur in conjunction with hyperglycaemia.

Topics: Animals; Blood Glucose; Body Weight; Epinephrine; Glucose; Glycogen; Glycogen Synthase; Infusions, Intravenous; Insulin; Lactates; Male; Muscle, Skeletal; Norepinephrine; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Receptors, Adrenergic, beta

The present study was aimed to evaluate the hypoglycemic efficacy in an aqueous extract of seeds of two varieties, namely a country and a hybrid variety of Momordica charantia (MCSEt1 and MCSEt2) respectively in streptozotocin (STZ) induced diabetic rats. STZ-induced diabetic rats were treated with aqueous extracts of MCSEt1 and t2 for a period of 30 days. MCSEt1 and t2 extract treatment to diabetic rats resulted in a significant reduction in blood glucose, glycosylated hemoglobin, lactate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase and glycogen phosphorylase, and a concomitant increase in the levels of hemoglobin, glycogen and activities of hexokinase and glycogen synthase. These results clearly show the antidiabetic properties of Momordica charantia. Both the varieties showed safe and significant hypoglycemic effects which were more pronounced in MCSEt1 compared to MCSEt2 and glibenclamide.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Fructose-Bisphosphatase; Glucose Tolerance Test; Glucose-6-Phosphatase; Glycogen; Hemoglobins; Hypoglycemic Agents; L-Lactate Dehydrogenase; Liver; Male; Momordica; Plant Extracts; Rats; Rats, Wistar; Seeds

Patients with diabetic nephropathy, characterised pathologically by glomerulosclerosis, may account for up to 40% of end-stage renal cases. The short-term (within 3 months) streptozotocin- or alloxan-induced rat model is often used but glomerulosclerosis is seldom reported and it is unclear what the primary renal lesions are. Diabetic rats were studied at 1, 3 and 6 months after a single injection of alloxan. Both methacrylate and paraffin-embedded renal sections were obtained and stained with PAS and haematoxylin. A morphometric study was performed with stereological methods to obtain the volumes and lengths or diameters of renal tubules and glomeruli. A key morphological change associated with sustained hyperglycaemia was the accumulation of glycogen granules in about half of the distal tubules and thin segments starting from 1 month after the experiment, which was then extended to about half of the proximal tubules at 6 months. Renal hypertrophy was seen with a 9% increase in the tubule diameter but not in the total length; glomerular morphology was basically unaffected. Further studies are needed to establish whether glomerulosclerosis would occur in longer term and whether this animal model would be appropriate to study the human condition of diabetes mellitus in terms of renal damage.

Topics: Animals; Body Weight; Diabetes Mellitus, Experimental; Female; Glycogen; Kidney Glomerulus; Kidney Tubules; Male; Rats; Rats, Sprague-Dawley; Reference Values

In the present study, we investigated whether replacement of tap water by fructose or sucrose solutions affect rat body weight and insulin action in skeletal muscles.. Rats were fed standard rodent chow ad libitum with water, or water containing fructose (10.5% or 35%) or sucrose (10.5% or 35%) for 11 weeks. Body weight and energy intake from chow and drinking solutions were measured. Urinary catecholamines secretion was determined after 50-60 days. At the end of the feeding period, soleus and epitrochlearis were removed for in vitro measurements of glucose uptake (with tracer amount of 2-[3H]-deoxy-D-glucose) and PKB Ser473 phosphorylation (assessed by Western Blot) with or without insulin.. Fructose and sucrose solutions enhanced daily energy intake by about 15% without increasing rat body weight. Secretion of urinary noradrenaline was higher in rats drinking a 35% sucrose solution than in rats drinking water. In the other groups, urinary noradrenaline secretion was similar to rats consuming water. Urinary adrenaline secretion was similar in all groups. Insulin-stimulated glucose uptake and insulin-stimulated PKB phosphorylation were not reduced by intake of fructose or sucrose solution.. Fructose and sucrose solutions enhanced energy intake but did not increase body weight. Although noradrenaline may regulate body weight in rats drinking 35% sucrose solution, body weight seems to be regulated by other mechanisms. Intake of fructose or sucrose solution did not impair insulin-stimulated glucose uptake or signaling in skeletal muscles.

Topics: Administration, Oral; Animals; Beverages; Body Weight; Catecholamines; Deoxyglucose; Dietary Carbohydrates; Energy Intake; Energy Metabolism; Glucose; Glycogen; Heart; Insulin; Liver; Liver Glycogen; Male; Muscle, Skeletal; Myocardium; Rats; Rats, Wistar; Solutions

To determine whether the hepatic insulin resistance of obesity and type 2 diabetes is due to impaired insulin-induced suppression of glycogenolysis as well as gluconeogenesis, 10 lean nondiabetic, 10 obese nondiabetic, and 11 obese type 2 diabetic subjects were studied after an overnight fast and during a hyperinsulinemic-euglycemic clamp. Gluconeogenesis and glycogenolysis were measured using the deuterated water method. Before the clamp, when glucose and insulin concentrations differed among the three groups, gluconeogenesis was higher in the diabetic than in the obese nondiabetic subjects (P < 0.05) and glycogenolysis was higher in the diabetic than in the lean nondiabetic subjects (P < 0.05). During the clamp, when glucose and insulin concentrations were matched and glucagon concentrations were suppressed, both glycogenolysis and gluconeogenesis were higher (P < 0.01) in the diabetic versus the obese and lean nondiabetic subjects. Furthermore, glycogenolysis and gluconeogenesis were higher (P < 0.01) in the obese than in the lean nondiabetic subjects. Plasma free fatty acid concentrations correlated (P < 0.001) with glucose production and gluconeogenesis both before and during the clamp and with glycogenolysis during the clamp (P < 0.01). We concluded that defects in the regulation of glycogenolysis as well as gluconeogenesis cause hepatic insulin resistance in obese nondiabetic and type 2 diabetic humans.

Topics: Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Female; Gluconeogenesis; Glucose Clamp Technique; Glycogen; Humans; Hyperinsulinism; Insulin; Male; Middle Aged; Obesity

Undernutrition in fetal life programmes risk of obesity and the metabolic syndrome in adult life. Rat studies indicate that exposure to a maternal low-protein diet throughout fetal life establishes a preference for high-fat foods. The present study aimed to assess the effect of low protein exposure during discrete 7-day periods of gestation upon feeding behaviour (full gestation 22 days). Pregnant rats were fed control or low-protein diet, with low-protein feeding targeted at day 0--7 (LP Early), day 8--14 (LP Mid) or day 15--22 (LP Late) of gestation. At 12 weeks of age, offspring were placed on a macronutrient self-selection regimen. Prenatal protein restriction programmed feeding behaviour in female, but not male, offspring. Among females, all low-protein exposed groups consumed less fat than the control group (P<0.05). Male offspring showed no changes in feeding behaviour. In males and females fed a low-fat chow diet, there were metabolic differences between the groups. LP Early and LP Late males had greater hepatic glycogen stores than control animals. There were no differences in the size of abdominal fat depots in either male or female rats exposed to low-protein diet at any point in gestation. The data suggest that programming of feeding behaviour is likely to be gender-specific and dependent upon the timing of nutrient insult in fetal life. This work may have implications for the development of the metabolic syndrome.

Topics: Adipose Tissue; Animal Nutritional Physiological Phenomena; Animals; Appetite; Blood Glucose; Body Weight; Cholesterol; Diet; Diet, Protein-Restricted; Dietary Fats; Energy Intake; Female; Food Preferences; Glycogen; Insulin; Liver; Male; Pregnancy; Prenatal Exposure Delayed Effects; Prenatal Nutritional Physiological Phenomena; Rats; Rats, Wistar

Treatment with glucocorticoids, especially at high doses, induces insulin resistance. The aims of the present study were to identify the potential defects in insulin signalling that contribute to dexamethasone-induced insulin resistance in skeletal muscles, and to investigate whether the glycogen synthase-3 (GSK-3) inhibitor CHIR-637 could restore insulin-stimulated glucose metabolism.. Skeletal muscles were made insulin-resistant by treating male Wistar rats with dexamethasone, a glucocorticoid analogue, for 12 days. Insulin-stimulated glucose uptake, glycogen synthesis and insulin signalling were studied in skeletal muscles in vitro.. Dexamethasone treatment decreased the ability of insulin to stimulate glucose uptake, glycogen synthesis and glycogen synthase fractional activity. In addition, the dephosphorylation of glycogen synthase by insulin was blocked. These defects were paralleled by reduced insulin-stimulated protein kinase B (PKB) and GSK-3 phosphorylation. While expression of PKB, GSK-3 and glycogen synthase was not reduced by dexamethasone treatment, expression of the p85alpha subunit of phosphatidylinositol 3-kinase (PI 3-kinase) was increased. Inhibition of GSK-3 by CHIR-637 increased glycogen synthase fractional activity in soleus muscle from normal and dexamethasone-treated rats, although the effect was more pronounced in control rats. CHIR-637 did not improve insulin-stimulated glucose uptake in muscles from dexamethasone-treated rats.. We demonstrated that chronic dexamethasone treatment impairs insulin-stimulated PKB and GSK-3 phosphorylation, which may contribute to insulin resistance in skeletal muscles. Acute pharmacological inhibition of GSK-3 activated glycogen synthase in muscles from dexamethasone-treated rats, but GSK-3 inhibition did not restore insulin-stimulated glucose uptake.

Topics: Animals; Antibodies; Blood Glucose; Blotting, Western; Body Weight; Enzyme Inhibitors; Glucocorticoids; Glucose; Glycogen; Glycogen Synthase Kinase 3; Insulin; Insulin Resistance; Male; Muscle, Skeletal; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Signal Transduction

It has been argued that dairy cows with a high genetic milk production potential can maintain high milk production even with total omission of the dry period. Further, when omitting the dry period, cows are believed to experience fewer metabolic changes during the transition from late gestation to early lactation compared with cows having a traditional dry period. The performance and metabolic response to omission of the dry period for cows with an expected peak milk yield higher than 45 kg/d were studied in 28 Holstein dairy cows. The cows were followed in late gestation and in the subsequent 5 wk of early lactation. Fourteen cows were milked through late gestation (CM) and another 14 dairy cows underwent a 7-wk dry period (DRY). In the early lactation period, the cows had the same dry matter (DM) intake but cows in the CM group had a 22% reduction in milk yield compared with the cows in the DRY group. At calving, the experimental groups had the same average body weight and body condition score and there were no significant differences in body weight and body condition score changes in early lactation. However, the cows in the CM group compared with the cows in the DRY group had a higher plasma concentration of glucose and insulin and a lower plasma concentration of nonesterified fatty acids and beta-hydroxybutyrate in the following 5 wk of early lactation. Furthermore, the cows in the CM group had lower liver triacylglycerol concentration and higher liver glycogen concentration in the following early lactation. It is concluded that, even in dairy cows with an expected peak milk yield above 45 kg/d, omission of the dry period results in a relatively high reduction in milk yield in the following early lactation. Furthermore, these cows are in less metabolic imbalance in the following early lactation.

Topics: 3-Hydroxybutyric Acid; Animals; Blood Glucose; Body Composition; Body Weight; Calcium; Cattle; Dairying; Eating; Fatty Acids, Nonesterified; Female; Glycogen; Growth Hormone; Insulin; Lactation; Liver; Milk; Parturition; Pregnancy; Triglycerides

Although CCAAT/enhancer-binding protein alpha (C/EBPalpha) is essential for initiating or sustaining several metabolic processes during the perinatal period, the consequences of total ablation of C/EBPalpha during postnatal development have not been investigated. We have created a conditional knock-out model in which the administration of poly(I:C) caused a virtually total deletion of c/ebpalpha (C/EBPalpha(Delta/-) mice) in the liver, spleen, white and brown adipose tissues, pancreas, lung, and kidney of the mice. C/EBPalpha itself was completely ablated in the liver by day 4 after the injection of poly(I:C). There was no noticeable change in phenotype during the first 15 days after the injection. The mice maintained a normal level of fasting blood glucose and responded to the diabetogenic action of streptozotocin. From day 16 onward, the mice developed hypophagia, exhibited severe weight loss, lost triglyceride in white but not brown adipose tissue, became hypoglycemic and hypoinsulinemic, depleted their hepatic glycogen, and developed fatty liver. They also exhibited lowered plasma levels of free fatty acid, triglyceride, and cholesterol, as well as marked changes in hepatic mRNA for C/EBPdelta, peroxisome proliferator-activated receptor alpha, sterol regulatory element-binding protein 1, hydroxymethylglutaryl-coenzyme A reductase, and apolipoproteins. Although basal levels of hepatic mRNA for the cytosolic isoform of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase were reduced, transcription of the genes for these enzymes was inducible by dibutyryl cyclic AMP in C/EBPalpha(Delta/-) mice. The animals died about 1 month after the injection of poly(I:C). These findings demonstrate that C/EBPalpha is essential for the survival of animals during postnatal life and that its ablation leads to distinct biphasic change in metabolic processes.

Topics: Adipose Tissue; Alleles; Animals; Apolipoproteins; Blood Glucose; Blotting, Northern; Blotting, Southern; Blotting, Western; Body Weight; CCAAT-Enhancer-Binding Protein-alpha; CCAAT-Enhancer-Binding Protein-delta; Cholesterol; Crosses, Genetic; Cyclic AMP; Cytosol; Fatty Liver; Gene Deletion; Genotype; Glucokinase; Glucose; Glucose-6-Phosphatase; Glucose-6-Phosphate; Glycogen; Hydroxymethylglutaryl CoA Reductases; Kinetics; Liver; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Knockout; Mice, Transgenic; Models, Genetic; Oligonucleotide Array Sequence Analysis; Phosphoenolpyruvate Carboxykinase (ATP); Poly C; Poly I; Polymerase Chain Reaction; PPAR alpha; Protein Isoforms; RNA, Messenger; Streptozocin; Time Factors; Tissue Distribution; Transcription, Genetic; Triglycerides

Phytic acid (PA) is present in considerable amounts in the seeds of many plant species consumed by animals. Little is known about its influence on metabolic processes. In the performed experiment the effect of rats feeding a standard laboratory diet (Murigran) with increasing supplements of PA on some hormones and biochemical parameters was tested. Male Wistar rats were divided into five groups of eight animals each. In the first group (control) rats were fed a diet without any supplement whereas the groups II-V received food with added PA: 0.1, 0.2, 0.3 and 1%. After 20 days animals were decapitated, blood serum, liver and tight muscles were sampled. In rats fed a diet enriched in PA the concentration of thyroid hormones was diminished. Simultaneously, T(3)/T(4) ratio was slightly reduced. These changes were accompanied by a rise in blood glucose level and an augmentation in liver and muscle glycogen stores and were found in spite of unchanged blood insulin. Consumption of food with increased amounts of PA resulted in a substantial reduction of liver triglyceride content, but serum triglycerides were not affected. In rats from groups II and III serum free-fatty acids concentration was reduced. However, in animals receiving highest PA supplement this effect was not observed. Serum calcium and magnesium were not affected by PA. Serum iron was significantly reduced, but only in rats on the highest supplement of the tested compound. Results obtained in this experiment clearly indicate that the PA is able to induce hormonal and metabolic changes in animals. These changes seem to result not only from reduced bioavailability of minerals but also from interactions of PA with nutrients and enzymes in the liver.

Topics: Animals; Biological Availability; Blood Glucose; Body Weight; Dose-Response Relationship, Drug; Fatty Acids, Nonesterified; Glycogen; Iron; Liver; Liver Glycogen; Male; Muscle, Skeletal; Organ Size; Phytic Acid; Rats; Rats, Wistar; Thyroid Hormones; Triglycerides

The enzymes of glucose and lipid metabolism are markedly altered in experimental diabetes. In the present study, we investigated the effect of tetrahydrocurcumin (THC), one of the active metabolites in curcumin, on the key hepatic metabolic enzymes involved in carbohydrate metabolism in streptozotocin-induced diabetic rats. Different doses of THC (20, 40, and 80 mg\\kg body weight) were orally administered to diabetic rats for 45 days. The activities of hexokinase, glucose-6-phosphate dehydrogenase (G6PD), glucose-6-phosphatase, fructose-1,6-bisphosphatase, and sorbitol dehydrogenase in liver, and glycogen content in liver and muscle were assayed. In untreated diabetic control rats, the activities of the gluconeogenic enzymes were significantly increased, whereas hexokinase and G6PD activity and glycogen levels were significantly decreased. Both THC and curcumin were able to restore the altered enzyme activities to near normal levels. Tetrahydrocurcumin was more effective than curcumin. Our results indicate that the administration of THC to diabetic animals normalizes blood glucose and causes a marked improvement of altered carbohydrate metabolic enzymes.

Topics: Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Curcumin; Diabetes Mellitus, Experimental; Glucose Tolerance Test; Glycated Hemoglobin; Glycogen; Hemoglobins; Insulin; Liver; Male; Rats; Rats, Wistar

To assess the role of the alpha1b-adrenergic receptor (AR) in glucose homeostasis, we investigated glucose metabolism in knockout mice deficient of this receptor subtype (alpha1b-AR-/-). Mutant mice had normal blood glucose and insulin levels, but elevated leptin concentrations in the fed state. During the transition to fasting, glucose and insulin blood concentrations remained markedly elevated for at least 6 h and returned to control levels after 24 h whereas leptin levels remained high at all times. Hyperinsulinemia in the post-absorptive phase was normalized by atropine or methylatropine indicating an elevated parasympathetic activity on the pancreatic beta cells, which was associated with increased levels of hypothalamic NPY mRNA. Euglycemic clamps at both low and high insulin infusion rates revealed whole body insulin resistance with reduced muscle glycogen synthesis and impaired suppression of endogenous glucose production at the low insulin infusion rate. The liver glycogen stores were 2-fold higher in the fed state in the alpha1b-AR-/- compared with control mice, but were mobilized at the same rate during the fed to fast transition or following glucagon injections. Finally, high fat feeding for one month increased glucose intolerance and body weight in the alpha1b-AR-/-, but not in control mice. Altogether, our results indicate that in the absence of the alpha1b-AR the expression of hypotalamic NPY and the parasympathetic nervous activity are both increased resulting in hyperinsulinemia and insulin resistance as well as favoring obesity and glucose intolerance development during high fat feeding.

Topics: Animals; Blood Glucose; Body Weight; Glucagon; Glucose; Glycogen; Homeostasis; Hyperinsulinism; Insulin Resistance; Leptin; Liver; Male; Mice; Mice, Mutant Strains; Mice, Obese; Receptors, Adrenergic; Receptors, Adrenergic, alpha-1; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Time Factors

Organisms exposed to suboptimal environments incur a cost of dealing with stress in terms of metabolic resources. The total amount of energy available for maintenance, growth and reproduction, based on the biochemical analysis of the energy budget, may provide a sensitive measure of stress in an organism. While the concept is clear, linking cellular or biochemical responses to the individual and population or community level remains difficult. The aim of this study was to validate, under field conditions, using cellular energy budgets [i.e. changes in glycogen-, lipid- and protein-content and mitochondrial electron transport system (ETS)] as an ecologically relevant measurement of stress by comparing these responses to physiological and organismal endpoints. Therefore, a 28-day in situ bioassay with zebra mussels (Dreissena polymorpha) was performed in an effluent-dominated stream. Five locations were selected along the pollution gradient and compared with a nearby (reference) site. Cellular Energy Allocation (CEA) served as a biomarker of cellular energetics, while Scope for Growth (SFG) indicated effects on a physiological level and Tissue Condition Index and wet tissue weight/dry tissue weight ratio were used as endpoints of organismal effects. Results indicated that energy budgets at a cellular level of biological organization provided the fastest and most sensitive response and energy budgets are a relevant currency to extrapolate cellular effects to higher levels of biological organization within the exposed mussels.

Topics: Adaptation, Physiological; Animals; Bivalvia; Body Weight; Cells; Electron Transport; Energy Metabolism; Environmental Exposure; Glycogen; Lipid Metabolism; Proteins; Water Pollutants, Chemical

We show that granulocytes (PMN) have a dual role in the development of Ehrlich Ascites Tumor (EAT) in mice. EAT intraperitoneal inoculation causes a local inflammatory reaction, ascites development and mortality that distinguish resistant and susceptible strains. In resistant mice (CAF1), there is a less pronounced PMN influx after EAT inoculation than in susceptible Swiss mice. Accordingly, the increase in peritoneal PMN numbers enhanced tumor growth in CAF1 mice, but had no effect in the susceptible Swiss animals. Contrastingly, PMN depletion had no effect in resistant mice but facilitated tumor growth in susceptible animals. Though no differences were noted between the strains in peritoneal cell spreading and hydrogen peroxide release after tumor inoculation, in vitro PMN cytotoxic activity against EAT was significantly higher in susceptible Swiss mice. These data indicate a paradoxical dual role for PMN against EAT: while they help control tumor development in susceptible animals, they seem to enhance tumor growth in resistant mice.

Topics: Analysis of Variance; Animals; Antibodies, Monoclonal; Body Weight; Carcinoma, Ehrlich Tumor; Cytotoxicity, Immunologic; Glycogen; Hydrogen Peroxide; Inflammation; Injections, Intraperitoneal; Male; Mice; Mice, Inbred BALB C; Neoplasm Transplantation; Neutrophils; Tetrazolium Salts; Thiazoles; Time Factors

A study was conducted to elucidate hormonal control of ketogenesis and glycogen deposition in primary cultures of porcine hepatocytes. Hepatocytes were isolated from pigs (54-68 kg) by collagenase perfusion and seeded into collagen-coated T-25 flasks. Monolayers were established in medium containing fetal bovine serum for 1 day and switched to a serum-free medium for the remainder of the culture period. Hepatocytes were maintained in DMEM/M199 containing 1% DMSO, dexamethasone (10(-6) or 10(-7) M), linoleic acid (3.4 x 10(-5) M), and carnitine (10(-3) M) for 3 days. On the first day of serum-free culture, insulin was added at 1 or 100 ng/ml and glucagon was added at 0, 1, or 100 ng/ml. Recombinant human leptin (200 ng/ml) was added during the final 24 h; medium and all cells were harvested on the third day. Concentrations of acetoacetate and beta-hydroxybutyrate (ketone bodies) in media and glycogen deposition in the cellular compartment were determined. Ketogenesis was highly stimulated by glucagon (1 and 100 ng/ml) and inhibited by insulin. In contrast, glycogen deposition was stimulated by insulin and attenuated by glucagon; high insulin was also associated with a reduction in the ketone body ratio (acetoacetate:beta-hydroxybutyrate). High levels of dexamethasone stimulated ketogenesis, but inhibited glycogen deposition at low insulin. Culture of cells with leptin for 24 h, over the range of insulin, glucagon, and dexamethasone concentrations had no effect on either glycogen deposition or ketogenesis. These data suggest that while adult porcine hepatocytes are indeed sensitive to hormonal manipulation, leptin has no direct influence on hepatic energy metabolism in swine.

Topics: Animals; Body Weight; Carnitine; Cells, Cultured; Culture Media, Serum-Free; Dexamethasone; Glucagon; Glucocorticoids; Glycogen; Hepatocytes; Humans; Insulin; Ketone Bodies; Leptin; Linoleic Acid; Recombinant Proteins; Swine

To assess the effect of taurine supplementation on respiratory gas exchange, which might reflect the improved metabolism of glucose and/or lipid in the type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats.. Male OLETF rats (16 weeks of age) were randomly divided into two groups: unsupplemented group and taurine-supplemented (3% in drinking water) group. After 9 weeks of treatment, indirect calorimetry and insulin tolerance tests were conducted. The amounts of visceral fat pads, tissue glycogen, the blood concentrations of glucose, triacylglycerol, taurine, and electrolytes, and the level of hematocrit were compared between groups. A nondiabetic rat strain (Long-Evans Tokushima Otsuka) was used as the age-matched normal control.. The indirect calorimetry showed that the treatment of OLETF rats with taurine could reduce a part of postprandial glucose oxidation possibly responsible for the increase of triacylglycerol synthesis in the body. Taurine supplementation also improved hyperglycemia and insulin resistance and increased muscle glycogen content in the OLETF rats. Supplementation with taurine increased the blood concentration of taurine and electrolyte and fluid volume, all of which were considered to be related to the improvement of metabolic disturbance in OLETF rats.. Taurine supplementation may be an effective treatment for glucose intolerance and fat/lipid accumulation observed in type 2 diabetes associated with obesity. These metabolic changes might be ascribed, in part, to the alteration of circulating blood profiles, where the improved hyperglycemia and/or the blood accumulation of taurine itself would play roles.

Topics: Animal Nutritional Physiological Phenomena; Animals; Blood; Blood Glucose; Blood Pressure; Body Weight; Calorimetry, Indirect; Diabetes Mellitus, Type 2; Dietary Supplements; Drinking; Eating; Electrolytes; Food; Glycogen; Hematocrit; Insulin; Insulin Resistance; Male; Osmolar Concentration; Pulmonary Gas Exchange; Rats; Rats, Inbred OLETF; Taurine

Mice bearing IL-1beta-secreting tumor were used to study the chronic effect of IL-1beta on glucose metabolism. Mice were injected with syngeneic tumor cells transduced with the human IL-1beta gene. Serum IL-1beta levels increased exponentially with time. Secretion of IL-1beta from the developed tumors was associated with decreased food consumption, reduced body weight, and reduced blood glucose levels. Body composition analysis revealed that IL-1beta caused a significant loss in fat tissue without affecting lean body mass and water content. Hepatic phosphoenolpyruvate carboxykinase and glucose-6-phosphatase activities and mRNA levels of these enzymes were reduced, and 2-deoxy-glucose uptake by peripheral tissues was enhanced. mRNA levels of glucose transporters (Gluts) in the liver were determined by real-time PCR analysis. Glut-3 mRNA levels were up-regulated by IL-1beta. Glut-1 and Glut-4 mRNA levels in IL-1beta mice were similar to mRNA levels in pair-fed mice bearing nonsecreting tumor. mRNA level of Glut-2, the major Glut of the liver, was down-regulated by IL-1beta. We concluded that both decreased glucose production by the liver and enhanced glucose disposal lead to the development of hypoglycemia in mice bearing IL-1beta-secreting tumor. The observed changes in expression of hepatic Gluts that are not dependent on insulin may contribute to the increased glucose uptake.

Topics: Animals; Anorexia; Blood Glucose; Body Composition; Body Weight; C-Peptide; Cell Line, Tumor; Eating; Female; Fibrosarcoma; Gluconeogenesis; Glucose; Glucose-6-Phosphatase; Glycogen; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Interleukin-1; Leptin; Liver; Mice; Mice, Inbred C57BL; Monosaccharide Transport Proteins; Neoplasm Transplantation; Protein Serine-Threonine Kinases; RNA, Messenger

Recent research has reported that high sugar diets increase insulin resistance, without abdominal obesity, in male, but not female Wistar rats. Whether a high sucrose (SU) diet increased insulin resistance in ovariectomized (OVX) rats was determined.. Female Sprague Dawley rats, weighing 273 +/- 20 g, had either an ovariectomy or a sham operation (sham). OVX and sham rats were divided into two groups: one group had a 68 En% SU diet and the other a 68 En% starch (ST) diet for 8 weeks.. The body weight was higher in the OVX than the sham rats, regardless of dietary carbohydrate subtype. The fasting serum glucose levels did not differ according to diet and ovariectomy. However, the fasting serum insulin levels were higher in the OVX than the sham rats, and in the OVX rats, a high SU diet increased the serum insulin levels more than a high ST diet. The whole body glucose disposal rates, which referred to the state of insulin sensitivity, were lower in the OVX rats fed both the high SU and ST diets, compared to sham rats. Glycogen deposits in the soleus and quadriceps muscles were lower in the OVX rats fed high SU and ST diets than in sham rats. The glucose transporter 4 content and fraction velocity of glycogen synthase in muscles showed similar glucose disposal rates. However, the triacylglycerol content in the muscles were higher in the OVX rats with a high SU diet than those with a high ST diet.. These results suggested that an OVX increased the weight gain due to higher food intakes, regardless of dietary carbohydrate subtypes. OVX-induced obesity may be involved in the induction of insulin resistance from an increased triacylglycerol content, decreased glucose uptake and glycogen synthesis in skeletal muscles, regardless of dietary carbohydrate subtypes.

Topics: Animals; Blood Glucose; Body Weight; Dietary Carbohydrates; Energy Intake; Estradiol; Female; Glucose Clamp Technique; Glucose Transporter Type 4; Glycogen; Glycogen Synthase; Insulin; Insulin Resistance; Leptin; Models, Animal; Muscle, Skeletal; Ovariectomy; Rats; Rats, Sprague-Dawley; Time Factors; Triglycerides

Glycogen synthase kinase-3 (GSK-3) protein levels and activity are elevated in skeletal muscle in type 2 diabetes, and inversely correlated with both glycogen synthase activity and insulin-stimulated glucose disposal. To explore this relationship, we have produced transgenic mice that overexpress human GSK-3beta in skeletal muscle. GSK-3beta transgenic mice were heavier, by up to 20% (P < .001), than their age-matched controls due to an increase in fat mass. The male GSK-3beta transgenic mice had significantly raised plasma insulin levels and by 24 weeks of age became glucose-intolerant as determined by a 50% increase in the area under their oral glucose tolerance curve (P < .001). They were also hyperlipidemic with significantly raised serum cholesterol (+90%), nonesterified fatty acids (NEFAs) (+55%), and triglycerides (+170%). At 29 weeks of age, GSK-3beta protein levels were 5-fold higher, and glycogen synthase activation (-27%), glycogen levels (-58%) and insulin receptor substrate-1 (IRS-1) protein levels (-67%) were significantly reduced in skeletal muscle. Hepatic glycogen levels were significantly increased 4-fold. Female GSK-3beta transgenic mice did not develop glucose intolerance despite 7-fold overexpression of GSK-3beta protein and a 20% reduction in glycogen synthase activation in skeletal muscle. However, plasma NEFAs and muscle IRS-1 protein levels were unchanged in females. We conclude that overexpression of human GSK-3beta in skeletal muscle of male mice resulted in impaired glucose tolerance despite raised insulin levels, consistent with the possibility that elevated levels of GSK-3 in type 2 diabetes are partly responsible for insulin resistance.

Topics: Animals; Blotting, Western; Body Composition; Body Weight; DNA Primers; DNA, Complementary; Female; Glucose Intolerance; Glucose Tolerance Test; Glycogen; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Insulin Receptor Substrate Proteins; Insulin Resistance; Lipids; Liver; Male; Mice; Mice, Transgenic; Muscle, Skeletal; Phenotype; Phosphoproteins; Promoter Regions, Genetic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

To develop and evaluate the efficacy of diabetes-targeted cell therapies in humans, a reliable model in larger animals is highly desirable. This article reports the surgical technique of total pancreatectomy in pigs and the biochemical analysis of the characteristics of totally pancreatectomized pigs.. Surgical total pancreatectomy was conducted in 23 pigs. Blood glucose, insulin, biochemistries, activity index, and intravenous glucose tolerance test (IVGTT) were examined to assess the pathophysiological profiles of diabetic pigs.. A total of 14 pigs successfully underwent total pancreatectomy without requiring biliary reconstruction and were analyzed in the present study. Activity index was decreased from day 5 on and the mean survival of totally pancreatectomized pigs was 7.6 +/- 2.7 days. No endogenous insulin secretion was confirmed in these pigs. Pigs which received total pancreatectomy demonstrated significantly higher levels of ketone bodies. IVGTT performed within 4 days after total pancreatectomy showed a spontaneous decrease in blood glucose levels despite an absence of endogenous insulin secretion. IVGTT on day 5 or later showed continued hyperglycemia in pigs with total pancreatectomy. Histological examination showed atrophy of hepatocytes and decreased glycogen storage in the liver and decreased mucus production of the small intestine.. This article describes a porcine model of diabetes created by total pancreatectomy and it analyzes the pathophysiological profiles in the animals. The present study has suggested that IVGTT on day 5 or later after total pancreatectomy is a reliable method to evaluate the efficacy of cell therapies.

Topics: Alanine Transaminase; Animals; Area Under Curve; Aspartate Aminotransferases; Atrophy; Blood Glucose; Blood Urea Nitrogen; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diarrhea; Disease Models, Animal; Glucose Tolerance Test; Glycogen; Hepatocytes; Intestinal Mucosa; Ketone Bodies; L-Lactate Dehydrogenase; Liver; Pancreatectomy; Potassium; Swine

The objective of this study was to determine if broiler strain and breeder flock age affect eggshell conductance, fertility, and hatchability parameters; heart and hepatic glycogen concentrations at hatch; and embryonic metabolism throughout incubation. The 3 broiler strains investigated were HBY, a modern commercial broiler strain selected for high breast yield; WBM, a modern commercial broiler strain selected for the whole bird market; and UN78, a female broiler parent strain unselected since 1978. Fertility and hatchability parameters for each of the 3 strains were determined when the flocks were 32, 34, 37, and 38 wk of age. Eggshell conductance was measured on separate eggs produced from flocks at 37, 45, and 53 wk of age. Concurrently, fertile hatching eggs from the 3 broiler strains at 2 flock ages (33 and 38 wk) were incubated in individual metabolic chambers. Total daily CO2 production of each embryo was measured. Strain and flock age did not influence any of the fertility or hatchability parameters. Strain had no effect on conductance, but eggs from the 37-wk-old flocks had higher conductance than eggs from the 45- or 53-wk-old flocks, which did not differ from one another. Strain had no significant effect on average total CO2 production over the entire 21.5 d of incubation. However, embryos from the 38-wk-old flock produced more total CO2 than did embryos from the 33-wk-old flocks. Also, there was an interaction between strain and flock age for total CO2 production; UN78 embryos from the 33-wk flocks had higher CO2 production than WBM embryos, and the CO2 production of HBY did not differ from either strain. When embryos from the 38-wk flocks were compared, WBM embryos had higher CO2 production than did UN78 embryos, and HBY embryos did not differ from either strain. The data showed that in the 3 strains examined in this study, genetic differences in embryonic metabolic rate were dependent upon breeder flock age.

Topics: Age Factors; Animals; Body Weight; Breeding; Chick Embryo; Chickens; Egg Shell; Female; Fertility; Glycogen; Liver; Myocardium; Organ Size; Species Specificity; Thermogenesis

Improvement of insulin sensitivity and lipid and glucose metabolism by coactivation of both nuclear peroxisome proliferator-activated receptor (PPAR)gamma and PPARalpha potentially provides beneficial effects over existing PPARgamma and alpha preferential drugs, respectively, in treatment of type 2 diabetes. We examined the effects of the dual PPARalpha/gamma agonist ragaglitazar on hyperglycemia and whole body insulin sensitivity in early and late diabetes stages in Zucker diabetic fatty (ZDF) rats and compared them with treatment with the PPARgamma preferential agonist rosiglitazone. Despite normalization of hyperglycemia and Hb A(1c) and reduction of plasma triglycerides by both compounds in both prevention and early intervention studies, ragaglitazar treatment resulted in overall reduced circulating insulin and improved insulin sensitivity to a greater extent than after treatment with rosiglitazone. In late-intervention therapy, ragaglitazar reduced Hb A(1c) by 2.3% compared with 1.1% by rosiglitazone. Improvement of insulin sensitivity caused by the dual PPARalpha/gamma agonist ragaglitazar seemed to have beneficial impact over that of the PPARgamma-preferential activator rosiglitazone on glycemic control in frankly diabetic ZDF rats.

Topics: Animals; Body Composition; Body Weight; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Eating; Fatty Acids, Nonesterified; Glucose Clamp Technique; Glycated Hemoglobin; Glycogen; Hypoglycemic Agents; Insulin Resistance; Islets of Langerhans; Liver; Male; Oxazines; Phenylpropionates; Rats; Rats, Zucker; Receptors, Cytoplasmic and Nuclear; Rosiglitazone; Thiazoles; Thiazolidinediones; Transcription Factors

This study aimed to investigate the effect of long-term oral nicotine administration on insulin resistance in an animal model of obesity. Eight-week-old male Zucker fatty rats (ZFRs) were administered nicotine tartrate dihydrate (4.6 mg/kg/day) in the drinking water. The control group was pair-fed. The body weights and food intake over 8 weeks were similar in both groups. Plasma glucose levels at 3, 6, 9, 12, and 15 min after insulin administration (0.5 U/kg) in the nicotine group were significantly lower than those in the control group. The calculated K(ITT) value for the nicotine group was significantly higher than that for the control group. Wet weight of the liver in the nicotine group was significantly lower than that in the control group. Transaminases and histological examination of the liver revealed no alteration by nicotine administration. Glycogen, glycogen synthetase activity and gluconeogenesis in the liver in the nicotine group were significantly lower than those in the control group. Phosphorylase-a activity of the liver in the nicotine group was significantly higher than that in the control group. Glycogen, glycogen synthetase, and phosphorylase-a activity of skeletal muscle were similar in both groups. These results suggest that long-term oral nicotine administration may reduce insulin resistance in obese diabetic rats through a reduced hepatic glucose release and, in part, contribute to lowering blood glucose levels.

Topics: Administration, Oral; Animals; Blood Glucose; Body Weight; Eating; Ganglionic Stimulants; Gluconeogenesis; Glycogen; Glycogen Synthase; Insulin; Insulin Resistance; Liver; Male; Muscle, Skeletal; Nicotine; Obesity; Organ Size; Phosphorylase a; Rats; Rats, Zucker; Time Factors

Caesalpinia bonducella, widely distributed throughout the coastal region of India and used ethnically by the tribal people of India for controlling blood sugar was earlier reported by us to possess hypoglycemic activity in animal model. This prompted us to undertake a detail study with the aqueous and ethanolic extracts of the seeds of this plant in both type 1 and 2 diabetes mellitus in Long Evans rats. Significant blood sugar lowering effect (P < 0.05) of C. bonducella was observed in type 2 diabetic model. Special emphasis was given on the mechanistic study by gut absorption of glucose and liver glycogen.

Topics: Animals; Blood Glucose; Body Weight; Caesalpinia; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Glycogen; Hypoglycemic Agents; Intestinal Absorption; Lipids; Liver; Male; Plant Extracts; Rats; Rats, Long-Evans

AMP-activated protein kinase (AMPK) is viewed as a fuel sensor for glucose and lipid metabolism. To better understand the physiological role of AMPK, we generated a knockout mouse model in which the AMPKalpha2 catalytic subunit gene was inactivated. AMPKalpha2(-/-) mice presented high glucose levels in the fed period and during an oral glucose challenge associated with low insulin plasma levels. However, in isolated AMPKalpha2(-/-) pancreatic islets, glucose- and L-arginine-stimulated insulin secretion were not affected. AMPKalpha2(-/-) mice have reduced insulin-stimulated whole-body glucose utilization and muscle glycogen synthesis rates assessed in vivo by the hyperinsulinemic euglycemic clamp technique. Surprisingly, both parameters were not altered in mice expressing a dominant-negative mutant of AMPK in skeletal muscle. Furthermore, glucose transport was normal in incubated isolated AMPKalpha2(-/-) muscles. These data indicate that AMPKalpha2 in tissues other than skeletal muscles regulates insulin action. Concordantly, we found an increased daily urinary catecholamine excretion in AMPKalpha2(-/-) mice, suggesting altered function of the autonomic nervous system that could explain both the impaired insulin secretion and insulin sensitivity observed in vivo. Therefore, extramuscular AMPKalpha2 catalytic subunit is important for whole-body insulin action in vivo, probably through modulation of sympathetic nervous activity.

Topics: Alleles; AMP-Activated Protein Kinases; Animals; Biological Transport; Blotting, Southern; Body Weight; Catalytic Domain; Dose-Response Relationship, Drug; Genotype; Glucose; Glucose Tolerance Test; Glycogen; Insulin; Liver; Mice; Mice, Inbred C57BL; Mice, Knockout; Multienzyme Complexes; Muscle, Skeletal; Muscles; Protein Serine-Threonine Kinases; Protein Structure, Tertiary; Time Factors

To study effects of sex on free fatty acid (FFA)-induced insulin resistance, we have examined the effects of acute elevations of plasma FFA levels on insulin-stimulated total body glucose uptake in nine healthy young women. Euglycemic-hyperinsulinemic (approximately 500 pmol/l) clamps were performed for 4 h with coinfusion of either lipid/heparin (L/H) to acutely raise plasma FFA levels (from approximately 600 to approximately 1,200 micro mol/l) or saline/glycerol to lower fatty acids (from approximately 600 to approximately 50 micro mol/l). L/H infusion inhibited insulin-stimulated glucose uptake (determined with [3-(3)H]glucose) and glycogen synthesis by 31 and 40%, respectively (P < 0.01), almost completely abolished insulin suppression of endogenous glucose production (EGP) (13.6 vs. 10.0 micro mol x kg(-1) x min(-1), NS), prevented the insulin induced increase in carbohydrate oxidation (8.1 vs. 7.4 micro mol x kg(-1) x min(-1), NS), and stimulated fat oxidation (from 3.6 to 5.1 micro mol x kg(-1) x min(-1), P < 0.01). These data showed that acute increases in plasma FFA levels inhibited the actions of insulin on glucose uptake, glycogen synthesis, and EGP in women to a degree similar to that previously reported in men. We conclude that at insulin and FFA levels in the postprandial range, women and men were susceptible to FFA-induced peripheral and hepatic insulin resistance.

Topics: Adipose Tissue; Adult; Black People; Blood Glucose; Body Constitution; Body Mass Index; Body Weight; Calorimetry, Indirect; Emulsions; Fat Emulsions, Intravenous; Fatty Acids, Nonesterified; Female; Glucose; Glucose Clamp Technique; Glycogen; Glycolysis; Heparin; Humans; Hyperinsulinism; Insulin; Lecithins; Philadelphia; Reference Values; Safflower Oil; Soybean Oil; White People

Clinical and laboratory evidence shows that enteral feeding significantly reduces pneumonia and intra-abdominal abscess formation after celiotomy for severe trauma. Supplementation of total parenteral nutrition (TPN) with glutamine (GLN) supports impaired immunity induced by TPN in several animal and human studies. This work investigates the peritoneal cellular response and polymorphonuclear neutrophil (PMN) bactericidal function after mouse chemical peritonitis after TPN with and without GLN. Thirty-three mice received chow, TPN, or 2% GLN-supplemented TPN (GLN-TPN) for 5 days. All mice then received 2 mL of a 1% glycogen solution intraperitoneally to induce cell exudation, and peritoneal exudative cells (PECs) were recovered 4 h later. Total and differential PEC numbers, as well as PMN phagocytosis, reactive oxygen intermediate production (ROI), CD11b (integrin aM chain) expression, and CD16/32 (Fcgamma II/III receptor) expression were measured. PMN, macrophage, and lymphocyte cell numbers were significantly lower with TPN than with chow or GLN-TPN groups, with no differences between chow and GLN-TPN. TPN significantly lowered peritoneal PMN phagocytosis compared with chow (P < 0.05) and approached significance with GLN-TPN (P = 0.06). There were no significant differences in ROI production or CD11b and CD16/32 expression on peritoneal PMN. GLN supplementation improved the reduction in cell exudation and PMN phagocytosis induced by TPN after chemical peritonitis.

Topics: Animals; Body Weight; CD11b Antigen; Cell Adhesion; Flow Cytometry; Glutathione; Glycogen; Inflammation; Macrophages; Mice; Neutrophils; Phagocytosis; Reactive Oxygen Species; Receptors, IgG

In utero overexposure to glucocorticoids may explain the association between low birth weight and subsequent development of the metabolic syndrome. We previously showed that prenatal dexamethasone (dex) exposure in the rat lowers birth weight and programs adult fasting and postprandial hyperglycemia, associated with increased hepatic gluconeogenesis driven by elevated liver glucocorticoid receptor (GR) expression. This study aimed to determine whether prenatal dex (100 microg/kg per day from embryonic d 15 to embryonic d 21) programs adult GR expression in skeletal muscle and/or adipose tissue and whether this contributes to altered peripheral glucose uptake or metabolism. In utero dex-exposed rats remained lighter until 6 months of age, despite some early catch-up growth. Adults had smaller epididymal fat pads, with a relative increase in muscle size. Although glycogen storage was reduced in quadriceps, 2-deoxyglucose uptake into extensor digitorum longus muscle was increased by 32% (P < 0.05), whereas uptake in other muscles and adipose beds was unaffected by prenatal dex. GR mRNA was not different in most muscles but selectively reduced in soleus (by 23%, P < 0.05). However, GR mRNA was markedly increased specifically in retroperitoneal fat (by 50%, P < 0.02). This was accompanied by a shift from peroxisomal proliferator-activated receptor gamma 1 to gamma 2 expression and a reduction in lipoprotein lipase mRNA (by 28%, P < 0.02). Adipose leptin, uncoupling protein-3 and resistin mRNAs, muscle GLUT-4, and circulating lipids were not affected by prenatal dex. These data suggest that hyperglycemia in 6-month-old rats exposed to dexamethasone in utero is not due to attenuated peripheral glucose disposal. However, increased GR and attenuated fatty acid uptake specifically in visceral adipose are consistent with insulin resistance in this crucial metabolic depot and could indirectly contribute to increased hepatic glucose output.

Topics: Adipose Tissue; Animals; Birth Weight; Blood Glucose; Body Weight; Deoxyglucose; Dexamethasone; Epididymis; Fatty Acids; Female; Glucocorticoids; Glucose Transporter Type 4; Glycogen; Hyperglycemia; Insulin Resistance; Male; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; Organ Size; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Wistar; Receptors, Cytoplasmic and Nuclear; Receptors, Glucocorticoid; RNA, Messenger; Transcription Factors

The Indian traditional system of medicine prescribed plant therapies for diseases including diabetes mellitus called madhumeh in Sanskrit. One such plant mentioned in Ayurveda is Trigonella foenumgraecum (FG). In the present study, FG (1g/kg PO) was assessed for its effect on glycogen levels of insulin dependent (skeletal muscle and liver), insulin independent tissues (kidneys and brain) and enzymes such as glucokinase (GK), hexokinase (HK), and phosphofructokinase (PFK). Administration of FG led to decrease in blood glucose levels by 14.4 and 46.64% on 15th and 30th day of the experiment. Liver and 2-kidney weight expressed as percentage of body weight was significantly increased in diabetics (P<0.0005) versus normal controls and this alteration in the renal weight (P<0.0005) but not liver weight was normalized by feeding of FG. Renal glycogen content increased by over 10 folds while hepatic and skeletal muscle glycogen content decreased by 75 and 68% in diabetic controls versus controls and these alteration in glycogen content was partly prevented by FG. Activity of HK, GK and PFK in diabetic controls was 35, 50 and 60% of the controls and FG partially corrected this alteration in PFK, HK and GK.

Topics: Animals; Blood Glucose; Body Weight; Bone and Bones; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Glucokinase; Glycogen; India; Kidney; Liver; Male; Medicine, Ayurvedic; Organ Size; Phosphofructokinases; Plant Extracts; Rats; Tissue Distribution; Trigonella

The purpose of this study was to investigate the metabolic alterations in the recipient and microcirculatory changes to the graft in the first 3 months after orthotopic liver transplantation (OLT) of nonsteatotic liver grafts from lean rats into obese Zucker rats.. Body weight and plasma lipids were measured for 3 months post-OLT. Graft perfusion (hepatic microcirculatory perfusion [HMP]) and vascular structure were measured in vivo at 3 months. Liver biopsy specimens were obtained throughout for morphologic analysis. Sham-operation obese and lean Zucker rats acted as controls.. Plasma cholesterol levels were elevated from 2 months after OLT, whereas plasma triglyceride levels were reduced (P<0.05). Plasma high-density lipoprotein cholesterol concentrations increased from the first month after OLT (P<0.05). HMP in OLT animals (137+/-3 perfusion units [PU]) (P<0.05) was intermediate between lean (221+/-11 PU) and obese controls (113+/-5 PU). Hepatic cord width in the OLT group was similar to that in lean controls. Mean liver-to-body weight ratios in OLT animals (4.12%+/-0.39%) were significantly higher than in lean controls (3.25%+/-0.1%). The number of viable hepatocytes per high-power field in the OLT animals was lower than in the lean animals but higher than in obese controls (P<0.05). The transplanted livers showed moderate to marked microvesicular fatty change (MIFC) and glycogen deposition at 3 months after OLT.. Transplantation of a nonsteatotic liver into an obese Zucker rat initially has a positive effect on lipid metabolism. However, 3 months after OLT, the donor liver became steatotic with MIFC changes and reduced perfusion. The authors' results emphasize the importance of the recipient's metabolic status in the maintenance of liver graft function after OLT.

Topics: Animals; Biopsy; Body Weight; Cholesterol; Cholesterol, HDL; Fatty Liver; Glycogen; Graft Survival; Liver Circulation; Liver Transplantation; Male; Microcirculation; Obesity; Rats; Rats, Zucker; Triglycerides

The effects of short-term food deprivation (7 days) and refeeding (2 days) on different biochemical and neuroendocrine parameters were studied in tench. A 7-days fast resulted in a significant reduction of plasma glucose and glycogen hepatic content, supporting the key role of liver glycogen as energy depot for being consumed during fasting. The rapid recovery of normal values of blood glucose and glycogen stores by refeeding indicates a rapid replenishment of liver glycogen stores. The short-term starvation decreased circulating thyroid hormones (both T3 and T4) and T4 release from thyroid, supporting an interaction between nutritional state and thyroid function in tench. All these metabolic and hormonal changes were partial or totally reversed under refeeding conditions. An increase in hypothalamic content of norepinephrine and dopamine was found in fasted fish. This result might be a consequence of stress induced by starvation.

Topics: Analysis of Variance; Animals; Blood Glucose; Body Weight; Catecholamines; Cyprinidae; Dopamine; Eating; Epinephrine; Glucose; Glycogen; Hypothalamus; Liver; Norepinephrine; Organ Size; Starvation; Thyroid Gland; Thyroid Hormones; Thyroxine; Triiodothyronine

The aim of this study was to investigate the profile of metabolites in male rats subjected to 50-60 min of swimming on three protocols: group A, a single 50 min swimming session; group B, one session a day for three days (5 min on day 1, 15 min on day 2 and 30 min on day 3); and group C, one session a day for 5 days, with increasing duration from 5 min on day 1, 15, 30, 45 and 60 min on consecutive days. The interval between sessions was 24 h. Measurements were made after the last swimming session. Controls did not swim. The glycogen content of liver and gastrocnemius and soleus muscle was depleted in the three groups that swam, but blood glucose concentration was significantly increased only in group B. Serum lactate concentrations were greater than the controls in groups A and B. There were significant increases in serum free fatty acid concentrations in all groups that swam. The increases in plasma free fatty acids may have resulted from lipolysis stimulated by endogenous catecholamines in groups A and C, since basal lipolysis measured in vitro was unchanged by swimming. The large increase in basal lipolysis in group B may have contributed to the rise in plasma free fatty acids. Adipocytes from rats in groups A and B were supersensitive to epinephrine, whereas those from group C were not. We conclude that the metabolic alterations were less pronounced after the last of five swimming sessions over 5 days than after a single session, even though session duration and the contribution of the physical component were similar. Glucose mobilization, but probably not utilization, was similar in the three groups that swam. The mechanisms of lipid mobilization from adipose tissue differed, depending on the stress paradigm. The metabolic changes in groups A and B indicated that three daily swimming sessions were insufficient to cause adaptation. The results contrast with previous findings for foot-shock stress, which leads to sensitization rather than adaptation in response to repeated stimuli.

Topics: Adipocytes; Animals; Blood Glucose; Body Weight; Catecholamines; Fatty Acids, Nonesterified; Glycogen; Lipolysis; Liver; Male; Muscle, Skeletal; Rats; Rats, Wistar; Stress, Physiological; Swimming

Forty-eight multiparous Holstein cows were fed treatments consisting of either 0, 45, 60, or 75 g/d of a rumen-protected choline (RPC) source in a completely randomized design from 21 d before expected calving to 63 d postpartum to determine whether choline supplementation to the diet would affect hepatic fatty acid and glucose metabolism, key metabolites in plasma, and cow performance. Dry matter intake (DMI), milk yield, body condition score, and body weights (BW) were similar for cows receiving the four treatments. Feeding RPC tended to increase yields of milk fat, 3.5% fat-corrected milk, and total solids. Plasma concentrations of nonesterified fatty acids and beta-hydroxybutyrate were not different among cows fed the four treatments. Concentrations of triglycerides in liver were similar, but concentrations of glycogen in liver increased as cows consumed increasing amounts of RPC. Hepatic capacity for storage of [1-(14)C]palmitate as esterified products within liver slices tended to decrease as the amount of RPC consumed by cows increased; however, effects of treatment on hepatic capacity for oxidation of [1-(14)C]palmitate to CO2 were not significant. These data imply that choline may increase the rate of very low density lipoprotein synthesis and secretion of esterified lipid products from liver. Hepatic capacities for conversion of [1-(14)C] propionate to CO2 and to glucose in liver were similar among cows fed the four treatments. Collectively, these results suggest that hepatic fatty acid metabolism and cow performance are responsive to increasing the supply of choline during the periparturient period.

Topics: 3-Hydroxybutyric Acid; Animals; Body Composition; Body Weight; Cattle; Choline; Dietary Supplements; Eating; Fatty Acids; Fatty Acids, Nonesterified; Female; Glucose; Glycogen; Lactation; Lipoproteins, LDL; Liver; Milk; Oxidation-Reduction; Palmitic Acid; Parturition; Pregnancy; Propionates; Rumen; Triglycerides

Muscle glucose uptake (MGU) is distributively controlled by three serial steps: delivery of glucose to the muscle membrane, transport across the muscle membrane, and intracellular phosphorylation to glucose 6-phosphate by hexokinase (HK). During states of high glucose fluxes such as moderate exercise, the HK activity is of increased importance, since augmented muscle perfusion increases glucose delivery, and increased GLUT4 at the cell membrane increases glucose transport. Because HK II overexpression augments exercise-stimulated MGU, it was hypothesized that a reduction in HK II activity would impair exercise-stimulated MGU and that the magnitude of this impairment would be greatest in tissues with the largest glucose requirement. To this end, mice with a HK II partial knockout (HK+/-) were compared with their wild-type control (WT) littermates during either sedentary or moderate exercise periods. Rg, an index of glucose metabolism, was measured using 2-deoxy-[3H]glucose. No differences in glucose metabolism were detected between sedentary groups. The increase in Rg due to exercise was impaired in the highly oxidative heart and soleus muscles of HK+/- compared with WT mice (7 +/- 10 vs. 29 +/- 9 and 8 +/- 3 vs. 25 +/- 7 micromol. 100 g-1. min-1, respectively). However, the increase in Rg due to exercise was not altered in gastrocnemius and superficial vastus lateralis muscles in HK+/- and WT mice (8 +/- 2 vs. 12 +/- 3 and 5 +/- 2 vs. 8 +/- 2 micromol. 100 g-1. min-1, respectively). In conclusion, MGU is impaired by reductions in HK activity during exercise, a physiological condition characterized by high glucose flux. This impairment is critically dependent on the tissue's glucose metabolic rate and correlates with tissue oxidative capacity.

Topics: Animals; Blood Glucose; Body Weight; Deoxyglucose; Fasting; Fatty Acids, Nonesterified; Glucose; Glycogen; Hexokinase; Insulin; Male; Mice; Mice, Inbred BALB C; Mice, Inbred DBA; Mice, Knockout; Muscle, Skeletal; Myocardium; Oxidation-Reduction; Physical Exertion; Tritium

The present study was undertaken to identify the metabolic and contractile characteristics of fast- and slow-twitch skeletal muscles in a transgenic mouse model of amyotrophic lateral sclerosis (ALS). In addition, we investigated the effects of oral creatine supplementation on muscle functional capacity in this model. Transgenic mice expressing a mutant (G93A) or wild type human SOD1 gene (WT) were supplemented with 2% creatine monohydrate from 60 to 120 days of age. Body weight, rotorod performance and grip strength were evaluated. In vitro contractility was evaluated on isolated m. soleus and m. extensor digitorum longus (EDL), and muscle metabolites were determined. Body weight, rotorod performance and grip strength were markedly decreased in G93A compared to WT mice, but were unaffected by creatine supplementation. Muscle ATP content decreased and glycogen content increased in G93A versus WT in both muscle types, but were unaffected by creatine supplementation. Muscle creatine content increased following creatine intake in G93A soleus. Twitch and tetanic contractions showed markedly slower contraction and relaxation times in G93A versus WT in both muscle types, with no positive effect of creatine supplementation. EDL but not soleus of G93A mice showed significant atrophy, which was partly abolished by creatine supplementation. It is concluded that overexpression of a mutant SOD1 transgene has profound effects on metabolic and contractile properties of both fast- and slow-twitch skeletal muscles. Furthermore, creatine intake does not exert a beneficial effect on muscle function in a transgenic mouse model of ALS.

Topics: Adenosine Triphosphate; Amyotrophic Lateral Sclerosis; Animals; Body Weight; Creatine; Glycogen; Humans; Mice; Mice, Transgenic; Models, Animal; Motor Activity; Muscle Contraction; Muscle Fibers, Fast-Twitch; Muscle Fibers, Slow-Twitch; Muscle, Skeletal; Muscular Atrophy; Mutation; Superoxide Dismutase; Superoxide Dismutase-1

In this study we investigated the effect of lifelong supplementation of the diet with coconut oil (CO, rich in saturated fatty acids) or fish oil (FO, rich in n-3 polyunsaturated fatty acids, PUFAs) on tumor growth, animal survival, and metabolic indicators of cachexia in adult rats. Female Wistar rats were supplemented with CO or FO prior to mating and then throughout pregnancy and gestation, and then the male offspring were supplemented from weaning until 90 days of age. Then they were inoculated subcutaneously with Walker 256 tumor cells. Tumor weight at 14 days in control rats (those fed standard chow) was approximately 20 g. These animals displayed cancer cachexia, which was characterized by loss of weight, hypoglycemia, hyperlacticidemia, hypertriacylglycerolemia, and depletion of glycogen stores. Supplementation of the diet with CO did not change these parameters, except that there was a smaller decrease in serum triacylglycerol concentration. Supplementation of the diet with FO significantly decreased tumor growth (by approximately 60%), increased survival (50% at 30 days postinoculation vs. 30% in the controls and 13.5% in the CO group), and prevented the fall in body weight. Furthermore, FO supplementation partly abolished the fall in serum glucose, totally prevented the elevation in serum lactate concentrations, partly prevented the hypertriacylgylcerolemia, and preserved tissue glycogen stores. Lifelong consumption of FO, rich in n-3 PUFAs, protects against tumor growth and cancer cachexia and improves survival.

Topics: Analysis of Variance; Animals; Blood Glucose; Body Weight; Cachexia; Carcinoma 256, Walker; Dietary Supplements; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Female; Glycogen; Hypolipidemic Agents; Lactic Acid; Lipid Metabolism; Male; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Wistar; Survival Rate; Triglycerides

Increased serum levels of resistin, a molecule secreted by fat cells, have been proposed as a possible mechanistic link between obesity and insulin resistance. To further investigate the effects of resistin on glucose metabolism, we derived a novel transgenic strain of spontaneously hypertensive rats expressing the mouse resistin gene under the control of the fat-specific aP2 promoter and also performed in vitro studies of the effects of recombinant resistin on glucose metabolism in isolated skeletal muscle. Expression of the resistin transgene was detected by Northern blot analysis in adipose tissue and by real-time PCR in skeletal muscle and was associated with increased serum fatty acids and muscle triglycerides, impaired skeletal muscle glucose metabolism, and glucose intolerance in the absence of any changes in serum resistin concentrations. In skeletal muscle isolated from non-transgenic spontaneously hypertensive rats, in vitro incubation with recombinant resistin significantly inhibited insulin-stimulated glycogenesis and reduced glucose oxidation. These findings raise the possibility that autocrine effects of resistin in adipocytes, leading to release of other prodiabetic effector molecules from fat and/or paracrine actions of resistin secreted by adipocytes embedded within skeletal muscle, may contribute to the pathogenesis of disordered skeletal muscle glucose metabolism and impaired glucose tolerance.

Topics: Adipocytes; Animals; Animals, Genetically Modified; Blotting, Northern; Blotting, Western; Body Weight; Glucose; Glucose Tolerance Test; Glycogen; Hormones, Ectopic; Intercellular Signaling Peptides and Proteins; Lipid Metabolism; Mice; Mice, Inbred BALB C; Models, Biological; Muscle, Skeletal; Nerve Growth Factor; Oxygen; Phenotype; Promoter Regions, Genetic; Proteins; Rats; Rats, Inbred SHR; Recombinant Proteins; Resistin; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Transgenes; Triglycerides

Short-term cold exposure of homeothermic animals leads to higher thermogenesis and food consumption accompanied by weight loss. An analysis of cDNA-macroarray was employed to identify candidate mRNA species that encode proteins involved in thermogenic adaptation to cold. A cDNA-macroarray analysis, confirmed by RT-PCR, immunoblot, and RIA, revealed that the hypothalamic expression of melanin-concentrating hormone (MCH) is enhanced by exposure of rats to cold environment. The blockade of hypothalamic MCH expression by antisense MCH oligonucleotide in cold-exposed rats promoted no changes in feeding behavior and body temperature. However, MCH blockade led to a significant drop in body weight, which was accompanied by decreased liver glycogen, increased relative body fat, increased absolute and relative interscapular brown adipose tissue mass, increased uncoupling protein 1 expression in brown adipose tissue, and increased consumption of lean body mass. Thus, increased hypothalamic MCH expression in rats exposed to cold may participate in the process that allows for efficient use of energy for heat production during thermogenic adaptation to cold.

Topics: Adaptation, Physiological; Adipose Tissue, Brown; Animals; Body Composition; Body Temperature Regulation; Body Weight; Carrier Proteins; Cold Temperature; Eating; Energy Metabolism; Gene Expression Profiling; Glycogen; Hypothalamic Hormones; Hypothalamus; Ion Channels; Liver; Male; Melanins; Membrane Proteins; Mitochondrial Proteins; Muscle, Skeletal; Oligonucleotide Array Sequence Analysis; Oxygen Consumption; Pituitary Hormones; Rats; Rats, Wistar; Uncoupling Protein 1

Mutagenesis provides a powerful way of isolating genetic and physiological processes underlying complex traits, but this approach has rarely been applied to investigating water balance in insects. Here, we describe the isolation of a desiccation-resistant mutant of Drosophila melanogaster. Mutagenesis of a desiccation sensitive line resulted in the isolation of a mutant with two-fold higher resistance. The mutant was partially dominant and mapped to the second chromosome. Mutant flies showed lower rates of water loss, and had a higher water content, but showed no change in body mass, glycogen content, hemolymph volume or water content tolerated at death from desiccation. These physiological differences are contrasted to changes in lines of D. melanogaster mass selected for altered stress resistance. Isolation of this mutant provides an opportunity to identify a gene involved in water balance in insects.

Topics: Alleles; Animals; Body Water; Body Weight; Chromosomes; Crosses, Genetic; Desiccation; Drosophila melanogaster; Female; Genes, Dominant; Glycogen; Hemolymph; Male; Mutation; Water; Water-Electrolyte Balance

Cancer cachexia is characterized by anorexia and intense peripheral catabolism. We examine the potential benefits of combination of different anabolic agents such as insulin and clenbuterol associated to prostaglandin synthesis inhibitor (naproxen) on tumor growth, cachexia and renal function in Walker 256 tumor-bearing rats (WK). Groups were separated into WK, and WK with naproxen (WK N) or naproxen plus clenbuterol (WK NCb) or naproxen plus clenbuterol plus insulin (WK NCbI). Treatment begins at the 4th day after tumor inoculation, at the 14th day they were killed, glycemia, lacticidemia, glycogen content from liver, soleus and gastrocnemius muscles, tumor mass, body weight and kidney function were determined. Glycemia and glycogen content were reduced and lacticidemia increased in WK (p<0.05) as compared to control rats. The glycogen content recovered in all treated groups. Tumor weight was significantly reduced by the different treatments. At the 14th weight change (carcass-initial body weight) in the control increased by 38% and in the WK -2%. Naproxen treatment (WK N) induced an increased by 14%. The inclusion of clenbuterol (WK NCb) and insulin (WK NCbI) by 38 and 41%, respectively. Mean glomerular filtration rate (GFR) increased in the WK (p<0.05) as compared to control, but in the WK NCb the GFR was similar to control. Our results suggest that naproxen is able to reduce tumor growth and its association with insulin and clenbuterol induce mass weight gain and recovery energy fuel.

Topics: Adrenergic beta-Agonists; Animals; Blood Glucose; Body Weight; Cachexia; Carcinoma 256, Walker; Clenbuterol; Cyclooxygenase Inhibitors; Drug Therapy, Combination; Eating; Energy Intake; Glycogen; Insulin; Kidney; Liver; Muscle, Skeletal; Naproxen; Rats; Rats, Wistar

In the present study the effects of some C18 fatty acids on hepatic fatty acid metabolism have been compared. Male rats were fed cholesterol-free diets containing either C18:0, C18:1 cis or C18:1 trans isomers as the variables. In accordance with previous work, oleic acid in the diet caused an increase in cholesterol concentration in the liver and in the lipoprotein fraction of density (d; kg/l) < 1.006. Oleic acid also reduced the triacylglycerol:cholesterol value in this fraction. Surprisingly, the C18:1 trans isomers diet induced a decrease in the amount of cholesterol in total plasma as well as in the 1.019 < d < 1.063 lipoprotein fraction. Both oleic acid and C18:1 trans isomers increased the concentration of triacylglycerols in the liver. The two C18:1 fatty acids differently influenced the hepatic activities of carnitine palmitoyltransferase-I and 3-hydroxy-acyl-CoA dehydrogenase; both enzymes were inhibited by C18:1 trans isomers, while no change was induced by oleic acid. The activity of the citrate carrier was lower in the oleic acid- and C18:1 trans isomers-fed rats, when compared with the rats fed stearic acid. No diet effects were seen for the activities of acetyl-CoA carboxylase, fatty acid synthase, diacylglycerol acyltransferase, citrate synthase and phosphofructokinase. The results are interpreted in that oleic acid raised liver triacylglycerol by reducing the secretion of it with the d < 1.006 lipoprotein fraction whereas the C18:1 trans isomers enhanced liver triacylglycerol by lowering the hepatic oxidation of fatty acids.

Topics: Animals; Body Weight; Carbon; Cholesterol; Diet; Eating; Fatty Acids; Glycogen; Isomerism; Lipoproteins; Liver; Male; Oleic Acid; Organ Size; Phospholipids; Rats; Rats, Wistar; Triglycerides

The aim of this study was to investigate structural changes that occurred in the skeletal muscle of rats with experimental hyperthyroidism and the effect of melatonin on these changes. Groups of animals were designated as controls, 3,3',5-triiodothyronine (T3) injected and T3 + melatonin injected group. At the end of the study the tissue specimens were harvested and their structure examined. In the skeletal muscle of T3 injected rats a decrease was observed in muscle fiber diameter, splitting of fiber, collections of adipose tissue in perimysium, and gathering of nuclei in central compared to the control. Electron microscopic examination showed that mitochondria were dilated and the I band was less clear. In the T3 + melatonin injected group, the structure of fibers was similar to control. In conclusion, this study showed that T3 injection caused structural changes in the skeletal muscle and that melatonin had a positive effect on these changes.

Topics: Adipose Tissue; Animals; Blood Vessels; Body Weight; Glycogen; Hyperthyroidism; Male; Mast Cells; Melatonin; Mitochondria; Muscle Fibers, Skeletal; Muscle, Skeletal; Rats; Rats, Wistar; Triiodothyronine

The aim of the present study was to investigate how zinc (Zn) deficiency and supplementation affect glycogen content of the liver and plasma lactate and leptin levels of rats performing acute swimming exercise just before the blood samples were obtained. Four sets of 10 rats each served as the (1) Zn-deficient group, (2) Zn-supplemented group, (3) swimming controls, and (4) normal controls. Plasma lactate levels of Zn-deficient animals were significantly higher than those in the other three groups (p<0.01), and those in the swimming controls (group 3) were significantly higher than in the Zn-supplemented animals, group 2 (p<0.01). The plasma glucose of the Zn-deficient group was significantly higher than all other groups (p<0.01) and that of group 2 was significantly lower than group 4 (p<0.01). Glycogen levels in liver of the Zn-deficient animals was significantly lower than groups 2 and 4 (p<0.01), and, in turn, were higher than for group 3 (p<0.01). The plasma leptin and Zn levels of group 1 were significantly lower than in all other groups (p<0.01). These results suggest that Zn deficiency exerts a negative influence in the above-mentioned parameters and that Zn supplementation has the opposite effect.

Topics: Animals; Blood Glucose; Body Weight; Dietary Supplements; Glycogen; Lactic Acid; Leptin; Liver; Physical Conditioning, Animal; Plasma; Rats; Rats, Sprague-Dawley; Zinc

The aim of this study was to investigate the energy metabolism of the burbot (Lota lota, n=38) before, during, and after spawning, which represents the greatest annual metabolic demand for the species. A decrease in body mass, relative weight of the livers, and glycogen concentration of the livers was observed toward the end of spawning. The prespawning period was characterized by high rates of liver glycogenolysis and lipid mobilization. Also, plasma triiodothyronine and sex steroid levels were high before reproduction. During spawning, liver lipolysis was reduced and muscle glycogenolysis stimulated. The levels of triiodothyronine and sex steroids decreased. After reproduction, liver glycogenolysis was suppressed and the rate of gluconeogenesis increased. Thyroid hormone levels were elevated after spawning. Leptin protein and a ghrelin-immunoreactive peptide were detected in burbot plasma. Their concentrations were relatively low before and during reproduction but increased after spawning. The functions of leptin and the ghrelin-immunoreactive peptide in the physiology of the burbot are not consistent with the models of their function in mammals.

Topics: Animals; Body Mass Index; Body Weight; Energy Metabolism; Female; Fishes; Ghrelin; Glycogen; Leptin; Liver; Male; Peptide Hormones; Peptides; Reproduction

Glycogen storage disease type II (GSD II) is an inherited progressive muscle disease in which lack of functional acid alpha-glucosidase (AGLU) results in lysosomal accumulation of glycogen. We report on the impact of a null mutation of the acid alpha-glucosidase gene (AGLU(-/-)) in mice on the force production capabilities, contractile mass, oxidative capacity, energy status, morphology, and desmin content of skeletal muscle. Muscle function was assessed in halothane-anesthetized animals, using a recently designed murine isometric dynamometer. Maximal torque production during single tetanic contraction was 50% lower in the knockout mice than in wild type. Loss of developed torque was found to be disproportionate to the 20% loss in muscle mass. During a series of supramaximal contraction, fatigue, expressed as percentile decline of developed torque, did not differ between AGLU(-/-) mice and age-matched controls. Muscle oxidative capacity, energy status, and protein content (normalized to either dry or wet weight) were not changed in knockout mice compared to control. Alterations in muscle cell morphology were clearly visible. Desmin content was increased, whereas alpha-actinin was not. As the decline in muscle mass is insufficient to explain the degree in decline of mechanical performance, we hypothesize that the large clusters of noncontractile material present in the cytoplasm hamper longitudinal force transmission, and hence muscle contractile function. The increase in muscular desmin content is most likely reflecting adaptations to altered intracellular force transmission.

Topics: Actinin; Adenosine Diphosphate; Adenosine Monophosphate; Adenosine Triphosphate; alpha-Glucosidases; Animals; Body Weight; Desmin; Glucan 1,4-alpha-Glucosidase; Glycogen; Glycogen Storage Disease Type II; Inosine Monophosphate; Mice; Mice, Knockout; Muscle Contraction; Muscle Fibers, Skeletal; Muscle Weakness; Muscle, Skeletal; Phosphocreatine; Stress, Mechanical

In the present study, the chemopreventive effect of the active metabolite of vitamin D, 1alpha,25-dihydroxyvitamin D(3) (VD(3)), against chemically-induced and diabetes-promoted rat liver carcinogenesis was investigated. Hepatocarcinogenesis was initiated with a single intraperitoneal (i.p.) injection of diethylnitrosamine (DEN) (125 mg kg(-1) body weight) at week 4 followed by promotion with streptozotocin (STZ) (65 mg kg(-1) body weight with a single i.p. injection) at week 7. With this basic experimental regimen, the effect of VD(3) (0.3 microg (0.1 ml)(-1) propylene glycol per os twice a week) was investigated with effect from 4 weeks prior to the exposure of DEN. The results showed that VD(3) supplementation throughout the experimental period reduced the incidence, total number and multiplicity and altered the size of visible persistent nodules (PNs) in DEN- or DEN + STZ-treated rats as compared with their respective controls. In these two groups, it also caused a significant decrease in the number (p < 0.002 and 0.001 respectively) and focal area (p < 0.05) of gamma-glutamyltranspeptidase (GGT)-positive hepatic foci. Moreover, continuous supplementation of VD(3) exhibits a protective effect in maintaining the normal cellular architecture of the hepatocytes in DEN- or DEN + STZ-treated rats. Our results thus strongly suggest that VD(3) is very effective in the inhibition of DEN-initiated and STZ-induced diabetes-promoted rat liver carcinogenesis.

Topics: Animals; Body Weight; Calcitriol; Cytoplasm; Diabetes Mellitus, Experimental; Diethylnitrosamine; Endoplasmic Reticulum; gamma-Glutamyltransferase; Glycogen; Hepatocytes; Liver; Liver Neoplasms; Male; Microscopy, Electron; Models, Genetic; Organ Size; Rats; Rats, Sprague-Dawley; Streptozocin; Time Factors

The organochlorine o,p'- dichlorodiphenyldichloroethane (o,p'-DDD) is a metabolite of dichlorodiphenyltrichloroethane (DDT), known for its adrenolytic actions in birds and mammals. The effects of o,p'-DDD on the cortisol stress response were investigated in rainbow trout, Oncorhynchus mykiss, in a dose-response study in vivo. A dose-dependent decrease in plasma cortisol levels was observed on days 7 and 14 after a single i.p. injection of o,p'-DDD. Treatment with o,p'-DDD had no effect on weight gain, hematocrit, and gonado- or hepatosomatic index but decreased liver glycogen reserves. The results indicate that o,p'-DDD is an adrenotoxic compound in rainbow trout and that its effects can be detected even 14 d postinjection.

Topics: Adrenal Glands; Animals; Antineoplastic Agents, Hormonal; Body Weight; Glycogen; Hematocrit; Hydrocortisone; Injections, Intraperitoneal; Liver; Mitotane; Oncorhynchus mykiss

The aim of this investigation was to determine if resistance training exercise improved glucose uptake and transport in rodent skeletal muscle. Sprague-Dawley rats were assigned to one of the three groups: control (CON), resistance trained (RT) and aerobic exercise trained (AT). Resistance trained rats were placed in a rodent squat apparatus and performed three sets of 10 repetitions at 75% of their one repetition maximum 3 days week-1 for 12 weeks. Aerobic exercise training consisted of running the rats 3 days week-1 for 45 min over a 12-week period on a motor-driven treadmill (32 m min-1, 15% grade). Following the training period, all animals were subjected to hind limb perfusion in the presence of 500 microU mL-1 insulin. Hind limb glucose uptake was similar in the RT (9.91 +/- 0.7 micromol g-1 h-1) and AT (10.23 +/- 1.0 micromol g-1 h-1) animals and significantly greater than control (CON) (6.40 +/- 0.6 micromol g-1 h-1). Rates of 3-O-methyl-d-glucose transport in the RT animals were elevated in the muscles utilized for RT while in the AT animals rates of 3-O-methyl-d-glucose transport were increased in those muscles recruited for running. The increased rates of 3-O-methyl-d-glucose transport in the skeletal muscles of the resistance trained and aerobic exercise trained animals appeared to be, in part, because of an increased GLUT4 protein concentration. These findings suggest that both resistance or aerobic training exercise can improve insulin-stimulated skeletal muscle glucose uptake and transport, but the training adaptations are restricted to the muscles recruited for the exercise performance.

Topics: 3-O-Methylglucose; Aerobiosis; Animals; Biological Transport; Body Weight; Citrate (si)-Synthase; Glucose; Glucose Transporter Type 4; Glycogen; Hexokinase; Male; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley

The composition of the preexercise food intake is known to affect substrate utilization during exercise and thus can affect long-term changes in body weight and composition. These parameters were measured in male rats exercised 2 h daily over 5 wk, either in the fasting state or 1 h after they ingested a meal enriched with glucose (Glc), whole milk protein (WMP), or alpha-lactalbumin-enriched whey protein (CPalphaL). Compared with fasting, the Glc meal increased glucose oxidation and decreased lipid oxidation during and after exercise. In contrast, the WMP and CPalphaL meals preserved lipid oxidation and increased protein oxidation, the CPalphaL meal increasing protein oxidation more than the WMP meal. At the end of the study, body weight was larger in the WMP-, Glc-, and CPalphaL-fed rats than in the fasted ones. This resulted from an increased fat mass in the WMP and Glc rats and to an increased lean body mass, particularly muscles, in the CPalphaL rats. We conclude that the potential of the CPalphaL meal to preserve lipid oxidation and to rapidly deliver amino acids for use during exercise improved the efficiency of exercise training to decrease adiposity.

Topics: Adipose Tissue; Animal Feed; Animals; Blood; Body Composition; Body Weight; Glucose; Glycogen; Hindlimb; Lactalbumin; Lipid Metabolism; Liver; Male; Milk Proteins; Motor Activity; Muscle, Skeletal; Oxidation-Reduction; Proteins; Rats; Whey Proteins

The effects of heavy metals on growth, intermediary metabolism and enzyme activities were investigated in yellow perch (Perca flavescens), sampled in summer and fall from lakes situated along a contamination gradient of Cd, Zn and Cu in the mining region of Rouyn-Noranda, Québec. An exposure-dependent decrease in condition factor was observed in both seasons. Liver glycogen and triglyceride reserves were higher in summer than in fall in fish from the reference lake, while the seasonal pattern was different in fish from the contaminated lakes. Plasma free fatty acids (FFA) levels were also influenced by season and contamination. Activities of malic enzyme (ME) and glucose 6-phosphate dehydrogenase (G6PDH) in the liver were higher in the summer than in the fall in reference lakes whereas no seasonal variations were detected in fish from contaminated lakes. Activities of pyruvate kinase (PyK), aspartate transaminase (AST), phosphoenolpyruvate carboxykinase (PEPCK) and malate dehydrogenase (MDH), were higher in fish from contaminated lakes in fall but not in summer. Chronic exposure of yellow perch to sublethal levels of heavy metals impairs growth and alters the seasonal cycling of liver glycogen and triglycerides as well as the activities of metabolic enzymes.

Topics: Animals; Body Weight; Carbohydrate Metabolism; Environmental Exposure; Fatty Acids, Nonesterified; Female; Glycogen; Lipid Metabolism; Liver; Male; Metals, Heavy; Perches; Quebec; Seasons; Triglycerides; Water Pollutants, Chemical

To investigate the role of high concentrations of dl-3-hydroxybutyrate (DL-3-HB) in preventing heart damage after prolonged fasting, infarct size and the incidence of apoptosis caused by ischemia-reperfusion were determined in four groups of Wistar rats. Fed rats (+/-DL-3-HB group) and fasted rats (+/-DL-3-HB group) were subjected to 30 min of left coronary artery occlusion and 120 min of reperfusion. DL-3-HB was administered intravenously 60 min before the coronary artery occlusion. Infarct size, defined by triphenylyetrazolium chloride (TTC) staining, was reduced from 72 +/- 3% (fed group), 75 +/- 5% (fed + DL-3-HB group), and 70 +/- 5% (fasting group), respectively, to 26 +/- 4% (P < 0.01 vs. fasting + DL-3-HB group). Apoptosis, as defined by single-stranded DNA staining, was significantly reduced in the subendocardial region in the fasting + DL-3-HB group (9 +/- 2%) compared with the other groups (39 +/- 6% in the fed group, 37 +/- 5% in the fed + DL-3-HB group, and 34 +/- 3% in the fasting group; P < 0.01). In addition, levels of ATP in the fasting + DL-3-HB group were significantly higher compared with other groups after 30 min of ischemia and 120 min of reperfusion (P < 0.01). In conclusion, the present study demonstrates that high concentrations of DL-3-HB reduces myocardial infarction size and apoptosis induced by ischemia-reperfusion, possibly by providing increased energy substrate to the fasted rat myocardium.

Topics: 3-Hydroxybutyric Acid; Acetoacetates; Adenosine Triphosphate; Animals; Apoptosis; Blood Glucose; Blood Pressure; Body Weight; Coronary Disease; Fasting; Fatty Acids, Nonesterified; Glycogen; Heart Rate; Insulin; Lactic Acid; Male; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Rats; Rats, Wistar

Adrenomedullin (AM) is a potent vasodilating peptide and is involved in cardiovascular and renal disease. In the present study, we investigated the role of AM in cardiac and renal function in streptozotocin (STZ)-induced diabetic rats. A single tail-vein injection of adenoviral vectors harboring the human AM gene (Ad.CMV-AM) was administered to the rats 1-wk post-STZ treatment (65 mg/kg iv). Immunoreactive human AM was detected in the plasma and urine of STZ-diabetic rats treated with Ad.CMV-AM. Morphological and chemical examination showed that AM gene delivery significantly reduced glycogen accumulation within the hearts of STZ-diabetic rats. AM gene delivery improved cardiac function compared with STZ-diabetic rats injected with control virus, as observed by decreased left ventricular end-diastolic pressure, increased cardiac output, cardiac index, and heart rate. AM gene transfer significantly increased left ventricular long axis (11.69 +/- 0.46 vs. 10.31 +/- 0.70 mm, n = 10, P < 0.05) and rate of pressure rise and fall (+6,090.1 +/- 597.3 vs. +4,648.5 +/- 807.1 mmHg/s), (-4,902.6 +/- 644.2 vs. -3,915.5 +/- 805.8 mmHg/s, n = 11, P < 0.05). AM also significantly attenuated renal glycogen accumulation and tubular damage in STZ-diabetic rats as well as increased urinary cAMP and cGMP levels, along with increased cardiac cAMP and Akt phosphorylation. We also observed that delivery of the AM gene caused an increase in body weight along with phospho-Akt and membrane-bound GLUT4 levels in skeletal muscle. These results suggest that AM plays a protective role in hyperglycemia-induced glycogen accumulation and cardiac and renal dysfunction via Akt signal transduction pathways.

Topics: Adenoviridae; Adrenomedullin; Animals; Blood Glucose; Body Weight; Cyclic AMP; Cyclic GMP; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; Gene Expression; Genetic Therapy; Genetic Vectors; Glucose Transporter Type 4; Glycogen; Heart; Heart Function Tests; Humans; Kidney; Male; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; Myocardium; Peptides; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Streptozocin; Ventricular Function, Left

AMP-activated protein kinase (AMPK) consists of three subunits: alpha, beta, and gamma. Two isoforms exist for the alpha-subunit (alpha(1) and alpha(2)), two for the beta-subunit (beta(1) and beta(2)), and three for the gamma-subunit (gamma(1), gamma(2), and gamma(3)). Although the specific roles of the beta- and gamma-subunits are not well understood, the alpha-subunit isoforms contain the catalytic site and also the phosphorylation/activation site for the upstream kinase. This study was designed to determine the role of thyroid hormones in controlling expression levels of these AMPK subunits and of one downstream target, acetyl-CoA carboxylase (ACC), in muscle. AMPK subunit and ACC levels were determined by Western blots in control rats, in rats given 0.01% propylthiouracil (PTU) in drinking water for 3 wk, and in rats given 3 mg of thyroxine and 1 mg of triiodothyronine per kilogram chow for 1 or 3 wk. In gastrocnemius muscle, all isoforms of AMPK subunits were significantly increased in rats given thyroid hormones for 3 wk vs. those treated with PTU. Similar patterns were seen in individual muscle types. Expression of muscle ACC was also significantly increased in response to 3 wk of treatment with excess thyroid hormones. Muscle content of malonyl-CoA was elevated in PTU-treated rats and depressed in thyroid hormone-treated rats. These data provide evidence that skeletal muscle AMPK subunit and ACC expression is partially under the control of thyroid hormones.

Topics: Acetyl-CoA Carboxylase; Adipose Tissue; AMP-Activated Protein Kinases; Animals; Antithyroid Agents; Blotting, Western; Body Weight; Eating; Glycogen; Male; Malonyl Coenzyme A; Multienzyme Complexes; Muscle, Skeletal; Phosphorylation; Propylthiouracil; Protein Serine-Threonine Kinases; Rats; Rats, Sprague-Dawley; Thyroid Gland; Thyroxine; Triiodothyronine

The Indian traditional system of medicine prescribed plant therapies for diseases including diabetes mellitus called madhumeh in Sanskrit. One such plant mentioned in Ayurveda is Pterocarpus marsupium (PM). In the present study, aqueous extract of PM (1 g/kg PO) was assessed for its effect on glycogen levels of insulin dependent (skeletal muscle and liver), insulin-independent tissues (kidneys and brain) and enzymes such as glucokinase (GK), hexokinase (HK), and phosphofructokinase (PFK). Administration of PM led to decrease in blood glucose levels by 38 and 60% on 15th and 30th day of the experiment. Liver and 2-kidney weight expressed as percentage of body-weight was significantly increased in diabetics (p < 0.0005) vs. normal controls and this alteration in the renal weight (p < 0.0005) but not liver weight was normalized by feeding of PM extract. Renal glycogen content increased by over 10-fold while hepatic and skeletal muscle glycogen content decreased by 75 and 68% in diabetic controls vs. controls and these alteration in glycogen content was partly prevented by PM. Activity of HK, GK and PFK in diabetic controls was 35,50 and 60% of the controls and PM completely corrected this alteration in PFK and only partly in HK and GK.

Topics: Animals; Body Weight; Carbohydrate Metabolism; Glucokinase; Glycogen; Hexokinase; Kidney; Liver; Male; Organ Size; Phosphofructokinases; Plant Extracts; Pterocarpus; Rats

Oral administration (80 mg/kg body wt/day for 30 days) of solasodine (extracted and isolated from the berries of the Solanum xanthocarpum) to intact dogs significantly decreased the epithelial cell height of cauda epididymides. The cells became atrophic and the lumen was devoid of spermatozoa. Castration followed by the adminstration of solasodine further reduced the epithelial cell height in comparison to castrated controls. Concurrent treatment of solasodine along with testosterone propionate was unable to restore the normal epithelial lumen parameters. Total protein, sialic acid, glycogen and acid phosphatase activities were significantly reduced in solasodine treated cauda epididymides. These result suggest antiandrogenic potency of solasodine.

Topics: Acid Phosphatase; Animals; Body Weight; Dogs; Epididymis; Epithelial Cells; Glycogen; Male; N-Acetylneuraminic Acid; Plant Extracts; Solanaceous Alkaloids; Testosterone; Time Factors

Hepatic glucose production is increased as a metabolic consequence of insulin resistance in type 2 diabetes. Because fructose 2,6-bisphosphate is an important regulator of hepatic glucose production, we used adenovirus-mediated enzyme overexpression to increase hepatic fructose 2,6-bisphosphate to determine if the hyperglycemia in KK mice, polygenic models of type 2 diabetes, could be ameliorated by reduction of hepatic glucose production. Seven days after treatment with virus encoding a mutant 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase designed to increase fructose 2,6-bisphosphate levels, plasma glucose, lipids, and insulin were significantly reduced in KK/H1J and KK.Cg-A(y)/J mice. Moreover, high fructose 2,6-bisphosphate levels downregulated glucose-6-phosphatase and upregulated glucokinase gene expression, thereby reversing the insulin-resistant pattern of hepatic gene expression of these two key glucose-metabolic enzymes. The increased hepatic fructose 2,6-bisphosphate also reduced adiposity in both KK mice. These results clearly indicate that increasing hepatic fructose 2,6-bisphosphate overcomes the impairment of insulin in suppressing hepatic glucose production, and it provides a potential therapy for type 2 diabetes.

Topics: Adipose Tissue; Animals; Blood; Body Weight; Diabetes Mellitus, Type 2; Epididymis; Female; Fructosediphosphates; Glucokinase; Glucose-6-Phosphatase; Glycogen; Insulin; Insulin Resistance; Liver; Male; Mice; Mice, Inbred Strains; Phosphofructokinase-2

Phytosterols or plant sterols (PS) are consumed as natural remedies and margarines by the general population in developed countries to lower elevated serum cholesterol levels. They are also present in high concentrations in pulp mill effluents. The aim of the study was to screen the endocrine and metabolic parameters of the European polecat (Mustela putorius) for the effects of PS. The results showed an increase in the plasma estradiol and TH levels with no effects on the hypophyseal regulatory hormones. The plasma ghrelin levels decreased. PS also affected intermediary metabolism. The liver glycogen content increased as did the kidney glucose-6-phosphatase activity. The liver lipase esterase activity, on the other hand, decreased due to PS. In serum lipids the total cholesterol did not change, but the low-density lipoprotein levels increased and the high-density lipoprotein-cholesterol ratio decreased. PS had widespread previously unreported effects on the physiology of the polecat. The multiple effects indicate the need of a thorough risk assessment of the effects and interactions of PS.

Topics: Animals; Body Weight; Carnivora; Dose-Response Relationship, Drug; Endocrine Glands; Estradiol Congeners; Estrogens, Non-Steroidal; Female; Glycogen; Hormones; Hypolipidemic Agents; Inactivation, Metabolic; Isoflavones; Kidney; Lipids; Liver; Male; Metabolism; Organ Size; Phytoestrogens; Phytosterols; Plant Preparations; Sitosterols

Previous studies have shown that undernutrition induces an impairment of the respiratory muscle function in patients with chronic lung disease. To explain this, we hypothesized that undernutrition could decrease oxidative metabolism in the diaphragm. We therefore examined the effect of prolonged undernutrition on diaphragm mitochondrial oxygen uptake with pyruvate and palmitate as substrates in adult rats. Ten rats served as controls (CTL). Ten nutritionally deprived rats (ND) received 40% of their estimated daily nutrition. Five weeks of undernutrition induced a 33% decrease in state 3 respiration with pyruvate plus malate as substrate (993 +/- 171 versus 1488 +/- 167 nmol atomic O/mg/min, P < 0.01) and a 39% decrease with palmitate plus malate (516 +/- 89 versus 850 +/- 165 nmol atomic O/mg/min, P < 0.05). With succinate plus rotenone, there was no significant difference in the respiratory rate between groups. In the ND group, we found a significant decrease in citrate synthase activity (P < 0.01), and also in reduced nicotinamine adenine dinucleotide (NADH) dehydrogenase activity (P < 0.05), which cannot alone induce such a state 3 respiratory decrease. This showed that undernutrition in rat diaphragm does not induce an alteration in protein complexes I, II, III, and IV, or the F complex containing the mitochondrial ATPase of the electron transport chain. In conclusion, the main result of this study was that prolonged undernutrition induced a decrease in mitochondrial respiration secondary to a significant reduction in NADH generation by the Krebs cycle, which may affect respiratory muscle function with implications for patient care.

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cell Respiration; Citrate (si)-Synthase; Diaphragm; Glycogen; Male; Mitochondria; Myosin Heavy Chains; NADH Dehydrogenase; Organ Size; Oxygen; Palmitates; Protein Isoforms; Pyruvic Acid; Random Allocation; Rats; Rats, Wistar

Considerable evidence suggests that skeletal muscle insulin resistance is an inherent feature of type 2 diabetes and contributes to the pathogenesis of the disease. In patients with poorly controlled diabetes, hyperglycemia is thought to produce additional insulin resistance in muscle. The magnitude and nature of hyperglycemia-induced insulin resistance is not known. The purpose of the present study was to determine the biochemical mechanisms responsible for increased insulin-stimulated glucose disposal after the achievement of tight glycemic control with a mixed-split regimen. We performed hyperinsulinemic-euglycemic clamps with indirect calorimetry and vastus lateralis muscle biopsies in eight type 2 diabetic patients who had poor glycemic control (HbA(1c) 10.1%) and again after 3 months of intensive insulin therapy designed to produce near-normoglycemia (HbA(1c) 6.6%). Improved glycemic control increased insulin-stimulated glucose disposal (5.16 +/- 0.32 vs. 3.69 +/- 0.33 mg x kg(-1) x min(-1); P < 0.01); nonoxidative glucose disposal, which primarily reflects glycogen synthesis (2.11 +/- 0.26 vs. 0.90 +/- 0.16 mg x kg(-1) x min(-1); P < 0.01); and glycogen synthase fractional velocity (0.094 +/- 0.017 vs. 0.045 +/- 0.007; P < 0.05). There was no improvement in insulin-stimulated glucose oxidation (3.05 +/- 0.25 vs. 2.79 +/- 0.20 mg x kg(-1) x min(-1)), hexokinase II mRNA expression (increase over basal values), or hexokinase II enzymatic activity (0.51 +/- 0.16 vs. 0.42 +/- 0.18 pmol x min(-1) x microg(-1) protein). All of the increase in insulin-stimulated glucose disposal could be accounted for by increased glycogen synthesis, which is likely attributable to increased activation of glycogen synthase by insulin.

Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Female; Glycogen; Glycogen Synthase; Hexokinase; Humans; Insulin; Male; Middle Aged; Osmolar Concentration; Reference Values; RNA, Messenger

To clarify the mechanism by which insulin resistance develops in obesity, Zucker fatty rats (ZFR) and lean litter mates (ZLR) were temporally subjected to oral glucose tolerance tests (OGTT) at 6 and 15 weeks of age.. As candidates for causative factors of insulin resistance, plasma leptin, free fatty acids (FFA) and tumor necrosis factor (TNF)-alpha levels were evaluated.. There was no difference in the body weight between the two groups at 6 weeks of age, but ZFR were significantly heavier than ZLR at 15 weeks of age. At 6 weeks of age, blood glucose levels and area under the curve of glucose (AUCg) during OGTT were not significantly different between the two groups, while plasma insulin levels and area under the curve of insulin (AUCi) in the ZFR group were significantly higher than those in the ZLR group. At 15 weeks of age, the blood glucose levels and AUCg as well as plasma insulin levels and AUCi in the ZFR group during OGTT were significantly higher than those in the ZLR group. The ratio of fasting insulin to glucose in the ZFR group was significantly higher than that in the ZLR group at 6 and 15 weeks of age. Peripheral and portal plasma leptin and FFA levels were significantly higher in ZFR than ZLR both at 6 weeks and 15 weeks of age. Meanwhile, at 6 weeks, plasma TNF-alpha levels and expression of TNF-alpha protein in subcutaneous and visceral fat tissues were similar in both groups; however at 15 weeks, these were significantly higher in the ZFR group than the ZLR group.. These results suggest that FFA rather than TNF-alpha may play an important role in early events involved in the development of insulin resistance and TNF-alpha accelerates insulin resistance together with FFA in the later stage.

Topics: Adipose Tissue; Animals; Blood Glucose; Blotting, Western; Body Weight; Eating; Fasting; Fatty Acids, Nonesterified; Glucose Tolerance Test; Glycogen; Insulin; Insulin Resistance; Leptin; Liver; Male; Obesity; Organ Size; Rats; Rats, Zucker; Tumor Necrosis Factor-alpha

To evaluate the possible antifertility activity of Sarcostemma acidum (Roxb) Voigt. stem extract in male rats.. Male rats were given 70% methanol extract of S. acidum stem orally at dose levels of 50 and 100 mg/kg/day for 60 days. Fertility was evaluated with mating test. Sperm motility and sperm density in cauda epididymides were also assessed. Biochemical and histological analyses were performed on blood samples and on the reproductive organs.. S. acidum stem extract resulted in an arrest of spermatogenesis without any systemic side effect. Sperm motility as well as sperm density was reduced significantly. Treatment caused a 80% reduction in fertility at the 50 mg dose and complete suppression of fertility at the 100 mg dose. There was no significant change in RBC and WBC count, hemoglobin, haematocrit, sugar and urea in the whole blood and cholesterol, protein and phospholipid in the serum. The protein and glycogen content of the testes, fructose in the seminal vesicle and protein in epididymides were significantly decreased. Cholesterol in the testes was elevated. Treatment at both of the doses caused a marked reduction in the number of primary spermatocytes (preleptotene and pachytene), secondary spermatocytes and spermatids. The number of mature Leydig cells was decreased, and degenerating Leydig cells was increased proportionately.. S. acidum stem extract arrests spermatogenesis in male rats without noticable side effects.

Topics: Animals; Blood Cell Count; Body Weight; Cholesterol; Contraceptive Agents, Male; Glycogen; Leydig Cells; Male; Phospholipids; Plant Extracts; Plants, Medicinal; Rats; Rats, Sprague-Dawley; Spermatids; Spermatocytes; Spermatogenesis

We determined the interaction of exercise and diet on glucose transporter (GLUT-4) protein and mRNA expression in type I (soleus) and type II [extensor digitorum longus (EDL)] skeletal muscle. Forty-eight Sprague Dawley rats were randomly assigned to one of two dietary conditions: high-fat (FAT, n=24) or high-carbohydrate (CHO, n=24). Animals in each dietary condition were allocated to one of two groups: control (NT, n=8) or a group that performed 8 weeks of treadmill running (4 sessions week-1 of 1000 m @ 28 m min-1, RUN, n=16). Eight trained rats were killed after their final exercise bout for determination of GLUT-4 protein and mRNA expression: the remainder were killed 48 h after their last session for measurement of muscle glycogen and triacylglycerol concentration. GLUT-4 protein expression in NT rats was similar in both muscles after 8 weeks of either diet. However, there was a main effect of training such that GLUT-4 protein was increased in the soleus of rats fed with either diet (P < 0.05) and in the EDL in animals fed with CHO (P < 0.05). There was a significant diet-training interaction on GLUT-4 mRNA, such that expression was increased in both the soleus (100% upward arrowP < 0.05) and EDL (142% upward arrowP < 0.01) in CHO-fed animals. Trained rats fed with FAT decreased mRNA expression in the EDL ( downward arrow 45%, P < 0.05) but not the soleus ( downward arrow 14%, NS). We conclude that exercise training in CHO-fed rats increased both GLUT-4 protein and mRNA expression in type I and type II skeletal muscle. Despite lower GLUT-4 mRNA in muscles from fat-fed animals, exercise-induced increases in GLUT-4 protein were largely preserved, suggesting that control of GLUT-4 protein and gene expression are modified independently by exercise and diet.

Topics: Animals; Body Weight; Diet; Dietary Carbohydrates; Dietary Fats; Female; Gene Expression; Glucose; Glucose Transporter Type 4; Glycogen; Insulin Resistance; Monosaccharide Transport Proteins; Muscle Fibers, Fast-Twitch; Muscle Fibers, Slow-Twitch; Muscle Proteins; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; RNA, Messenger; Triglycerides

1. The effects of combined treatment with pioglitazone.HCl and metformin on diabetes and obesity were investigated in Wistar fatty rats, which are hyperglycaemic and hypertriglyceridaemic and have higher plasma levels of total ketone bodies than lean rats. 2. Plasma glucose was significantly decreased when pioglitazone.HCl or metformin was administered alone and combined treatment accentuated this decrease. The administration of pioglitazone.HCl, but not metformin, also decreased plasma levels of triglyceride and total ketone bodies. 3. The glycogen content of skeletal muscle was not increased by pioglitazone.HCl or metformin alone, but was increased by combined treatment (P=0.003, ANOVA). 4. Pioglitazone.HCl produced increased food intake and bodyweight in hyperphagic Wistar fatty rats; however, concurrent administration of metformin significantly ameliorated these pioglitazone.HCl-induced increases. 5. These results indicate that combined treatment with pioglitazone.HCl and metformin induces a marked hypoglycaemic effect accompanied by a reduction in plasma levels of total ketone bodies and prevention of excessive bodyweight gain in Wistar fatty rats. These favourable effects suggest that the combination would be beneficial in treating patients with type 2 diabetes.

Topics: Adipose Tissue; Animals; Body Weight; Diabetes Mellitus; Drug Therapy, Combination; Eating; Glycogen; Hypoglycemic Agents; Ketone Bodies; Liver; Male; Metformin; Muscle, Skeletal; Obesity; Organ Size; Pioglitazone; Rats; Rats, Wistar; Thiazoles; Thiazolidinediones

Metabolic changes during the transition from post-feeding to fasting were studied in Brycon cephalus, an omnivorous teleost from the Amazon Basin in Brazil. Body weight and somatic indices (liver and digestive tract), glycogen and glucose content in liver and muscle, as well as plasma glucose, free fatty acids (FFA), insulin and glucagon levels of B. cephalus, were measured at 0, 12, 24, 48, 72, 120, 168 and 336 h after the last feeding. At time 0 h (the moment of food administration, 09.00 h) plasma levels of insulin and glucagon were already high, and relatively high values were maintained until 24 h post-feeding. Glycemia was 6.42+/-0.82 mM immediately after food ingestion and 7.53+/-1.12 mM at 12 h. Simultaneously, a postprandial replenishment of liver and muscle glycogen reserves was observed. Subsequently, a sharp decrease of plasma insulin occurred, from 7.19+/-0.83 ng/ml at 24 h of fasting to 5.27+/-0.58 ng/ml at 48 h. This decrease coincided with the drop in liver glucose and liver glycogen, which reached the lowest value at 72 h of fasting (328.56+/-192.13 and 70.33+/-14.13 micromol/g, respectively). Liver glucose increased after 120 h and reached a peak 168 h post-feeding, which suggests that hepatic gluconeogenesis is occurring. Plasma FFA levels were low after 120 and 168 h and increased again at 336 h of fasting. During the transition from post-feeding to fast condition in B. cephalus, the balance between circulating insulin and glucagon quickly adjust its metabolism to the ingestion or deprivation of food.

Topics: Animals; Blood Glucose; Body Weight; Brazil; Fasting; Fatty Acids, Nonesterified; Fishes; Food Deprivation; Glucagon; Glucose; Glycogen; Insulin; Liver; Muscles; Postprandial Period; Time Factors

Insulin resistance results in accumulation of triglyceride content and reduction of glycogen content in skeletal muscle. However, very few studies have measured lipid content and glycogen content in liver associated with insulin resistance. We studied the relationship between liver lipid content, liver glycogen, and insulin resistance in high-fat-fed rats, which are animal models of insulin resistance. High-fat-fed rats were hyperlipidemic, hyperglycemic, and hyperinsulinemic. Furthermore, the glucose infusion rates (GIR) were lower (normal rats, 10.35 +/- 1.66; high-fat-fed rats, 4.86 +/- 0.93 mg/kg/min; P <.01) and the triglyceride and cholesterol contents in liver were higher in the high-fat-fed rats than in normal rats. On the other hand, the glycogen content in liver was lower than in normal rats. There was an inverse relationship between liver triglyceride content and liver glycogen content. When the lipoprotein lipase (LPL) activator NO-1886 was administered to the high-fat-fed rats at a daily dose of 50 mg/kg body weight for 10 weeks, GIR (9.87 +/- 3.76 mg/kg/min, P <.05 v high-fat-fed control group) improved, causing an improvement of the hyperlipidemia, hyperglycemia, and hyperinsulinemia. Furthermore, NO-1886 decreased triglyceride and cholesterol concentrations and increased glycogen content in liver of the high-fat-fed rats. In this study, we found that insulin resistance caused fatty liver and reduced glycogen content in liver. Administration of the LPL activator NO-1886 improved the insulin resistance, resulting in an improvement in the relationship between triglyceride and glycogen content in liver of high-fat-fed rats.

Topics: Animals; Benzamides; Blood Glucose; Body Weight; Cholesterol; Dietary Fats; Enzyme Activation; Glucose Clamp Technique; Glycogen; Hypolipidemic Agents; Insulin; Insulin Resistance; Lipid Metabolism; Lipids; Lipoprotein Lipase; Liver; Male; Organophosphorus Compounds; Rats; Rats, Sprague-Dawley; Triglycerides

Chronic attenuation of hyperinsulinemia by diazoxide (DZ), an inhibitor of glucose-mediated insulin secretion, improved insulin sensitivity and glucose tolerance and caused down-regulation of lipid metabolizing enzymes in adipose tissue and decreased the rate of weight gain in mildly hyperglycemic obese Zucker rats. Since the liver plays a central role in glucose homeostasis, we studied the effect of chronic insulin suppression on key insulin-sensitive enzymes regulating hepatic gluconeogenesis.. DZ (150 mg/kg per day) or vehicle (control) was administered to 7-week-old female obese and lean Zucker rats for a period of 4 weeks.. DZ-treated animals showed lower fasting plasma insulin levels (P<0.001) than their controls. Plasma glucose levels were lower in DZ obese rats than in controls (P<0.001), without a significant change in DZ lean animals. DZ had no effect on glucose transporter 2 protein expression in either strain. DZ treatment resulted in lower hepatic glucokinase (P<0.001) and glucose-6-phosphatase (P<0.0001) and phosphoenolpyruvate carboxykinase (PEPCK) activities only in obese rats compared with controls (P<0.001). However, DZ-treated lean rats demonstrated higher PEPCK activity than controls (P<0.002). DZ-treated animals demonstrated enhanced hepatic glucose-6-phosphate content (P<0.01), glycogen synthase activity (P<0.0001) and glycogen content (P<0.02) compared with their controls despite increased hepatic glycogen phosphorylase a activity in these animals (P<0.02).. Chronic suppression of hyperinsulinemia in obese Zucker rats by DZ decreased the activities of key enzymes regulating hepatic gluconeogenesis, implying that attenuation of the hyperinsulinemic state by DZ may be therapeutically beneficial.

Topics: Animals; Blood Glucose; Body Weight; Diazoxide; Eating; Female; Glucokinase; Gluconeogenesis; Glucose Transporter Type 2; Glucose-6-Phosphatase; Glycogen; Glycogen Phosphorylase; Glycogen Synthase; Hyperinsulinism; Insulin; Lipids; Liver; Monosaccharide Transport Proteins; Obesity; Protein Serine-Threonine Kinases; Rats; Rats, Zucker; Thinness

Hepatic gluconeogenic capacity was studied in young (4 months of age) and old (24 months of age) male Fischer 344 rats fasted for 24 hours using the isolated hepatocyte technique. Following the isolation of liver cells, the following precursors were added to the cell suspensions and incubated for 30 minutes: lactate (5 mmol/L), pyruvate (5 mmol/L), alanine (5 mmol/L), glutamine (5 mmol/L), oxaloacetate (5 mmol/L), glycerol (5 mmol/L), dihydroxyacetone (10 mmol/L), fructose (10 mmol/L), or saline (no precursor addition). To confirm that glucose production reflects gluconeogenic capacity, there was significant depletion of hepatic glycogen after the 24-hour fast and minimal alterations in glycogen content once substrates were added. Adjusting the gluconeogenic rates to reflect 100% cell viability resulted in no difference between young and old animals for any substrate used with the sole exception of fructose. The hepatic glucose production from fructose was 34% greater for young versus old animals. The results suggest that following a period of starvation the basal glucose production rates from hepatocytes, incubated with precursors entering the gluconeogenic pathway prior to fructose-6-phosphate, are equivalent in young and old rats.

Topics: Aging; Alanine; Animals; Body Weight; Cell Separation; Cell Survival; Dihydroxyacetone; Fasting; Fructose; Gluconeogenesis; Glucose; Glutamine; Glycerol; Glycogen; Hepatocytes; Lactic Acid; Liver; Male; Oxaloacetates; Pyruvic Acid; Rats; Rats, Inbred F344

In humans, stress can increase the risk of cardiovascular disease by altering lipoprotein metabolism. Scarce experimental and clinical data are available on this effect. Therefore, we studied the metabolic response to acute and chronic stress following a model of immobilization (IMO) in rats and we evaluated the resulting circulating lipoprotein levels. Repeated IMO treatment (2 hours daily, always between 9:00 AM and 11:00 AM, for 2 periods of 5 and 4 consecutive days, separated by 2 days of rest) daily decreased body weight gain and food intake, increased adrenal weight, and slightly reduced liver glycogen and plasma insulin (without considerable variations of blood glucose), which is characteristic of chronic stress. A single IMO application (30 minutes of an unexpected IMO starting at 2:00 PM immediately before the animals were killed) significantly increased the circulating levels of corticosterone, glucose, insulin, glycerol, and ketone bodies, which is the typical response to acute stress. Both acute and chronic stress decreased the plasmatic triacylglycerol (TAG) concentration, as reflected by the reduction in the number of very-low-density lipoprotein (VLDL) particles. This may be due to an increase in the metabolization of TAG, as suggested by the slightly higher amounts of circulating LDLs. Chronic stress, but not acute stress, significantly increased both the number and the estimated size of circulating high-density lipoprotein (HDLs), as shown by the plasma cholesterol concentration. Acute stress did not have an additive effect over chronic stress on the lipoprotein parameters studied. The metabolic effects of these IMO-induced alterations on lipoprotein profiles are discussed, and future studies in lipidic metabolism are suggested.

Topics: Adrenal Glands; Animals; Blood Glucose; Body Weight; Cholesterol; Corticosterone; Eating; Glycerol; Glycogen; Insulin; Ketone Bodies; Lipoproteins; Lipoproteins, VLDL; Liver; Male; Models, Animal; Organ Size; Rats; Rats, Wistar; Restraint, Physical; Stress, Physiological; Time; Triglycerides

The p90 ribosomal S6 kinase (RSK), a cytosolic substrate for the extracellular signal-regulated kinase (ERK), is involved in transcriptional regulation, and one isoform (RSK2) has been implicated in the activation of glycogen synthase by insulin. To determine RSK2 function in vivo, mice lacking a functional rsk2 gene were generated and studied in response to insulin and exercise, two potent stimulators of the ERK cascade in skeletal muscle. RSK2 knockout (KO) mice weigh 10% less and are 14% shorter than wild-type (WT) mice. They also have impaired learning and coordination. Hindlimb skeletal muscles were obtained from mice 10, 15, or 30 min after insulin injection or immediately after strenuous treadmill exercise for 60 min. While insulin and exercise significantly increased ERK phosphorylation in skeletal muscle from both WT and KO mice, the increases were twofold greater in the KO animals. This occurred despite 27% lower ERK2 protein expression in skeletal muscle of KO mice. KO mice had 18% less muscle glycogen in the fasted basal state, and insulin increased glycogen synthase activity more in KO than WT mice. The enhanced insulin-stimulated increases in ERK and glycogen synthase activities in KO mice were not associated with higher insulin receptor or with IRS1 tyrosine phosphorylation or with IRS1 binding to phosphatidylinositol 3-kinase. However, insulin-stimulated serine phosphorylation of Akt was significantly higher in the KO animals. c-fos mRNA was increased similarly in muscle from WT and KO mice in response to insulin (2. 5-fold) and exercise (15-fold). In conclusion, RSK2 likely plays a major role in feedback inhibition of the ERK pathway in skeletal muscle. Furthermore, RSK2 is not required for activation of muscle glycogen synthase by insulin but may indirectly modulate muscle glycogen synthase activity and/or glycogen content by other mechanisms, possibly through regulation of Akt. RSK2 knockout mice may be a good animal model for the study of Coffin-Lowry syndrome.

Topics: Animals; Body Weight; Cognition; Disease Models, Animal; Enzyme Activation; Feedback; Gene Deletion; Gene Expression Regulation, Enzymologic; Gene Targeting; Glycogen; Glycogen Synthase; Insulin; MAP Kinase Signaling System; Mice; Mice, Knockout; Mitogen-Activated Protein Kinases; Muscle, Skeletal; Phosphorylation; Physical Conditioning, Animal; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6 Kinases

Most organic pollutants are supposed to act via the mechanism of nonpolar narcosis upon acute exposure. Because the chronic effects of these compounds are still relatively unknown, in this study a chronic toxicity experiment was performed with zebrafish, Danio rerio, exposed to 1,2,3-trichlorobenzene (123TCB), a nonpolar narcotic. Fish were exposed in a flow-through system for 68 and 147 days. Parameters measured are survival, growth, reproduction, and glycogen and protein content. The only parameter which was influenced was the number of eggs produced per female, resulting in an EC(50) of 40 microg/L. Using this value and acute toxicity data for 123TCB, an acute to chronic ratio (ACR) of 80 was calculated, which is larger than ACRs for other species exposed to nonpolar narcotics. This finding might indicate that compounds acting by nonpolar narcosis in acute tests can have completely different effects upon chronic exposure.

Topics: Animals; Body Weight; Chlorobenzenes; Energy Metabolism; Glycogen; Growth; Proteins; Reproduction; Survival Analysis; Water; Zebrafish

The effects of acute insulin deficiency on the kidney have been investigated in animal models of experimental diabetes; however, the impact of long-term diabetes has not been determined.. We measured renal glycogen contents in streptozotocin (STZ)-diabetic rats 3 weeks (n = 12) or 9 months (n = 12) after the induction of diabetes, and in 2 groups of control rats of similar age (n = 16 and n = 12, respectively), in the fed state and after a 24-hour fast.. Diabetic rats had high glucose levels, low insulin but normal glucagon concentrations in portal blood. In the fasting state, kidney glycogen content was very low in both young control and young diabetic rats (54 +/- 15 and 189 +/- 26 microg/g, respectively, mean +/- SD); in contrast, glycogen levels were markedly elevated in rats with long-standing diabetes as compared to old nondiabetic animals (2,628 +/- 1,023 +/- and 1,968 +/- 989 microg/g of diabetic rat, fasting and fed, respectively, p < 0.001 vs. 0 +/- 0 and 4 +/- 6 microg/g of control rats). On electron microscopy, large glycogen clusters were localized to the renal tubules. Kidney phosphorylase activity was higher, and synthase activity lower in diabetic than control rats (p < 0.05 for both), whereas kidney glycogen was strongly related to plasma glucose levels, suggesting that the enzyme changes were secondary to glycogen accumulation itself. Renal hexosephosphates and fructose-2,6-bisphosphate contents were both increased in long-term diabetic rats (p < 0.05), implying enhanced fluxes through both glycolysis and gluconeogenesis.. In chronic, untreated diabetes glycogen accumulates in the renal tubules; prolonged hyperglycemia is the sole driving force for this phenomenon.

Topics: Aging; Animals; Body Weight; Chronic Disease; Diabetes Mellitus, Experimental; Glycogen; Kidney Glomerulus; Kidney Tubules, Distal; Kidney Tubules, Proximal; Male; Microscopy, Electron; Rats; Rats, Wistar; Time Factors

The present study was conducted to determine the effect of chronic administration of the long-acting beta(2)-adrenergic agonist clenbuterol on rats that are genetically prone to insulin resistance and impaired glucose tolerance. Obese Zucker rats (fa/fa) were given 1 mg/kg of clenbuterol by oral intubation daily for 5 wk. Controls received an equivalent volume of water according to the same schedule. At the end of the treatment, rats were catheterized for euglycemic-hyperinsulinemic (15 mU insulin. kg(-1). min(-1)) clamping. Clenbuterol did not change body weight compared with the control group but caused a redistribution of body weight: leg muscle weights increased, and abdominal fat weight decreased. The glucose infusion rate needed to maintain euglycemia and the rate of glucose disappearance were greater in the clenbuterol-treated rats. Furthermore, plasma insulin levels were decreased, and the rate of glucose uptake into hindlimb muscles and abdominal fat was increased in the clenbuterol-treated rats. This increased rate of glucose uptake was accompanied by a parallel increase in the rate of glycogen synthesis. The increase in muscle glucose uptake could not be ascribed to an increase in the glucose transport protein GLUT-4 in clenbuterol-treated rats. We conclude that chronic clenbuterol treatment reduces the insulin resistance of the obese Zucker rat by increasing insulin-stimulated muscle and adipose tissue glucose uptake. The improvements noted may be related to the repartitioning of body weight between tissues.

Topics: Adrenergic beta-Agonists; Animals; Blood Glucose; Body Weight; Clenbuterol; Female; Glucose; Glycogen; Insulin; Insulin Resistance; Muscle, Skeletal; Obesity; Organ Size; Rats; Rats, Zucker; Triglycerides

To understand the long-term metabolic and functional consequences of increased GLUT4 content, intracellular substrate utilization was investigated in isolated muscles of transgenic mice overexpressing GLUT4 selectively in fast-twitch skeletal muscles. Rates of glycolysis, glycogen synthesis, glucose oxidation, and free fatty acid (FFA) oxidation as well as glycogen content were assessed in isolated EDL (fast-twitch) and soleus (slow-twitch) muscles from female and male MLC-GLUT4 transgenic and control mice. In male MLC-GLUT4 EDL, increased glucose influx predominantly led to increased glycolysis. In contrast, in female MLC-GLUT4 EDL increased glycogen synthesis was observed. In both sexes, GLUT4 overexpression resulted in decreased exogenous FFA oxidation rates. The decreased rate of FFA oxidation in male MLC-GLUT4 EDL was associated with increased lipid content in liver, but not in muscle or at the whole body level. To determine how changes in substrate metabolism and insulin action may influence energy balance in an environment that encouraged physical activity, we measured voluntary training activity, body weight, and food consumption of MLC-GLUT4 and control mice in cages equipped with training wheels. We observed a small decrease in body weight of MLC-GLUT4 mice that was paradoxically accompanied by a 45% increase in food consumption. The results were explained by a marked fourfold increase in voluntary wheel exercise. The changes in substrate metabolism and physical activity in MLC-GLUT4 mice were not associated with dramatic changes in skeletal muscle morphology. Collectively, results of this study demonstrate the feasibility of altering muscle substrate utilization by overexpression of GLUT4. The results also suggest that as a potential treatment for type II diabetes mellitus, increased skeletal muscle GLUT4 expression may provide benefits in addition to improvement of insulin action.

Topics: Animals; Biological Transport; Body Weight; Eating; Fatty Acids, Nonesterified; Female; Glucose; Glucose Transporter Type 4; Glycogen; Glycolysis; Insulin; Liver; Male; Mice; Monosaccharide Transport Proteins; Muscle Fibers, Skeletal; Muscle Proteins; Muscle, Skeletal; Oleic Acid; Organ Size; Oxidation-Reduction; Physical Conditioning, Animal; Sex Characteristics; Tissue Distribution; Triglycerides

Carnosine is a naturally occurring dipeptide (beta-alanyl-L-histidine) found in muscles, brain and other tissues. This study was designed to test the ability of carnosine to offset metabolic disturbances induced by Schistosoma mansoni parasitism. Results indicate that parasitic infection caused elevation of liver weight/body weight in S. mansoni-infected hamsters, induced lipid peroxidation and reduced glycogen levels. Moreover, adenylate energy charge (AEC) and ATP/ADP and ATP/AMP concentration ratios were markedly lower in infected hamsters. Administration of carnosine (10 mg/day) for 15 days concurrent with infection effectively reduced worm burden and egg count. Administration of carnosine 2 and 4 weeks post-exposure only partially ameliorated the S. mansoni effects on metabolism. Carnosine treatment also normalized most of the parameters measured, including glycogen repletion, the antioxidant status and AEC. These finding support the use of carnosine for possible intervention in schistosomiasis.

Topics: Adenine; Animals; Body Weight; Carnosine; Cricetinae; Glycogen; Lipid Peroxidation; Lipid Peroxides; Liver; Male; Organ Size; Perfusion; Schistosoma mansoni; Time Factors

Obesity results from positive energy balance and, perhaps, abnormalities in lipid and glycogen metabolism. The purpose of this study was to determine whether differences in lipogenesis, retention of dietary fat, and/or glycogenesis influenced susceptibility to dietary obesity. After 1 wk of free access to a high-fat diet (HFD; 45% fat by energy) rats were separated on the basis of 1 wk body weight gain into obesity-prone (OP; > or =48 g) or obesity-resistant groups (OR; < or =40 g). Rats were either studied at this time (OR1, OP1) or continued on the HFD for an additional 4 wk (OR5, OP5). Weight gain and energy intake were greater (P < or = 0.05) in OP vs. OR at both 1 (53 +/- 2 vs. 34 +/- 1 g; 892 +/- 27 vs. 755 +/- 14 kcal) and 5 (208 +/- 7 vs. 170 +/- 7 g; 4,484 +/- 82 vs. 4,008 +/- 72 kcal) wk, respectively. Rats were injected with (3)H(2)O and were either provided free access to an HFD meal containing labeled fatty acids (fed; n = 10 or 11/group) or were fasted (n = 10/group) overnight. The amount of food or (14)C tracer eaten overnight was equivalent between OP and OR rats. In liver, the fraction of (3)H retained in glycogen or lipid was not significantly different between OR and OP groups. Retention of dietary fat in the liver was not increased in OP rats. In adipose tissue, retention of (3)H was approximately 49% greater (P < or = 0.05) in OP1 vs. OR1 and approximately 30% greater in OP5 vs. OR5, but retention of dietary fat was not elevated in OP vs. OR. At the same time, fat pad weight (sum of epididymal, retroperitoneal, mesenteric) was 49% greater in OP1 rats vs. OR1 rats and 65% greater in OP5 vs. OR5 rats (P < or = 0.05). Thus a greater capacity for lipogenesis or retention of dietary fat does not appear to be included in the OP phenotype. The characteristic increase in energy intake associated with OP rats appears to be necessary and critical to accelerated weight and fat gain.

Topics: Adipose Tissue; Animals; Body Weight; Dietary Fats; Disease Susceptibility; Energy Intake; Glycogen; Lipids; Liver; Male; Obesity; Organ Size; Osmolar Concentration; Rats; Rats, Wistar; Triglycerides

As judged from morphological criteria, glycogen accumulates to a larger extent in insulin-producing B-cells than in acinar cells of the pancreas in situations of sustained hyperglycemia. In the present study, the glycogen content of the pancreatic gland and liver was measured in either euglycemic or glucose-infused hyperglycemic control rats, as well as in streptozotocin-induced diabetic rats. Whilst the glycogen content of the pancreas was significantly higher in STZ rats than in control euglycemic rats, it was further enhanced in glucose-infused control rats, despite the fact that the latter animals were not more severely hyperglycemic and for a shorter time than STZ rats. From these measurements, it was estimated that, relative to wet weight, the glycogen content was, under the present experimental conditions, about 75 times higher in insulin-producing than other pancreatic cells. Moreover, it is proposed that the intravenous administration of glucagon may help in distinguishing between the glycogen present in the endocrine and exocrine moieties of the pancreatic gland, this hormone being apparently unable to provoke glycogenolysis in the exocrine pancreas, at variance with the situation prevailing in isolated pancreatic islets.

Topics: Aminoglycosides; Animals; Anti-Bacterial Agents; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Glycogen; Hyperglycemia; Injections, Intravenous; Insulin; Insulin Secretion; Islets of Langerhans; Liver Glycogen; Organ Size; Pancreas; Rats; Rats, Wistar; Time Factors

This study was performed to assess the effects of short-term, extremely high-intensity intermittent exercise training on the GLUT-4 content of rat skeletal muscle. Three- to four-week-old male Sprague-Dawley rats with an initial body weight ranging from 45 to 55 g were used for this study. These rats were randomly assigned to an 8-day period of high-intensity intermittent exercise training (HIT), relatively high-intensity intermittent prolonged exercise training (RHT), or low-intensity prolonged exercise training (LIT). Age-matched sedentary rats were used as a control. In the HIT group, the rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 2, the next 4, and the last 2 days, respectively. Between exercise bouts, a 10-s pause was allowed. RHT consisted of five 17-min swimming bouts with a 3-min rest between bouts. During the first bout, the rat swam without weight, whereas during the following four bouts, the rat was attached to a weight equivalent to 4 and 5% of its body weight for the first 5 days and the following 3 days, respectively. Rats in the LIT group swam 6 h/day for 8 days in two 3-h bouts separated by 45 min of rest. In the first experiment, the HIT, LIT, and control rats were compared. GLUT-4 content in the epitrochlearis muscle in the HIT and LIT groups after training was significantly higher than that in the control rats by 83 and 91%, respectively. Furthermore, glucose transport activity, stimulated maximally by both insulin (2 mU/ml) (HIT: 48%, LIT: 75%) and contractions (25 10-s tetani) (HIT: 55%, LIT: 69%), was higher in the training groups than in the control rats. However, no significant differences in GLUT-4 content or in maximal glucose transport activity in response to both insulin and contractions were observed between the two training groups. The second experiment demonstrated that GLUT-4 content after HIT did not differ from that after RHT (66% higher in trained rats than in control). In conclusion, the present investigation demonstrated that 8 days of HIT lasting only 280 s elevated both GLUT-4 content and maximal glucose transport activity in rat skeletal muscle to a level similar to that attained after LIT, which has been considered a tool to increase GLUT-4 content maximally.

Topics: Animals; Biological Transport, Active; Body Weight; Citrate (si)-Synthase; Deoxyglucose; Electric Stimulation; Glucose; Glucose Transporter Type 4; Glycogen; Insulin; Male; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; Swimming

Rats exposed to repeated restraint weigh less than controls even 8 weeks after stress. Stress-induced weight loss is lean tissue, but the post-stress difference in weight between control and restrained rats is lean and fat mass. Whole-body glucose clearance is enhanced 1 day after stress, but adipocyte glucose utilization is inhibited and muscle glucose transport is unchanged. The studies described here demonstrated that glucose transport was increased in both restrained and pair-fed rats, but that glycogen synthesis was increased only in restrained rats, which may account for the improved whole-body glucose clearance. Adipocyte glucose transport was inhibited and adipose plasma membrane beta-adrenergic receptor number was increased 1 day post-stress in restrained rats when weight loss was lean tissue, but were not different from control rats 5 days post-stress, when both fat and lean tissue were reduced. Thus, repeated restraint induces reversible changes in adipocyte metabolism that may represent a transition from the catabolic state of stress to a new energetic equilibrium in rats that maintain a reduced body weight for an extended period of time.

Topics: Adipocytes; Animals; Biological Transport; Body Weight; Eating; Glucose; Glycogen; Lipid Metabolism; Liver; Male; Rats; Rats, Sprague-Dawley; Restraint, Physical; Stress, Physiological; Time Factors

High-fat feeding has been shown to cause hepatic insulin resistance. The aims of this study were to investigate the biochemical steps responsible for enhanced gluconeogenesis as a result of increased dietary fat intake and the site or sites at which the antihyperglycemic agent metformin acts to inhibit this process. Male Hooded Wistar rats were fed either a standard chow diet (5% fat by weight) or a high-fat diet (60% fat by weight) for 14 days with or without metformin. Total endogenous glucose production and gluconeogenesis were determined using [6-(3)H]glucose and [U-(14)C]alanine, respectively. Gluconeogenic enzyme activity and, where appropriate, protein and mRNA levels were measured in liver tissues. The high-fat diet increased endogenous glucose production (21.9 +/- 4.4 vs. 32.2 +/- 4.8 micromol x kg(-1) x min(-1), P < 0.05) and alanine gluconeogenesis (4.5 +/- 0.9 vs. 9.6 +/- 1.9 micromol x kg(-1) x min(-1), P < 0.05). Metformin reduced both endogenous glucose production (32.2 +/- 4.8 vs. 16.1 +/- 2.1 micromol x kg(-1) x min(-1), P < 0.05) and alanine gluconeogenesis (9.6 +/- 1.9 vs. 4.7 +/- 0.8 micromol x kg(-1) x min(-1), P < 0.05) after high-fat feeding. These changes were reflected in liver fructose-1,6-bisphosphatase protein levels (4.5 +/- 0.9 vs. 9.6 +/- 1.9 arbitrary units, P < 0.05 chow vs. high-fat feeding; 9.5 +/- 1.9 vs. 4.7 +/- 0.8 arbitrary units, P < 0.05 high fat fed in the absence vs. presence of metformin) but not in changes to the activity of other gluconeogenic enzymes. There was a significant positive correlation between alanine gluconeogenesis and fructose-1,6-bisphosphatase protein levels (r = 0.56, P < 0.05). Therefore, excess supply of dietary fat stimulates alanine gluconeogenesis via an increase in fructose-1,6-bisphosphatase protein levels. Metformin predominantly inhibits alanine gluconeogenesis by preventing the fat-induced changes in fructose-1,6-bisphosphatase levels.

Topics: Administration, Oral; Alanine; Animals; Blood Glucose; Body Weight; Dietary Fats; Fatty Acids, Nonesterified; Fructose-Bisphosphatase; Gluconeogenesis; Glucose; Glucose-6-Phosphatase; Glycogen; Hypoglycemic Agents; Insulin; Liver; Male; Metformin; Phosphoenolpyruvate Carboxykinase (GTP); Rats; Rats, Wistar

It is well known that troglitazone and voluntary running have the capacity to improve insulin resistance. The purpose of this study was to evaluate the combination effect of troglitazone and voluntary running on insulin action. Female rats aged 7 weeks were divided into high-fat diet (HF), high-fat diet + troglitazone (0.3% in diet; Tg), high-fat diet + voluntary running (for 3 wks; Tr), high-fat diet + troglitazone + voluntary running (Tg-Tr), and control (C) groups. A sequential euglycemic clamp experiment with two different insulin infusion rates of 3.0 (L-clamp) and 30.0 mU/kg BW/min (H-clamp) was performed on these rats after an overnight fast. Blood glucose concentrations were kept at fasting levels by periodic adjustment of the intravenous glucose infusion rate during the clamp experiment. Glucose infusion rates (GIRs) calculated from 60 to 90, 150 to 180 min were regarded as an index of whole body insulin action. After the clamp experiment, we determined the amount of glycogen content in the gastrocnemius muscle. Fat feeding markedly reduced GIRs in both L- and H- clamp experiments compared with C. Troglitazone treatment did not improve high-fat induced insulin resistance. In both L- and H-clamp experiments, GIRs were increased by voluntary running compared with HF, and reached the same levels as in C. GIRs of Tg-Tr were not greater than those of Tr. Glycogen content in gastrocnemius muscle showed the same trend as the results for GIRs. Therefore, the combination effect of troglitazone and voluntary running on insulin action was not found, but the effect of voluntary running was shown in fat-induced insulin resistance.

Topics: Animals; Blood Glucose; Body Weight; Chromans; Dietary Fats; Female; Glucose; Glucose Clamp Technique; Glycogen; Hypoglycemic Agents; Insulin; Insulin Resistance; Muscle, Skeletal; Rats; Rats, Wistar; Running; Thiazoles; Thiazolidinediones; Troglitazone

Dogwhelks Nucella lapillus feed mainly on mussels and barnacles, and may experience periods of starvation. We report effects of nutritional state and prey type on the survival, growth, cadmium (Cd) accumulation, metallothionein (MT) induction and glycogen stores in N. lapillus exposed to Cd in water. Adult dogwhelks, with similar shell length (30.0+/-1.5 mm), were either starved or fed to satiation with barnacles Semibalanus balanoides, mussels Mytilus edulis or Cd-dosed M. edulis, and kept in filtered natural seawater (< 0.01 microg Cd 1(-1)) or Cd-contaminated (400 microg Cd 1(-1)) seawater for 80 days. Mortality and individual growth rate were determined. Cd, MT and glycogen were measured in different tissues. Prolonged starvation and exposure to Cd significantly reduced the survivorship of N. lapillus, but feeding could help dogwhelks to combat Cd toxicity and minimise mortality. Extended starvation also caused tissue wastage, leading to higher concentrations of Cd and MT in tissues, whereas fed animals increased in weight and had lower Cd and MT concentrations because of the tissue dilution effect. Prey type significantly affected growth rate of dogwhelks and indirectly influenced Cd accumulation, MT induction and glycogen stores. Eating mussels promoted better growth and higher glycogen reserves than eating barnacles. Individual growth rate decreased with increasing Cd accumulation. Cd-exposed survivors grew faster and consumed more than control animals, implying that these survivors may have better fitness and greater tolerance to Cd toxicity. The use of growth, condition index, MT and glycogen as biomarkers of environmental pollution are discussed. These results indicate a need to incorporate biological data including growth (or at least condition index) and prey type into biomonitoring programmes to allow sound interpretation.

Topics: Animals; Body Weight; Cadmium; Environmental Exposure; Food Chain; Glycogen; Metallothionein; Mollusca; Nutritional Status; Predatory Behavior; Starvation; Tissue Distribution; Water Pollutants, Chemical

Physical exercise is frequently recommended for the treatment of type 2 diabetes, whether as primary therapy with diet modification or as an adjunct to drug therapy. We hypothesized that mild exercise would enhance the glucose-lowering effects of 2 oral antihyperglycemic drugs, metformin and acarbose, in an animal model of type 2 diabetes. Eight-week-old male C57BL/Ks (db/db) mice were sorted into control and exercise groups and dosed daily for 4 weeks with vehicle, metformin (150 mg/kg/d), or acarbose (40 mg/kg/d). Exercise consisted of swimming (initially 5 min/d and ultimately 1 h/d for the last 2 weeks). Exercise, metformin, and acarbose independently reduced serum glucose concentrations 15% to 25% compared with the respective controls (P <.0001), but the effect on glucose concentration of combining drug therapy with exercise was no greater than the sum of the individual effects. Exercise training independently increased muscle glycogen (30%; P <.05) and liver glycogen (250%; P <.05) levels and slightly reduced serum high-density lipoprotein cholesterol (-8%; P <.05), whereas drug treatment had no effect on these variables. In addition, exercise but not drug treatment prevented the approximately 30% decline in serum insulin concentrations that occurred in the control animals (P <.05). Twenty-four hours after the last drug or exercise treatment, oral glucose tolerance and hemoglobin A1c were not significantly different between groups. Treatment also did not greatly affect triglyceride, glycerol, or total cholesterol concentrations. In conclusion, exercise and drug therapy independently decreased serum glucose in db/db mice, and these effects did not appear to be synergistic. In addition, exercise training maintained serum insulin concentrations and increased tissue glycogen storage. These results suggest that exercise has the potential to add to the efficacy of oral antihyperglycemic drugs.

Topics: Acarbose; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Disease Models, Animal; Eating; Glucose Tolerance Test; Glycated Hemoglobin; Glycogen; Hypoglycemic Agents; Insulin; Lipids; Liver; Male; Metformin; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Muscle, Skeletal; Physical Exertion; Swimming; Treatment Outcome

It has been observed that opposite changes in cardiac workload result in similar changes in cardiac gene expression. In the current study, the hypothesis that altered gene expression in vivo results in altered substrate fluxes in vitro was tested. Hearts were perfused for 60 minutes with Krebs-Henseleit buffer containing glucose (5 mmol/L) and oleate (0.4 mmol/L). At 30 minutes, either insulin (1 mU/mL) or epinephrine (1 micromol/L) was added. Hearts weighed 35% less after unloading and 25% more after aortic banding. Contractile function in vitro was decreased in transplanted and unchanged in banded hearts. Epinephrine, but not insulin, increased cardiac power. Basal glucose oxidation was initially decreased and then increased by aortic banding. The stimulatory effects of insulin or epinephrine on glucose oxidation were reduced or abolished by unloading, and transiently reduced by banding. Oleate oxidation correlated with cardiac power both before and after stimulation with epinephrine, whereas glucose oxidation correlated only after stimulation. Malonyl-coenzyme A levels did not correlate with rates of fatty acid oxidation. Pyruvate dehydrogenase was not affected by banding or unloading. It was concluded that atrophy and hypertrophy both decrease insulin responsiveness and shift myocardial substrate preference to glucose, consistent with a shift to a fetal pattern of energy consumption; and that the isoform-specific changes that develop in vivo do not change the regulation of key metabolic enzymes when assayed in vitro.

Topics: Animals; Atrophy; Body Weight; Cardiomegaly; Enzyme Activation; Epinephrine; Fatty Acids; Glucose; Glycogen; Heart; Heart Transplantation; In Vitro Techniques; Insulin; Insulin Resistance; Male; Malonyl Coenzyme A; Myocardial Contraction; Myocardium; Oleic Acid; Organ Size; Oxidation-Reduction; Perfusion; Pyruvate Dehydrogenase Complex; Rats; Rats, Inbred WF

The purpose of this study was to determine the effect of muscle glycogen depletion and subsequent replenishment on anaerobic capacity of horses. In a blinded crossover study, seven fit horses performed glycogen-depleting exercise on two occasions. Horses were infused after glycogen-depleting exercise with either 6 g/kg body wt of glucose as a 13.5% solution in 0.9% NaCl (Glu) or with 0.9% NaCl (Sal) of equivalent volume. Subsequently, horses performed a high-speed exercise test (120% of maximal rate of oxygen consumption) to estimate maximum accumulated oxygen deficit. Replenishment of muscle glycogen was greater (P < 0.05) in Glu [from 24.7 +/- 7.2 (SE) to 116.5 +/- 7 mmol/kg wet wt before and after infusion, respectively] than in Sal (from 23.4 +/- 7.2 to 47.8 +/- 5.7 mmol/kg wet wt before and after infusion, respectively). Run time to fatigue during the high-speed exercise test (97.3 +/- 8.2 and 70.8 +/- 8.3 s, P < 0.05), maximal accumulated oxygen deficit (105.7 +/- 9.3 and 82.4 +/- 10.3 ml O(2) equivalent/kg, P < 0.05), and blood lactate concentration at the end of the high-speed exercise test (11.1 +/- 1.4 and 9.2 +/- 3.7 mmol/l, P < 0.05) were greater for Glu than for Sal, respectively. We concluded that decreased availability of skeletal muscle glycogen stores diminishes anaerobic power generation and capacity for high-intensity exercise in horses.

Topics: Anaerobic Threshold; Animals; Blood Glucose; Body Weight; Calorimetry, Indirect; Female; Glucose; Glycogen; Hematocrit; Horses; Kinetics; Male; Muscle Fatigue; Muscle, Skeletal; Oxygen Consumption; Physical Exertion

The objective of this study was to examine the effect of winter feeding and fasting at both high (10 degrees ) and low (2.5 degrees ) temperatures on growth, metabolic stores, and endocrinology of coho salmon. Treatments were as follows: warm-fed, warm-not fed, cold-fed, and cold-not fed during the winter (January-February). The following parameters were measured: length, weight, whole body lipid, liver glycogen, hepatosomatic index, and plasma levels of insulin, insulin-like growth factor-I (IGF-I), and thyroxine (T4). Warm-fed fish grew continuously throughout the experiment from 21.5 +/- 0.3 to 43.4 +/- 1.4 g and were larger than fish in the other treatments. Fish in all other treatments grew from 21.5 +/- 0.3 to approximately 32 g and showed depressed growth during January and February. During the winter, liver glycogen, hepatosomatic index, plasma insulin, and IGF-I were highly influenced by manipulations in rearing conditions, whereas whole body lipid and plasma T4 were less affected. Plasma insulin levels fluctuated dramatically (from 2 to 7 ng/ml) in the two cold-acclimated groups shortly after the change in temperature. In general, the plasma insulin levels of the warm-fed fish were the highest (8-9 ng/ml), those of the warm-not fed fish were the lowest (2-5 ng/ml), and those of the two cold-acclimated groups were more variable but intermediate. In contrast, plasma IGF-I levels showed a decline with temperature decrease (from 9 to 5 ng/ml) and more gradual changes than insulin with the change in feeding. The highest plasma IGF-I levels were found in the warm-fed fish (10-15 ng/ml), the lowest levels were in the cold-not fed fish (4-5 ng/ml), and those of the warm-not fed and cold-fed fish were intermediate. During the treatment period the T4 levels were relatively unaffected by manipulations in feeding and temperature compared with either insulin or IGF-I. These data suggest that the insulin, IGF-I, and thyroid axes are differentially regulated under changing seasonal and/or environmental conditions in yearling salmon.

Topics: Animals; Biometry; Body Weight; Cold Temperature; Fasting; Glycogen; Hormones; Insulin; Insulin-Like Growth Factor I; Lipid Metabolism; Liver; Oncorhynchus kisutch; Seasons; Thyroxine

High-fat and high-sucrose diets increase the contribution of gluconeogenesis to glucose appearance (glc R(a)) under basal conditions. They also reduce insulin suppression of glc R(a) and insulin-stimulated muscle glycogen synthesis under euglycemic, hyperinsulinemic conditions. The purpose of the present study was to determine whether these impairments influence liver and muscle glycogen synthesis under hyperglycemic, hyperinsulinemic conditions. Male rats were fed a high-sucrose, high-fat, or low-fat, starch control diet for either 1 (n = 5-7/group) or 5 wk (n = 5-6/group). Studies involved two 90-min periods. During the first, a basal period (BP), [6-3H]glucose was infused. In the second, a hyperglycemic period (HP), [6-3H]glucose, [6-14C]glucose, and unlabeled glucose were infused. Plasma glucose (BP: 111.2 +/- 1.5 mg/dl; HP: 172.3 +/- 1.5 mg/dl), insulin (BP: 2.5 +/- 0.2 ng/ml; HP: 4.9 +/- 0.3 ng/ml), and glucagon (BP: 81.8 +/- 1.6 ng/l; HP: 74.0 +/- 1.3 ng/l) concentrations were not significantly different among diet groups or with respect to time on diet. There were no significant differences among groups in the glucose infusion rate (mg x kg(-1) x min(-1)) necessary to maintain arterial glucose concentrations at approximately 170 mg/dl (pooled average: 6.4 +/- 0.8 at 1 wk; 6.4 +/- 0.7 at 5 wk), percent suppression of glc R(a) (44.4 +/- 7.8% at 1 wk; 63.2 +/- 4.3% at 5 wk), tracer-estimated net liver glycogen synthesis (7.8 +/- 1.3 microg x g liver(-1) x min(-1) at 1 wk; 10.5 +/- 2.2 microg x g liver(-1) x min(-1) at 5 wk), indirect pathway glycogen synthesis (3.7 +/- 0.9 microg x g liver(-1) x min(-1) at 1 wk; 3.4 +/- 0.9 microg x g liver(-1) x min(-1) at 5 wk), or tracer-estimated net muscle glycogenesis (1.0 +/- 0.3 microg x g muscle(-1) x min(-1) at 1 wk; 1.6 +/- 0.3 microg x g muscle(-1) x min(-1) at 5 wk). These data suggest that hyperglycemia compensates for diet-induced insulin resistance in both liver and skeletal muscle.

Topics: Analysis of Variance; Animals; Body Weight; Diet; Dietary Fats; Dietary Sucrose; Glucagon; Glucose; Glucose Clamp Technique; Glycogen; Hyperglycemia; Insulin; Insulin Resistance; Liver; Male; Muscle, Skeletal; Rats; Rats, Sprague-Dawley; Starch

The purpose of this study was to determine the influence of insulin receptor substrate-1 (IRS-1) expression on GLUT1 and GLUT4 glucose transporter protein abundance, contraction-stimulated glucose uptake, and contraction-induced glycogen depletion by skeletal muscle. Mice (6 months old) from three genotypes were studied: wild-type (IRS-1(+/+)), heterozygous (IRS-1(+/-)) for the null allele, and IRS-1 knockouts (IRS-1(-/-)) lacking a functional IRS-1 gene. In situ muscle contraction was induced (electrical stimulation of sciatic nerve) in one hindlimb using contralateral muscles as controls. Soleus and extensor digitorum longus were dissected and 2-deoxyglucose uptake was measured in vitro. 2-Deoxyglucose uptake was higher in basal muscles (no contractions) from IRS-1(-/-) vs. both other genotypes. Contraction-stimulated 2-deoxyglucose uptake and glycogen depletion did not differ among genotypes. Muscle IRS-1 protein was undetectable for IRS-1(-/-) mice, and values were approximately 40 % lower in IRS-1(+/-) than in IRS-1(+/+) mice. No difference was found in IRS-1(+/+) compared to IRS-1(-/-) groups regarding muscle abundance of GLUT1 and GLUT4. Substantial reduction or elimination of IRS-1 did not alter the hallmark effects of contractions on muscle carbohydrate metabolism--activation of glucose uptake and glycogen depletion.

Topics: Animals; Body Weight; Deoxyglucose; Electric Stimulation; Female; Glucose Transporter Type 1; Glucose Transporter Type 4; Glycogen; Insulin Receptor Substrate Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Monosaccharide Transport Proteins; Muscle Contraction; Muscle Proteins; Muscle, Skeletal; Organ Size; Phosphoproteins; Sciatic Nerve

We investigated the dose-effect of the long-term intake of conjugated linoleic acid (CLA) on the energy metabolism and fat accumulation in mice. Five-week-old male Std ddY mice were fed on a diet containing none (control), 0.25%, 0.5% or 1.0% CLA for 4 or 8 weeks. The body weight was lower in the CLA groups than in the control group, and significant differences were detected between the 1.0% CLA group and the control group at both 4 and 8 weeks. The epididymal and perirenal adipose tissue weights were significantly lower in the CLA groups than in the control group. The liver weight and hepatic triglyceride values were higher in the 1.0% CLA group than in the other groups. The metabolic rate was measured after 8 weeks by using a gas analyzer. The oxygen consumption of the mice in the CLA groups was significantly higher than that of the control mice. Since there was a significant effect on the mice supplemented with 0.25% CLA, low concentration of CLA is suggested to suppress the body fat accumulation and increase the energy metabolism.

Topics: Adipose Tissue; Animals; Basal Metabolism; Body Weight; Calorimetry, Indirect; Energy Metabolism; Glycogen; Linoleic Acid; Liver; Male; Mice; Organ Size; Oxygen Consumption; Random Allocation; Statistics, Nonparametric; Triglycerides

In the present study, we have examined the possible mechanism of the hypoglycemic action of the semi-purified fractions of an ethanolic extract of Averrhoa bilimbi Linn (Oxalidaceae) leaves (ABe) in streptozotocin-diabetic male Sprague-Dawley (SD) rats. The ABe was partitioned with water and butanol to yield a butanol-soluble fraction (BuF) and a water-soluble fraction (AF). The AF was further partitioned with ethyl acetate and hexane to obtain ethyl acetate (EF) and hexane (HF) soluble fractions. The hypoglycemic property of each fraction was assessed by the oral glucose tolerance test (OGTT) at a dose of 125-mg/kg-body weight in streptozotocin (STZ)-diabetic rats (STZ 60 mg/kg i.p.). Fractions AF, BuF and the reference drug metformin (500 mg/kg body weight), produced significant blood glucose-lowering effect in the diabetic rats when compared to the vehicle (distilled water). In the long-term study, the diabetic rats were randomly divided into 4 groups and treated orally by gavage with vehicle, AF (125 mg/kg body weight), BuF (125 mg/kg body weight), and metformin (500 mg/kg body weight) respectively twice a day for 14 days. On day 7 and day 14, AF and BuF, like the reference drug, metformin, lowered the fasting blood glucose concentration significantly (P < 0.05) when compared with the vehicle. The serum insulin level was significantly increased in the AF-treated rats only on day 14 when compared to that in the vehicle-treated rats on day zero (P < 0.05). The serum insulin level in BuF-treated rats was also significantly higher (P < 0.05) on both day 7 and day 14 compared to that on day zero. Hepatic glucose-6-phosphatase activity was significantly lower (P<0.05) in AF- and metformin-treated groups, but not in BuF-treated groups, compared to that in vehicle-treated group. However, there was no change in hepatic glycogen content in AF-, BuF- and metformin-treated group compared to the vehicle-treated group. These results indicate that AF is more potent than BuF in the amelioration of hyperglycemia in STZ-diabetic rats and is a potential source for the isolation of new orally active agent(s) for anti-diabetic therapy.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Drinking; Eating; Glucose Tolerance Test; Glucose-6-Phosphatase; Glycogen; Insulin; Kidney; Lipid Peroxidation; Liver; Male; Microsomes, Liver; Plant Extracts; Plant Leaves; Plants, Medicinal; Rats; Rats, Sprague-Dawley; Thiobarbituric Acid Reactive Substances

Topics: Analysis of Variance; Animals; Body Weight; Diabetes Mellitus, Experimental; Disease Models, Animal; Glycogen; Heart; Hemodynamics; Humans; Isoproterenol; L-Lactate Dehydrogenase; Lactates; Male; Myocardial Infarction; Myocardial Ischemia; Myocardium; Necrosis; Organ Size; Rats; Rats, Wistar

Young rabbits (Oryctolagus cuniculus) are only nursed for 3-5 min every 24 h. They show a circadian increase in activity in anticipation of this, which is entrained by suckling. Our aim was to determine whether serum and liver metabolites show diurnal fluctuations which could act to regulate this circadian pattern. Stomach weight, liver glycogen and serum metabolites were measured every 3 h in 7- to 8-day-old pups when normally nursed (up to 24 h after suckling) and fasted (up to 48 h after suckling). The results suggest: 1. Energy balance between feeds was maintained by a cascade in the use of fuels, first glucose from the milk, then glycogen stores and gluconeogenesis from circulating products of proteins and triglycerides, and finally, in late-fasted animals, the mobilization of free fatty acids. 2. The empty stomach and depletion of glycogen 23-24 h after the last feed could act to trigger anticipatory arousal in normally nursed pups, and the release of free fatty acids 45 48 h after the last feed could trigger this in fasted pups. 3. Unmasking of rhythmicity by fasting in serum levels of glucose and proteins suggests their regulation by endogenous oscillators, which may also be the case for the mobilization of free fatty acids.

Topics: Animals; Animals, Newborn; Animals, Suckling; Arousal; Blood Glucose; Blood Proteins; Body Weight; Circadian Rhythm; Energy Metabolism; Fatty Acids; Female; Glycogen; Hunger; Liver; Pregnancy; Rabbits; Satiation

Previous studies have demonstrated enhanced insulin sensitivity in calorie-restricted [CR, fed 60% ad libitum (AL) one time daily] compared with AL-fed rats. To evaluate the effects of reduced food intake, independent of temporal differences in consumption, we studied AL (unlimited food access)-fed and CR (fed one time daily) rats along with groups temporally matched for feeding [fed 3 meals (M) daily]: MAL and MCR, eating 100 and 60% of AL intake, respectively. Insulin-stimulated glucose transport by isolated muscle was increased in MCR and CR vs. AL and MAL; there was no significant difference for MCR vs. CR or MAL vs. AL. Intramuscular triglyceride concentration, which is inversely related to insulin sensitivity in some conditions, did not differ among groups. Muscle concentration of UDP-N-acetylhexosamines [end products of the hexosamine biosynthetic pathway (HBP)] was lower in MCR vs. MAL despite unaltered glutamine-fructose-6-phosphate aminotransferase activity (rate-limiting enzyme for HBP). These results indicate that the CR-induced increase in insulin-stimulated glucose transport in muscle is attributable to an altered amount, not timing, of food intake and is independent of lower triglyceride concentration. They further suggest that enhanced insulin action might involve changes in HBP.

Topics: 3-O-Methylglucose; Adipose Tissue; Animals; Blood Glucose; Body Weight; Energy Intake; Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing); Glycogen; Hexosamines; Hexoses; Insulin; Leptin; Liver; Male; Muscle Proteins; Muscle, Skeletal; Organ Size; Rats; Rats, Inbred F344; Triglycerides

This study aims at investigating the possible beneficial effect of succinic acid dimethyl ester (SAD), injected intraperitoneally (5.0 micromol/g body wt.), upon the metabolic and hormonal response to a 60 min exercise in both fed and overnight starved rats. In fed rats, the injection of SAD minimized the fall in plasma D-glucose concentration, and the increase in plasma lactate, beta-hydroxybutyrate, free fatty acid and glycerol concentrations, otherwise provoked by exercise. SAD, however, failed to prevent the decrease in plasma insulin concentration and liver glycogen content caused by exercise. Starved rats displayed lower plasma D-glucose and insulin concentrations and higher plasma beta-hydroxybutyrate and free fatty acid concentrations than fed rats. The body weight, liver weight and paraovarian fat weight, as well as the glycogen content of both liver and heart were also decreased in the starved rats. In the latter animals, the injection of SAD again opposed the exercise-induced increase in plasma beta-hydroxybutyrate, free fatty acid and glycerol concentrations, and again failed to prevent the more modest decreases in plasma insulin concentration and liver glycogen content caused by exercise in the starved, as distinct from fed rats. These findings suggest that, independently of any obvious change in plasma insulin concentration, SAD minimizes the exercise-induced mobilization and enhanced utilization of endogenous nutrients, especially fatty acids and glycerol produced by hydrolysis of triglycerides in adipose tissue, presumably through its capacity to act as an oxidizable nutrient in various cell types and as a gluconeogenic precursor in hepatocytes.

Topics: 3-Hydroxybutyric Acid; Animals; Blood Glucose; Body Weight; Fatty Acids; Female; Glycerol; Glycogen; Heart; Hormones; Insulin; Lactic Acid; Liver; Organ Size; Ovary; Physical Conditioning, Animal; Rats; Rats, Wistar; Starvation; Succinates

The effects of endurance training on lactate transport capacity remain controversial. This study examined whether endurance training 1) alters lactate transport capacity, 2) can protect against exhaustive exercise-induced lactate transport alteration, and 3) can modify heart and oxidative muscle monocarboxylate transporter 1 (MCT1) content. Forty male Wistar rats were divided into control (C), trained (T), exhaustively exercised (E), and trained and exercised (TE) groups. Rats in the T and TE groups ran on a treadmill (1 h/day, 5 days/wk at 25 m/min, 10% incline) for 5 wk; C and E were familiarized with the exercise task for 5 min/day. Before being killed, E and TE rats underwent exhaustive exercise (25 m/min, 10% grade), which lasted 80 and 204 min, respectively (P < 0.05). Although lactate transport measurements (zero-trans) did not differ between groups C and T, both E and TE groups presented an apparent loss of protein saturation properties. In the trained groups, MCT1 content increased in soleus (+28% for T and +26% for TE; P < 0.05) and heart muscle (+36% for T and +33% for TE; P < 0.05). Moreover, despite the metabolic adaptations typically observed after endurance training, we also noted increased lipid peroxidation byproducts after exhaustive exercise. We concluded that 1) endurance training does not alter lactate transport capacity, 2) exhaustive exercise-induced lactate transport alteration is not prevented by training despite increased MCT1 content, and 3) exercise-induced oxidative stress may enhance the passive diffusion responsible for the apparent loss of saturation properties, possibly masking lactate transport regulation.

Topics: Animals; Biological Transport; Body Weight; Carrier Proteins; Glycogen; Lactic Acid; Lipid Peroxidation; Male; Malondialdehyde; Monocarboxylic Acid Transporters; Muscle, Skeletal; Myocardium; Physical Conditioning, Animal; Physical Endurance; Rats; Rats, Wistar; Sarcolemma

The purpose of the present study was to examine the effect of detraining on the glucose transport system after short-term swim training (5 days), long-term swim training (5 wk), and treadmill run training (5 wk). Skeletal muscles were isolated from female Wistar rats at 24 or 48 h posttraining. SST produces a 48% increase in GLUT-4 mRNA, a 30% increase in GLUT-4 protein, and a 60% increase in insulin-stimulated glucose transport activity at 24 h posttraining but not at 48 h posttraining. Similar to SST, long-term swim training produces a 60% increase in GLUT-4 mRNA and a 30% increase in GLUT-4 protein content at 24 h posttraining but not at 48 h posttraining. Finally, treadmill run training produces a transient 35% increase in GLUT-4 protein content that is completely reversed at 48 h after the last bout of exercise. These results demonstrate that the increase in GLUT-4 mRNA and GLUT-4 protein occurs during the first week of exercise training and is rapidly lost after training cessation. We believe that the transient enhancement in GLUT-4 protein after exercise training is due to a short GLUT-4 half-life, a process that is primarily regulated by pretranslational mechanisms.

Topics: Animals; Biological Transport; Body Weight; Citrate (si)-Synthase; Female; Forelimb; Glucose; Glucose Transporter Type 4; Glycogen; Insulin; Monosaccharide Transport Proteins; Motor Activity; Muscle Proteins; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Wistar; RNA, Messenger; Swimming; Time Factors

Malonyl-CoA acutely regulates fatty acid oxidation in liver in vivo by inhibiting carnitine palmitoyltransferase. Thus rapid increases in the concentration of malonyl-CoA, accompanied by decreases in long-chain fatty acyl carnitine (LCFA-carnitine) and fatty acid oxidation have been observed in liver of fasted-refed rats. It is less clear that it plays a similar role in skeletal muscle. To examine this question, whole body respiratory quotients (RQ) and the concentrations of malonyl-CoA and LCFA-carnitine in muscle were determined in 48-h-starved rats before and at various times after refeeding. RQ values were 0.82 at baseline and increased to 0.93, 1. 0, 1.05, and 1.09 after 1, 3, 12, and 18 h of refeeding, respectively, suggesting inhibition of fat oxidation in all tissues. The increases in RQ at each time point correlated closely (r = 0.98) with increases (50-250%) in the concentration of malonyl-CoA in soleus and gastrocnemius muscles and decreases in plasma FFA and muscle LCFA-carnitine levels. Similar changes in malonyl-CoA and LCFA-carnitine were observed in liver. The increases in malonyl-CoA in muscle during refeeding were not associated with increases in the assayable activity of acetyl-CoA carboxylase (ACC) or decreases in the activity of malonyl-CoA decarboxylase (MCD). The results suggest that, during refeeding after a fast, decreases in fatty acid oxidation occur rapidly in muscle and are attributable both to decreases in plasma FFA and increases in the concentration of malonyl-CoA. They also suggest that the increase in malonyl-CoA in this situation is not due to changes in the assayable activity of either ACC or MCD or an increase in the cytosolic concentration of citrate.

Topics: Acetyl-CoA Carboxylase; Allosteric Regulation; Animals; Blood Glucose; Body Weight; Carboxy-Lyases; Carnitine; Citric Acid; Eating; Fatty Acids; Fatty Acids, Nonesterified; Food Deprivation; Glycogen; Insulin; Liver; Male; Malonyl Coenzyme A; Muscle, Skeletal; Oxidation-Reduction; Pulmonary Gas Exchange; Rats; Rats, Sprague-Dawley

This study was designed to assess the effect of the dimethyl ester of succinic acid (SAD) upon the hormonal and metabolic response to a 60-min exercise in overnight-starved Goto-Kakizaki rats. Twenty Goto-Kakizaki rats were starved overnight and then either maintained at rest or obliged to swim for 60 min. Half of the rats were injected intraperitoneally with the dimethyl ester of succinic acid (SAD, 5.0 micromol g(-1) body wt) immediately before exercise (or 60 min of rest). In the hereditarily diabetic rats, overnight starvation lowered the plasma D- glucose, insulin and lactate concentrations, while increasing that of free fatty acids and beta-hydroxybutyrate. In resting rats, the injection of SAD increased the glycogen content of liver, heart and muscle and the plasma concentration of D-glucose, insulin, glycerol and free fatty acids. In control animals, not injected with SAD, exercise increased the plasma concentration of D- glucose, lactate and glycerol, whilst lowering both that of insulin and the glycogen content of liver, heart and muscle. The injection of SAD before exercise failed to prevent and, on occasion, even accentuated the changes in both the glycogen content of liver, heart and muscle and the plasma concentration of D-glucose, insulin, glycerol and free fatty acids, whilst minimizing the increase in lactate concentration otherwise caused by exercise. Nevertheless, the comparison between resting and exercising rats, both injected with SAD, suggested that the ester abolished the exercise-induced rise in D-glucose, glycerol and fatty acid concentrations. By comparison with comparable experiments conducted in overnight-starved normal rats, these findings emphasize both the difference between normal and diabetic rats in their metabolic response to exercise, especially in terms of changes in glycemia, and the usefulness of SAD to compensate for the increased consumption of endogenous nutrients during exercise.

Topics: 3-Hydroxybutyric Acid; Animals; Body Weight; Diabetes Mellitus, Experimental; Fatty Acids, Nonesterified; Food Deprivation; Glucose; Glycerol; Glycogen; Insulin; Lactic Acid; Liver; Male; Muscles; Myocardium; Organ Size; Physical Conditioning, Animal; Rats; Rats, Mutant Strains; Succinates

Select hepatic changes in the freeze-tolerant hatchling turtle, Chrysemys picta marginata, were studied in response to freezing at -2.5 degrees C and thawing. Upon freezing, a small, selective increase in the liver weight with no increase in body weight was seen suggestive of an hepatic capacitance response. In all turtles studies, lobular differences in the hepatic content of glycogen were evident: the smaller lobe contained twice as much glycogen as the larger lobe. The response to freezing and thawing was comparable. Total hepatic glycogen levels of turtles were reduced approximately 60 per cent from control levels in the frozen state and recovered to >80 per cent of control levels in the thawed state. Compared to the control state, turtle blood glucose levels were: unchanged after 12 h in the cool state; reduced 28 per cent after 24 h and increased two-fold after 48 h in the frozen state; and increased 4.5-fold in the thawed state. Thus, changes in hepatic glycogen metabolism occur without large changes in blood glucose levels. In turtle liver plasma membranes, the hepatic alpha(1)-adrenergic receptor was barely detectable and did not change. The beta(2)-adrenergic receptor was expressed at high levels and, compared to control levels, was: unchanged after 12 h in the cool state; reduced 20 per cent after 24 h and 40 per cent after 48 h in the frozen state. On thawing, this receptor was 50 per cent of control levels. While catecholamines working through the beta(2)-adrenergic receptor may effect early hepatic glycogen breakdown in response to freezing, other factors must be involved to complete the process. The plasma membrane-bound enzyme gamma-glutamyltranspeptidase displayed a different pattern of changes indicative of selective modulation: it was increased 2.7-fold over control levels in the cool state; unchanged in the frozen state; and increased 1.8-fold in the thawed state. The activity of the kidney enzyme was decreased in the cool state and slightly increased in the frozen and thawed states emphasizing the tissue-specific nature of the changes in the activity of gamma-glutamyltranspeptidase in response to freezing and thawing. The similarities and differences of the hepatic changes in response to freezing and thawing in the freeze-tolerant hatchling turtle to those we have previously reported for the freeze-tolerant frog are discussed.

Topics: Animals; Blood Glucose; Body Weight; Cell Membrane; Freezing; gamma-Glutamyltransferase; Glycogen; Kidney; Liver; Organ Size; Protein Binding; Receptors, Adrenergic, alpha; Receptors, Adrenergic, beta; Temperature; Time Factors; Turtles

In our previous study, we found that myricetin, a naturally occurring bioflavonoid, was able to stimulate glucose transport in rat adipocytes and enhance insulin-stimulated lipogenesis. We report here that after 2 days of treatment with myricetin (3 mg/12 h), hyperglycemia in diabetic rats was reduced by 50% and the hypertriglyceridemia that is often associated with diabetes was normalised. Treatment with myricetin increased hepatic glycogen and glucose-6-phosphate content. It increased hepatic glycogen synthase I activity without having any effect on total glycogen synthase nor phosphorylase a activity. It lowered phosphorylase a activity in the muscle. Thus, the hypoglycemic effect of myricetin is likely to be due to its effect on glycogen metabolism. There was no indication of serious hepatotoxicity with myricetin treatment and therefore, myricetin could be of therapeutic potential in diabetes.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Dose-Response Relationship, Drug; Eating; Flavonoids; Glucose-6-Phosphate; Glycogen; Glycogen Synthase; Hindlimb; Hyperglycemia; Hypertriglyceridemia; Hypoglycemic Agents; Liver; Liver Glycogen; Male; Muscle, Skeletal; Phosphorylase a; Rats; Rats, Wistar

Previous studies of the estrogen receptor-alpha knockout (alpha ERKO) in the male mouse demonstrate that the rete testis and efferent ductules are targets of estrogen. Because the alpha ERKO mouse lacks a functional estrogen receptor alpha (ER alpha) throughout development, it was not known whether the morphological and physiological abnormalities observed in the alpha ERKO male were due to developmental defects or to dysfunctions concurrent with the lack of ER alpha in the tissue. This study was designed to determine if treatment of normal wild-type (WT) mice with the pure antiestrogen, ICI 182,780, (ICI) could reproduce the morphological characteristics seen in alpha ERKO mice. Thirty-day-old male mice were treated for 35 days with either castor oil or ICI. Age-equivalent alpha ERKO mice were used for comparison. Light microscopic examinations of the reproductive tracts revealed dramatic changes in the efferent ductules of treated mice: a 1.7-fold increase in luminal diameter, a 56% reduction in epithelial cell height, a 60% reduction in brush boarder height of nonciliated cells, and an apparent reduction of the number of observable lysosomes and endocytotic vesicles. Testes of ICI-treated mice showed swollen rete testes area (6.5 times larger than control) and a 65% reduction in rete testis epithelium height. However, there were no significant changes in body and testis weights. These results indicate that ER blockage with ICI in WT mice results in morphological changes of the efferent ductules resembling those seen in alpha ERKO siblings of the same age. Based on this study, we conclude that ER alpha has a functional role in the mouse reproductive tract and the aberrant morphology observed in the efferent ductules of the alpha ERKO mouse is likely the result of a concurrent response to the lack of functional ER alpha, and not solely due to the lack of ER alpha during early developmental times.

Topics: Animals; Body Weight; Cell Size; Ejaculatory Ducts; Epididymis; Epithelial Cells; Estrogen Antagonists; Estrogen Receptor alpha; Glycogen; Image Processing, Computer-Assisted; Male; Mice; Mice, Inbred Strains; Mice, Knockout; Organ Size; Receptors, Estrogen; Rete Testis; Sperm Count; Testis

The objective of the current study was to determine the effects of incubating turkey eggs in the presence of incandescent light on hatching times, as well as liver and heart growth and function of the hatched poult. In each of two independent trials, 180 commercial turkey eggs were incubated either in a 12-h incandescent light:dark schedule or continuous darkness throughout the incubation period (n = 360). Hatching time was observed at 8-h intervals following 25 d of incubation. Hatchability was calculated as a percentage of total eggs set, and was also calculated as a percentage of fertilized eggs. Poult weights, blood glucose, liver weights, and heart weights were measured at hatch. Liver and heart glycogen concentrations were analyzed, and comparisons were made of light-treated hatchlings and controls exposed to continuous darkness. The photostimulation of eggs accelerated hatching times (P < or = 0.01) without affecting hatchability or poult weight at hatching. Neither organ weights nor organ glycogen contents of photostimulated poults differed significantly from controls incubated in the dark. Results of this experiment indicate that the incubation length of turkey eggs may be shortened by photostimulation of eggs during the incubation period without significantly affecting embryonic survival, liver or heart growth, or glycogen content.

Topics: Animals; Body Weight; Embryo, Nonmammalian; Female; Glycogen; Heart; Incubators; Light; Lighting; Liver; Myocardium; Organ Size; Turkeys

The hypothesis was proposed that embryonic growth could be influenced paternally in the absence of changes in egg weight or eggshell conductance. Sire families were established by selecting 11 sires based on blood sampling of approximately 50 commercial turkey males. Southern blot analysis was used to identify the most distantly related individuals in the subpopulation. Five hen siblings or half-siblings of the males were randomly assigned to each male to randomize effects of egg size and eggshell conductance. Artificial inseminations were performed weekly for 17 wk, using each sire with the assigned hens. Fertilized eggs were collected and set in incubators at biweekly intervals. Offspring were observed at the time of hatching for sex, body weight, and blood glucose concentration. Significant differences among sires were observed at hatching for poult weights and blood glucose concentration, and a significant correlation between the BW and glucose concentration was noted. Progeny of sires with the highest and lowest BW and blood glucose concentrations were subsequently compared. Mean BW of poults from different sires differed by as much as 10 g, although they were hatched from eggs of the same weight. Elevated blood glucose was associated with heavier BW; heavier heart, liver, and muscle weights; a rapid utilization of glycogen at pipping; and increased gluconeogenesis as measured by plasma organic acids and glucose-6-phosphatase activity. We conclude that poult embryonic growth differs even when not mediated by egg size and functional characteristics.

Topics: Animals; Blood Glucose; Body Weight; Egg Shell; Eggs; Female; Gluconeogenesis; Glucose-6-Phosphatase; Glycogen; Heart; Insemination, Artificial; Liver; Male; Muscles; Organ Size; Turkeys

The negative correlation between selection for rapid growth and embryonic survival was investigated. Embryonic growth was assessed with hatchling weights of a closed population of commercial turkey breeders. Hatchling weights were highly significantly (P < 0.0001) and positively correlated with blood glucose concentrations at hatching. This relationship existed for both tom and hen poults. Significant differences among dams for hatchling blood glucose were observed. Further experiments examined dams selected for producing poults hatching with high (High) or low (Low) blood glucose concentrations. The High embryos were in larger-sized eggs with the same eggshell conductance but with significantly lower conductance constants than the Low embryos, suggesting that Low had longer incubation periods. High embryos grew faster than Low embryos with elevated organ glycogen concentrations. Organic acid analysis indicated elevated plasma alpha-ketoglutarate, urate, and beta-hydroxy butyrate concentrations, suggesting a greater reliance on gluconeogenesis for the High group. Posthatch growth was significantly positively correlated with hatchling blood glucose concentrations in toms but not in hens. Tom poults hatching with elevated glucose were heavier than low glucose hatch mates until 22 wk of age, but hen poults displayed no differences until 16 wk when High hens weighed less than Low hens. These data suggest that the negative correlation between rapid growth and embryonic survival is related to egg-shell conductance constants and embryonic energy metabolism.

Topics: 3-Hydroxybutyric Acid; Animals; Blood Glucose; Body Weight; Egg Shell; Embryo, Nonmammalian; Embryonic Development; Energy Metabolism; Female; Gluconeogenesis; Glycogen; Ketoglutaric Acids; Male; Mortality; Turkeys; Uric Acid

The maximal activity of a selection of enzymes involved in muscle carbohydrate handling, citric acid cycle and fatty acyl beta-oxidation were studied after treatment with the fluorinated corticosteroid triamcinolone and compared to a similar treatment of the non-fluorinated corticosteroid prednisolone in an equipotent anti-inflammatory dose. Furthermore, because triamcinolone causes loss of body mass and muscle wasting, the effects of triamcinolone were investigated relative to a control group, with the same loss of body mass, due to nutritional deprivation. The study was performed in male Wistar rats in the following treatment groups: TR, triamcinolone treatment (0.25 mg x kg(-1) x day(-1) for 2 weeks), which resulted in a reduction of body mass (24%); ND, nutritional deprivation (30% of normal daily food intake for 2 weeks) resulting in a similar (24%) decrease of body mass as TR; PR, prednisolone treatment (0.31 mg x kg(-1) x day(-1) for 2 weeks), with a 10% increase in body mass; FF, free-fed control group, with a 12% increase in body mass in 2 weeks. Compared to FF, TR induced an increase in phosphofructokinase (PFK) activity (P < 0.01), glycogen synthase [GS(i + d)] activity (P < 0.05) and glycogen content (P < 0.01) in the tibialis anterior muscle. The PR and ND caused no alterations in PFK or citrate synthase (CS) activity compared to FF. Compared to PR, TR induced an increase in PFK (P < 0.01), CS (P < 0.05) and GS(i + d) activity (P < 0.01). Both TR and PR caused an increased muscle glycogen content, being more pronounced in TR (P < 0.05). Compared to ND, TR induced an increased CS (P < 0.05) and GS(i + d) activity (P < 0.01) and glycogen content (P < 0.01). The ND resulted in a decreased glycogen content compared to FF (P < 0.05). None of the treatments affected the activity of glycogen phosphorylase, beta-hydroxyacyl coenzyme A dehydrogenase and lactate dehydrogenase. It was concluded that corticosteroids led to an increased muscle glycogen content; however, the changes in the enzymes of carbohydrate metabolism were corticosteroid type specific and did not relate to undernutrition, which accompanied the triamcinolone treatment.

Topics: Animals; Body Weight; Eating; Food Deprivation; Glucocorticoids; Glycogen; Male; Muscle, Skeletal; Nutritional Status; Organ Size; Prednisolone; Rats; Rats, Wistar; Triamcinolone

The protective effects of various kinds of dietary amino acids against the hepatotoxic action of D-galactosamine (GalN) were examined. Male Wistar rats fed with 20% casein diets containing 10% or 5% amino acid for one week were injected with GalN (800 mg/kg body weight), and the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) activities, the hepatic glycogen concentration, and the serum glucose-level were examined 20 hours after the injection. In the groups with the 10% amino acid diets, activities of AST, ALT, and LDH in serum of 10% L-glutamine (Gln), 10% L-asparagine (Asn), and 10% L-serine (Ser) groups were significantly lower than those of the control group, and in the groups with the 5% amino acid diets, those activities of 5% L-histidine (His), 5% L-tyrosine (Tyr), 5% L-lysine (Lys), and 5% L-glycine (Gly) groups were also lower than those of the control group. The concentration of liver glycogen of 10% Gln-, 10% Asn-, and 10% Ser- groups and those levels of 5% His-, 5% Tyr-, 5% Lys-, and 5% Gly-groups were also significantly higher than that of the control group. As a result, it was found that some kinds of dietary amino acid such as L-Ser, L-Asn, L-His, L-Lys, L-Tyr, and L-Gly, in addition to L-Gln were effective to protect the rats from GalN-induced injury.

Topics: Alanine Transaminase; Amino Acids; Animals; Aspartate Aminotransferases; Blood Glucose; Body Weight; Caseins; Eating; Galactosamine; Glycogen; Hepatitis, Animal; L-Lactate Dehydrogenase; Liver; Male; Rats; Rats, Wistar

We undertook this study to determine if the metabolism of exogenous glucose and glycogen in hypertrophied hearts differed from that in normal hearts during severe ischemia. Thus, rates of glycolysis (3H2O production) and oxidation (14CO2 production) from exogenous glucose and glycogen were measured in isolated working control (n = 13) and hypertrophied (n = 12) hearts from sham-operated and aortic-banded rats during 40 min of severe low-flow ischemia. Hearts, in which glycogen was prelabelled with [5-3H]- or [14C]-glucose, were paced and perfused with Krebs-Henseleit solution containing 1.2 mM palmitate, 5.5 mM [5-3H]- or [14C]-glucose (different from the isotope used to label glycogen), 0.5 mM lactate and 100 microU/ml insulin during ischemia. Rates of glycolysis from exogenous glucose (3301 +/- 122 v 2467 +/- 167 nmol/min/g dry wt, mean +/- S.E.M., P < 0.05) and glucose from glycogen (808 +/- 27 v 725 +/- 21 nmol/min/g dry wt, P < 0.05) were accelerated in hypertrophied hearts compared to control hearts. However, rates of oxidation of exogenous glucose and glucose from glycogen were not significantly different between the two groups. As observed in normoxic non-ischemic hearts, glucose from glycogen was preferentially oxidized compared to exogenous glucose. Additionally, rates of glycogen synthesis (167 +/- 7 v 140 +/- 9 nmol/min/g dry wt, P < 0.05) were increased in hypertrophied hearts compared to control hearts during severe low-flow ischemia indicating that glycogen turnover (i.e. simultaneous synthesis and degradation) was accelerated in the hypertrophied heart. Thus, we demonstrate that glucose utilization and glycogen turnover are accelerated in the hypertrophied heart during severe low-flow ischemia as compared to the normal heart.

Topics: Animals; Body Weight; Cardiomegaly; Glucose; Glycogen; Male; Myocardial Ischemia; Rats; Rats, Sprague-Dawley; Time Factors

The goal of the present experiment was to measure the volume of the different compartments in liver of exercised rats and to get some insights into the appropriate working of the hepatic function following exercise. Hence, livers from male rats were isolated and perfused after treadmill exercise or rest. This procedure was performed on rats that were overnight semifasted (50% food restriction) or well fed. To evaluate the hepatocyte cell volume, the multiple-indicator dilution curve technique was used after 40 min of perfusion. Radioactive tracers for red blood cells, sucrose, and water were used to measure liver vascular space, liver interstitial space, and water cellular space, respectively. The hepatocyte function was assessed by taurocholate and propanolol clearance. Oxygen consumption, intrahepatic resistance, bile secretion, and lactate dehydrogenase release estimated liver viability. Liver viability and hepatocyte function were not changed following exercise either in the fed or in the semifasted animals. As expected, liver glycogen levels were significantly (P < 0.01) reduced in the food-restricted rats. Consequently, liver glycogen levels following exercise were decreased significantly (P < 0.01) only in the fed rats. Despite this, exercise decreased the hepatocyte water space in both food-restricted and fed groups ( approximately 15%; P < 0.01) without altering the sinusoidal and interstitial space. The present data show that acute exercise decreased the hepatocyte volume and that this volume change is not entirely linked to a decrease in hepatic glycogen level.

Topics: Animals; Bile; Body Weight; Cell Survival; Detergents; Fasting; Fatty Acids, Nonesterified; Glucagon; Glycogen; Insulin; L-Lactate Dehydrogenase; Liver; Male; Organ Culture Techniques; Oxygen Consumption; Physical Exertion; Propranolol; Rats; Rats, Sprague-Dawley; Taurocholic Acid; Vasodilator Agents; Water

To investigate whether brain leptin involves neuropeptidergic pathways influencing ingestion, metabolism, and gastrointestinal functioning, leptin (3.5 micrograms) was infused daily into the third cerebral ventricular of rats for 3 days. To distinguish between direct leptin effects and those secondary to leptin-induced anorexia, we studied vehicle-infused rats with food available ad libitum and those that were pair-fed to leptin-treated animals. Although body weight was comparably reduced (-8%) and plasma glycerol was comparably increased (142 and 17%, respectively) in leptin-treated and pair-fed animals relative to controls, increases in plasma fatty acids and ketones were only detected (132 and 234%, respectively) in pair-fed rats. Resting energy expenditure (-15%) and gastrointestinal fill (-50%) were reduced by pair-feeding relative to the ad libitum group, but they were not reduced by leptin treatment. Relative to controls, leptin increased hypothalamic mRNA for corticotropin-releasing hormone (CRH; 61%) and for proopiomelanocortin (POMC; 31%) but did not reduce mRNA for neuropeptide Y. These results suggest that CNS leptin prevents metabolic/gastrointestinal responses to caloric restriction by activating hypothalamic CRH- and POMC-containing pathways and raise the possibility that these peripheral responses to CNS leptin administration contribute to leptin's anorexigenic action.

Topics: Animals; Arousal; Blood Glucose; Body Weight; Corticosterone; Corticotropin-Releasing Hormone; Digestive System; Eating; Fats; Gene Expression; Glycogen; Grooming; Hypothalamus; In Situ Hybridization; Insulin; Leptin; Male; Oxidation-Reduction; Pro-Opiomelanocortin; Proteins; Rats; Rats, Long-Evans; Rest; RNA, Messenger; Sympathetic Nervous System; Triglycerides

To determine whether the slimming effects of treatment with oleoyl-estrone (OE) in liposomes of normal and obese rats are permanent, or disappear as soon as the treatment with the drug ceased. This study was devised to gain further knowledge on the postulated role of OE as a ponderostat signal, evaluating whether (in addition) it can lower the ponderostat setting of the rat.. The rats were infused for 14d (using osmotic minipumps) with oleoyl-estrone in liposomes at a dose of 3.5 micromol/kg x d, and were studied up to one month after the treatment ceased.. Young adult lean controls (CL) or treated (TL) and obese controls (CO) or treated (TO) Zucker rats.. Energy balance, blood glucose, liver glycogen, plasma insulin, leptin corticosterone, ACTH and estrone (free and total) concentrations, and expression of the OB gene in white adipose tissue (WAT).. The loss of body weight caused by OE was recovered quickly in the TO, which gained weight at the same rate as the CO. TL rats, however remained at the low weight attained for one month after the treatment ceased. However, no differences were observed in calculated energy expenditure (EE) between the TL and TC rats once treatment had stopped. In TL and TO rats, liver glycogen concentrations decreased to normal shortly after treatment ceased, and leptin expression and concentrations remained normal and unchanged after the end of OE treatment. In TO rats, plasma glucose, insulin and leptin were lower than in the CO. Total estrone concentrations decreased rapidly in TL rats and more slowly in the TO, and free estrone followed a similar pattern.. Continuous infusion of liposomes loaded with OE resulted in a decreased energy intake (EI), maintenance of EE and the utilization of body fat reserves in lean and obese rats alike. This process ended in obese rats as soon as the infusion ceased, so that even when the levels of free and total estrone in plasma remained high, there was a marked (and relatively fast) shift toward the basal situation, which translated into an increase in EI, maintenance of estimated EE and a marked buildup of energy stores. In lean rats, the effects of OE on leptin concentrations and OB gene expression persisted after infusion ended.

Topics: Adrenocorticotropic Hormone; Animals; Anti-Obesity Agents; Blood Glucose; Body Weight; Energy Intake; Energy Metabolism; Estrone; Female; Glycogen; Insulin; Leptin; Liposomes; Liver; Obesity; Oleic Acids; Proteins; Rats; Rats, Zucker; Urea

Elevated serum and tissue lipid stores are associated with skeletal muscle insulin resistance and diminished glucose-stimulated insulin secretion, the hallmarks of type 2 diabetes. We studied the effects of 6-wk treatment with the insulin sensitizer troglitazone on substrate storage and utilization in lean control and Zucker diabetic fatty (ZDF) rats. Troglitazone prevented development of diabetes and lowered serum triglycerides (TG) in ZDF rats. Soleus muscle glycogen and TG content were elevated twofold in untreated ZDF rats, and both were normalized by troglitazone to lean control levels (P < 0.05). Troglitazone also normalized insulin-stimulated glucose uptake as well as basal and insulin-stimulated glycogen synthesis, implying increased skeletal muscle glycogen turnover. The proportion of active pyruvate dehydrogenase (PDH) in soleus muscle was reduced in ZDF relative to lean control rat muscle (16 +/- 2 vs. 21 +/- 2%) but was restored by troglitazone treatment (30 +/- 3%). Increased PDH activation was associated with a 70% increase in glucose oxidation. Muscle lipoprotein lipase activity was decreased by 35% in ZDF compared with lean control rats and was increased twofold by troglitazone. Palmitate oxidation and incorporation into TG were higher in ZDF relative to lean control rats but were unaffected by troglitazone treatment. Troglitazone decreased the incorporation of glucose into the acyl group of TG by 60% in ZDF rats. In summary, ZDF rats demonstrate increased skeletal muscle glycogen and TG stores, both of which were reduced by troglitazone treatment. Troglitazone appears to increase both glycogen and TG turnover in skeletal muscle. Normalization of PDH activity and decreased glucose incorporation into acyl TG may underlie the improvements in intracellular substrate utilization and energy stores, which lead to decreased serum TG and glucose.

Topics: Animals; Body Weight; Chromans; Eating; Glucose; Glycogen; In Vitro Techniques; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Lipoprotein Lipase; Muscle, Skeletal; Palmitates; Pyruvate Dehydrogenase Complex; Rats; Rats, Zucker; Thiazoles; Thiazolidinediones; Triglycerides; Troglitazone

The nutritional value of glycerol-1,2,3-tris(methylsuccinate), a novel ester of succinic acid with high insulinotropic efficiency both in vitro and in vivo, was assessed in both fed and starved rats. The infusion of the ester, given in a daily amount (1.2 micromol. g body wt-1) well in excess of what could result from its repeated intravenous administration as an insulinotropic agent in non-insulin-dependent diabetes (0.07 micromol. g body wt-1 for each administration), failed to prevent the fall in body weight, liver and muscle glycogen contents, and plasma d-glucose or insulin concentration, as well as the increase in plasma free fatty acid and beta-hydroxybutyrate concentrations caused by starvation. The sole indications that the ester may serve, to a limited extent, as an alternative nutrient in starved rats consisted in a somewhat higher weight of both liver and paraovarian adipose tissue and somewhat higher activity of liver glucokinase in rats receiving the ester than in animals infused with saline. The low nutritional value of this ester thus answers the objection of its possible role as an extrapancreatic nutrient or gluconeogenic precursor in the perspective of its use as an insulinotropic tool in type 2 diabetes.

Topics: 3-Hydroxybutyric Acid; Animals; Blood Glucose; Body Weight; Chloride Channels; Diabetes Mellitus, Type 2; Eating; Fatty Acids, Nonesterified; Female; Food Deprivation; Glucokinase; Glycerol; Glycogen; Insulin; Insulin Secretion; Liver; Muscle, Skeletal; Nutritive Value; Proteins; Rats; Rats, Wistar; Succinates

Leptin decreases visceral fat (VF) and increases peripheral and hepatic insulin action. Here, we generated similar decreases in VF using leptin (Lep), beta(3)-adrenoreceptor agonism (beta3), or food restriction (FR) and asked whether insulin action would be equally improved. For 8 days before the in vivo study, Sprague-Dawley rats (n = 24) were either fed ad libitum [control (Con)], treated with Lep or beta3 (CL-316,243) by implanted osmotic mini-pumps, or treated with FR. Total VF was similarly decreased in the latter three groups (Lep, 3.11 +/- 0.96 g; beta3, 2.87 +/- 0.48 g; and FR, 3.54 +/- 0.77 g compared with 6.91 +/- 1.41 g in Con; P < 0.001) independent of total fat mass (by (3)H(2)O) and food intake. Insulin (3 mU. kg(-1). min(-1)) clamp studies were performed to assess hepatic and peripheral insulin sensitivity. Decreased VF resulted in similar and marked improvements in insulin action on glucose production (GP) (Lep, 1.19 +/- 0.51; beta3, 1.46 +/- 0.68; FR, 2.27 +/-0.71 compared with 6.06 +/- 0.70 mg. kg(-1). min(-1) in Con; P < 0.001). By contrast, reduction in VF by beta3 and FR failed to reproduce the stimulation of insulin-mediated glucose uptake ( approximately 60%), glycogen synthesis ( approximately 80%), and glycolysis ( approximately 25%) observed with Lep. We conclude that 1) a moderate decrease in VF uniformly leads to a marked increase in hepatic insulin action, but 2) the effects of leptin on peripheral insulin action are not due to the associated changes in VF or beta3 activation.

Topics: Adipose Tissue; Adrenergic beta-Agonists; Animals; Body Weight; Energy Intake; Food Deprivation; Gluconeogenesis; Glycogen; Glycolysis; Insulin; Leptin; Liver; Male; Proteins; Rats; Rats, Sprague-Dawley; Viscera

The effect of moderate hyperleptinemia ( approximately 20 ng/ml) on liver and skeletal muscle glycogen metabolism was examined in Wistar rats. Animals were studied approximately 90 h after receiving recombinant adenoviruses encoding rat leptin (AdCMV-leptin) or beta-galactosidase (AdCMV-betaGal). Liver and skeletal muscle glycogen levels in the fed and fasted (18 h) states were similar in AdCMV-leptin- and AdCMV-betaGal-treated rats. However, after delivery of a glucose bolus, liver glycogen levels were significantly greater in AdCMV-leptin compared with AdCMV-betaGal rats (P < 0.05). To investigate the mechanism(s) of these differences, glycogen levels were measured immediately after the cessation of a 3- or 6-h glucose infusion or 3, 6, and 9 h after the cessation of a 6-h glucose infusion. Similar increases in liver and skeletal muscle glycogen occurred in hyperleptinemic and control rats in response to glucose infusions. However, 3 and 6 h after the cessation of a glucose infusion, liver glycogen levels were approximately twofold greater (P < 0.05) in AdCMV-leptin-treated compared with AdCMV-betaGal-treated animals. Skeletal muscle glycogen levels were similar in AdCMV-leptin-treated and AdCMV-betaGal-treated animals at the same time points. Glycogen phosphorylase, phosphodiesterase 3B, and glycogen synthase activities were unaltered by hyperleptinemia. We conclude that moderate increases in plasma leptin levels decrease liver glycogen degradation during the fed-to-fasted transition.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Adipose Tissue; Animals; beta-Galactosidase; Body Weight; Cyclic Nucleotide Phosphodiesterases, Type 3; Eating; Epididymis; Fasting; Glycogen; Glycogen Synthase; Leptin; Liver; Male; Muscle, Skeletal; Organ Size; Phosphorylases; Rats; Rats, Wistar

The effect of a single bout of exhaustive exercise on muscle lactate transport capacity was studied in rat skeletal muscle sarcolemmal (SL) vesicles. Rats were assigned to a control (C) group (n = 14) or an acutely exercised (E) group (n = 20). Exercise consisted of treadmill running (25 m/min, 10% grade) to exhaustion. SL vesicles purified from C and E rats were sealed because of sensitivity to osmotic forces. The time course of 1 mM lactate uptake in zero-trans conditions showed that the equilibrium level in the E group was significantly lower than in the C group (P < 0.05). The initial rate of 1 mM lactate uptake decreased significantly from 2.44 +/- 0.22 to 1.03 +/- 0.08 nmol. min(-1). mg protein(-1) (P < 0.05) after exercise, whereas that of 50 mM lactate uptake did not differ significantly between the two groups. For 100 mM external lactate concentration ([lactate]), exhaustive exercise increased initial rates of lactate uptake (219.6 +/- 36.3 to 465.4 +/- 80.2 nmol. min(-1). mg protein(-1), P < 0.05). Although saturation kinetics were observed in the C group with a maximal transport velocity of 233 nmol. min(-1). mg protein(-1) and a Michealis-Menten constant of 24.5 mM, saturation properties were not seen after exhaustive exercise in the E group, because initial rates of lactate uptake increased linearly with external [lactate]. We conclude that a single bout of exhaustive exercise significantly modified SL lactate transport activity, resulting in a decrease in 1 mM lactate uptake and was associated with alterations in the saturable properties at [lactate] above 50 mM. These results suggest that changes in sarcolemmal lactate transport activity may alter lactate and proton exchanges after exhaustive exercise.

Topics: Animals; Biological Transport, Active; Body Weight; Glycogen; Lactic Acid; Male; Muscle, Skeletal; Osmolar Concentration; Physical Exertion; Rats; Rats, Wistar; Running; Sarcolemma

Commercial broiler chickens killed in two processing plants, one in the south of England, the other in Scotland, in two seasons (winter and summer) and on two occasions in each season, were used to investigate the effects of killing the birds immediately on arrival or holding them in lairage for one, two, three or four hours. The two most important consequences of holding the birds in lairage were that their body temperature increased and their liver glycogen was depleted. The body temperature increased with the time they were held in lairage, although most of the increase occurred in the first hour and the increase was greater in summer when ambient temperatures were higher. Liver glycogen depletion became apparent after about one to two hours in lairage. No evidence was obtained that the birds were significantly dehydrated or physically stressed by being kept longer in lairage.

Topics: Animal Welfare; Animals; Body Temperature; Body Weight; Chickens; Glycogen; Housing, Animal; Humidity; Hydrogen-Ion Concentration; Liver Glycogen; Meat-Packing Industry; Muscle, Skeletal; Poultry Products; Seasons; Temperature; Time Factors; Transportation

The present study was carried out to assess the effect of chronic dichlorvos exposure on various aspects of glucose homeostasis in different regions of rat brain. Dichlorvos administration caused a significant depletion in the brain glycogen content accompanied with an increase in the activity of glycogen phosphorylase. The activities of key glycolytic enzymes, hexokinase, phosphofructokinase and lactate dehydrogenase were decreased significantly following dichlorvos exposure. The decreased glycolytic flux was further reflected in terms of decreased regional glucose utilization, determined by measuring 14C-glucose influx. The altered neuronal glucose homeostasis had a significant impact on the neurobehavioural patterns of dichlorvos treated animals which was reflected in terms of severe deterioration in their memory and learning functions.

Topics: Acetylcholinesterase; Animals; Behavior, Animal; Blood Glucose; Body Weight; Brain; Carbon Radioisotopes; Dichlorvos; Electron Transport Complex IV; Glucose; Glycogen; Hexokinase; Homeostasis; Insecticides; L-Lactate Dehydrogenase; Male; Neurons; Rats; Rats, Wistar

We analyzed the biochemical mechanisms involved in the liver glycogen repletion upon refeeding for 360 min in 48 and 96 h-fasted rats. In 48 h-fasted rats, the glycogen synthesis involved a rapid and further sustained induction of glucokinase (GK) (increased twice from 90 min) and a rapid but transient activation of glycogen synthase a (GSa) (maximal increase by 150% at 90 min). It did not involve the inhibition of glycogen phosphorylase a (GPa). In 96 h-fasted rats, the glycogen repletion did not involve the induction of GK for the first 180 min of refeeding. It involved a slow activation of GSa (maximal 150% increase at 180 min) and a rapid inhibition of GPa (significant from 90 min, maximal 50% inhibition by 180 min). In both groups of rats, there was a progressive inhibition of the glucose-6 phosphatase (Glc6Pase) activity (maximal suppression by 30% in both groups at 360 min). These results highlighted a key role for the inhibition of Glc6Pase activity in the liver glycogen repletion upon refeeding.

Topics: Animals; Blood Glucose; Body Weight; Eating; Fasting; Glucose-6-Phosphatase; Glycogen; Glycogen Synthase; Liver; Male; Organ Size; Postprandial Period; Rats; Rats, Sprague-Dawley; Time Factors

The effect of warm-up exercise on energy metabolism and muscle glycogenolysis during sprint exercise (Spr) was examined in six fit Standardbred horses exercised at 115% of maximal O(2) consumption (VO(2 max)) until fatigued, 5 min after each of three protocols: 1) no warm-up (NWU); 2) 10 min at 50% of VO(2 max) [low-intensity warm-up (LWU)]; and 3) 7 min at 50% VO(2 max) followed by 45-s intervals at 80, 90, and 100% VO(2 max) [high-intensity warm-up (HWU)]. Warm-up increased (P < 0.0001) muscle temperature (T(m)) at the onset of Spr in LWU (38.3 +/- 0.2 degrees C) and HWU (40.0 +/- 0. 3 degrees C) compared with NWU (36.6 +/- 0.2 degrees C), and the rate of rise in T(m) during Spr was greater in NWU than in LWU and HWU (P < 0.01). Peak VO(2) was higher and O(2) deficit lower (P < 0. 05) when Spr was preceded by warm-up. Rates of muscle glycogenolysis were lower (P < 0.05) in LWU, and rates of blood and muscle lactate accumulation and anaerobic ATP provision during Spr were lower in LWU and HWU compared with NWU. Mean runtime (s) in LWU (173 +/- 10 s) was greater than HWU (142 +/- 11 s) and NWU (124 +/- 4 s) (P < 0. 01). Warm-up was associated with augmentation of aerobic energy contribution to total energy expenditure, decreased glycogenolysis, and longer run time to fatigue during subsequent sprint exercise, with no additional benefit from HWU vs. LWU.

Topics: Adenosine Triphosphate; Anaerobic Threshold; Animals; Body Temperature; Body Weight; Energy Metabolism; Glycogen; Hematocrit; Horses; Lactic Acid; Muscle Proteins; Muscle, Skeletal; Oxygen; Oxygen Consumption; Physical Exertion; Pulmonary Gas Exchange; Running

The purpose of this study was to measure noninvasively the absolute concentrations of muscle adenosine triphosphate [ATP], phosphocreatine [PCr], inorganic phosphate (Pi), and glycogen [Gly] of elite soccer players.. Magnetic resonance spectroscopy (31P- and 13C-MRS) was used to measure the concentrations of metabolites in the calf muscles of 18 young male players [age = 17.5 +/- 1.0 (SD) yr].. Average muscle [PCr] and [ATP] were 17.8 +/- 3.3 and 6.0 +/- 1.2 mmol x (kg wet weight)(-1), respectively. The ratios of Pi/PCr and PCr/ATP were 0.15 +/- 0.05 and 3.00 +/- 0.26, respectively. The muscle [Gly] was 144 +/- 54 mmol x (kg wet weight)(-1). There was a high correlation (r = 0.93, P < 0.0001) between muscle ATP and PCr concentrations, but there was no correlation between [Gly] and [PCr] or [ATP]. The concentrations of the different metabolites determined in the present study with noninvasive MRS methods were within the ranges of values reported in human muscle from biochemical analysis of muscle biopsies.. MRS methods can be utilized to assess noninvasively the muscle energetic status of elite soccer players during a soccer season. The high correlation between ATP and PCr might be indicative of fiber type differences in the content of these two metabolites.

Topics: Adenosine Triphosphate; Adolescent; Biopsy; Body Weight; Carbon Isotopes; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Energy Intake; Glycogen; Humans; Leg; Magnetic Resonance Spectroscopy; Male; Muscle, Skeletal; Phosphates; Phosphocreatine; Phosphorus Isotopes; Reproducibility of Results; Soccer

The influence of muscle glycogen content on basal and contraction-induced glucose transport and cell surface GLUT-4 content was studied in rat skeletal muscle. Wistar rats were preconditioned by a combination of swimming exercise and diet, resulting in 40% lower (LG) or threefold higher (HG) muscle glycogen content compared with nonexercised controls (NG). At rest and during contractions, 2-deoxy-D-glucose uptake in perfused fast-twitch muscle, but not slow-twitch muscle, was significantly lower in HG compared with LG. Cell surface GLUT-4 content in the fast-twitch plantaris was 994 +/- 180, 1,173 +/- 311, and 2,155 +/- 243 dpm/g in the basal condition and increased (P < 0.05) to 2,285 +/- 239, 3,230 +/- 464, and 4,847 +/- 654 dpm/g during contractions with HG, NG, and LG, respectively, the increase being significantly smaller in HG compared with LG. The contraction-induced increments in glucose transport and in cell surface GLUT-4 content were negatively correlated with the initial glycogen content (P <0.01). In conclusion, glucose transport and cell surface GLUT-4 content in resting and contracting fast-twitch muscle are dependent on the muscle glycogen content.

Topics: Animals; Antimetabolites; Biological Transport; Body Weight; Deoxyglucose; Glucose; Glucose Transporter Type 4; Glycogen; Hindlimb; In Vitro Techniques; Male; Membrane Proteins; Monosaccharide Transport Proteins; Muscle Contraction; Muscle Proteins; Muscle, Skeletal; Oxygen Consumption; Perfusion; Physical Exertion; Rats; Rats, Wistar

Recent studies have demonstrated that troglitazone has the capacity to improve insulin resistance. The present study was undertaken to determine the effect of troglitazone on in vivo insulin action, the activities of the pyruvate dehydrogenase (PDH) complex and 3-hydroxyacyl-CoA dehydrogenase (3-HADH) in muscle, and muscle GLUT-4 and glycogen content in obese and lean Zucker rats. Rats were fed a normal chow diet with and without troglitazone as a food admixture (0.2%) for 3 weeks. In vivo insulin action was measured by the sequential euglycemic clamp technique at two different insulin infusion rates (6 and 30 mU/kg BW/min). At the basal (fasting) state and after the clamp studies, the activities of PDH complex and 3-HADH, and the amounts of GLUT-4 and glycogen contained in the red gastrocnemius muscles were determined. Troglitazone treatment produced a significant rise in the metabolic clearance rate of glucose (MCR) during the 6-mU/kg BW/min insulin clamp study (19.5+/-3.9 vs 9.9+/-1.5 ml/kg BW/min, mean+/-SE, P<0.05) in obese rats, but not in lean rats. Troglitazone significantly increased the muscle glycogen content after the clamp study, compared to non-treated rats, in obese rats (9.9+/-0.5 vs 6.5+/-0.4 mg/g tissue, P<0.05) and has the tendency to increase the activity state of PDH complex in obese and lean rats at the fasting state. However, no effect of the drug on muscle GLUT-4 content was found. These results indicate that troglitazone may improve insulin sensitivity associated with increased muscle glycogen content.

Topics: 3-Hydroxyacyl CoA Dehydrogenases; Animals; Blood Glucose; Body Weight; Chromans; Eating; Glucose Clamp Technique; Glucose Transporter Type 4; Glycogen; Hypoglycemic Agents; Insulin; Male; Metabolic Clearance Rate; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; Obesity; Pyruvate Dehydrogenase Complex; Rats; Rats, Zucker; Thiazoles; Thiazolidinediones; Troglitazone

Pompe disease is a fatal genetic muscle disorder caused by a deficiency of acid alpha-glucosidase (GAA), a glycogen degrading lysosomal enzyme. GAA-deficient (AMD) Japanese quails exhibit progressive myopathy and cannot lift their wings, fly, or right themselves from the supine position (flip test). Six 4-wk-old acid maltase-deficient quails, with the clinical symptoms listed, were intravenously injected with 14 or 4.2 mg/kg of precursor form of recombinant human GAA or buffer alone every 2-3 d for 18 d (seven injections). On day 18, both high dose-treated birds (14 mg/kg) scored positive flip tests and flapped their wings, and one bird flew up more than 100 cm. GAA activity increased in most of the tissues examined. In heart and liver, glycogen levels dropped to normal and histopathology was normal. In pectoralis muscle, morphology was essentially normal, except for increased glycogen granules. In sharp contrast, sham-treated quail muscle had markedly increased glycogen granules, multi-vesicular autophagosomes, and inter- and intrafascicular fatty infiltrations. Low dose-treated birds (4.2 mg/kg) improved less biochemically and histopathologically than high dose birds, indicating a dose-dependent response. Additional experiment with intermediate doses and extended treatment (four birds, 5.7-9 mg/kg for 45 d) halted the progression of the disease. Our data is the first to show that an exogenous protein can target to muscle and produce muscle improvement. These data also suggest enzyme replacement with recombinant human GAA is a promising therapy for human Pompe disease.

Topics: alpha-Glucosidases; Animals; Bird Diseases; Body Weight; CHO Cells; Coturnix; Cricetinae; Glucan 1,4-alpha-Glucosidase; Glycogen; Glycogen Storage Disease Type II; Humans; Male; Muscles; Recombinant Fusion Proteins; Tissue Distribution

A data set was used to determine how various factors affect the occurrence of dark-cutting beef and selected carcass traits in finished beef cattle. Data were collected in 1989 and 1990 from one packer with plants located in Amarillo, TX; Boise, ID; Dakota City, NE; and Garden City, KS. The data set consisted of 3,659 lots consisting of 724,639 cattle. Compared with those at Boise and Dakota City, cattle slaughtered in Amarillo and Garden City had a higher incidence of dark cutters (1.1 vs .3%; P < .01) and a lower quality grade (50 vs 64% Choice plus Prime; P < .01). The highest incidences of dark cutters occurred during August, September, and October (1.1 to 1.4%; P < .01), with incidences of .4 to .7% during the other months. Carcass quality grade was higher during January, February, and March compared with May through November (60 to 62% Choice plus Prime vs 52 to 58%; P < .01). As the number of cattle in a lot increased, the incidence of dark cutters increased from .4 to 1.2% (P < .01), and quality grade declined from 62 to 52% Choice plus Prime (P < .01). As the mean weight of cattle in the lot increased, the incidence of dark cutters declined from .94 to .6% (P < .01), and carcasses grading Choice plus Prime increased from 56 to 62% (P < .01). With cattle held over a weekend or holiday, ("carry cattle") the incidence of dark cutters increased from .8 to 1.6% (P < .01). We conclude that packing plant location, month of the year, weight of cattle, carry cattle, and number of cattle in a lot are most likely to influence the incidence of dark cutters and carcass quality traits.

Topics: Abattoirs; Animal Feed; Animals; Body Weight; Cattle; Glycogen; Idaho; Kansas; Meat; Muscle, Skeletal; Nevada; Quality Control; Seasons; Texas

Insulin resistance and increased fat mass (FM) are common in human aging. We aimed to investigate the relationship between the age-dependent increase in FM and insulin resistance (by euglycemic hyperinsulinemic clamp technique), in a homogenous rodent model. The decline in insulin responsiveness was linear until late adulthood when body weight, FM, and epididymal fat reached a critical amount (r > .750, for all). Above this critical point, there was no further decline in insulin responsiveness with aging and with increased BW (p < .00001 for all spline curve analyses). This decline in insulin-mediated glucose uptake was accounted for by a decrease in whole body glycolytic rate with no change in the rate of glycogen synthesis. Thus, in this homogenous model, an early increase in FM is associated with impairment in insulin action until a critical FM is achieved, after which there is no additional insulin resistance with aging. We suggest that decreasing insulin responsiveness, in a heterogeneous group such as humans, will only occur within a specific accretion of visceral or total FM.

Topics: Adipose Tissue; Aging; Animals; Body Composition; Body Weight; Epididymis; Glucose; Glucose Clamp Technique; Glycogen; Glycolysis; Insulin; Insulin Resistance; Male; Rats; Rats, Sprague-Dawley

The antidiabetic effects of 3-¿4-[2-(5-methyl-2-phenyl-oxazol-4- yl)ethoxy]phenyl¿-2S-propylamino-propionic acid (CAS 185679-16-7, HQL-975), a novel oral agent, on a genetically obese non-insulin-dependent diabetes mellitus (NIDDM) model (db/db mice) were examined. HQL-975 administration (3.7-34.1 mg/kg/d for 7 days) decreased the levels of plasma glucose, triglyceride, total cholesterol, non-esterified fatty acid and insulin in the mice. In an intraperitoneal glucose tolerance test (IPGTT), HQL-975 administration decreased the fasting plasma glucose level and improved the glucose tolerance in the mice. The HQL-975 administration also significantly increased the glycogenesis and lipogenesis from 14C-glucose in liver, but did not alter the glycogenesis in the diaphragm or the lipogenesis in adipose tissues at 2 h after the glucose loading. In the HQL-975-treated db/db mice, the radioactivity of 14C-glucose incorporated into hepatic glycogen was higher than that incorporated into hepatic total lipids. After the administration of HQL-975 (34.1 mg/kg/d for 7 days) to db/db mice, the hepatic hexokinase and fatty acid synthetase activities were significantly increased, the glycogen synthase I activity was increased but not significantly, and the glucose-6-phosphatase and the phosphoenolpyruvate carboxykinase activities were decreased. These results suggest that HQL-975 increases the hepatic glucose utilization and decreases the hepatic glucose production. Since hepatic glycogenesis is regulated by glucose itself but not by insulin in normoglycemic ICR mice, HQL-975 is thought to enhance the effect of glucose on the stimulation of hepatic glycogenesis. It is concluded that the enhancement of the hepatic glucose utilization played an important role in the hypoglycemic action of HQL-975.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Glycogen; Hypoglycemic Agents; Insulin; Lactic Acid; Lipids; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR

Experiments described here show that in vivo glucose uptake is impaired in mice given 30 micrograms leptin by intraperitoneal injection 2 hours before an oral glucose tolerance test (GTT). When mice were infused for 7 days with 10 micrograms/day leptin, the 4-fold increase in circulating leptin caused a transient hypophagia, a sustained weight loss and significantly inhibited insulin release in response to an oral GTT. Adipocytes from these mice were not insulin responsive whereas insulin-stimulated muscle and liver glycogen synthesis were increased. In contrast, leptin added to 2 hour in vitro incubations had an insulin-like effect on muscle glucose utilization and augmented insulin stimulation of adipocyte lipid synthesis. Thus, normal mice treated chronically with leptin develop tissue specific changes in insulin sensitivity and compensate for inhibition of glucose-stimulated insulin release. The contrasting response to acute leptin exposure suggests these changes are not a direct effect of the protein.

Topics: Adipocytes; Animals; Blood Glucose; Body Weight; Eating; Female; Glucose; Glucose Tolerance Test; Glycogen; Insulin; Leptin; Liver; Mice; Mice, Inbred Strains; Muscles; Organ Size; Proteins

Animal and clinical studies have shown respiratory muscle dysfunction caused by treatment with glucocorticoids. The present study was designed to investigate whether anabolic steroids are able to antagonize the loss of diaphragm force induced by long-term low-dose methylprednisolone (MP) administration. Male adult rats were randomized to receive saline or MP (0.2 mg . kg-1 .day-1 sc) during 9 mo, with or without nandrolone decanoate (ND; 1 mg . kg-1 . wm -1 im) during the last 3 mo. The approximately 10% reduction in force generation of isolated diaphragm bundles induced by MP was completely abolished by addition of ND. The MP-induced decrease in number of fibers expressing type IIb myosin heavy chains was not reversed by ND. MP slightly reduced type I, IIa, and IIx fiber cross-sectional areas (CSA), but not type IIb fiber CSA. Addition of ND abolished the reduction in IIa and IIx fiber CSA. The MP-induced alterations in glycogenolytic activity and fatty acid oxidation capacity were not reversed by ND. In conclusion, the marked reduction in diaphragm force caused by long-term low-dose MP was completely abolished by addition of ND. ND in part also antagonized the effects of MP on diaphragm morphology but showed no beneficial effects on biochemical changes.

Topics: 3-Hydroxyacyl CoA Dehydrogenases; Anabolic Agents; Animals; Body Weight; Citrate (si)-Synthase; Diaphragm; Fatty Acids; Glucocorticoids; Glycogen; Male; Methylprednisolone; Muscle Contraction; Muscle Fibers, Skeletal; Myosin Heavy Chains; Nandrolone; Nandrolone Decanoate; Phosphorylases; Rats; Rats, Wistar; Respiration

Glucose is usually chosen as the energy source for total parenteral nutrition. However, the optimal glucose:fat ratio for peripheral parenteral nutrition has not been examined sufficiently. We compared glucose:fat ratios in hypocaloric nutrition. Male SD rats were given hypocaloric parenteral nutrition (approx. 190 kcal/kg/d) for 5 d after laparotomy. The hypocaloric solutions used contained 0, 33, 50, 67 or 100% of the non-protein energy in the form of fat. Body weight change, nitrogen balance, organ weights, and hepatic, splenic and plasma biochemistries were assessed. Body weight increase in the 67 and 100% fat groups was significantly greater than that in the 0% fat group. Nitrogen balance was the same in all groups. Hepatic glycogen content was significantly lower in the 100% fat group than that in the 0% fat group. The weight of epididymal fat deposits was significantly lower in the 0% fat group than in the 50 and 67% fat groups. On the other hand, tissue triglyceride content and plasma lipid levels in the 100% fat group were significantly higher than in the 0% fat group, and were also higher than in the control group. It is suggested that combinations of glucose and fat have sparing effects on body fat and hepatic glycogen. Combinations of glucose and fat as non-protein energy sources were superior to glucose or fat alone for hypocaloric parenteral nutrition.

Topics: Animals; Body Weight; Energy Intake; Fatty Acids, Nonesterified; Glucose; Glycogen; Lipids; Liver; Male; Nitrogen; Organ Size; Parenteral Nutrition; Rats; Rats, Sprague-Dawley; Solutions; Triglycerides

Although intermediate metabolism is known to follow circadian rhythms, little information is available on the variations in lipoprotein lipase (LPL) and hepatic lipase (HL) activities during the 24-h period, and there is also a lack of adequate statistical analysis. Here, adult male rats were fed ad libitum and kept at 21 degrees C under 12:12-h light-dark cycles. They were killed in batches every 3 h over a 24-h period. Lipase activities were determined in plasma and fresh homogenates of epididymal white adipose tissue (EWAT), interscapular brown adipose tissue (IBAT), heart, skeletal muscle, and liver. Plasma insulin, corticosterone, glucose, triacylglycerol (TAG), cholesterol, glycerol, beta-hydroxybutyrate, and liver and muscle glycogen were determined. Cosinor analysis was used to evaluate the presence (significance of fit of cosine curve to data and variance explained by rhythm) and characteristics of possible circadian rhythms [acrophase (phi), mesor, and amplitude]. Statistically significant circadian rhythms were detected for 1) all metabolites studied, except TAG, cholesterol, and liver HL activity; 2) LPL and HL activity in plasma (both phi in light phase); and 3) LPL activity in all tissues studied (phi: heart in light phase; skeletal muscle, IBAT, and EWAT in dark phase). Liver also showed a circadian rhythm of LPL activity, with phi near that in plasma. These findings demonstrate for the first time that, in physiological conditions, LPL activities in plasma and various tissues, including liver, and HL activity in plasma follow circadian rhythms. Their metabolic significance is discussed.

Topics: 3-Hydroxybutyric Acid; Adipose Tissue; Adipose Tissue, Brown; Animals; Body Weight; Circadian Rhythm; Corticosterone; Eating; Epididymis; Glycogen; Hydroxybutyrates; Insulin; Lipase; Lipids; Lipoprotein Lipase; Liver; Male; Muscle, Skeletal; Myocardium; Rats; Rats, Wistar

We hypothesized that central fatigue may have a role in limiting the endurance capacity of horses. Therefore, we tested the effect of infusing tryptophan and/or glucose on endurance time and plasma concentrations of free tryptophan and other substrates thought to affect tryptophan uptake into the brain of seven mares (3-4 yr of age, 353-435 kg) that ran on a treadmill at 50% of maximal O2 consumption to fatigue. With use of a counterbalanced crossover design, the horses were infused with tryptophan (100 mg/kg in saline solution) or a similar volume of saline solution (placebo) before exercise. During exercise, horses received infusions of glucose (2 g/min, 50% wt/vol) or a similar volume of saline. Thus the treatments were 1) tryptophan and glucose (T & G), 2) tryptophan and placebo (T & P), 3) placebo and glucose (P & G), and 4) placebo and placebo (P & P). Mean heart rate, hematocrit, and concentration of plasma total solids before and during exercise were similar for all trials. Mean time to exhaustion was reduced (P < 0.05) for T & P and T & G compared with P & P [86.1 +/- 6.9 and 87.1 +/- 6.8 vs. 102.3 +/- 10.3 (SE) min], whereas endurance for P & G (122.4 +/- 11.9 min) was greater than for all other trials (P < 0.05). Compared with nontryptophan trials, during the tryptophan trials plasma prolactin increased (P < 0.05) nearly threefold before exercise and almost twofold early in exercise. Muscle glycogen concentrations were reduced (P < 0.05) below preexercise values in the P & G and P & P trials only. However, glucose infusions (P & G) did not affect (P > 0.05) concentrations of plasma free fatty acids or ratios of branched-chain amino acids to free tryptophan. In conclusion, tryptophan infusion reduced endurance time, which was consistent with the central fatigue hypothesis. The failure of glucose infusion to alleviate the effects of tryptophan and the absence of significant muscle glycogen reduction in the tryptophan trials suggest that the early onset of fatigue in the tryptophan trials is not due to a lack of readily available substrate.

Topics: Animals; Blood Glucose; Blood Proteins; Body Weight; Diet; Fatty Acids, Nonesterified; Female; Glucose; Glycogen; Heart Rate; Hematocrit; Horses; Muscle, Skeletal; Oxygen Consumption; Physical Endurance; Physical Exertion; Prolactin; Time Factors; Tryptophan

This study examined the nutritional and performance status of elite soccer players during intense training. Eight male players (age 17+/-2 years) of the Puerto Rican Olympic Team recorded daily activities and food intake over 12 days. Daily energy expenditure was 3,833+/-571 (SD) kcal, and energy intake was 3,952+/-1,071 kcal, of which 53.2+/-6.2% (8.3 g x kg BW(-1)) was from carbohydrates (CHO), 32.4+/-4.0% from fat, and 14.4+/-2.3% from protein. With the exception of calcium, all micronutrients examined were in accordance with dietary guidelines. Body fat was 7.6+/-1.1% of body weight. Time to completion of three runs of the soccer-specific test was 37.65+/-0.62 s, and peak torques of the knee flexors and extensors at 60 degrees x s(-1) were 139+/-6 and 225+/-9 N x m, respectively. Players' absolute amounts of CHO seemed to be above the minimum recommended intake to maximize glycogen storage, but calcium intakes were below recommended. Their body fat was unremarkable, and they had a comparatively good capacity to endure repeated bouts of intense soccer-specific exercise and to exert force with their knee extensors and flexors.

Topics: Activities of Daily Living; Adipose Tissue; Adolescent; Body Mass Index; Body Weight; Calcium, Dietary; Diet; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Energy Intake; Energy Metabolism; Glycogen; Humans; Knee Joint; Male; Micronutrients; Motor Skills; Muscle, Skeletal; Nutritional Physiological Phenomena; Physical Endurance; Puerto Rico; Soccer; Torque

Insulin and insulin growth factor-I (IGF-I) binding to skeletal muscle semipurified receptors were assessed in rainbow trout (Oncorhynchus mykiss) fed with different enriched carbohydrate diets. The animals were fed for 2 months, either in spring, summer or autumn with a control diet (C, commercial diet containing 21% raw carbohydrates) or with two diets supplied with highly digestible carbohydrates (E1, 22% expanded wheat; and E2, 37% expanded wheat). Insulin and IGF-I receptors were semipurified by affinity chromatography (WGA-agarose). Fish fed with a carbohydrate enriched diet did not show lower growth rates than those fed with the control diet. Independently of the season, rainbow trout fed E1 and E2 presented higher insulin and glucose plasma levels as well as higher tissue glycogen reserves than fish fed C. An increase in the number of insulin receptors during the diet adaptation was observed especially in fish fed with E2. No differences in the affinity of receptors were observed. IGF-I specific binding in skeletal muscle was higher than that of insulin in all groups and in all seasons. Furthermore, IGF-I receptors showed the same tendency as insulin receptors, with increases in their number in experimentally fed fish, especially those fed with E2. Insulin and IGF-I receptors TKA increased only slightly, as a consequence of E1 and E2 diet adaptation. In conclusion, rainbow trout can be fed high-carbohydrate levels and show good rates of growth. This adaptation determines increases in circulating glucose and insulin, and muscle insulin receptors, which indicate an adaptation of the fish to higher levels of glucose supply. The response of IGF-I receptors also suggests a possible role in the regulation of metabolism.

Topics: Adaptation, Biological; Animals; Blood Glucose; Body Weight; Carbohydrates; Diet; Glycogen; Insulin; Muscle, Skeletal; Oncorhynchus mykiss; Protein Binding; Protein-Tyrosine Kinases; Receptor, IGF Type 1; Receptor, Insulin; Seasons

Eight groups of five farmed red deer were transported by road for three hours, after which they were either slaughtered immediately (TO) or held in lairage for three, six or 18 hours (T3, T6 and T18). Liveweight loss increased with lairage time but hot carcase weight was unaffected. Deer spent much of the initial period in lairage standing stationary in 'alert' postures. After eight to 10 hours the proportions of time spent in various postures (standing stationary, moving and lying down) were similar to pre-journey values. None of the blood components associated with dehydration (packed cell volume, osmolality, total protein and sodium) changed significantly with lairage time. Compared with T0 deer, plasma creatine kinase activity was significantly decreased in T18 deer. Lairage time had no effect on skin damage, bruising or muscle glycogen content, although liver glycogen content increased with longer lairage time. Although lairage time had a statistically significant effect on muscle pHu (with T6 deer having the lowest values), the differences were small and none of the carcases had a pHu greater than 6-0.

Topics: Abattoirs; Animals; Behavior, Animal; Body Weight; Deer; Female; Glycogen; Posture; Time Factors; Transportation

The nutritional reserves and body weight of autogenous and anautogenous strains of Culex tarsalis Coquillett were determined for 4th instars, pupae, females, and males. Starvation tolerance and survivorship of adult females and males also were studied. The autogenous individuals contained significantly greater amounts of total lipids (except the total lipids in 4th instars), total carbohydrates, glycogen, and total proteins, which resulted in a heavier mean body weight of autogenous than anautogenous mosquitoes (except the fresh weight in pupae). Results of the body fluid coefficient determination were inconclusive. Nutritional reserves in the immature stages, especially the pupal stage, were significantly greater (except the total proteins in 4th instars and female adults) than those in the adult stage. There were no significant differences in median longevity between autogenous and anautogenous females, and between autogenous and anautogenous males, provided with distilled water alone after emergence. The median longevity of females and males was significantly different in both autogenous and anautogenous strains. Our findings strongly indicate a relationship between autogenous reproduction and differences in nutritional reserves of autogenous and anautogenous strains.

Topics: Animals; Body Weight; Carbohydrates; Culex; Female; Glycogen; Lipids; Male; Proteins; Starvation

The most rapid age-related decrease in insulin-stimulated glucose uptake in skeletal muscle occurs between 3 and 5 wk of age in rats. Therefore, we studied unstimulated, insulin-stimulated, and in vitro hypoxia-stimulated 2-deoxy-D-[G-3H]glucose (2-DG) uptake in isolated soleus, flexor digitorum brevis (FDB), and epitrochlearis muscles from rats at 21, 28, and 35 days of age. Age-related decrements in insulin- (approximately 40-60%) and hypoxia-stimulated (approximately 50%) 2-DG uptake occurred in all muscles, and most of the decline was evident by 28 days. Unstimulated 2-DG uptake declined significantly with advancing age in the epitrochlearis (73%) and FDB (60%) and tended to decrease in the soleus (38%). The time course and relative magnitude of these decrements were similar under unstimulated, insulin-stimulated, and hypoxic conditions. GLUT-4 protein concentration was unaltered by age in each muscle. These results indicate that a substantial age-related decrement in 2-DG uptake occurs in several limb muscles from rats at 21 vs. 28-35 days by a mechanism that is independent of GLUT-4 levels and not specific for the insulin-dependent pathway.

Topics: Age Factors; Animals; Biological Transport; Blood Glucose; Body Weight; Glucose; Glucose Transporter Type 4; Glycogen; Hypoxia; Insulin; Male; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; Organ Size; Rats

In male rats, 2 wk of high-sucrose feeding results in insulin resistance and hypertriglyceridemia [Pagliassotti, M.J., P.A. Prach, T.A. Koppenhafer, and D.A. Pan. Am. J. Physiol. 271 (Regulatory Integrative Comp. Physiol. 40): R1319-R1326, 1996]. The present study aimed to determine if female rats also become insulin resistant and hypertriglyceridemic in response to high-sucrose feeding. Female Wistar rats (7 wk old) were fed either a high-sucrose diet (68% energy) (SU) or a high-starch diet (68% energy) (ST) for 3, 5, or 8 wk. In each animal, glucose kinetics were measured using [3-(3)H]glucose under basal and hyperinsulinemic conditions (insulin infusion 4.0 mU.kg-1.min-1). Body weight and basal glucose kinetics were not different between diet groups at 3, 5, or 8 wk. Glucose infusion rate (mg.kg-1.min-1) was not different between groups (3 wk: 17.7 +/- 1.6 ST, 16.6 +/- 0.9 SU; 5 wk: 16.1 +/- 0.9 ST, 15.1 +/- 2.0 SU; 8 wk: 18.3 +/- 1.9 ST, 16.1 +/- 1.5 SU). Clamp rate of glucose appearance (mg.kg-1.min-1) was also not different between diet groups (3 wk: 4.0 +/- 1.6 ST, 3.6 +/- 1.4 SU; 5 wk: 2.6 +/- 1.0 ST, 2.3 +/- 1.14 SU; 8 wk: 5.9 +/- 1.8 ST, 7.7 +/- 1.2 SU). No difference was observed in plasma and tissue triglycerides or tissue glycogen between sucrose- and starch-fed animals. We therefore conclude that female rats, in contrast to males, do not develop sucrose-induced insulin resistance and hypertriglyceridemia.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Dietary Sucrose; Energy Intake; Female; Glycogen; Insulin; Insulin Resistance; Liver; Muscles; Organ Size; Rats; Rats, Wistar; Sex Factors; Triglycerides

In rats injected with bacterial lipopolysaccharide (LPS; 5 gamma mg/g body weight [BWT]), the toxin provokes death within 24 h in 23% of the animals and, in surviving rats, causes a decrease in BWT, hyperlactacidemia, hyperlipacidemia, and hyperketonemia, as well as depletion of both liver and muscle glycogen content. In the liver, LPS severely lowers the ATP and total adenine nucleotide content, ATP/ADP ratio, and adenylate charge. In hepatocytes from LPS-injected rats, the oxidation of D-glucose is first increased 2 h after administration of the toxin, despite close-to-normal phosphorylation of the hexose. In hepatocytes prepared from rats killed 24 h after injection of LPS, the phosphorylation of D-glucose, its incorporation into glycogen, and its oxidation are all severely impaired. This sequence of changes, which coincides with a decreased ratio between pyruvate and lactate production from exogenous D-glucose, is comparable to that found with agents that uncouple oxidative phosphorylation. The injection of LPS also alters the metabolic response of hepatocytes to the dimethyl ester of succinic acid (SAD), in terms, for instance, of the sparing action of the ester upon both the production of 14CO2 by hepatocytes prelabeled with L-[U-14C] glutamine and the output of NH4+, and its inhibitory action on glycogenolysis and futile cycling in the reactions catalyzed by glucokinase and glucose-6-phosphatase. Nevertheless, the infusion of SAD protects the rats against the deleterious effect of LPS upon such variables as the plasma concentration of free fatty acids and beta-hydroxybutyrate, the liver ATP content, and the oxidation of D-glucose, as well as the pyruvate/lactate ratio, in hepatocytes prepared from the LPS-injected rats. The infusion of SAD also virtually suppresses lethality in the LPS-injected animals. It is proposed, therefore, that the infusion of succinic acid esters may represent a novel therapeutic approach in endotoxemia and multiple-organ failure.

Topics: Adenine Nucleotides; Animals; Blood Glucose; Body Weight; Endotoxemia; Female; Glucose; Glycogen; Insulin; Ketones; Kinetics; Lactic Acid; Lipopolysaccharides; Liver; Mitochondria, Liver; Muscles; Oxygen Consumption; Quaternary Ammonium Compounds; Rats; Succinates

In animal studies, high dosages of corticosteroids cause changes in diaphragm structure and function. The present study was designed to investigate the effects of long-term low-dose methylprednisolone (MP) administration on rat diaphragm contractile properties and morphology. Thirty adult rats were treated with saline or MP (0.2 mg/kg/day s.c.) during 6 months. Contractile properties of isolated diaphragm strips, immunohistochemical characteristics analyzed by means of antibodies reactive with myosin heavy chain isoforms, and enzyme activities were determined in the diaphragm muscle. MP significantly reduced diaphragm force generation by -15% over a wide range of stimulation frequencies. The number of type IIb fibers was reduced by MP. There was a mild but significant decrease in type I and IIa fiber cross-sectional area (CSA), whereas type IIx and IIb CSA did not change. These changes resulted in a reduction in the relative contribution of type IIb fibers to total diaphragm muscle area. Biochemically, MP decreased glycogenolytic activity, while fatty acid oxidation and oxidative capacity were increased. In conclusion, long-term low-dose MP administration caused a marked impairment in diaphragm function. This is accompanied by changes in diaphragm muscle morphology and enzyme capacity.

Topics: Animals; Anti-Inflammatory Agents; Body Weight; Diaphragm; Dose-Response Relationship, Drug; Glycogen; Immunohistochemistry; Male; Methylprednisolone; Muscle Contraction; Muscle Fibers, Skeletal; Rats; Rats, Wistar

By immunocytochemistry we have studied the effect of recombinant human insulin-like growth factor I (rhIGF-I) on expression of renal GLUT-1, -2, and -5 in rats with streptozotocin (STZ)-induced diabetes. In the renal tubules of these rats, expression of GLUT-1 was reduced and that of GLUT-2 was increased. GLUT-1 expression was restored, and GLUT-2 expression was normalized by 2-wk administration of rhIGF-I. We have shown that GLUT-5 was expressed at the brush-border membrane of the proximal convoluted tubules (PCT) of the cortex and at the glomerular mesangial cells (GMC) in normal rat kidney. In the diabetic rats, GLUT-5 expression was increased at both sites, along with an increase of GLUT-2 expression at the basolateral membrane of PCT, and was decreased to normal level at both sites by treatment with rhIGF-I. Thus, like GLUT-2, GLUT-5 is suggested to regulate glucose reabsorption in PCT. The relationship between overexpression of GLUT-5 in GMC and accumulation of sorbitol and advanced glycosylation end products are discussed. Regulation of GLUT expression may play an important role on renal glucose homeostasis.

Topics: Analysis of Variance; Animals; Body Weight; Cell Membrane; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Gene Expression; Glomerular Mesangium; Glucose Transporter Type 1; Glucose Transporter Type 2; Glucose Transporter Type 4; Glycogen; Humans; Immunohistochemistry; Insulin; Insulin-Like Growth Factor I; Kidney; Kidney Cortex; Kidney Tubules, Proximal; Male; Microvilli; Models, Biological; Monosaccharide Transport Proteins; Muscle Proteins; Organ Size; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Reference Values; Weight Gain

Exercise training increases contraction-stimulated maximal glucose transport and muscle glycogen level in skeletal muscle. However, there is a possibility that more muscle contractions are required to maximally activate glucose transport in trained than in untrained muscle, because increased glycogen level after training may inhibit glucose transport. Therefore, the purpose of this study was to investigate the relationship between the increase in glucose transport and the number of tetanic contractions in trained and untrained muscle. Male rats swam 2 h/day for 15 days. In untrained epitrochlearis muscle, resting glycogen was 26.6 micromol glucose/g muscle. Ten, 10-s-long tetani at a rate of 1 contraction/min decreased glycogen level to 15.4 micromol glucose/g muscle and maximally increased 2-deoxy-D-glucose (2-DG) transport. Training increased contraction-stimulated maximal 2-DG transport (+71%; P < 0.01), GLUT-4 protein content (+78%; P < 0.01), and resting glycogen level (to 39.3 micromol glucose/g muscle; P < 0.01) on the next day after the training ended, although this training effect might be due, at least in part, to last bout of exercise. In trained muscle, 20 tetani were necessary to maximally activate glucose transport. Twenty tetani decreased muscle glycogen to a lower level than 10 tetani (18.9 vs. 24.0 micromol glucose/g muscle; P < 0.01). Contraction-stimulated 2-DG transport was negatively correlated with postcontraction muscle glycogen level in trained (r = -0.60; P < 0.01) and untrained muscle (r = -0.57; P < 0.01).

Topics: Animals; Body Weight; Electric Stimulation; Forelimb; Glycogen; Male; Monosaccharide Transport Proteins; Muscle Contraction; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; Reference Values; Swimming

Mice bearing interleukin-6 (IL-6)-secreting tumor were used to study the chronic effect of IL-6 on carbohydrate metabolism. Mice were injected with allogeneic tumor cells transduced with the murine IL-6 gene. Serum IL-6 levels were correlated exponentially with tumor weight. Secretion of IL-6 from the developed tumors was associated with decreased food consumption, reduced body weight, and reduced blood glucose levels. Insulin levels did not change, and 2-deoxyglucose uptake was not affected in most tissues examined. A significant increase of 2-deoxyglucose uptake was measured in the liver. Glycogen content in the liver determined 0, 6, 12, and 18 days after tumor inoculation was 42, 23, 12, and 3 mg/g, respectively. The activity of phosphoenolpyruvate carboxykinase was not affected. The activity of glucose-6-phosphatase (G-6-Phase) determined 6, 12, and 18 days after tumor injection was 84, 70, and 50% of G-6-Pase activity in pair-fed mice bearing nonsecreting tumors, respectively. G-6-Pase mRNA levels were markedly reduced due to inhibition of G-6-Pase gene transcriptional rate.

Topics: Animals; Blood Glucose; Body Weight; Deoxyglucose; Eating; Female; Fibrosarcoma; Gene Expression; Glucose-6-Phosphatase; Glycogen; Insulin; Interleukin-6; Liver; Mice; Mice, Inbred C57BL; Neoplasm Transplantation; Transduction, Genetic

We assessed the effects of GLUT4 glucose transporter expression on substrate metabolism and glycogen regulation during exercise. Transgenic mice overexpressing human (h)GLUT4 in muscle and fat (TG) and their wild-type littermates (WT) were studied by indirect calorimetry at rest and during acute treadmill exercise (30 minutes) and recovery (30 minutes). The rate of carbon dioxide production (VCO2) increased to a greater degree in TG during exercise, whereas resting VCO2, resting oxygen production (VO2), and exercise-induced increments in VO2 were similar in TG and WT. As a result, the respiratory quotient (RQ) was increased by .03 to .05 in TG during exercise, due to greater consumption of carbohydrate (up to approximately 64% more) and less consumption of lipid (up to approximately 40% less) compared with WT, without differences in overall energy expenditure. These differences in substrate metabolism were observed despite relative hypoglycemia and elevated free fatty acids (FFAs) in TG that persisted throughout resting, exercise, and recovery periods. To further assess substrate availability, glycogen content and glycogen synthase activity were measured in skeletal muscle and liver. At rest, muscle glycogen content was 50% higher and glycogen synthase I was 40% lower in TG compared with WT. During exercise and recovery, muscle glycogen was more profoundly depleted in TG than in WT, and glycogen synthase I increased to levels observed in WT, with no change in total glycogen synthase. In the liver, glycogen content and total glycogen synthase were similar in TG and WT under resting conditions, while glycogen synthase I was reduced by 48%. Exercise and recovery induced a more profound depletion of liver glycogen (76% v 30%) and greater increments in both I-form and total glycogen synthase in TG. In conclusion, (1) TG overexpressing GLUT4 exhibit greater muscle glycogen content at rest than WT; (2) during exercise, TG metabolize more carbohydrate, made possible by increased glycogenolysis in muscle and liver, and this predominates as a fuel source despite hypoglycemia and increased availability of FFA; (3) increased carbohydrate metabolism is linked to a decrease in lipid metabolism such that there is no change in overall energy expenditure; and (4) glycogen synthase I activity is inversely proportional to tissue glycogen content despite differences in circulating glucose, insulin, and FFA concentrations, indicating that glycogen content has an overriding re

Topics: Animals; Basal Metabolism; Blood Glucose; Body Weight; Energy Metabolism; Fatty Acids, Nonesterified; Female; Gene Expression Regulation, Developmental; Genetic Engineering; Glucose Transporter Type 4; Glycogen; Glycogen Synthase; Humans; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Monosaccharide Transport Proteins; Muscle Proteins; Muscles; Oxygen Consumption; Physical Conditioning, Animal

The effects of nutritional level on glycogen content and pH of semimembranosus (SM) and semitendinosus (ST) rabbit muscles were investigated. Rabbits weaned at 30 d of age were fed one of three diets in which grain had been replaced with 0, 15, and 45% coast cross bermudagrass (Cynodon dactylon Pers.). Muscles were sampled at .5, 3.5, 6.5, and 24 h after slaughter. Results showed that these isoenergetic and isoproteic diets did not affect the total number of days required for rabbits to attain 2 kg of live weight. The SM muscle of animals fed the 0% forage diet exhibited higher glycogen content than the SM muscle of rabbits maintained on 15 and 45% forage diets at all sampling times. At .5 h after slaughter, the glycogen content of SM from the 15 and 45% dietary groups was decreased by 65 and 79%, respectively, in relation to the 0% dietary group. For ST, glycogen content was higher only at the first sampling time for the 0% forage diet (diet with no addition of bermudagrass) when compared with animals maintained on diets with forage. For SM and ST, significant differences in muscle pH among dietary groups was observed at 6.5 and 24 h after slaughter, and rabbits maintained on a 45% forage diet showed a higher ultimate pH than animals fed 0 or 15% forage diets. These results demonstrate that grain replacement with forage in diets for rabbits causes a decrease in glycogen content in two types of muscles and results in higher ultimate pH, which may affect the shelf-life quality of the meat.

Topics: Analysis of Variance; Animal Feed; Animals; Body Composition; Body Weight; Diet; Edible Grain; Glycogen; Hydrogen-Ion Concentration; Meat; Muscle, Skeletal; Poaceae; Rabbits

We have investigated the antidiabetic action of troglitazone in aP2/DTA mice, whose white and brown fat was virtually eliminated by fat-specific expression of diphtheria toxin A chain. aP2/DTA mice had markedly suppressed serum leptin levels and were hyperphagic, but did not gain excess weight. aP2/DTA mice fed a control diet were hyperlipidemic, hyperglycemic, and had hyperinsulinemia indicative of insulin-resistant diabetes. Treatment with troglitazone alleviated the hyperglycemia, normalized the tolerance to intraperitoneally injected glucose, and significantly decreased elevated insulin levels. Troglitazone also markedly decreased the serum levels of cholesterol, triglycerides, and free fatty acids both in wild-type and aP2/DTA mice. The decrease in serum triglycerides in aP2/DTA mice was due to a marked reduction in VLDL- and LDL-associated triglyceride. In skeletal muscle, triglyceride levels were decreased in aP2/DTA mice compared with controls, but glycogen levels were increased. Troglitazone treatment decreased skeletal muscle, but not hepatic triglyceride and increased hepatic and muscle glycogen content in wild-type mice. Troglitazone decreased muscle glycogen content in aP2/DTA mice without affecting muscle triglyceride levels. The levels of peroxisomal proliferator-activated receptor gamma mRNA in liver increased slightly in aP2/DTA mice and were not changed by troglitazone treatment. The results demonstrate that insulin resistance and diabetes can occur in animals without significant adipose deposits. Furthermore, troglitazone can alter glucose and lipid metabolism independent of its effects on adipose tissue.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Cholesterol; Chromans; Diabetes Mellitus, Type 2; Eating; Fatty Acids; Glycogen; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Leptin; Lipoproteins, LDL; Lipoproteins, VLDL; Mice; Mice, Transgenic; Organ Size; Proteins; Receptors, Cytoplasmic and Nuclear; Thiazoles; Thiazolidinediones; Transcription Factors; Triglycerides; Troglitazone

The causality of vascular and parenchymal damage to the central nervous system (CNS) was examined in rats with thiamine deficiency. Male Sprague-Dawley rats were divided into two groups; one was given a thiamine-deficient diet (TDD) and injected intraperitoneally with 10 micrograms/100 g bodyweight pyrithiamine (PT) in order to analyze morphometrically the topographical and sequential relationship between vascular and parenchymal changes and vasodilatation, and the other was given a TDD and 50 micrograms/100 g bodyweight PT in order to determine hemorrhagic sites using serial sections. Histological examination showed that spongiotic change occurred selectively in the inferior colliculus (100%) from day 19, and thereafter in the thalamus (95%), mammillary body (50%) and nuclei olivaris and vestibularis of the pons (25%), with or without hemorrhage. Simultaneously, glycogen accumulation was also observed in these regions at a frequency similar to that of hemorrhage. Ultrastructurally, however, hydropic swelling of astrocytic and neuronal processes without glycogen accumulation was observed as early as day 9 in the inferior colliculus, at which time an increase of glial fibrillary acidic protein-positive processes was also recognized. The superior colliculus was completely spared. From day 22 vasodilatation of the inferior colliculus occurred, concomitantly with bodyweight loss and neurological symptoms. Twenty-two examined hemorrhages, which occurred in the thalamus and inferior colliculus, were distributed along the arterioles or capillaries on the arterial side. In conclusion, the morphological CNS changes caused by thiamine deficiency with administration of low-dose PT in rats begin as hydropic swelling of neuronal and astrocytic processes, followed by hemorrhage and, thereafter, by vasodilation. The predilection for hemorrhage on the arterial side without parenchymal changes suggests that petechial hemorrhage is not simply secondary to parenchymal changes, but is due to hemodynamic change resulting from thiamine deficiency-induced vascular dysfunction.

Topics: Animals; Antimetabolites; Ataxia; Body Weight; Brain; Cerebral Hemorrhage; Glial Fibrillary Acidic Protein; Glycogen; Hypothermia; Immunohistochemistry; Inferior Colliculi; Male; Mammillary Bodies; Pyrithiamine; Rats; Rats, Sprague-Dawley; Seizures; Thalamus; Thiamine Deficiency; Vasodilation; Wernicke Encephalopathy

The role of increased lipid availability in the generation of insulin resistance by growth hormone has not been established. We investigated this in rats infused with saline (controls) or human growth hormone (hGH) (500 micrograms x kg-1 x 24 h-1) for 5 h or 3 days. hGH infusion increased basal plasma insulin at 5 h (335 +/- 33 vs. 197 +/- 15 [controls]; P < 0.005) and at 3 days (396 +/- 34 vs. 218 +/- 14 pmol/l; P < 0.0001). Plasma nonesterified fatty acid (0.26 +/- 0.01 vs. 0.21 +/- 0.01 [controls] g/l) and liver long-chain acyl-CoA (21.2 +/- 1.9 vs. 14.1 +/- 1.1 [controls] nmol/g wet wt) were elevated at 5 h (P < 0.01 for both) but were below control levels after 3 days of hGH infusion (P < 0.01 for both); indirect calorimetry after 3 days demonstrated decreased lipid oxidation. Clamp studies showed similar degrees of peripheral insulin resistance at 5-h and 3-day hGH infusion (glucose disposal reduced by 25% versus controls). Insulin-stimulated glucose metabolic index (Rg') in red gastrocnemius muscle (red muscle) was reduced (P < 0.05 and P < 0.01) at 5 h and 3 days of hGH infusion, respectively (e.g., 5 h, 10.0 +/- 1.8 vs. 24.1 +/- 4.4 [controls] micromol x 100 g-1 x min-1), whereas insulin-mediated muscle glycogen synthesis was reduced (P < 0.03) only in rats infused with hGH for 3 days. We conclude that in the rat, hGH rapidly induces persistent peripheral insulin resistance and basal hyperinsulinemia. However, the transient nature of increased lipid mobilization suggests that it is not an important factor in the manifestation of muscle insulin resistance during prolonged hGH elevation. The persistent insulin resistance is not associated with increased lipid oxidation but is associated with hyperinsulinemia and reduced insulin-mediated muscle glycogen synthesis.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Epididymis; Fatty Acids, Nonesterified; Glycogen; Growth Hormone; Humans; Hyperinsulinism; Infusions, Intravenous; Insulin; Insulin Resistance; Kinetics; Male; Muscle, Skeletal; Myocardium; Patch-Clamp Techniques; Rats; Rats, Wistar; Reference Values; Triglycerides

The primary purpose of this study was to determine the impact of brief dietary restriction (DR; 5 or 20 days) on skeletal muscle glucose transport activity (GTA) of 24-month-old female Fischer 344 rats. Basal GTA of isolated epitrochlearis muscles was unaffected by DR. Insulin-stimulated GTA was significantly increased by DR only at 20 days (51%). We also assessed the influence of DR on energy sources (blood-borne and stored). An approximately 20% decline in glycemia occurred in each DR group, but plasma-free fatty acid and beta-hydroxybutyrate concentrations were unaffected. Plasma insulin was reduced by 50% after 20 days. Hepatic glycogen was rapidly mobilized (-69% at 5 days; -83% at 20 days). The depletions of visceral adipose stores was slower (no significant decline at 5 days; -30% at 20 days), but the eventual reduction accounts for a significant amount of energy. The results demonstrate that muscle from old rats can rapidly upregulate GTA in response to brief DR. The relative magnitude of this increase represents a substantial portion of the increases previously observed after prolonged DR.

Topics: 3-Hydroxybutyric Acid; 3-O-Methylglucose; Aging; Animals; Biological Transport; Body Weight; Diet; Fatty Acids, Nonesterified; Female; Glucose; Glycogen; Hydroxybutyrates; Insulin; Liver Glycogen; Methylglucosides; Muscle Proteins; Muscle, Skeletal; Organ Size; Rats; Rats, Inbred F344

Insulin resistance of muscle glucose metabolism is a hallmark of NIDDM. The obese Zucker (fa/fa) rat--an animal model of muscle insulin resistance--was used to test whether acute (100 mg/kg body wt for 1 h) and chronic (5-100 mg/kg for 10 days) parenteral treatments with a racemic mixture of the antioxidant alpha-lipoic acid (ALA) could improve glucose metabolism in insulin-resistant skeletal muscle. Glucose transport activity (assessed by net 2-deoxyglucose [2-DG] uptake), net glycogen synthesis, and glucose oxidation were determined in the isolated epitrochlearis muscles in the absence or presence of insulin (13.3 nmol/l). Severe insulin resistance of 2-DG uptake, glycogen synthesis, and glucose oxidation was observed in muscle from the vehicle-treated obese rats compared with muscle from vehicle-treated lean (Fa/-) rats. Acute and chronic treatments (30 mg.kg-1.day-1, a maximally effective dose) with ALA significantly (P < 0.05) improved insulin-mediated 2-DG uptake in epitrochlearis muscles from the obese rats by 62 and 64%, respectively. Chronic ALA treatment increased both insulin-stimulated glucose oxidation (33%) and glycogen synthesis (38%) and was associated with a significantly greater (21%) in vivo muscle glycogen concentration. These adaptive responses after chronic ALA administration were also associated with significantly lower (15-17%) plasma levels of insulin and free fatty acids. No significant effects on glucose transporter (GLUT4) protein level or on the activities of hexokinase and citrate synthase were observed. Collectively, these findings indicate that parenteral administration of the antioxidant ALA significantly enhances the capacity of the insulin-stimulatable glucose transport system and of both oxidative and nonoxidative pathways of glucose metabolism in insulin-resistant rat skeletal muscle.

Topics: Animals; Antioxidants; Biological Transport; Body Weight; Female; Glucose; Glycogen; Insulin; Insulin Resistance; Muscles; Organ Size; Rats; Rats, Mutant Strains; Thioctic Acid

Topics: Analysis of Variance; Animals; Blood Glucose; Body Weight; Cadmium; Carbohydrate Metabolism; Carbohydrates; Fructose-Bisphosphatase; Glycogen; Glycogen Synthase; Lactates; Lethal Dose 50; Liver; NAD; NADP; Organ Size; Phosphofructokinase-1; Phosphorylases; Salmon; Seawater; Water Pollutants, Chemical

1. The effects of fasting for 48 h were investigated in C57BL/10 (wild type) and age-matched C57BL/10 dystrophin-deficient (mdx) mice. 2. Fasting resulted in an increased percentage of necrotic fibres in muscles from the hindlimb and lumbar regions of mdx mice. The percentage of necrotic fibres of forelimb and chest muscles of mdx mice was unaltered by fasting. In wild-type mice, very few necrotic fibres were observed after fasting. 3. The necrotic changes in fasted mdx muscle were not accompanied by altered energy status as evaluated by muscle ATP and phosphocreatine concentrations. 4. A significantly decreased rectal temperature was observed in mdx but not in wild-type mice after fasting. 5. Fasting would normally be expected to cause a reduction in muscle fibre size. The high prevalence of necrosis in fasted mdx mice is therefore an unusual response that may be related to disturbance of the mechanisms which, in the fed state, compensate for the dystrophin deficiency in these animals.

Topics: Animals; Body Temperature; Body Weight; Dystrophin; Fasting; Glycogen; Mice; Mice, Inbred mdx; Muscle Proteins; Muscle, Skeletal; Necrosis

The myotomal muscle of Synbranchus marmoratus was investigated using histochemical and immunohistochemical reactions. This musculature is composed of a superficial red compartment, uniformly distributed around the trunk circumferentially and also in the lateral line. The red compartment fibers are small in diameter and have an oxidative metabolism, a high rate of glycogen and a negative reaction to alkaline and acid myofibrillar ATPase (mATPase). The white muscle forms the bulk of the muscle mass. Its fibers are large in diameter and have a glycolytic metabolism, a negative reaction to glycogen, a strong reaction to alkaline mATPase and a negative reaction to acid mATPase. Between these two compartments there is an intermediate layer of fibers presenting a mosaic metabolism pattern with a high rate of glycogen. These fibers stained moderately for alkaline and acid m-ATPase. Several clusters of red muscles were observed inside the white muscle. Each cluster is composed of three fiber types, with a predominance of red and intermediate fibers. Reactivity to anti-MHC BA-D5 was positive only in the intermediate fibers. Reactivity to anti-MHC SC-71 was negative in all fiber types.

Topics: Adenosine Triphosphatases; Animals; Body Weight; Dihydrolipoamide Dehydrogenase; Fishes; Glycogen; Glycolysis; Histocytochemistry; Muscle Fibers, Fast-Twitch; Muscle Fibers, Skeletal; Muscle, Skeletal; Myofibrils

Serotoninergic neuronal networks are included in regulation and modification of eating behavior and energy metabolism. Dexfenfluramine (dF), a serotonin releaser and reuptake inhibitor, was used to investigate changes in food intake, body weight development, energy expenditure, respiratory quotient, and substrate oxidation rates for 12 days. Rats which had been made obese by postnatal overfeeding received an energy-controlled mash diet and water ad libitum and were intraperitoneally injected with either saline or 5 or 10 mg dF/kg. As compared with controls, food intake and energy expenditure were significantly decreased in a dose-dependent manner, especially during the first 6 days. Lipid oxidation was increased, while the oxidation of carbohydrates was decreased. The body weight was only slightly reduced after 2 days of dF treatment. After 4 days, dF-treated rats resumed body weight, but as compared with controls both dF groups exhibited lower body weights at the end of the experiment. After 12 days the plasma glucose concentration was unchanged, whereas plasma free fatty acids were significantly decreased. Plasma insulin levels were unchanged after dF, but 10 mg dF/kg led to increased muscle and, especially liver glycogen contents, indicating an improved nonoxidative glucose disposal. Muscle pyruvate kinase was slightly but not significantly increased after dF treatment but that of the liver was significantly decreased, indicating a reduced glycolytic activity of the liver. Whereas the renal N excretion was rather decreased, the plasma concentrations of urea, citrulline, arginine, and ornithine were increased, and the liver contents of glutamine and arginine were decreased. Possibly, there is a shift of ammonia removal from glutamine synthesis to production of urea. The sum of all large neutral amino acids in muscle was significantly decreased after dF treatment, indicating a diminished proteolysis. Pair-feeding experiments over 2 days revealed that this was not solely a result of diminished food intake, but also an additional metabolic effect of dF, different from its anorectic effect. It is concluded that both increased oxidation of endogenous fat and reduced food intake could mediate the body weight reducing effect of dF.

Topics: Amino Acids; Animals; Blood Glucose; Body Weight; Calorimetry, Indirect; Dose-Response Relationship, Drug; Eating; Energy Metabolism; Fatty Acids, Nonesterified; Fenfluramine; Glycogen; Insulin; Liver; Male; Muscle, Skeletal; Obesity; Oxidation-Reduction; Pyruvate Kinase; Rats; Rats, Wistar; Serotonin Receptor Agonists; Urea

Frequent coexistence of insulin resistance, central obesity, and hypertriglyceridemia in the same individual suggests an underlying common pathogenesis. Insulin resistance and hypertriglyceridemia can be induced by carbohydrate feeding in rats. Golden Syrian hamsters are believed to be resistant to the metabolic effects of dietary carbohydrates. We investigated the effects of diets containing 60% fructose or sucrose on glucose and lipid metabolism in hamsters, both in the fasting state and during an intravenous glucose tolerance test. Fructose caused obesity (weight after treatment: 131 +/- 7 gm in the control group, 155 +/- 5 gm in the fructose group, 136 +/- 7 gm in sucrose group, p < 0.04). Fructose also reduced glucose disappearance rate (KG: 2.69% +/- 0.39% in the control group, 1.45% +/- 0.18% in the fructose group, p < 0.02). Sucrose caused a marginal decrease in glucose disappearance (KG: 1.93% +/- 0.21%, p = 0.08 vs the control group). Only fructose feeding increased fasting plasma nonesterified fatty acids (0.645 +/- 0.087 mEq/L in the control group, 1.035 +/- 0.083 mEq/L in the fructose group, 0.606 +/- 0.061 mEq/L in the sucrose group, p < 0.002), plasma triglycerides (84 +/- 6 mg/dl in the control group, 270 +/- 65 mg/dl in the fructose group, 94 +/- 16 mg/dl in the sucrose group, p < 0.0002), and liver triglycerides (1.88 +/- 0.38 mg/gm liver weight in the control group, 2.35 =/- 0.24 mg/gm in the fructose group, 1.41 +/- 0.13 mg/gm in the sucrose group, p < 0.04). Previous studies in the rat have suggested that dietary carbohydrates induce insulin resistance by increasing plasma nonesterified fatty acids and triglycerides, which are preferentially used by the muscles. The present report shows that sucrose also can cause some decrease in glucose disappearance in the hamster without causing hypertriglyceridemia or increasing plasma nonesterified fatty acids. Thus other mechanisms may also contribute to the insulin resistance in the hamster. These findings suggest that hamsters provide a good model for investigation of hormonal and nutritional regulation of glucose and lipid metabolism.

Topics: Animals; Blood Glucose; Body Weight; Cricetinae; Diet; Fatty Acids, Nonesterified; Fructose; Glucose; Glycogen; Insulin; Liver Glycogen; Male; Mesocricetus; Muscles; Organ Size; Sucrose; Triglycerides

Endurance training is associated with glycogen (Gly) sparing, generally attributed to less carbohydrate (CHO) oxidation. However, untrained individuals commit a greater fraction of CHO to lactate (La), accounting for a portion of the Gly "spared." We examined the effects of training (running 1 h/day at 30 m/min up an 8 degrees grade) on whole body CHO distribution and oxidation. Female Long Evans rats (n = 27) were assigned to control (Untr) and trained (Tr) groups. Two days before the experiment, animals were chronically catheterized. On the day of the experiment, animals ran for 20 min at a speed of 28 m/min and were killed with an overdose of pentobarbital sodium injection while running. Whole carcasses were then promptly freeze-clamped with a liquid N2-cooled press. Whole body carcass powder was assayed for La, Gly, and glucose. Resting whole body values were not different between groups (La = 0.78 +/- 0.06 vs. 0.83 +/- 0.07, Gly = 4.46 +/- 0.62 vs. 3.77 +/- 0.35, glucose = 0.19 +/- 0.07 vs. 0.23 +/- 0.09 mmol/body for Tr and Untr rats, respectively). However, postexercise La was higher in Untr vs. Tr group (2.01 +/- 0.28 vs. 1.13 +/- 0.09 mmol/body), and Gly was lower in the Untr vs. Tr rats (1.58 +/- 0.25 vs. 3.42 +/- 0.43 mmol/body). Similarly, Untr animals displayed higher epinephrine levels than Tr at the end of the exercise bout (4.9 +/- 1.0 vs. 1.7 +/- 0.4 ng/ml). Differences between groups in La and glucose masses (postexercise minus rest data) accounted for 60% of the Gly differences. Gly spared from oxidation and replaced by increased fat oxidation only accounted for 40% of the differences in Gly levels between Tr and Untr animals. We conclude that untrained mammals commit a significant portion of their CHO pool to La, which accounts for almost one-half of the apparent Gly spared during moderate-intensity exercise in the trained state.

Topics: Animals; Blood Glucose; Body Weight; Epinephrine; Exercise Test; Female; Glucose; Glucose Clamp Technique; Glycogen; Lactic Acid; Norepinephrine; Oxygen Consumption; Physical Conditioning, Animal; Physical Endurance; Physical Exertion; Rats; Rest

Physiological mechanisms were measured in embryos from turkey hens of different ages to determine associations with declines in hatchability as breeder hens age. As the hens aged from 32 to 54 wk of age, embryonic viability declined (P < 0.05). The greatest proportional increase (P < 0.01) in embryonic mortality of aging hens occurred at the plateau stage in oxygen consumption or immediately thereafter at pipping. Eggshell conductance constants increased (P < 0.01) as hens aged but did not change after mid-lay, suggesting an alteration in respiration for the embryos in eggs produced by older hens compared to eggs produced by the same hens at younger ages. The alteration may cause embryos in eggs from older hens to reach the plateau stage in oxygen consumption (approximately 25 to 26 d of incubation) earlier in development than embryos from young hens. Hepatic and cardiac glycogen concentrations were greatest (P < 0.001) in embryos from hens at the youngest age and then declined (P < 0.05) as the hens aged. Embryonic blood plasma glucose concentrations declined (P <0.05) similarly. Plasma thyroxine (T4) and triiodothyronine (T3) concentrations were measured in embryos from the hens at different ages as well. Increased (P < 0.05) T4 was evidenced in embryos from the youngest hens, whereas increased (P < 0.05) T3 activity was evident in embryos from hens of older ages. It was concluded that the decline in hatchability seen as turkey breeder hens age may have a basis in the differences seen in the physiology of hatching in embryos. Specifically, thyroid influences on growth and carbohydrate metabolism may be involved in decreased embryonic viability.

Topics: Aging; Animals; Blood Glucose; Body Weight; Breeding; Carbohydrate Metabolism; Egg Shell; Energy Metabolism; Female; Glycogen; Liver; Myocardium; Oxygen Consumption; Respiration; Thyroid Hormones; Turkeys

Metabolic changes associated with sustained 48-hr shivering thermogenesis were studied in piglets maintained at 34 (thermoneutrality) or 25 degrees C (cold) between 6 and 54 hr of life. Despite their high shivering activity and elevated heat production, cold-exposed piglets exhibited a slightly lower rectal temperature than thermoneutral animals (-1.1 degrees C; P < 0.01) at the end of the treatment. The enhancement of heat production and shivering activity were associated with a decrease in muscle glycogen (-47%; P < 0.05) and total lipid content (-23%; P < 0.05), a reduction of blood lactate levels (P < 0.05) and an enhancement of muscle cytochrome oxidase activity (+20%; P < 0.05) which suggests that muscle oxidative potential was increased by cold exposure. Potential for capturing lipids (lipoprotein lipase activity) was also higher in the red rhomboideus muscle (+71%; P < 0.01) and lower in adipose tissue (-58%; P < 0.01) of the cold-exposed piglets. Measurements performed at the mitochondrial level show no changes in rhomboideus muscle, but respiratory capacities (state IV and FCCP-stimulated respiration) and intermyofibrillar mitochondria oxidative and phosphorylative (creatine kinase activity) capacities were enhanced in longissimus dorsi muscle (P < 0.05). These changes may contribute to provide muscles with nonlimiting amount of readily oxidable substrates and ATP necessary for shivering thermogenesis. A rise in plasma norepinephrine levels was also observed during the second day of cold exposure (P < 0.05).

Topics: Animals; Animals, Newborn; Blood Glucose; Body Weight; Creatine Kinase; Electron Transport Complex IV; Energy Metabolism; Epinephrine; Glycogen; Lactic Acid; Lipoprotein Lipase; Mitochondria, Muscle; Muscles; Norepinephrine; Shivering; Swine

Effects of capsaicin, a pungent principle of hot red pepper, on glycogen contents in the liver and skeletal muscle at rest and during exercise were studied in rats. The contents of glycogen in the liver and soleus muscle, and the concentrations of serum glucose, lactate, free fatty acid and glycerol were examined. Capsaicin was supplemented at 0.014% of the experimental diet. Each group of rats was fed the capsaicin-diet ad libitum for 7 days, and then both groups of rats were fed isoenergetic diets with or without capsaicin for 7 days. Rats were trained running with a treadmill for 14 days. At the final stage of the experiments, 1 h running was loaded after the capsaicin diet or the control diet. The glycogen contents in the liver and soleus muscle were not significantly different between the capsaicin-diet group and the control-diet group after the meal and during exercise. The concentrations of serum glucose, lactate, free fatty acid and glycerol were not significantly different between the two dietary groups after the meal and during exercise. The results in this study suggest that the intake of capsaicin have little effect on glycogen contents in the liver and soleus muscle at rest and during exercise in rats previously fed a capsaicin-diet ad libitum for 1 week.

Topics: Animals; Blood Glucose; Body Weight; Capsaicin; Diet; Fatty Acids, Nonesterified; Glycerol; Glycogen; Kinetics; Lactic Acid; Liver; Male; Muscle, Skeletal; Organ Size; Physical Exertion; Rats; Rats, Sprague-Dawley

To determine the influence of body weight, fat mass, and fat distribution on resting endogenous glucose production in healthy lean and overweight individuals.. measurements were performed in the resting postabsorptive state in individuals receiving an unrestricted diet.. Institute of Physiology of Lausanne University.. resting post absorptive glucose production, glycogenolysis and gluconeogenesis; resting energy expenditure and net substrate oxidation.. Endogenous glucose production was positively correlated with body weight, lean body mass, energy expenditure and carbohydrate oxidation. Gluconeogenesis was positively correlated with net lipid oxidation and energy expenditure, and negatively correlated with net carbohydrate oxidation. No correlation with body fat or fat distribution was observed.. Gluconeogenesis shows a large interindividual variability. Net lipid oxidation and not body fat appears to be a major determinant of gluconeogenesis.

Topics: Adult; Body Composition; Body Mass Index; Body Weight; Carbohydrate Metabolism; Energy Metabolism; Female; Gluconeogenesis; Glucose; Glycogen; Humans; Kinetics; Lipid Metabolism; Male; Oxidation-Reduction

The effects of short-term diet change from high fat (F) to high carbohydrate (C) (or vice versa) on the storage and utilization of glycogen and triacylglycerol (TG) in muscle and liver were studied in untrained rats. Rats were fed on an F or C diet for 28 days. For an additional 3 days, half of the rats in both F and C groups were fed the same diets as before (F-F and C-C) and the other half of the rats were switched to the counterpart diets (F-C and C-F). On the final day of the experiment, half of the rats in each diet group were exercised by swimming for 1.5 h and the other half were rested. Short-term diet change from F to C diets increased, but the change from C to F diets decreased, glycogen stores of soleus and plantaris muscles and liver, resulting in no difference in glycogen stores between F-C and C-C, and between F-F and C-F. The dietary change also had an affect on TG stores of red gastrocnemius muscle and liver-however, muscle TG stores were still higher in F-C than in C-C and C-F, and there were no differences in liver TG stores between F-C and C-F. Exercise decreased muscle glycogen contents markedly in F-C and C-C, whereas, it decreased muscle TG concentrations in F-F and C-F. Liver glycogen depletion was lower in F-C than in other groups. Lipolytic activities of epididymal adipose tissue at rest and postexercise were no differences between F-F and F-C, and were higher in F-C than in C-C and C-F. beta-adrenergic receptor binding was determined with [125I] iodocyanopindolol, and maximal numbers of beta-adrenergic receptor of plasma membrane from perirenal adipose tissue were approximately 170%-200% higher in F-C than in other groups at rest and postexercise. These results suggested that short-term C diet fed rats adapted to F diet enhanced not only glycogen stores of muscle and liver but also did not decrease lipolytic activity of adipose tissue with increased beta-adrenergic receptor density, resulting in the preservation of energy reserves (glycogen and TG) of muscle at rest, and liver glycogen sparing during exercise.

Topics: Adipose Tissue; Animals; Body Weight; Diet; Dietary Carbohydrates; Dietary Fats; Glycogen; Hormones; Liver; Male; Muscle, Skeletal; Phosphorylases; Rats; Rats, Sprague-Dawley; Receptors, Adrenergic, beta; Triglycerides

Prolonged glucosamine (GlcN) infusion increases the skeletal muscle hexosamine concentration and induces peripheral insulin resistance in conscious rats. IGF-1 and insulin share common steps in signal transduction, and the action of IGF-1 on carbohydrate metabolism is preserved in certain insulin-resistant states. In our study, we attempted to delineate whether increased GlcN availability also impairs the effects of IGF-1 on glucose uptake (Rd), glycolysis, and glycogen synthesis. We performed euglycemic IGF-1 (5 and 15 microg x kg(-1) x min(-1)) and insulin (3 and 18 mU mg x kg(-1) x min(-1)) clamp studies at 0-2 h and 5-7 h in conscious rats (n = 44) during saline or GlcN infusions. GlcN infusion raised plasma GlcN levels to approximately 2.0 mmol/l and skeletal muscle uridinediphospho-n-acetylglucosamine to 80-150 nmol/g (approximately three- to fivefold over basal). During physiological hyperinsulinemia (3 mU x kg(-1) x min(-1), plasma insulin approximately 50 microU/ml), GlcN infusion caused comparable decreases in Rd (15.7 +/- 1.0 [5-7 h] vs. 21.7 +/- 2.3 [0-2 h] mg x kg(-1) x min(-1); P < 0.01) and glycogen synthesis (5.4 +/- 0.5 [5-7 h] vs. 10.4 +/- 1.9 [0-2 h] mg x kg(-1) x min(-1); P < 0.005). Furthermore, GlcN markedly decreased Rd by 7.8 +/- 1.2 mg x kg(-1) x min(-1) (18.7 +/- 0.7 [5-7 h] vs. 26.5 +/- 1.3 [0-2 h] mg x kg(-1) x min(-1); P < 0.001 vs. control) during IGF-1 (5 microg x kg(-1) x min(-1)) clamp studies. This decline was associated with a 26% decrease in the steady-state concentration of skeletal muscle Glc-6-P (286 +/- 45 vs. 386 +/- 36 nmol/g; P < 0.01) and was primarily caused by impaired glycogen synthesis (6.7 +/- 0.5 [5-7 h] vs. 13.9 +/- 0.9 [0-2 h] mg x kg(-1) x min(-1); P < 0.005). The effects of GlcN infusion on glucose disposal (percentage decrease in Rd) were correlated (r2 = 0.803; P < 0.01) with the skeletal muscle concentration of UDP-GlcNAc. To investigate whether IGF-1 can overcome GlcN-induced insulin resistance, GlcN and insulin (18 mU x kg(-1) x min(-1)) were infused for 7 h during euglycemic clamps, and IGF-1 (15 microg x kg(-1) x min(-1)) was superimposed during the final 2 h. GlcN infusion induced severe impairment of insulin action on Rd (39.4 +/- 3.2 [4-5 h] vs. 49.8 +/- 3.6 [1-2 h] mg x kg(-1) x min(-1); P < 0.05), which the addition of IGF-1 failed to improve (35.9 +/- 2.3 [6-7 h] vs. 39.4 +/- 3.2 [4-5 h] mg x kg(-1) x min(-1); P > 0.1). In summary, GlcN induced severe resistance to the actions of both insu

Topics: Animals; Blood Glucose; Body Weight; Glucosamine; Glucose; Glucose Clamp Technique; Glycogen; Glycogen Synthase; Hexosamines; Insulin; Insulin Resistance; Insulin-Like Growth Factor I; Kinetics; Liver; Male; Muscle, Skeletal; Rats; Rats, Sprague-Dawley; Uridine Diphosphate N-Acetylglucosamine

To study how diet composition affects exercise endurance and body composition, 48 male Sprague-Dawley rats were treadmill trained for 8 wk while consuming either a high-fat (F) diet or high-carbohydrate (C) diet. The diets were switched for one-half the number of rats in each group 3 days before the animals were killed, during which feeding time the rats did not exercise. One-half of rats receiving each of the four diet combinations were taken at rest (R) or exhaustion (E), resulting in eight groups: CCR, CFR, FFR, FCR, CCE CFE, FFE, and FCE. An analysis of variance revealed that resting glycogen in the FCR group was enhanced in muscle (19-33%) and liver (23%) compared with controls. Each F group's exercise time to exhaustion [CFE, 322.9 +/- 25.0; FFE, 356.8 +/- 37.8; FCE, 467.0 +/- 32.6 (SE) min] was different (P < 0.05) from control (CCE, 257.5 +/- 29.2 min). Postexercise glycogen was equivalent among all dietary groups, were muscle triglycerides. The FF and FC groups had higher 3-hydroxyacyl-CoA dehydrogenase activity in soleus muscle than either CC or CF animals. After training, body weights were similar between the two dietary groups; however, percent body fat was 17% greater after the F diet, even though F diet animals voluntarily consumed 12% less energy than did C diet animals. These data suggest that exercise endurance time is optimized in trained rats that receive a carbohydrate load after adaptation to a F diet. However, despite intense exercise training, the F diet promotes body fat deposition, and the health consequences of following such a regimen are still unknown.

Topics: Animals; Body Weight; Dietary Carbohydrates; Dietary Fats; Fats; Glycogen; Male; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; Time Factors; Tissue Distribution

Forty male Long-Evans rats were used in an 8-week experiment designed to study the possibilities of using fats to increase aerobic work capacity and to elucidate the mechanisms of aerobic adaptation. The animals were divided into four groups: group SD comprised control rats kept on a standard diet and sedentary regimen; group HFD were given a high-fat diet (78 en.% of fats) and no training; group SDT consumed standard diet and were trained submaximally; group HFDT was on a high-fat diet and submaximal training. Submaximal running endurance (SRE) and maximum oxygen uptake (VO2max) tests were carried out in all groups. To clarify some of the mechanisms of aerobic adaptation we measured the glycogen content in m. gastrocnemius and the activity of key enzymes for the carbohydrate and fat metabolism, citrate synthase (CS), 3-hydroxiacetyl-CoA-dehydrogenase (3-HAD), and carnitine palmitoyl transferase (CPT) in muscle homogenates. It was found that a high-fat diet (HFD) improved the submaximal running endurance and if combined with submaximal training increased its effect several-fold. HFD increased the maximum oxygen uptake, training made it even greater, but the effect on VO2max the greatest when the two were used in combination. CS activity in m. soleus in HFD-fed rats was 23% greater than that in group SD, while 3-HAD activity was 27% higher than that in group SD. CPT activity in group HFDT was twice as great as that of the control group. Under the influence of HFD the muscle fibres underwent a shift of the energy substrate from carbohydrates to fats which was proved by the economical muscle glycogen depletion during physical exercise.

Topics: 3-Hydroxyacyl CoA Dehydrogenases; Aerobiosis; Animals; Body Weight; Carnitine O-Palmitoyltransferase; Citrate (si)-Synthase; Dietary Fats; Glycogen; Lactic Acid; Male; Muscles; Oxygen; Physical Conditioning, Animal; Physical Endurance; Rats; Work Capacity Evaluation

The effects of body weight cycling on energy metabolism and body fat accumulation were examined in sedentary and exercised rats. Ten rats were sacrificed before the experiment to obtain basal data, and then 90 rats were divided into three groups; control (CN), food restricted (FR) and weight cycling (WC). Food intake in rats of the FR group was restricted constantly to 70% of the intake of the CN group. The rats of WC group were subjected to four bouts of weight cycling consisting of 7-days food restriction followed by 7-days refeeding, but were fed the same total amount of dietary energy as that of the FR group throughout the experimental period. The rats of all groups were meal-fed twice a day. Half of the rats in each group were exercised by running on a treadmill (30 min/day) throughout the experimental period. The body weight, abdominal adipose tissue weight, body fat, body protein and energy restoration for the study in both sedentary and exercised groups were greater in the WC group than in the FR group. The resting metabolic rate of the WC group after four bouts of weight cycling was lower than that of the FR group in the sedentary rats, but this difference was not observed in the exercised rats. Also, the thermic effect of food (TEF) in the sedentary rats for 6 h after a meal was significantly less in the WC group as compared to that of the FR group. However, the TEF for the exercised rats was not different between the two groups. The serum insulin level, activities of lipogenic enzymes and lipoprotein lipase in adipose tissue for the sedentary rats of the WC group were higher than those of the FR group, but did not differ in the exercised rats. These results suggest that weight cycling increases body fat deposition and energy efficiency by decreasing energy expenditure, particularly the TEF, and that exercise training can alleviate the effects of weight cycling on the energy metabolism.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Composition; Body Weight; Energy Metabolism; Fatty Acids, Nonesterified; Female; Food; Food Deprivation; Glycogen; Insulin; Lipoprotein Lipase; Organ Size; Oxygen Consumption; Physical Exertion; Proteins; Rats; Rats, Sprague-Dawley

Aggressive territorial behavior was studied in 15 colonies of wild rats (Rattus norvegicus), each consisting of 2 males and 1 female. One of the males attacked an intruder rat more frequently and had a higher body weight than the less aggressive one. In another experiment, male and female rats were raised in colonies from weaning to adulthood. Animals were weighed every 7 days until 90 days of age when plasma testosterone was measured in males, and plasma glucose, hepatic and muscle glycogen were measured in both males and females. THe heavier (and thus possibly dominant) males in the colonies of 3 males and 1 female also had a higher body weight than males raised with females, but without any male partner. In this long-term social relationship there were no significant differences in carbohydrate metabolism among the animals. The differential growth rate among males was established around the period of sexual maturity. Moreover, when adult, heavier males had higher plasma testosterone levels compared to the other members of the colony and also to males that had no other competitive male partner. This higher androgenic hormone level may be one of the causal factors involved in the weight increase of the dominant male in the colony.

Topics: Aggression; Animals; Animals, Laboratory; Body Weight; Carbohydrate Metabolism; Female; Glucose; Glycogen; Liver; Male; Muscles; Rats; Territoriality; Testosterone

The role of the lateral hypothalamic area (LHA) in intermediary metabolism was investigated by quantitation of [U-14C]glucose oxidation to 14CO2 and 14C incorporation into the glycogen and lipid fraction of the liver, epididymal fat pad, and diaphragm. Weanling male Sprague-Dawley rats received bilateral electrolytic lesions in the LHA (LHAL rats). Sham operated rats were either fed ad libitum (CON-ADLIB) or pair-gained to the LHAL rats (CON-PG). The experiment was terminated 1 month after lesion production. LHAL rats were significantly (SIG) lighter and shorter and ate less than CON-ADLIB; LHAL rats were also SIG shorter than CON-PG, pointing to a food intake-independent lesion effect. Both LHAL and CON-PG rats had SIG less percent carcass fat than CON-ADLIB, but there was no SIG difference between LHAL and CON-PG rats. Also, LHAL rats had a SIG higher percentage of carcass protein than both CON-ADLIB and CON-PG. Furthermore, LHAL rats incorporated SIG less glucose into liver glycogen than CON-ADLIB but SIG more into CON-PG, whereas CON-PG rats incorporated SIG less into liver glycogen than CON-ADLIB, again suggesting a food intake-independent effect. There was no difference among the groups in glucose oxidation and incorporation into lipids and glycogen in both diaphragm and epididymal fat pads and liver total lipid. However, livers of CON-PG metabolized SIG more [U-14C]glucose to CO2 than did livers of CON-ADLIB, suggesting a food intake-dependent effect. There was no difference between LHAL and CON-PG rats in this parameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adipose Tissue; Animals; Body Weight; Carbon Dioxide; Diaphragm; Eating; Energy Intake; Epididymis; Glucose; Glycogen; Hypothalamic Area, Lateral; Liver; Male; Rats; Rats, Sprague-Dawley; Time Factors; Weaning

The effect of 1 wk of glucocorticoid deprivation by surgical adrenalectomy (ADX) on tissue 2-deoxy(-)[U-14C]glucose (2-DG) uptake and hepatic glucose production (HGP) was assessed in conscious, catheterized mice 5 wk after the induction of obesity with gold thioglucose (GTG). Despite the prevailing hyperglycemia and hyperinsulinemia, glucose uptake by heart, quadriceps muscle, and interscapular brown adipose tissue (BAT) of GTG-obese mice was unchanged compared with controls, suggesting that the hyperglycemia of GTG-obese mice is able to compensate for the insulin resistance of these tissues. In contrast, epididymal white adipose tissue (WAT) of GTG-obese mice showed increased glucose uptake with hyperglycemia and hyperinsulinemia. ADX decreased the hyperglycemia and lowered the elevated glycogen content of the liver of GTG-obese mice. ADX reduced glucose uptake by heart and WAT of control and GTG-obese mice, consistent with the concomitant decrease in insulinemia. Glucose uptake by muscle of control and GTG-obese mice was not significantly decreased after ADX despite the decrease in insulin, and ADX increased glucose uptake by BAT of GTG-obese mice, suggesting increased sympathetically mediated thermogenesis in this tissue. HGP was increased in GTG-obese mice compared with controls, and ADX significantly reduced HGP in both GTG-obese and control mice. These results suggest that the improved glucose tolerance of ADX GTG-obese mice and ADX control mice is due to a decrease in HGP rather than an increase in peripheral glucose uptake.

Topics: Adipose Tissue; Adrenalectomy; Animals; Aurothioglucose; Blood Glucose; Body Weight; Corticosterone; Glucocorticoids; Glucose; Glycogen; Insulin; Liver; Male; Mice; Mice, Obese; Muscles; Organ Size

The hypothesis was tested that goats allowed ad libitum access to feed during the dry period develop higher post partum hepatic triacylglycerol concentrations than do goats given a restricted amount of feed during the dry period. Goats in their second or more pregnancies were either given a restricted amount of hay, maize silage and concentrate (n = 5) or had free access to this feed mixture while the composition was kept constant (n = 11). After parturition both groups were allowed ad libitum access to feed. Post partum liver triacylglycerol concentrations, as measured in liver biopsies, were significantly raised in goats allowed ad libitum access to feed during the dry period. The increase in liver triacylglycerols was associated with slightly higher plasma concentrations of non-esterified fatty acids but lower serum 3-hydroxybutyrate concentrations. The feeding regimen during the dry period did not significantly influence post partum liver glycogen concentrations and serum levels of glucose, cholesterol, and insulin. The increase in post partum liver triacylglycerol concentrations in the goats allowed ad libitum access to feed instead of a restricted ration during the dry period, was associated with a significant rise in serum alkaline phosphatase activities, whereas other liver function and cell damage indicators in serum, i.e. aspartate aminotransferase, lactate dehydrogenase, gamma glutamyl transpeptidase, and bilirubin, were unchanged. Feed intake after parturition tended to be higher in the goats allowed ad libitum access to feed during the dry period but milk production was significantly raised.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Analysis of Variance; Animals; Biomarkers; Body Weight; Carbohydrates; Eating; Fasting; Female; Glycogen; Goats; Labor, Obstetric; Lipids; Liver; Postpartum Period; Pregnancy; Triglycerides

The effects of cortisone and testosterone on in vivo diaphragmatic function and biochemistry were assessed in rabbits to determine whether androgens can prevent the effects of corticosteroids on diaphragmatic function and biochemistry and what mechanisms of muscle function may be altered. Cortisone altered respiratory muscle endurance and diaphragmatic glycogen and lactate levels but had little effect on diaphragmatic strength. Testosterone had no significant impact on diaphragmatic strength, endurance, or biochemistry. However, concomitant administration of testosterone with cortisone blunted the effect of cortisone on respiratory muscle endurance, even though it failed to block the effects of cortisone on diaphragmatic glycogen and lactate levels. Alterations in respiratory muscle endurance were not due to low- or high-frequency contractile fatigue of the diaphragm or diaphragmatic glycogen depletion or lactate accumulation in any of the treatment conditions. On the other hand, alterations in central drive played a dominant role, as evidenced by alterations in inspiratory duty cycle and a falloff in the intensity of central drive during loading. Although the exact mechanisms underlying the alterations in central drive remain unknown, concomitant administration of androgens with corticosteroids blunted the impact of corticosteroids on respiratory muscle function.

Topics: Animals; Body Weight; Cortisone; Diaphragm; Glycogen; Lactates; Lactic Acid; Male; Muscle Fatigue; Rabbits; Respiration; Respiratory Function Tests; Testosterone

The effects of long-term exposure (7 wk) to hyperinsulinaemia on insulin sensitivity were studied in female rats. The rats were made hyperinsulinaemic by implantation of osmotic minipumps that were changed once a week. Elevated adrenergic activity and secretion of glucocorticoids were controlled by another minipump with propranolol and adrenalectomy with corticosterone substitution, respectively. This resulted in hyperinsulinaemia and moderate hypoglycaemia, the latter probably counteracted by overeating and increased glucagon secretion, as indicated by increased body weight and lower liver glycogen contents, respectively. Euglycaemic, hyperinsulinaemic clamp measurements showed a significantly higher glucose disposal rate (P < 0.05) in the hyperinsulinaemic rats 18.8 +/- 1.1 mg kg-1 min-1 compared with the control groups 14.6 +/- 0.4 and 15.4 +/- 0.9 mg kg-1 min-1. Insulin stimulation of 2-deoxyglucose as well as glycogen synthesis was measured in the extensor digitorum longus muscle, the red and white part of the gastrocnemius, the soleus muscle, the liver and in parametrial, retroperitoneal, and inguinal adipose tissue. No differences were found between the groups in the insulin response of the 2-deoxyglucose uptake. Glycogen synthesis was significantly elevated in all muscles in the insulin treated compared with the control rats but no differences were found in the liver. Capillary density was significantly elevated per unit muscle surface area in the soleus and extensor digitorum longus muscles of the insulin-exposed rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blood Glucose; Body Weight; Deoxyglucose; Female; Glycogen; Hyperinsulinism; Insulin; Muscle, Skeletal; Propranolol; Rats; Rats, Sprague-Dawley

Blood sugar levels of normal rats treated with D-400 showed significant reduction (P < 0.05) as compared to control groups. The fall was seen at one month and remained so uptill 3 months. Hyperglycemic response to adrenaline was significantly lowered (P < 0.05) following D-400 treatment. D-400 potentiated the hypoglycemia following tolbutamide treatment. Blood sugar remained persistently low in tolbutamide plus D-400 treated group after 3 and 4 hours (P < 0.05). In the alloxan-induced diabetic rats, a significant lowering of blood and urinary sugar was noticed on day 20, 30 and 40 following treatment with D-400 (P < 0.05). Liver glycogen depletion was significantly inhibited in the D-400 treated group (P < 0.025). D-400 has significantly potentiated (P < 0.05) the hypoglycemic action of insulin in alloxan-induced diabetic rats.

Topics: Alloxan; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Epinephrine; Fasting; Female; Glycogen; Glycosuria; Liver; Male; Phytotherapy; Plant Extracts; Rats; Rats, Wistar; Tolbutamide

In terms of the LD50 values for alcohols, third-instar wild-type larvae of Drosophila melanogaster had a greater tolerance to ethanol, n-propanol and n-butanol than alcohol dehydrogenase (ADH)-deficient larvae. The tolerances of the two strains to methanol were similar. Methanol, ethanol, n-propanol and n-butanol all induced higher ADH activity in wild-type larvae. Ethanol, n-propanol, methanol and n-butanol slowed the growth for ADH-deficient larvae, whereas only methanol had this effect on wild-type larvae. The proportion of wild-type pupae to eclose was increased by n-butanol, n-propanol and ethanol. Cytometric methods to measure the densities of storage bodies--glycogen rosettes, protein bodies and lipid droplets--in fat body cells indicated that all of the test alcohols exerted some negative influence on the accumulation of at least one type of storage body. Analyses of total protein, glycogen and acylglycerols indicated that ethanol and n-butanol were associated with an accumulation of acylglycerols in both wild-type and ADH-deficient larvae; whereas, the other test alcohols resulted in low glycogen and protein concentrations in both test strains. The short-chain primary alcohols may in part be toxic to larvae because of disruptions in metabolism that lead to reductions in one or more kinds of storage bodies in the larval fat body.

Topics: 1-Butanol; 1-Propanol; Alcohol Dehydrogenase; Alcohols; Analysis of Variance; Animals; Body Weight; Butanols; Drosophila melanogaster; Ethanol; Fat Body; Flow Cytometry; Glycerides; Glycogen; Larva; Lethal Dose 50; Male; Methanol; Microscopy, Electron; Proteins; Pupa

To determine whether acute bouts of exercise during pregnancy would predispose the fetus to increased risk if maternal dietary carbohydrate were restricted, untrained pregnant rats were randomly assigned to a 0% (low), 12% (moderate) or 60% (high) glucose diet, and either rested or exercised daily for 20 min from d 16 to term on a rodent treadmill at a mild (15.5 m/min) or moderate (24.3 m/min) intensity. A 3 x 3 nested factorial model with and without food intake as a covariate was employed. Both greater exercise intensity and the lower levels of dietary carbohydrate independently decreased term maternal liver and plantaris glycogen concentrations and increased plasma lactate concentrations. However, significant differences due to exercise disappeared (except for plasma lactate) with food intake controlled for in the model, indicating that energy deficits modulated these exercise effects. In contrast, for the offspring, when food intake was controlled for, a restricted level of maternal dietary carbohydrate significantly lowered fetal weight, plasma glucose and insulin concentrations and liver glycogen concentrations measured at term. Exercise alone did not reduce mean fetal weight if nested weights within a litter were used in the statistical analysis. Mild to moderate maternal exercise lowered only fetal plasma glucose concentrations and only if maternal food intake was not controlled for. These results indicate that acute exercise during pregnancy can have detrimental effects on fetal development only if dietary glucose is severely restricted. Otherwise, adequate glucose and energy in the maternal diet in untrained pregnant rats during repeated bouts of acute exercise seem to protect the fetus.

Topics: Amniotic Fluid; Animals; Blood Glucose; Body Weight; Dietary Carbohydrates; Eating; Embryonic and Fetal Development; Female; Fetal Blood; Glucose; Glycogen; Heart; Homeostasis; Insulin; Lactates; Litter Size; Liver; Models, Statistical; Myocardium; Physical Conditioning, Animal; Pregnancy; Pregnancy, Animal; Random Allocation; Rats; Rats, Sprague-Dawley

Brown adipose tissue (BAT) contains glucocorticoid receptors; glucocorticoids are required for maintaining differentiated BAT in culture. These studies were performed to determine the effects of corticosterone on BAT thermogenic function and lipid storage. Rats were adrenalectomized and given subcutaneous corticosterone pellets in concentrations that maintained plasma corticosterone constant across the range of 0-20 micrograms/dl or were sham adrenalectomized. All variables were examined 5 days after surgery and corticosterone replacement. Measures of BAT function-thermogenic capacity [guanosine 5'-diphosphate (GDP) binding and uncoupling protein (UCP; a BAT-specific thermogenic protein)] and storage (BAT wet wt, protein, and DNA levels) were made. Plasma hormones (corticosterone, adrenocorticotropic hormone, insulin, 3,3',5-triiodothyronine, and thyroxine were measured. Corticosterone significantly affected BAT thermogenic measures: UCP content and binding of GDP to BAT mitochondria decreased with increasing corticosterone; GDP binding characteristics in BAT from similarly prepared rats examined by Scatchard analysis showed that maximum binding (Bmax) and dissociation constant (Kd) decreased with increasing corticosterone dose. BAT DNA was increased by adrenalectomy and maintained at intact levels with all doses of corticosterone; BAT lipid storage increased dramatically at corticosterone values higher than the daily mean level in intact rats. Histologically, the number and size of lipid droplets within BAT adipocytes increased markedly with increased corticosterone. White adipose depots were more sensitive to circulating corticosterone concentrations than were BAT depots and increased in weight at levels of corticosterone that were at or below the daily mean level of intact rats. We conclude that, within its diurnal range of concentration corticosterone acts to inhibit nonshivering thermogenesis and increase lipid storage.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adipocytes; Adipose Tissue; Adipose Tissue, Brown; Adrenalectomy; Adrenocorticotropic Hormone; Animals; Body Temperature Regulation; Body Weight; Carrier Proteins; Corticosterone; DNA; Dose-Response Relationship, Drug; Drug Implants; Epididymis; Glycogen; Guanosine Diphosphate; In Vitro Techniques; Insulin; Ion Channels; Lipid Metabolism; Male; Membrane Proteins; Mitochondrial Proteins; Pituitary Gland, Anterior; Rats; Rats, Sprague-Dawley; Thyroxine; Time Factors; Triiodothyronine; Uncoupling Protein 1

To compare the physiological response to a cocaine-exercise challenge in cocaine-conditioned animals with that of acute-cocaine animals, rats were injected i.p. with either cocaine (20 mg.kg-1) or saline, twice daily for 14 consecutive days. On the 15th day (test day) cocaine-conditioned rats received an i.v. injection of cocaine (5 mg.kg-1) (chronic group). One-half of the chronic saline rats also received the cocaine injection (acute group), while the other half received saline (saline group). Immediately after injection, all rats were either rested or exercised (22 m.min-1, 10% grade) for 30 min. For most parameters there was no difference between the responses of the chronic and acute cocaine groups at rest or to the cocaine-exercise challenge. During exercise, both cocaine groups had similarly higher lactate values than the saline animals (P < 0.05). Both groups had similarly greater reductions in glycogen content of the white and red vastus muscles than occurred in the saline group; and both groups had similar increases in corticosterone. In contrast, cocaine-conditioned animals had a greater rise in norepinephrine (P < 0.059) and epinephrine (P < 0.001) in response to cocaine-exercise than did the acute group. The mechanism responsible for the exaggerated catecholamine response in the chronic cocaine animals is unknown.

Topics: Adaptation, Physiological; Animals; Blood Glucose; Body Weight; Cocaine; Corticosterone; Dopamine; Epinephrine; Glycogen; Injections, Intraperitoneal; Lactates; Male; Muscle, Skeletal; Norepinephrine; Physical Exertion; Rats; Rats, Sprague-Dawley; Sodium Chloride

We have performed a comparative analysis of the effects of age of reproduction on the biochemical (protein, lipid, and glycogen content) and stress resistance (ability to survive starvation, desiccation, and exogenous paraquat) parameters on 10 sister lines of five different Drosophila strains. Four pairs of these sister lines were selected under different regimens for either early or delayed reproduction; the fifth pair was maintained in a nonselected state and served as the baseline strain to which all others were compared. It is generally accepted that the early regimens give rise to short-lived phenotypes, whereas the delayed regimens give rise to long-lived phenotypes. Our results suggest that a mechanism involving lipid and starvation resistance is not operative in our long-lived strains. In addition, a mechanism involving glycogen content and desiccation resistance is only weakly supported. Finally, there is strong support for a mechanism that gives rise to enhanced paraquat resistance and therefore may involve regulatory changes in the pattern of ADS gene expression. In addition, the 15-day early age of reproduction regimen (M type) shows qualitatively similar responses to that of the late age at reproduction regimen (L type). These results suggest that correlations between biochemical traits and longevity must be interpreted with caution. We discuss possible reasons for these results, including the possibility of multiple mechanisms, each leading to a different extended longevity phenotype.

Topics: Animals; Body Weight; Drosophila melanogaster; Female; Glycogen; Lipid Metabolism; Longevity; Paraquat; Proteins; Reproduction; Starvation; Water

To investigate the effect of dietary fish oil on the lipid and glucose metabolism, Wistar rats were fed lard (10% fat by weight) or fish oil (5% lard + 5% fish oil) diet for 7 weeks. Significantly (p < 0.05) lower plasma total cholesterol, low density lipoprotein cholesterol (VLDL-C) levels were observed in rats fed a diet containing fish oil when compared with rats fed lard diet. Fish oil supplementation decreased plasma lactic acid and free fatty acid levels. In addition, lower plasma lactate dehydrogenase (LDH) activity and an improved glucose tolerance ability were observed in rats fed fish oil diet. However, no significant change in plasma glucose level was found in rats between the two dietary groups. Although rats fed a diet containing fish oil had significantly (p < 0.05) decreased total cholesterol and phospholipid contents in the liver, there was no significant difference in liver triglyceride content between the two dietary groups. It is interesting to note that fish oil supplement significantly (p < 0.05) decreased liver glucose-6-phosphate dehydrogenase (G-6-PDH) and glucose-6-phosphatase (G-6-Pase) activities. Results from the present study suggest that dietary n-3 polyunsaturated fatty acids might play an important role in regulation of glucose and lipid metabolism in rats.

Topics: Animals; Body Weight; Dietary Fats, Unsaturated; Fatty Acids; Fish Oils; Glucose Tolerance Test; Glucose-6-Phosphatase; Glucosephosphate Dehydrogenase; Glycogen; Lipid Metabolism; Lipids; Lipoproteins; Liver; Organ Size; Rats; Rats, Wistar

The effect of intrauterine and postnatal protein-calorie malnutrition on the biochemical ability to perform exercise was investigated in young male rats. Malnourished rats were obtained by feeding dams a low-protein (6%) casein-based diet prepared in the laboratory during pregnancy and lactation. Control rats received an isocaloric diet containing 25% protein. The low-protein diet contained additional starch and glucose. At 45 days of age, malnourished rats showed lower body weight, serum protein, albumin and glucose levels, hematocrit values and heart glycogen content but higher circulating free fatty acids and gastrocnemius muscle glycogen than control rats. In response to exercise (50 min of swimming), control rats displayed lower heart, gastrocnemius and liver glycogen levels whereas malnourished rats showed low glycogen levels only in the gastrocnemius muscle. Both control and malnourished rats showed high serum glucose and free fatty acid levels after exercise. In conclusion, protein-calorie malnutrition improved muscle glycogen storage but this substrate was broken down to a greater extent in response to exercise. Malnourished rats were able to perform exercise maintaining high blood glucose levels, as observed in control rats, perhaps as a consequence of the elevated availability of circulating free fatty acids.

Topics: Adaptation, Physiological; Animals; Blood Proteins; Body Weight; Female; Glycogen; Hematocrit; Male; Physical Conditioning, Animal; Pregnancy; Pregnancy Complications; Protein-Energy Malnutrition; Rats; Rats, Wistar

Changes in neurobiological parameters were examined from early life (10 days post-natal) until late adulthood (8 months post-natal) in three successive generations of alcoholized rats. The mean daily consumption of alcohol by the 2nd and 3rd generation rats (7.40 +/- 0.22 and 7.70 +/- 0.20 g ethanol/kg body weight, respectively) was significantly greater than that of the 1st generation alcoholized group (4.26 +/- 0.33 g/kg). Brain/body weight ratios of alcoholized rats, 10 days post-natal, were significantly greater than controls, with 1st generation alcoholized rats presenting significantly greater brain/body weight ratios than those of the 2nd or 3rd generation, which tended toward control weights and ratios. This difference between alcoholized rats and controls persisted, although to a lesser extent, at 8 months post-natal. Glycogen content in the brains of rats of all alcoholized generations was significantly lower than in controls at 10 days post-natal, with a reversal of this situation in later life for 2nd and 3rd generation rats, which presented significantly greater cerebral glycogen levels than control or 1st generation alcoholized rats (which had an equivalent cerebral glycogen content). In 10-day-old rat pups, monoamine oxidase (MAO) activity in brain tissues had a tendency (mostly non-significant) to be greater in alcoholized rats than in controls, with a reversal of this situation, ie a statistically significant decrease in MAO activity in the 2nd and 3rd alcoholized generations with respect to controls, in 8-month-old rats. MAO activity in adrenal glands of alcoholized rats was greater than in controls at 10 days post-natal, and this difference persisted at 8 months.

Topics: Alcoholism; Animals; Body Weight; Brain; Brain Chemistry; Ethanol; Female; Glucose; Glycogen; Male; Monoamine Oxidase; Organ Size; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Wistar

Total body weight, total glycogen content and the percentage of body weight attributable to stored glycogen were measured in wild-type and two wing-mutant strains of 0-2-day-old (immature) and 5-7-day-old (mature) Drosophila melanogaster. Wild-type and wing mutant strains did not differ significantly in any of the measured parameters at 0-2 days of age. By 5-7 days of age, significant increases in glycogen content and glycogen percent had occurred in both wild-type and wing-mutant strains. Likewise, by 5-7 days of age, total body weight had increased significantly in the mature wild-type and vestigial strains but not in apterous flies. Mature wild-type flies displayed significantly greater total body glycogen content and glycogen percent when compared with the mature apterous and vestigial wing-mutant strains.

Topics: Animals; Body Weight; Drosophila melanogaster; Glycogen; Mutation; Wings, Animal

We have recently reported that rates of muscle glycogen repletion during the early period of recovery were increased by carbohydrate (CHO) loading in rats previously fed a high fat diet. However, the reason for this remained unanswered. The purpose of this study was to examine whether an increase of glycogen utilization due to an elevated pre-exercise glycogen store would enhance rates of glycogen repletion in muscle. Despite an equal degree of glycogen depletion, the rates of glycogen repletion of soleus, red and white gastrocnemius muscles by postexercise administration of glucose (3.0 g.kg-1 body mass) and citrate (0.5 g.kg-1 body mass) were faster in the CHO loaded (3 days) rats than in the nonloaded rats, as a result of elevated pre-exercise glycogen content and consequently the greater glycogen utilization. The higher rate of muscle glycogen repletion may in part be explained by increased postexercise glycogen synthase activity.

Topics: Animal Feed; Animals; Blood Chemical Analysis; Body Weight; Dietary Carbohydrates; Dietary Fats; Glycogen; Glycogen Synthase; Insulin; Liver Glycogen; Male; Muscle, Skeletal; Physical Exertion; Rats; Rats, Sprague-Dawley; Thyroid Hormones

Responses to insulin-induced hypoglycemia in fasted sham-operated (SHAM), adrenodemedullated (ADM), and epinephrine-infused ADM (ADM + E) rats were studied to ascertain the specific role of epinephrine in increasing resting skeletal muscle content of adenosine 3',5'-cyclic monophosphate (cAMP) and fructose 2,6-bisphosphate (F-2,6-P2), which are involved in stimulation of muscle glycogenolysis and lactate production. Rats from each group were fasted for 24 h and then infused intravenously with insulin (30, 60, or 90 min) to produce plasma insulin values of approximately 92 microU/ml. One-half of the insulin-infused ADM rats were also infused with epinephrine (ADM + E). Muscle and blood lactate, muscle cAMP, and muscle F-2,6-P2 increased and muscle glycogen decreased in SHAM rats. Each of these changes was prevented or attenuated in ADM rats and restored in ADM + E rats. Liver cAMP, glycogen, and F-2,6-P2 responses to hypoglycemia were similar in SHAM, ADM, and ADM + E rats. Blood glucose decreased to 0.74 +/- 0.05 mM in ADM rats compared with 1.54 +/- 0.11 mM in SHAM and 1.34 +/- 0.15 mM in ADM + E rats after 90 min of insulin infusion. The increase in plasma epinephrine is therefore essential in the counterregulatory response to insulin-induced hypoglycemia in fasted rats. Resting skeletal muscle glycogenolysis and lactate production for hepatic gluconeogenic substrate appear to be important components of the counterregulatory response in fasted rats.

Topics: Adrenal Medulla; Animals; Blood Glucose; Body Weight; Cyclic GMP; Epinephrine; Fasting; Glycogen; Hypoglycemia; Insulin; Lactates; Lactic Acid; Liver; Male; Muscle, Skeletal; Rats; Rats, Sprague-Dawley

The effects of salts of propionic acid on newly hatched turkeys were examined. In Experiment 1, poults were injected with .25 mL of 1 M solutions of either sodium propionate or calcium propionate. After a 24-h holding period, the poults were killed and assayed for blood glucose, liver weight, and liver glycogen. Sodium propionate increased blood glucose concentration but did not alter liver weight or liver glycogen compared with controls. Calcium propionate had no effect on blood glucose but increased liver weight and liver glycogen compared with controls. There was no mortality in saline-injected controls or sodium propionate poults; 4 of 10 poults injected with calcium propionate died. In Experiment 2, poults were administered 0 or 4% sodium propionate in the feed or 0 or 2% sodium propionate in the drinking water in a 2 x 2 factorial arrangement. Propionate depressed feed intake and body weight by both routes of administration. Propionate in the feed, but not drinking water, depressed liver weight and liver glycogen. Plasma uric acid was increased by propionate in either the feed or the water but was not above control amounts when propionate was given in both the feed and water at the same time. Plasma propionic acid was increased by propionate in the water but not by propionate in the feed. We conclude that the use of propionate in injectibles, drinking water, or feed of newly hatched turkeys is contraindicated.

Topics: Animals; Animals, Newborn; Blood Glucose; Body Weight; Contraindications; Eating; Food, Fortified; Glycogen; Injections, Subcutaneous; Liver; Organ Size; Propionates; Turkeys; Uric Acid

The time course (1, 5, or 20 days) for the effect of dietary restriction (DR; approximately 25% reduction below ad libitum intake) on epitrochlearis and flexor digitorum brevis (FDB) muscle glucose transport activity was studied in female Fischer 344 rats (8 mo old). Epitrochlearis glucose transport activity with 100 microU/ml insulin was increased by 38% after 5 days of DR (P < 0.05) despite no change in glucose transport activity with 0 or 20,000 microU/ml insulin. The increase with 100 microU/ml insulin was not further enhanced by 20 days of DR. DR did not result in a significant increase in the glucose transport activity of the FDB with 0, 100, or 20,000 microU/ml insulin. Abdominal fat content was significantly (P < 0.01) reduced below ad libitum levels only after 20 days of DR. These results demonstrate that DR-induced improvement in epitrochlearis glucose transport activity with a physiological insulin concentration can occur very rapidly, preceding detectable changes in basal or maximal insulin-stimulated glucose transport activity or abdominal fat pad mass, and the enhancement of insulin action does not occur simultaneously in all muscles.

Topics: 3-O-Methylglucose; Adipose Tissue; Animals; Biological Transport; Blood Glucose; Body Weight; Diet; Elbow; Female; Glucose; Glycogen; Insulin; Methylglucosides; Muscles; Organ Size; Rats; Rats, Inbred F344; Toes

The effect of adrenalectomy (ADX) on body weight, lipogenesis, and glucose tolerance was investigated in mice made obese by a single intraperitoneal injection of gold-thioglucose (GTG). Five weeks after ADX the weight of GTG-obese mice was significantly decreased (GTG-obese+sham-ADX: 39.8 +/- 0.8 g; GTG-obese+ADX: 27.6 +/- 1.1 g; P < 0.05). ADX also reduced serum glucose (GTG-obese+sham-ADX: 16.5 +/- 0.6 mmol/l; GTG-obese+ADX: 10.8 +/- 0.5 mmol/l; P < 0.05) and serum insulin concentrations (GTG-obese+sham-ADX: 197 +/- 36 microU/ml; GTG-obese+ADX: 38 +/- 7 microU/ml; P < 0.05) of fed GTG-obese mice and greatly improved glucose tolerance. ADX lowered liver glycogen content and reduced the fatty acid content of liver, epididymal white adipose tissue (WAT), and interscapular brown adipose tissue (BAT) of fed GTG-obese mice. Lipid synthesis in liver and WAT of GTG-obese mice was decreased by ADX, but lipogenesis in BAT was increased, possibly to provide substrate for increased thermogenesis in this tissue. Effects of ADX on metabolism were not confined to GTG-injected mice, as ADX also reduced body weight and altered the glucose tolerance of age-matched control mice. ADX increased lipid synthesis in liver, WAT, and BAT of fed control mice without an increase in lipid deposition, indicating that there was increased lipid turnover in these lipogenic tissues of ADX mice. ADX reduced the fasting blood glucose concentration of both control and GTG-obese mice to a level below that of sham-ADX control mice (sham-ADX control: 6.0 +/- 0.4 mM; ADX control: 2.9 +/- 0.5 mM; ADX GTG-obese: 3.3 +/- 0.2 mM).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adrenalectomy; Animals; Aurothioglucose; Blood Glucose; Body Weight; Corticosterone; Eating; Ether; Fatty Acids; Glucose; Glucose Tolerance Test; Glycogen; Insulin; Lipids; Liver; Male; Mice; Mice, Inbred CBA; Obesity

Serotoninergic neuronal networks are important for food intake and body weight regulation. However, the mechanisms by which some metabolic pathways are influenced are rather unclear. Dexfenfluramine (DF), a serotonin releaser and re-uptake inhibitor, was used to investigate changes in food intake, body weight development, energy expenditure, respiratory quotient and substrate oxidation rates for 12 days. Normal rats, receiving an energy-controlled mash diet and water ad libitum were intraperitoneally injected daily with either saline, 1, 2.5, 5 or 10 mg DF/kg. Compared to controls, food intake, body weight development and energy expenditure were decreased in a dose-dependent manner, especially during the first six days. Lipid oxidation was increased while oxidation of carbohydrates was decreased. Pair-feeding experiments over three days revealed that this was a clear pharmacological effect and not simply a result of diminished food intake. At the end of these experiments, plasma glucose and liver and muscle glycogen were unchanged after DF, but isoleucine, leucine and lysine were significantly decreased in plasma and liver. Therefore, the plasma tryptophan/large neutral amino acids ratio was slightly increased. Protein oxidation was unchanged after DF. It is concluded that a prompt decline in energy expenditure with increased fat oxidation rates could mediate the body weight reducing effect of DF.

Topics: Amino Acids; Animals; Blood Glucose; Body Weight; Calorimetry, Indirect; Eating; Energy Metabolism; Fenfluramine; Glycogen; Liver; Male; Muscles; Rats; Rats, Wistar; Serotonin

Voluntary wheel running (WR) by juvenile female rats was used as a noninterventional model of soleus muscle functional overload to study the regulation of insulin-stimulated glucose transport activity by the glucose transporter (GLUT-4 isoform) protein level and glycogen concentration. Soleus total protein content was significantly greater (+18%; P < 0.05) than in age-matched controls after 1 wk of WR, and this hypertrophic response continued in weeks 2-4 (+24-32%). GLUT-4 protein was 39% greater than in controls in 1-wk WR soleus, and this adaptation was accompanied by a similar increase in in vitro insulin-stimulated glucose transport activity (+29%). After 2 and 4 wk of WR, however, insulin-stimulated glucose transport activity had returned to control levels, despite a continued elevation (+25-28%) of GLUT-4 protein. At these two time points, glycogen concentration was significantly enhanced in WR soleus (+21-42%), which coincided with significant reductions in glycogen synthase activity ratios (-23 to -41%). These results indicate that, in this model of soleus muscle functional overload, the GLUT-4 protein level may initially regulate insulin-stimulated glucose transport activity in the absence of changes in other modifying factors. However, this regulation of glucose transport activity by GLUT-4 protein may be subsequently overridden by elevated glycogen concentration.

Topics: Animals; Body Weight; Female; Glucose; Glucose Transporter Type 4; Glycogen; Hexokinase; Insulin; Monosaccharide Transport Proteins; Muscle Proteins; Muscles; Organ Size; Physical Exertion; Rats; Rats, Sprague-Dawley

The effects of endurance training (running 30 m/min, 10% grade for 90 min, 5 days/wk for 12 wk) on skeletal muscle glucose uptake during steady-state exercise (running 20 m/min) were studied in fed rats. A bolus injection of 2-[1,2-3H]deoxyglucose was administered to assess the glucose metabolic index (R'g), an indicator of glucose uptake, in individual tissues of the animal. After 55 min of rest or moderate exercise, various tissues were analyzed for accumulation of phosphorylated 2-[1,2-3H]-deoxyglucose and/or glycogen content. No differences were observed between groups in the resting glycogen content for any of the muscle samples examined. Resting plasma glucose concentrations were not significantly different between groups. Furthermore, no significant differences were observed in R'g between groups for any of the muscle examined (tibialis anterior, extensor digitorum longus, soleus, white gastrocnemius, red gastrocnemius). During exercise, plasma glucose concentrations were not significantly different between groups. Exercise significantly elevated R'g above resting values in the tibialis anterior (5-fold), soleus (3-fold), and red gastrocnemius (7.5-fold). Despite an elevated R'g for specific muscles during exercise, no significant differences were observed in glucose uptake between groups for any tissue examined. Concomitantly, trained animals exhibited significantly less muscle glycogen depletion during exercise compared with control animals. Liver glycogen levels were also significantly higher post-exercise in trained vs. control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blood Glucose; Body Weight; Deoxyglucose; Female; Glucose; Glycogen; Lactates; Lactic Acid; Muscles; Physical Conditioning, Animal; Physical Endurance; Physical Exertion; Rats; Rats, Wistar

To evaluate markers for overtraining, seven male race horses were subjected to 272 days of training consisting of daily exercise bouts of either endurance running (heart rate 140/min) or interval training (maximal heart rate), both increasing in duration and intensity. An incremental exercise test was held every 4 wk, and from day 187 it was held every 2 wk. Muscle glycogen, muscle lactate, energy-rich phosphates, adrenal response to adrenocorticotropic hormone, plasma and red blood cell volumes, and a number of blood chemical variables were measured. The horses showed symptoms of weight loss, irritability, and an inability to complete the training after the intensity of the endurance exercise was increased. Test performance was not decreased. The adrenal response to adrenocorticotropic hormone was not changed during overtraining. The decline in muscle ATP concentration during maximal exercise was less during the period of staleness, whereas plasma volume, red blood cell volume, and blood chemical variables were unchanged. It was concluded that as long as exhaustive training is alternated by light exercise, overtraining is unlikely to occur. Furthermore, no single parameter can be used to detect early overtraining.

Topics: Adaptation, Physiological; Adrenal Glands; Adrenocorticotropic Hormone; Animals; Blood Urea Nitrogen; Blood Volume; Body Weight; Creatine Kinase; Creatinine; Exercise Test; Glycogen; Horses; Lactates; Lactic Acid; Male; Muscles; Phosphates; Physical Conditioning, Animal; Physical Exertion

The epinephrine-induced production of lactate in nonexercising muscles may be due in part to allosteric activation of 6-phosphofructo-1-kinase by fructose 2,6-bisphosphate (F-2,6-P2). To determine if a correlation exists between F-2,6-P2 and lactate production in skeletal muscle, isolated rat hindlimbs were perfused for 30 min with a medium containing epinephrine at concentrations varying between 1.7 +/- 0.5 and 72.4 +/- 4.2 nM. In comparison to control values, hindlimbs perfused with 72.4 +/- 4.2 nM epinephrine had a two- to threefold increase in F-2,6-P2 and a fourfold increase in muscle lactate production. Hindlimb lactate production was highly correlated to gastrocnemius adenosine 3',5'-cyclic monophosphate (r = 0.80), fructose 6-phosphate (r = 0.87), and F-2,6-P2 (r = 0.81). The adenosine 3',5'-cyclic monophosphate-mediated increase in glycogenolysis with consequent increase in fructose 6-phosphate (substrate for 6-phosphofructo-1-kinase and 6-phosphofructo-2-kinase) is likely important for induction of lactate production by inactive muscle. The high correlation between muscle F-2,6-P2 and muscle lactate production at varying concentrations of epinephrine supports the hypothesis that the epinephrine-induced activation of glycolysis and lactate production in nonexercising muscle is mediated in part by increases in F-2,6-P2 levels.

Topics: Animals; Body Weight; Cyclic AMP; Epinephrine; Fatty Acids, Nonesterified; Fructosediphosphates; Glucose; Glycogen; Hindlimb; In Vitro Techniques; Insulin; Lactates; Lactic Acid; Male; Muscles; Phosphofructokinase-1; Rats; Rats, Sprague-Dawley; Regional Blood Flow

The effect of age and streptozocin concentration on the induction by streptozocin of hyperglycaemia in fasting rats is investigated. The data show that there is a dose dependent effect of streptozocin on the hyperglycaemia induced by streptozocin, and 60 mg/kg streptozocin is significantly more effective than 20 or 40 mg/kg streptozocin in inducing hyperglycaemia. Moreover, the hyperglycaemia induced by 60 mg/kg streptozocin is greater in 8 week old rats than in 4 or 6 week old rats, suggesting an influence of age on streptozocin-induced hyperglycaemia.

Topics: Aging; Animals; Blood Glucose; Body Weight; Fasting; Glycogen; Hyperglycemia; Injections, Intravenous; Liver; Male; Rats; Rats, Sprague-Dawley; Streptozocin

The ability of dietary sucrose to induce insulin resistance independent of changes in body weight is controversial. In the present study male rats were fed a high-starch (ST) diet (starch 68% of total kcal) ad libitum for 2 wk and then were fed equicalorically either the ST diet or a high-sucrose (SU) diet (sucrose 68% of total kcal) for 8 wk. Euglycemic, hyperinsulinemic (0, 1.2, 4.1, 8, 15 mU.kg-1.min-1, n = 6-8/group per dose) clamps were then used to establish dose-response relationships for glucose kinetics and metabolism. Body weight (513 +/- 3 g) and composition were similar between groups after the 8-wk dietary period. Glucose infusion rates (GIR; mg.kg-1.min-1) were significantly less in SU (0.9 +/- 5.8 +/- 0.6, 14.8 +/- 1.3, and 18 +/- 1.1) than in ST rats (4.1 +/- 0.9, 12.3 +/- 1.2, 22.6 +/- 1.5, and 25.9 +/- 1.8) at 1.2, 4.1, 8, and 15 mU.kg-1.min-1, respectively. Impaired suppression of endogenous glucose production accounted for 46, 43, 23, and 0% of the reduction in GIR in SU rats at 1.2, 4.1, 8, and 15 mU.kg-1.min-1, respectively. Despite basal hyperinsulinemia (38 +/- 2 microU/ml in SU vs. 26 +/- 2 microU/ml in ST rats), liver phosphoenolpyruvate carboxykinase (PEPCK) activity was 50% higher in SU than in ST rats and remained elevated in SU rats (by 30-40%) at the two lower insulin doses. No skeletal muscle glycogen accumulation occurred in SU rats at any of the insulin doses, and glycogen synthase I activity was significantly lower in SU rats at the two highest insulin doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Dietary Carbohydrates; Dose-Response Relationship, Drug; Glucose Clamp Technique; Glycogen; Infusions, Intravenous; Insulin; Insulin Resistance; Liver; Liver Glycogen; Male; Muscles; Organ Size; Rats; Rats, Wistar; Sucrose

Female obese Zucker rats aged 5 wk were randomly assigned to a control diet or one of two experimental diets. Experimental diets contained 6% of energy as pyruvate in the form of calcium-pyruvate (Ca-pyr) or 6% pyruvylglycine (pyr-gly). Diets were pair-fed according to the experimental group with the lowest food consumption. During the 3 wk of dietary treatment, Ca-pyr- and pyr-gly-fed rats gained significantly less weight, had a lower food-conversion efficiency, and maintained a higher resting oxygen consumption (mL.min-1 x kg-0.67) than control rats. Ca-pyr and pyr-gly also lowered the respiratory exchange ratio of the rats resulting in a 90% increase in their lipid oxidation and a 50% decrease in their carbohydrate oxidation. Glucose tolerance, assessed by an oral glucose load, was not different among treatments, but the insulin response of the pyr-gly-fed rats was significantly less than that of the control rats despite elevated plasma triglyceride concentrations in the pyr-gly-fed rats (control, 1.43 +/- 0.16 vs pyr-gly, 3.76 +/- 0.87 mmol/L). These results suggest that pyr-gly, like Ca-pyr, favorably alters the metabolism of obese Zucker rats. In addition, pyr-gly appeared to reduce the insulin resistance that develops spontaneously in obese rats.

Topics: Analysis of Variance; Animals; Blood Glucose; Body Weight; Cholesterol; Energy Metabolism; Female; Glucose Tolerance Test; Glycine; Glycogen; Insulin; Insulin Resistance; Lipids; Obesity; Oxygen Consumption; Pyruvates; Pyruvic Acid; Random Allocation; Rats; Rats, Zucker; Time Factors; Triglycerides

Male Wistar rats were given for 14 days folic acid as an addition to standard LSM food at the doses of 0.22 mg (group II), 2.2 mg (group III), 2.6 mg (group IV), 11 mg (group V) and 16.5 mg (group VI) per day/rat. In the beginning a decrease in body weight was observed and from the 7th day the weight started to increase to reach control value in all groups on the 14th day. Food intake was deteriorating with the acid concentration. The increased glucose and decreased insuline level in rat blood serum which were highly significant for groups IV and V as compared to control for the former parameter and significant for group V as compared to groups I and II for insuline indicate an effect of the excess of vitamin on endocrine function of pancreas. Increase in the muscle glicogen may result from intensified glicogenesis and gliconeogenesis processes due to folic acid.

Topics: Animal Feed; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Feeding Behavior; Folic Acid; Food, Fortified; Glycogen; Insulin; Insulin Secretion; Liver; Liver Glycogen; Male; Muscle, Skeletal; Rats; Rats, Wistar; Time Factors

Topics: Adipose Tissue; Adult; Body Composition; Body Water; Body Weight; Diet, Reducing; Glycogen; Humans; Middle Aged; Minerals; Models, Biological; Neutron Activation Analysis; Nitrogen; Obesity; Proteins; Weight Loss

The effects of 17-beta-oestradiol (E2) and progesterone (P) on insulin sensitivity were determined in oophorectomized (OVX) rats by the euglycaemic hyperinsulinaemic clamp technique combined with measurements of insulin-stimulated 2-deoxy-D-glucose (2-DOG) transport and glycogen synthesis in white and red parts of the gastrocnemius, the extensor digitorum longus and soleus muscles as well as in the liver (only glycogen synthesis). OVX was followed by insulin resistance in the clamp measurements. This was paralleled by a decreased insulin-stimulated content of 2-DOG in muscles, an index of glucose transport. Glycogen synthesis in muscle was also decreased, although to less extent. E2, alone or in combination with P, restored this to values of intact controls, while P alone was followed by insulin resistance. Liver glycogen synthesis was also decreased by OVX but this required combination of E2 and P to be fully restored. It was concluded that particularly E2 plays an important role in the maintenance of normal insulin sensitivity while P alone seems to be followed by insulin resistance, both effects apparently mainly by regulation of glucose uptake in muscle. E2 + P may be of importance for maintenance of normal glycogen synthesis in the liver.

Topics: Animals; Blood Glucose; Body Weight; Deoxyglucose; Estradiol; Estrogens; Female; Glycogen; Insulin; Insulin Resistance; Liver; Muscles; Organ Size; Ovariectomy; Progesterone; Rats; Rats, Sprague-Dawley

We hypothesized that augmented responses of glucoregulatory hormones in iron deficiency would enhance liver and muscle glycogenolysis, leading to increased gluconeogenic precursor (lactate) supply and upregulation of hepatic gluconeogenesis. Female weanling rats were randomly placed on either a mildly iron-deficient (-Fe; 15 mg Fe/kg diet) or an iron-sufficient (+Fe; 50 mg Fe/kg diet) diet for 4 wk and studied at rest and during exhaustive treadmill running. Hemoglobin was 9.0 +/- 0.2 and 13.1 +/- 0.3 g/dl in -Fe and +Fe, respectively, after 3.5 wk of dietary iron deficiency. Arterial plasma epinephrine (Epi), norepinephrine (NE), adrenocorticotropic hormone (ACTH), corticosterone, insulin, and glucagon levels were similar at rest in both groups, as were liver, gastrocnemius, and superficial and deep vastus medialis glycogen levels. Liver and kidney phosphoenolpyruvate carboxykinase (PEPCK) activities were similar in both groups. Maximum O2 consumption was decreased (22%) in -Fe. Respiratory exchange ratio (CO2 production/O2 consumption) was unaffected at rest but increased at maximum O2 consumption in -Fe. Time to exhaustion during a standardized running test (13.4 m/min, 0% grade) was decreased 45% in -Fe (63 +/- 5 vs. 116 +/- 10 min). During exercise, euglycemia was maintained in both groups, but blood lactate was elevated in -Fe. The mean net glycogen utilization during exercise was increased in liver (43%), soleus (33%), and superficial vastus medialis (106%) and decreased in the gastrocnemius (36%) in -Fe. Liver and kidney PEPCK activities were increased similarly at exhaustion in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blood Glucose; Body Weight; Female; Glycogen; Hemoglobins; Hormones; Iron Deficiencies; Lactates; Lactic Acid; Osmolar Concentration; Oxidoreductases; Physical Endurance; Physical Exertion; Rats; Rats, Sprague-Dawley

Chronic effects of benfluorex on some parameters of carbohydrate metabolism have been studied in 24-month-old Sprague-Dawley rats. Treatment once a day for 14 days with 25 mg benfluorex per kg body weight lowered body weight, decreased circulating insulin and resulted in an increase in hepatic glycogen. Measurement of the activities of several important regulatory enzymes of hepatic carbohydrate metabolism showed a significant decrease in the activities of phosphoenolpyruvate carboxykinase and glycogen phosphorylase. The activity of glucose-6-phosphatase, on the other hand, was slightly increased. Taken collectively, our data offer an explanation for the observed inhibition of hepatic glucose production by chronic benfluorex treatment in cases of hyperinsulinemia.

Topics: Aging; Animals; Body Weight; Fenfluramine; Glucose; Glycogen; Insulin; Liver; Male; Phosphoenolpyruvate Carboxykinase (GTP); Phosphorylases; Rats; Rats, Sprague-Dawley

The effect of moderate hyperglycemia on renal ATP production and ATPase activity of rat fetus was investigated using the experimental procedure of maternal continuous infusion of glucose during the last 5 days of gestation. Glucose-infused mothers and their fetuses showed a high level of glycemia (8.8 and 5.5 mM, respectively) and a high level of insulinemia (3 times higher than in controls). No change in either ATP or ADP concentration was detectable but an increase in NaK ATPase activity occurred without any change in Mg ATPase activity. These modifications should be the result of an enhanced Na/glucose cotransport leading to an enhanced extrusion of Na at the basolateral membrane. These results indicate that immature kidney is able to increase NaK ATPase activity to maintain Na homeostasis.

Topics: Adenosine Triphosphatases; Animals; Body Weight; Female; Fetus; Glucose; Glycogen; Hyperglycemia; Infusions, Intravenous; Insulin; Kidney; Nucleotides; Osmolar Concentration; Pregnancy; Pregnancy Complications; Rats; Rats, Wistar; Sodium-Potassium-Exchanging ATPase

Administration of glucocorticoids and thyroid hormone can accelerate fetal lung development. To investigate whether the delayed fetal lung maturation seen in the diabetic rat gestation could be reversed by dexamethasone (DEX) or triiodothyronine (T3), control and streptozotocin-diabetic dams were injected daily from day 18 of gestation with either saline, 0.5 mg/kg DEX, or 1 mg/kg T3 until sacrifice on day 21 or day 22. While DEX did not change glucose levels in diabetic animals, T3 resulted in a slight reduction in both maternal (474 +/- 25 vs. 539 +/- 17 mg%; p < 0.07) and fetal (354 +/- 43 vs. 404 +/- 26 mg%; p < 0.05) serum glucose concentrations. DEX therapy exaggerated the reduction in body and lung weight seen in fetuses of streptozotocin-diabetic dams. Fetal lung phosphatidylcholine and disaturated phosphatidylcholine levels were significantly reduced in saline-treated diabetic animals as compared with controls. However, fetuses of T3- or DEX-treated diabetic rats had significantly increased lung phosphatidylcholine and disaturated phosphatidylcholine levels were significantly reduced in saline-treated diabetic animals as compared with controls. However, fetuses of T3- or DEX-treated diabetic rats had significantly increased lung phosphatidylcholine and disaturated phosphatidylcholine levels as compared with fetuses of untreated diabetic rats; these data suggest that maternal DEX or T3 therapy reverses the delayed fetal lung maturation seen in the diabetic rat gestation. Since glucocorticoids can exacerbate maternal diabetes, treatment with thyroid hormone may be more appropriate, although risks must be weighed against potential benefits.

Topics: Animals; Blood Glucose; Body Weight; Dexamethasone; Diabetes Mellitus, Experimental; Embryonic and Fetal Development; Female; Fetal Blood; Fetus; Glycogen; In Vitro Techniques; Lung; Organ Size; Phosphatidylcholines; Pregnancy; Pregnancy in Diabetics; Rats; Rats, Sprague-Dawley; Triiodothyronine

Two formulas were derived to estimate the energy content of the human body which use only body mass, total body water by 3H2O dilution space and body minerals assessed by anthropometry. The formulas were tested in a body composition database of 561 patients and 151 normal volunteers using established metabolizable energy values for protein, fat and glycogen. Total body protein was determined by in vivo neutron activation analysis (IVNAA), body water by dilution of tritium and body minerals from skeletal frame size. Body glycogen was assumed to be 14.6% of the mineral component. Body fat was obtained by difference, body mass less the sum of water, protein, minerals and glycogen. The standard deviation in the estimate of body energy content was 30 MJ or 4.1% of the energy content of reference man. Two formulas for body energy content were derived by regression with body mass, total body water and body minerals or height. Two formulas for energy density and formulas for percentage body fat were similarly derived.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Body Composition; Body Water; Body Weight; Disease; Energy Metabolism; Female; Glycogen; Humans; Lipid Metabolism; Male; Middle Aged; Minerals; Proteins; Regression Analysis

Whether or not a high intake of carbohydrate increases postprandial energy expenditure during exercise was studied in rats. The rats were meal-fed regularly twice a day (0800-0900 hours and 1800-1900 hours) on either a high carbohydrate (CHO) (carbohydrate/fat/protein = 70/5/25, % of energy) or high fat (FAT) (35/40/25) diet for 12 days. On the final day of the experiment, all of the rats in each dietary group were fed an evening meal containing equal amounts of energy (420 kJ.kg-1 body mass). After the meal, they were divided into three subgroups: pre-exercise control (PC), exercise (EX), and resting control (RC). The PC-CHO and PC-FAT groups were sacrificed at 2030 hours. The EX-CHO and EX-FAT groups were given a period of 3-h swimming, and then sacrificed at 2330 hours. The RC-CHO and RC-FAT groups rested after the meal and were sacrificed at 2330 hours. Total energy expenditure during the period 1.5 h from the commencement of exercise was higher in EX-CHO than in EX-FAT. The respiratory exchange ratio was also higher in EX-CHO than in EX-FAT, suggesting enhanced carbohydrate oxidation in the former. Compared with both PC-FAT and RC-FAT, the liver glycogen content of EX-FAT rats was significantly decreased by exercise. On the other hand, the liver glycogen content of both EX-CHO and RC-CHO was higher than that of PC-CHO rats. The glycogen content of soleus muscle of EX-FAT was slightly decreased during exercise, however, that of EX-CHO increased significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Diet; Dietary Carbohydrates; Dietary Fats; Eating; Energy Metabolism; Epinephrine; Glycogen; Liver Glycogen; Male; Muscles; Norepinephrine; Organ Size; Oxygen Consumption; Physical Exertion; Pulmonary Gas Exchange; Rats; Rats, Sprague-Dawley

The aim of the present study was to evaluate the effect of changes in dietary protein level on overall availability of amino acids for tissues. For this purpose, rats were adapted to diets containing various concentrations of casein (7.5, 15, 30, and 60%) and were sampled either during the postprandial or postabsorptive period. In rats fed the protein-deficient diet, glucogenic amino acids (except threonine) tended to accumulate in plasma, liver, and muscles. In rats fed high-protein diets, the hepatic balance of glucogenic amino acids was markedly enhanced and their liver concentrations were consistently depressed. This response was the result of a marked induction of amino acid catabolism (a 45-fold increase of liver threonine-serine dehydratase activity was observed with the 60% casein diet). The muscle concentrations of threonine, serine, and glycine underwent changes parallel to plasma and liver concentrations, and a significant reduction of glutamine was observed. During the postabsorptive period, adaptation to high-protein diets resulted in a sustained catabolism of most glucogenic amino acids, which accentuated the drop in their concentrations (especially threonine) in all the compartments studied. The time course of metabolic adaptation from a 60 to a 15% casein diet has also been investigated. Adaptation of alanine and glutamine metabolism was rapid, whereas that of threonine, serine, and glycine was delayed and required 7-11 days. This was paralleled by a relatively slow decay of liver threonine-serine dehydratase (T-SDH) activity in contrast to the rapid adaptation of pyruvate kinase activity after refeeding a high-carbohydrate diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adaptation, Physiological; Amino Acids; Animals; Arteries; Biological Availability; Body Weight; Caseins; Diet; Dietary Proteins; Glycogen; Liver; Liver Circulation; Male; Muscles; Organ Size; Rats; Rats, Wistar

This study was designed to examine the effect of non-weight-bearing conditions and the systemic influences of simulated microgravity on rat hindlimb muscles. For this purpose, rats were suspended (SUS) in a head-down position (45 degrees) with the left hindlimb non-weight bearing (NWB) and the right hindlimb bearing 20% of presuspension body mass (WB). Weight bearing by the SUS-WB limb was accomplished by using a platform connected to a rod in sleeve, cable, and pulley apparatus to which weight could be added. Rats (250-325 g) were assigned to SUS or cage control (CC) conditions for 14 days. The angle between the foot and leg for SUS-WB and CC remained similar (20-30 degrees) throughout the experiment while the SUS-NWB hindlimbs extended to approximately 140 degrees by day 12. On day 14, the soleus, plantaris, and gastrocnemius muscles from the SUS-NWB limbs exhibited significantly lower (P < or = 0.05) masses than presuspension mass values (29, 11, and 21%, respectively). Weight bearing by the SUS-WB limbs prevented the loss of mass by these muscles. In separate groups of SUS and CC rats, 2-deoxyglucose uptake during hindlimb perfusion was significantly higher in both SUS-NWB and SUS-WB hindlimbs at 24,000 microU/ml of insulin compared with CC for all the muscles examined (21-80%). In addition, extracellular space (ml/g) was significantly greater in the soleus muscles from both the SUS-NWB and SUS-WB hindlimbs (64%) compared with CC muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Atrophy; Body Weight; Deoxyglucose; Electromyography; Extracellular Space; Glucose; Glycogen; Hindlimb; Insulin; Male; Muscles; Organ Size; Rats; Rats, Sprague-Dawley; Regional Blood Flow; Weightlessness

1. The relationship between hypertension, obesity, non-insulin-dependent diabetes mellitus and various parameters of glucose metabolism was studied. Lean and obese rats of the SHR/N-cp and LA/N-cp congenic strains were studied at four months of age. 2. Tritium and 14C-labeled glucoses were infused in one set of rats while tritiated water and 14C-labeled alanine were infused in a second group. 3. Glucose oxidation, turnover, conversion to glycogen, fatty acid synthesis, and alanine conversion to glucose were determined, as were blood pressure, pulse pressure and heart rate. 4. The presence of obesity influenced body weight, body fat, de novo fatty acid synthesis, organ weights, glucose mass, glucose oxidation, glucose synthesis, glucose carbon turnover and pulse pressure. 5. It had no effect on glycogen synthesis, tissue glycogen levels, blood glucose, glucose space, or blood pressure. 6. Strain differences were observed in final body weight, organ weights, blood pressure, pulse pressure, hepatic fatty acid synthesis, glucose mass, glucose space, glucose synthesis, liver glycogen levels and glucose conversion to muscle glycogen. 7. Strain-phenotype interaction effects were observed on glucose incorporation into hepatic glycogen, Cori cycle activity, hepatic de novo fatty acid synthesis, final body weight, fat pad weight, heart weight, and mean arterial pressure. 8. These results suggest that although obesity and hypertension are genetic traits in these rats, these traits are independent in their influence on the metabolism of glucose and the development of non-insulin-dependent diabetes mellitus.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Disease Models, Animal; Fatty Acids; Glucose; Glycogen; Hemodynamics; Hypertension; Liver; Male; Muscles; Obesity; Organ Size; Rats; Rats, Inbred SHR

Neonates with congenital diaphragmatic hernia (CDH) continue to have unacceptably high mortality rates. To better understand the associated pulmonary pathology we measured biochemical parameters of lung maturity in neonatal rats with or without congenital diaphragmatic hernia created by maternal feeding of a single dose of nitrofen on day 9.5 or day 11.5 of gestation. Lungs from neonatal rats with large CDH (n = 9, 5 right-sided, 4 left-sided) had a significantly lower lung weight (P = .0001), lung weight/body weight ratio (P = .0001), disaturated phosphatidylcholine (DSPC) per microgram DNA (P < .005), total DSPC (P = .0001), total DNA (P < .05), protein per microgram DNA (P < .05), and total protein content (P < .005) when compared with lungs from the litter mates without congenital diaphragmatic hernia (n = 10). The lungs of rats with hernia also had significantly higher DNA concentrations (P < .05) and glycogen concentrations (P < .05). These data demonstrate that lungs in neonatal rats with large CDH are biochemically immature. Treatment directed toward correcting the pulmonary biochemical immaturity of affected fetuses before birth may improve the prognosis for these babies.

Topics: Animals; Body Weight; DNA; Female; Fetal Organ Maturity; Glycogen; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Lung; Organ Size; Phosphatidylcholines; Pregnancy; Pulmonary Surfactants; Rats; Rats, Sprague-Dawley

The effect of a high-carbohydrate (C) diet intake on muscle glycogen repletion during the early period of recovery from exercise was studied in rats previously fed a high-fat (F) diet. In experiment 1, 3 week-old male and in experiment 2, 3 week-old female rats were used. Rats were fed either the F or the C diet for 2-10 weeks ad libitum and then were meal-fed regularly twice a day for 25 days in experiment 1, or for 5 weeks in experiment 2. During the period of regular feeding, half of the rats in both dietary groups continued to eat as before (F-F and C-C) but the other half of the rats were switched to the counterpart diets (F-C and C-F) in experiment 1. In experiment 2, half of the F-F group were switched to the C diet (F-C) for 3, 7, and 14 days after the period of regular feeding. Pre-exercise glycogen content in soleus, red gastrocnemius, and heart muscles and liver was higher in rats fed the C diet (C-C and F-C) than in rats fed the F diet (F-F and C-F) in experiment 1. Glycogen repletion in red muscle 2 h after the ingestion of a glucose and citrate (3.0 and 0.5 g, respectively, per kg body mass) drink was also higher in the former than in the latter. There was a positive relationship in skeletal muscles between pre-exercise glycogen content and the rate of glycogen repletion.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: 3-Hydroxybutyric Acid; Analysis of Variance; Animals; Blood Glucose; Body Weight; Dietary Carbohydrates; Dietary Fats; Fatty Acids, Nonesterified; Female; Glycogen; Glycogen Synthase; Hydroxybutyrates; Insulin; Liver Glycogen; Male; Muscles; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; Time Factors

Changes in insulin, plasma glucose and tissue glycogen were considerable and statistically significant when the smaller dose of folic acid was given, comparing with the bigger one. In both cases the physiological proportions between examined parameters were not maintained.

Topics: Animals; Blood Glucose; Body Weight; Diet; Dietary Carbohydrates; Dose-Response Relationship, Drug; Eating; Folic Acid; Glycogen; Insulin; Liver; Male; Methionine; Muscle, Skeletal; Rats; Rats, Wistar

Reduction of physical activity due to disease or environmental restraints, such as total bed rest or exposure to spaceflight, leads to atrophy of skeletal muscle and is frequently accompanied by alterations in food intake and the concentration of metabolic regulatory hormones such as insulin. Hindlimb suspension of laboratory rats, as a model for microgravity, also shows marked atrophy of gravity dependent muscles along with a reduced gain in body weight. Suspended rats exhibit enhanced sensitivity to insulin-induced glucose uptake when compared with normal control rats and resistance to insulin action when compared with control rats matched similarly for reduced body weight gain. These changes are accompanied by decreased insulin binding and tyrosine kinase activity in soleus but not plantaris muscle, unchanged glucose uptake by perfused hindlimb and decreased sensitivity but not responsiveness to insulin-induced suppression of net proteolysis in hindlimb skeletal muscle. These findings suggest that loss of insulin sensitivity during muscle atrophy is associated with decreased insulin binding and tyrosine kinase activity in atrophied soleus muscle along with decreased sensitivity to the effects of insulin on suppressing net protein breakdown but not on enhancing glucose uptake by perfused hindlimb.

Topics: Animals; Body Weight; Glucose; Glycogen; Hindlimb; Immobilization; Insulin; Insulin Resistance; Liver; Liver Glycogen; Male; Muscle, Skeletal; Muscular Atrophy; Protein-Tyrosine Kinases; Rats; Rats, Sprague-Dawley; Receptor, Insulin; Weightlessness Simulation

The ontogeny of glucose regulation was studied in the rat by measuring the levels of plasma glucose, tissue glucose and tissue glycogen from fetal day 15 (E15) to adulthood. Since insulin and adrenaline are important glucose regulators in the adult, we also tested the effects of these hormones on above variables. The main findings are the following: 1) Umbilical blood glucose was very low (25 mg/100 ml) from E15 to E19, increasing to 66 mg/100 ml by E21 but still below maternal levels (110 mg/100 ml). 2) Umbilical venous-arterial (VEN-ART) glucose differences were very small (1 mg/100 ml) from E15 to E17, increased to 6 mg/100 ml by E19, but dropped again becoming negative (-15 mg/100 ml) just before birth when umbilical arterial blood glucose rose above venous blood glucose. 3) Glucose and glycogen concentrations rose drastically in liver towards the end of gestation. 4) Tissue glycogen and, to a much lesser degree, glucose, fell after birth to rise again in adulthood. 5) Insulin injection caused an increase in liver glycogen from E17 onwards, and also increased glycogen in brain and placenta on E19. However, insulin decreased glycogen in brain and kidney by E21. 6) Adrenaline caused an increase in the umbilical venous-arterial glucose difference at E15 and E17 with a concomitant increase in liver, brain and heart glycogen at E15. By E21 the response of liver glycogen to adrenaline was drastically reversed. Our data suggest that the mechanism regulating glucose homeostasis changes half way through fetal development. Tissue self-regulation is replaced with a centralized mechanism similar to that of the adult.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blood Glucose; Body Weight; Embryonic and Fetal Development; Epinephrine; Female; Fetus; Glucose; Glycogen; Insulin; Liver; Liver Glycogen; Organ Size; Pregnancy; Rats; Rats, Sprague-Dawley

The purpose of the present study was to examine the effects of exercise on maternal glycogen storage patterns and fetal outcome in mature (approximately 12 months of age) Sprague-Dawley rats. The exercise consisted of treadmill running at 30 m.min-1, on a 10 degree incline, for 60 min, 5 days per week, for 4 weeks prior to pregnancy, which continued until day 19 of gestation. In mature animals, chronic exercise increased (p < 0.05) liver glycogen concentration in both pregnant and nonpregnant rats. In pregnant exercised animals, the glycogen concentration of the maternal liver increased almost twofold (p < 0.05) compared with the sedentary pregnant group. There was no difference in the amount of glycogen stored in the gastrocnemius or soleus muscles in response to training, pregnancy, or chronic maternal exercise in the mature rat. In the pregnant groups, there were fewer (p < 0.05) viable fetuses and more (p < 0.05) resorption sites than in young rats. In addition, exercise during pregnancy in the mature animal decreased (p < 0.05) fetal body weight. These results demonstrate that a conflict may exist between maternal exercise and fetal demands for energy in the mature rat. This conflict seems to favour the maternal system, as evidenced by the enhanced maternal liver glycogen storage and the negative effect on fetal growth.

Topics: Aging; Animals; Body Weight; Embryonic and Fetal Development; Female; Glycogen; Gonadotropin-Releasing Hormone; Liver Glycogen; Muscles; Passive Cutaneous Anaphylaxis; Pregnancy; Rats; Rats, Sprague-Dawley

1. Dietary excess histidine caused an increase in the total activity of fructose 1,6-bisphosphatase, and a decrease in 6-phosphofructokinase in the liver. 2. The hepatic concentrations of free histidine and lysine were higher in rats fed a histidine-excess diet. 3. The addition of histidine, lysine or arginine to the assay mixture for fructose 1,6-bisphosphatase resulted in a significant increase in its activity. The 6-phosphofructokinase activity in the liver was not enhanced by the addition of histidine to the assay mixture.

Topics: Amino Acids; Animals; Arginine; Blood Glucose; Body Weight; Cholesterol; Diet; Enzyme Activation; Fructose-Bisphosphatase; Glycogen; Histidine; Liver; Lysine; Male; Organ Size; Phosphofructokinase-1; Rats; Rats, Inbred Strains

Endurance exercise training can result in increased rates of insulin-stimulated glucose uptake in skeletal muscle; however, this effect may be lost rapidly once training ceases. To examine a mechanism for these changes, the skeletal-muscle glucose transport system of female rats exercise-trained in wheelcages for 6 wk were studied against a group of untrained female rats. The trained rats were studied immediately following and 2 and 5 days after removal from wheelcages; both trained and untrained rats were studied 30 min after insulin (90 nmol/rat, intraperitoneal) or saline injection. The total number of skeletal-muscle plasma-membrane glucose transporters (R0), total muscle-homogenate and plasma-membrane GLUT4 protein, and rates of plasma-membrane vesicle D-facilitated glucose transport were higher in the exercise-trained rats immediately after exercise training and did not decrease significantly during the 5 days after cessation of training. On the other hand, exercise training did not alter microsomal-membrane total glucose-transporter number or GLUT4 protein, nor did training alter GLUT1 protein in total muscle homogenates nor either membrane fraction. The carrier-turnover number, an estimate of average functional activity of glucose transporters in the plasma membrane, was elevated slightly, but not significantly, in the trained muscle. In both the trained and untrained muscle, insulin administration resulted in translocation of glucose transporters from the microsomal-membrane fraction to the plasma membrane and an increase in the carrier-turnover number.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: 4-Nitrophenylphosphatase; Animals; Blood Glucose; Blotting, Western; Body Weight; Cell Membrane; Citrate (si)-Synthase; Cytochalasin B; Eating; Female; Glucose; Glucose Transporter Type 1; Glucose Transporter Type 4; Glycogen; Insulin; Isomerism; Monosaccharide Transport Proteins; Muscle Proteins; Muscles; Physical Conditioning, Animal; Rats; Rats, Inbred Strains; Subcellular Fractions

The neuroendocrine light green cells (LGCs), 4 clusters of together approximately 150 giant neurons in the cerebral ganglia of the freshwater gastropod, Lymnaea stagnalis, have been suggested to be involved in the control of growth. The present study examines in greater detail this role and possible actions on energy metabolism. Growth indices (total body and organ wet and dry weights, as well as protein and DNA contents of the organs) and metabolic indices (tissue lipid, polysaccharide and glucose levels) were compared in LGC extirpated/reimplanted with control groups. LGC extirpation in rapidly growing juvenile snails immediately arrested growth, which was restored by reimplantation of cerebral ganglia with LGCs but not by cerebral ganglia without LGCs, indicating their neuroendocrine control of growth. The LGCs stimulate a pattern of organ growth, which is in proportion to the growth of the whole body except for the shell, which shows a disproportionally faster growth due to calcium deposition over the whole surface. The data on protein and DNA in the organs strongly suggest that the LGCs induce growth by stimulating cell multiplication. The LGCs maintain low tissue glycogen reserves and hemolymph concentrations of both glycogen and glucose. The secretions of these cells stimulate the uptake of glucose by the growing tissues with no apparent effects on lipid metabolism.

Topics: Animals; Body Weight; Carbohydrate Metabolism; DNA; Energy Metabolism; Female; Glycogen; Hemolymph; Lipid Metabolism; Lipopolysaccharides; Lymnaea; Male; Neurotransmitter Agents; Protein Biosynthesis

The effects of decapitation and chicken growth hormone (cGH) replacement therapy on chick embryo growth has been investigated. Removal of the prosencephalon at 33-38 hrs (1.38 to 1.58 Days) of incubation decreased body (torso) and liver weights as well as skeletal growth as indicated by tibial length. A single pituitary gland transplanted onto the chorioallantoic membrane (CAM) partially restored torso growth and completely reversed the increase in body water content which characterizes decapitated embryos. Replacement therapy with cGH did not influence body weight but did, on Day 16.5 of incubation, increase tibial length and liver DNA content and concentration. These latter findings suggest that there may be limited hypothalamoadenohypophyseal (GH) axis function in the chick embryo. The effects of decapitation on torso growth are also discussed in conjunction with decapitation effects on albumen swallowing (absorption) and yolk absorption.

Topics: Albumins; Animals; Biometry; Body Weight; Chick Embryo; DNA; Embryo, Mammalian; Embryo, Nonmammalian; Embryonic and Fetal Development; Femur; Glycogen; Growth Hormone; Head; Hypothalamus; Liver; Organ Size; Pituitary Gland; Tibia; Yolk Sac

This study was designed to examine insulin- and exercise-stimulated glucose uptake and metabolism in the hindlimb muscles of rats after conditions of simulated microgravity. To simulate microgravity, male Sprague-Dawley rats were suspended in a head-down (45 degrees) position with their hindlimbs non-weight bearing (SUS) for 14 days. In addition, rats were assigned to suspension followed by exercise (SUS-E), to cage control (CC), or to exercising control (CC-E) groups. Exercise consisted of five 10-min bouts of treadmill running at the same relative intensity for the CC-E and SUS-E rats (80-90% of maximum O2 consumption). Hindlimb perfusion results indicated that glucose uptake for the entire hindquarter at 24,000 microU/ml insulin (maximum stimulation) was significantly higher in the SUS (8.9 +/- 0.5 mumol.g-1.h-1) than in the CC (7.6 +/- 0.4 mumol.g-1.h-1) rats, signifying an increased insulin responsiveness. Glucose uptake at 90 microU/ml insulin was also significantly higher in the SUS (48 +/- 4; % of maximum stimulation over basal) than in the CC (21 +/- 4%) rats. In addition, exercise-induced increases in glucose uptake for the hindlimbs (133%) and glucose incorporation into glycogen for the plantaris (8.4-fold), extensor digitorum longus (5.4-fold), and white gastrocnemius (4.8-fold) muscles were greater for the SUS-E rats than for the CC-E rats (39% and 1.9-, 1.9-, and 3.0-fold, respectively). Therefore, suspension of the rat with hindlimbs non-weight bearing leads to enhanced muscle responses to insulin and exercise when they were applied separately. However, insulin action appeared to be impaired after exercise for the SUS-E rats, especially for the soleus muscle.

Topics: Animals; Body Weight; Carbon Dioxide; Drinking; Eating; Glucose; Glucosephosphates; Glycogen; Hindlimb; Insulin; Lactates; Lactic Acid; Male; Muscles; Oxygen Consumption; Physical Exertion; Pyruvates; Pyruvic Acid; Rats; Rats, Sprague-Dawley; Regional Blood Flow; Weightlessness

1. Starvation of rats for 40 hr decreased the body weight, liver weight and blood glucose concentration. The hepatic and skeletal muscle glycogen concentrations were decreased by 95% (from 410 mumol/g tissue to 16 mumol/g tissue) and 55% (from 40 mumol/g tissue to 18.5 mumol/g tissue), respectively. 2. Fine structural analysis of glycogen purified from the liver and skeletal muscle of starved rats suggested that the glycogenolysis included a lysosomal component, in addition to the conventional phosphorolytic pathway. In support of this the hepatic acid alpha-glucosidase activity increased 1.8-fold following starvation. 3. Refeeding resulted in liver glycogen synthesis at a linear rate of 40 mumol/g tissue per hr over the first 13 hr of refeeding. The hepatic glycogen store were replenished by 8 hr of refeeding, but synthesis continued and the hepatic glycogen content peaked at 24 hr (approximately 670 mumol/g tissue). 4. Refeeding resulted in skeletal muscle glycogen synthesis at an initial rate of 40 mumol/g tissue per hr. The muscle glycogen store was replenished by 30 min of refeeding, but synthesis continued and the glycogen content peaked at 13 hr (approximately 50 mumol/g tissue). 5. Both liver and skeletal muscle glycogen synthesis were inhomogeneous with respect to molecular size; high molecular weight glycogen was initially synthesised at a faster rate than low molecular weight glycogen. These observations support suggestions that there is more than a single site of glycogen synthesis.

Topics: Animals; Body Weight; Food; Glycogen; Kinetics; Liver; Male; Molecular Weight; Muscles; Organ Size; Rats; Rats, Inbred Strains; Starvation

The responses of hepatic glycogen synthase and phosphorylase to fasting and refeeding were assessed as part of an investigation into possible sites of insulin resistance in gold thioglucose (GTG) obese mice. The active forms glycogen synthase and phosphorylase (synthase I and phosphorylase a) and the total activity of these enzymes were estimated in lean and GTG mice over 48 h of food deprivation, and for 120 min after glucose gavage (1 g/kg wt). In lean mice there was a maximal reduction in hepatic glycogen content after 12 h of starvation and the activity of phosphorylase a decreased from 23.8 +/- 1.9 to 6.8 +/- 0.7 mumol/g protein/min. These changes were accompanied by an increase in the activity of synthase I (from 0.14 +/- 0.01 to 0.46 +/- 0.04 mumol/g protein/min). In obese mice, similar changes in enzyme activity occurred after 48 h of starvation. These changes were accompanied by a significant reduction in the hyperinsulinemia and hyperglycemia of the GTG mice. After glucose gavage in both lean and obese mice, the activity of synthase I further increased over the first 30 min and declined thereafter. The activity of phosphorylase a increased progressively after refeeding. Results from this study suggest that despite increased hepatic glycogen deposition, the responses of glycogen synthase and phosphorylase, in livers of obese mice, to fasting and refeeding are similar to those of control mice even in the presence of insulin resistance.

Topics: Animals; Blood Glucose; Body Weight; Fasting; Food; Glycogen; Glycogen Synthase; Insulin; Liver; Male; Mice; Mice, Inbred CBA; Mice, Obese; Obesity; Organ Size; Phosphorylase a

Glycogen is stored in the liver, muscles, and fat cells in hydrated form (three to four parts water) associated with potassium (0.45 mmol K/g glycogen). Total body potassium (TBK) changes early in very-low-calorie diets (VLCDs) primarily reflect glycogen storage. Potassium released from glycogen can distort estimates of body composition during dieting. TBK changes due to glycogen mobilization were measured in 11 subjects after 4 d dieting with a VLCD. The influence of water-laden glycogen on weight fluctuations during the dieting process, the exaggerated regain if carbohydrate loading occurs, and the implications for weight control programs and overestimation of nitrogen losses with dieting are discussed.

Topics: Body Composition; Body Weight; Diet, Reducing; Energy Intake; Female; Glycogen; Humans; Obesity; Potassium; Weight Gain; Weight Loss

The effects of selenium (Se) deficiency on urinary ketone body excretion in starved rats were examined. Rats were fed a basal diet which was Se-deficient (Se content: 0.011 micrograms/g) or a Se-adequate diet (the basal diet supplemented with 0.1 micrograms Se/g as sodium selenite). On the 11th and 22nd week of the feeding period, Se-deficient status in rats fed the basal diet was verified by the observation that the Se content and glutathione peroxidase activity in their plasma, erythrocytes, and livers were markedly lowered. On the 4th, 6th, 11th, 15th, and 22nd week, the rats were starved for 48 h and the urinary excretion of ketone bodies (acetoacetate (AcAc) and 3-hydroxybutyrate (3-OHBA)), urea, and creatinine were examined. The urinary excretion of AcAc and 3-OHBA during the second 24 h of the 48-h starvation period were markedly higher in the Se-deficient rats than in the Se-adequate rats for all weeks examined, while the urine volume and the excretion of urea and creatinine were similar in the Se-deficient and Se-adequate rats, irrespective of the feeding period and the number of hours of starvation. On the 22nd week, the plasma ketone body levels were also determined and significantly higher plasma 3-OHBA levels were observed in the Se-deficient rats than in the Se-adequate rats 72 h after starvation began. These results indicate that Se deficiency causes an increase of urinary ketone body excretion in starved rats and that the increase is ketone-specific with no changes in major urinary profiles.

Topics: 3-Hydroxybutyric Acid; Acetoacetates; Animals; Blood Glucose; Body Weight; Creatinine; Erythrocytes; Glutathione Peroxidase; Glycogen; Hydroxybutyrates; Ketone Bodies; Liver; Male; Rats; Rats, Inbred Strains; Selenium; Starvation; Urea

Repeated phases of hypoxia (8 h daily for 2 to 5 days at pO2 11.33 kPa = 5.000 m in altitude) were induced to Sprague-Dawley rats in the postnatal period as well as up to the 64th day of age, and after different recovery phases the ultrastructure of hepatocytes was qualitatively and quantitatively analysed. Major results were as follows: 1. Increases in body and liver weights were delayed but were balanced off after 64 days. 2. Qualitative alterations are reversible spherical transformations of mitochondria, a degradation of lipids and a slight increase in autophagocytosis. 3. The quantitative mitochondrial parameters (volume density, number per unit area, average volume) were not even adjusted to control values after 64 days. Granular endoplasmic reticulum and ribosomes/polysomes were insignificantly reduced in comparison to control animals, structure and arrangement are regular. Lipids and glycogen were differently altered. 4. The findings of the hepatocytes after postnatal hypoxia were reversible, though the majority of parameters had not yet returned to normal after 2 months. An adaptation to repetitive hypoxic conditions is not provable.

Topics: Animals; Animals, Newborn; Body Weight; Endoplasmic Reticulum; Glycogen; Hypoxia; Lipid Metabolism; Liver; Microscopy, Electron; Mitochondria, Liver; Rats; Rats, Inbred Strains

The present investigation deals with determining the efficacy of a high protein diet (HPD) in combating toxicity in albino rats of some organophosphorus compounds (OPCs) that follow dissimilar metabolic patterns in a living system. As assessed by an increase or decrease in the levels of some biochemical and nutritional parameters, the high protein diet containing 59% protein seems to have a beneficial effect in alleviating toxicity of low but prolonged doses of OPCs over the standard diet (SD) containing 19% protein. OPCs undergoing direct detoxication in a living system like diisopropyl phosphoro-fluoridate (DFP) appear to be more susceptible to HPD than those undergoing biotoxication like EPN (O-ethyl O-p-nitrophenyl phenyl-phosphonothioate) and malathion (S-(1,2-dicarbethoxyethyl) O,O-dimethyldithiophosphate).

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Body Weight; Cholinesterase Inhibitors; Dietary Proteins; Dose-Response Relationship, Drug; Globulins; Glycogen; Isoflurophate; Liver; Malathion; Male; Organ Size; Organophosphorus Compounds; Phenylphosphonothioic Acid, 2-Ethyl 2-(4-Nitrophenyl) Ester; Rats; Rats, Inbred Strains; Serum Albumin

It has been suggested that the increased activity of the sympathetic nervous system and the resultant increase in the tissue catecholamine levels contribute to the pathogenesis of diabetes. In this study we evaluated the effect of clonidine, a central adrenergic agonist that decreases sympathetic tone, on the serum levels of glucose, insulin, glucagon and norepinephrine and on the hepatic glycogen content in normal and streptozotocin-diabetic rats. The animals were treated with clonidine 25 micrograms/kg/day interperitoneally for 3 weeks to suppress the central adrenergic impulses. Clonidine treatment significantly increased the weight gain, but did not affect plasma glucose, insulin, glucagon and norepinephrine in the diabetic animals. Pancreatic insulin and liver glycogen contents were significantly higher in the clonidine-treated than in the untreated diabetic rats. However, clonidine did not affect pancreatic insulin and liver glycogen content of nondiabetic animals. The intravenous administration of glucagon increased plasma glucose in the clonidine-treated, but not in the saline-treated diabetic rats. Insulin-induced hypoglycemia significantly enhanced glucagon release in clonidine-treated but not in saline-treated diabetic rats. We conclude that the suppression of central adrenergic activity may ameliorate the effects of insulin insufficiency on pancreatic hormone secretion and hepatic glycogen content.

Topics: Animals; Blood Glucose; Body Weight; Clonidine; Diabetes Mellitus, Experimental; Glucagon; Glycogen; Insulin; Insulin Secretion; Norepinephrine; Rabbits; Rats; Rats, Inbred WF; Sympathetic Nervous System

Rat livers were perfused with [15N]glycine and unlabeled sodium benzoate by the single-pass technique via the portal vein or in retrograde fashion via the inferior vena cava. Perfusate [15N]hippurate enrichment was significantly greater than that of hepatic free glycine from 15 to 90 min, regardless of the direction of the perfusion. This result implies that differential labeling by periportal versus perivenous hepatocytes is not likely. When fasted animals were compared to those fed a chow diet or a sucrose-enriched diet, the labeling ratio of medium hippurate/hepatic free glycine decreased by only 9% in spite of a 5-fold decrease in the concentration of intrahepatic free glycine. Administration of nembutal to the intact animal significantly increased the enrichment of medium hippurate by 24% but did not affect the enrichment of the hepatic free glycine. We conclude that the difference between hippurate and free glycine enrichment is related to intracellular compartmentation of glycine transport. We suggest that measurement of the enrichment of hippurate after the administration of [15N]glycine with benzoate in intact animals or human subjects can therefore be used to estimate the enrichment of the intracellular precursor pool of glycine with a correction factor that does not vary appreciably under fed or fasted conditions. When uniformly labeled deuteroglycine was used as the tracer, enrichment of hepatic free glycine was decreased fivefold compared with [15N]glycine. Isotopic enrichments of apoBH and apoBL from the d less than 1.063 g/ml lipoprotein fraction isolated from the perfusion medium between 30 and 90 min averaged 3.7 and 4.1% excess, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Apolipoproteins B; Body Weight; Glycine; Glycogen; Hippurates; In Vitro Techniques; Liver; Male; Nitrogen Isotopes; Organ Size; Pentobarbital; Perfusion; Rats; Rats, Inbred Strains

Previous studies have shown that dietary carbohydrate (CHO) can impact on cardiac isomyosin expression in hormonally deficient animals. The primary objective of this study was to determine whether a high-CHO diet alters cardiac isomyosin expression in severe thyroid-deficient rats. Also the effects of targeting the heart with episodes of biasing cardiac metabolism toward CHO were studied. Female Sprague-Dawley rats were assigned to one of two major groups: 1) normal control and 2) thyroidectomized (TX) propylthiouracil treated. The TX rats were allocated into four experimental subgroups as follows: 1) mixed diet; 2) high-CHO diet; 3) high-CHO diet and treated with oxfenicine, a fatty acid oxidation inhibitor; and 4) high-CHO diet, treated with oxfenicine, and trained. Results show that, at the end of 12 wk of thyroidectomy, there was a marked shift in cardiac isomyosin distribution to predominance of the V3 isoform. However, 6 wk of experimental manipulation failed to redirect cardiac isomyosin expression in TX rats. It is concluded that increased CHO utilization does not influence cardiac isoenzyme expression in markedly hypothyroid female rats. Dietary effects of CHO on cardiac isomyosin require some critical level of thyroid hormone for mediating the response.

Topics: 3-Hydroxyacyl CoA Dehydrogenases; Animals; Blood Glucose; Body Weight; Citrate (si)-Synthase; Dietary Carbohydrates; Female; Glycine; Glycogen; Heart; Hexokinase; Isoenzymes; Liver Glycogen; Muscles; Myocardium; Myofibrils; Myosins; Organ Size; Physical Exertion; Rats; Rats, Inbred Strains; Thyroidectomy

While previous findings suggest that increased carbohydrate (CHO) provision and/or utilization can be involved in the up regulation of V1 cardiac isomyosin expression in both the insulin deficient and the semi-starved rat, little is known about the role of CHO provision and/or utilization in regulating isomyosin expression in normal animals. This study was undertaken to ascertain whether a limited carbohydrate provision combined with repeated episodes of an increased cardiac energy demand can induce a down regulation of the V1 cardiac myosin inoenzyme in normal, young adult rats, i.e., a response similar to that seen in insulin deficient/food restricted rats. Animals were assigned to one of three major groups according to diet and/or drug treatment: (1) a mixed-diet control group; (2) a low-carbohydrate (LC)/high-fat-diet group; and (3) a low-carbohydrate-diet group treated with 3-mercaptopicolinic acid (MPA), an inhibitor of gluconeogenesis. In each of the above groups, subgroups of animals were metabolically challenged with daily isoproterenol injections (0.2 mg/kg/day) sufficient to markedly elevate cardiac work for at least 3 h. Four weeks of treatment reduced myofibrillar calcium activated ATPase activity by 17% (P less than 0.05) in the LC-diet-fed group treated with both isoproterenol and MPA. No change in myofibril ATPase was observed in any of the other experimental groups relative to the mixed diet control group. Isomyosin profile was not changed in any of the experimental groups. Tissue glycogen and plasma glucose and free fatty acid analyses provided indirect evidence of an increased utilization of fat for energy provision, especially in the low-carbohydrate-diet groups treated with MPA.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adenosine Triphosphatases; Animals; Blood Glucose; Body Weight; Dietary Carbohydrates; Female; Glucose; Glycogen; Heart; Isoproterenol; Liver; Myocardium; Myosins; Organ Size; Rats; Rats, Inbred Strains

Six conditioned Quarter Horse mares were used in a crossover design to assess the effect of the dietary protein level on intramuscular and hepatic glycogen and lactate, oxygen uptake and blood lactate, pyruvate and free fatty acids. After a 2-wk adaptation period to either a 9.0% (control) or an 18.5% crude protein diet, each horse performed an exercise test. The horses were exercised for 15 min on an 11% grade treadmill at 4.5 m/sec. The exercise test was performed 3-4 h after a meal. Venous, arterial and mixed-venous blood samples were taken simultaneously at rest and during exercise. Muscle and liver samples were taken at rest and after exercise. The dietary protein level did not affect hepatic or intramuscular glycogen utilization (P greater than 0.05). Exercise resulted in increased (P less than 0.001) lactate in venous blood, muscle and liver; however, dietary treatment did not affect (P greater than 0.05) lactate level. Venous blood lactate:pyruvate ratio was higher (P less than 0.05) in the control horses. Dietary protein level did not affect (P greater than 0.05) oxygen uptake or plasma free fatty acids; however, exercise increased (P less than 0.01) both. These results indicate the dietary protein did not affect substrate utilization during the absorptive phase of digestion in exercising horses; however, the higher lactate:pyruvate ratio in the control horses suggests that the intraconversion of lactate and pyruvate may be influenced by diet composition.

Topics: Animals; Body Weight; Dietary Proteins; Energy Metabolism; Fatty Acids, Nonesterified; Glycogen; Horses; Lactates; Liver; Male; Oxygen Consumption; Physical Exertion; Pyruvates

The effects of short periods of fasting on diaphragm contractile function remain unclear. The purpose of the present study was (1) to examine the relationship between duration of acute fasting and diaphragm contractile performance, and (2) to assess the effects of fasting on diaphragm glycogen stores and the relationship between changes in diaphragm function and alterations in muscle glycogen stores. Studies were performed on four groups of Syrian hamsters (nine animals in each group). One group served as a control and was allowed to feed normally, whereas the other three groups were fasted for either 1, 2, or 3 days. Diaphragm strips from animals were studied in vitro by measuring tension during electrically induced contractions. Two strips from each animal were studied; one strip was examined with a bath glucose equal to the prevailing blood glucose, and the second was preincubated in a high glucose solution (170 mg/dl) for 20 min. Fasting resulted in reductions in body weight, blood glucose concentrations, diaphragm strength, and diaphragm endurance in strips tested at the prevailing blood glucose levels. These effects were pronounced in animals fasted for 3 days, with little or no change in diaphragm contractility observed in animals fasted for shorter periods. Diaphragm weight, thickness, and glycogen content were unchanged in the fasted animals, as was the weight of the soleus muscle. Preincubation of strips from 3-day-fasted animals in a high glucose medium resulted in a significant increase in diaphragm strip strength and endurance.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blood Glucose; Body Weight; Cricetinae; Diaphragm; Fasting; Glycogen; In Vitro Techniques; Male; Mesocricetus; Muscle Contraction; Organ Size

To quantitatively examine the relationship between lysosomal acid alpha-glucosidase (LAAG, alpha-D-glucoside glucohydrolase, EC 3.2.1.20) inhibition and glycogen accumulation, rats were treated with castanospermine (CS), and liver lysosomal/mitochondrial fractions were analyzed for glycogen content and LAAG activity. Liver lysosomal glycogen accumulation positively correlated (r = 0.90) with the amount of LAAG inhibition when inhibition was about 50% or greater. Glycogen did not accumulate when LAAG inhibition was less than 50%. The route of CS administration had little effect on the amount of LAAG inhibition observed. In rats killed 17 hr after CS administration, the doses estimated to cause 50% LAAG inhibition were 0.77, 0.11, and 0.22 mg/kg for i.p., i.v., and oral administration respectively. After 89% inhibition of LAAG activity with a single oral dose of 10 mg CS/kg, LAAG activity returned to 50% of normal value in about 2.5 days. Accumulated glycogen disappeared as LAAG activity recovered. Surprisingly, twelve daily CS doses of 1 mg/kg had only a small cumulative effect on LAAG inhibition and did not cause more glycogen accumulation than a single dose.

Topics: Alkaloids; Animals; Body Weight; Dose-Response Relationship, Drug; Glycogen; Glycoside Hydrolase Inhibitors; Indolizines; Liver; Lysosomes; Rats; Time Factors

At a late stage of fetal development, the mammalian alveolar epithelium undergoes an abrupt differentiation as a part of the preparation of the lung for the postnatal demands of gas exchange. Some of the most striking changes occur in the type II pneumocytes as they lose their glycogen and start to produce the lamellated inclusion granules that contain pulmonary surfactant. Premature birth before adequate type II cell maturation results in the neonatal respiratory distress syndrome, which is frequently fatal. We have used serial ultrathin sectioning, electron microscopy, and three-dimensional reconstructions to study the ultrastructural features of maturation of rat type II cells from a single rat each at age gestational day 20 through adult stages. We found evidence over this time span for compartmentation of several secretory granule precursors within type II cells. Changes in the polarization of lamellar bodies were observed over the time period studied. We also found marked gestational changes in the number and morphology of type II cell cytoplasmic processes that perforate the basement membrane. Type II cell mitochondria changed in shape during postnatal development from single, spherical to complex, branched structures. Volume composition obtained from serial sections of a small number of type II cells agreed closely with published morphometric data, indicating that throughout the animal's lifespan, type II cells are a homogenous population.

Topics: Aging; Animals; Basement Membrane; Body Weight; Epithelial Cells; Epithelium; Female; Gestational Age; Glycogen; Lung; Microscopy, Electron; Mitochondria; Models, Structural; Organelles; Pregnancy; Rats; Rats, Inbred Strains

To elucidate insulin action on hepatic glucose output (glycogenolysis) in the state exposed to an excess glucocorticoid, the fed rat liver was isolated and cyclically perfused with a medium containing 5 mM glucose and various concentrations of insulin. The rat was subcutaneously injected with 1 mg/kg of dexamethasone (Dex) for 7 days. Dex-treated rats showed marked increases of serum insulin and plasma glucose level compared with those in control rats. Hepatic glycogen contents in Dex group were markedly increased compared with those in control (115 +/- 5 and 28 +/- 4 mg/g, respectively). Insulin extraction rate in the perfused liver was not different between control and Dex group. Perfusate glucose level after 60 min perfusion was much higher in the Dex-treated rat liver than that of the control at 0 microU/ml insulin (34.5 +/- 2.5 vs 23.0 +/- 2.0 mM, P less than 0.01), and reduced to the nadir level (19.0 +/- 3.0 and 13.0 +/- 1.5 mM, respectively) at 100 microU/ml insulin in both groups, i.e., the decreasing rate in perfusate glucose level was not different between Dex and control group (43% and 44%, respectively). These results suggest that Dex-treatment augments hepatic glucose output, but does not affect the sensitivity and responsiveness of that to insulin.

Topics: Animals; Blood Glucose; Body Weight; Dexamethasone; Glucose; Glucose Tolerance Test; Glycogen; In Vitro Techniques; Injections, Subcutaneous; Insulin; Liver; Male; Rats; Rats, Inbred Strains

The effects of replacing dietary fat with a fat substitute on food intake, body composition and lipid metabolism were examined in rats. Female Sprague-Dawley rats (250 g) were fed diets containing between 2 and 63% of energy as fat for 64 d. Inclusion of a substitute resulted in diets of different fat content but similar texture. When 10% corn oil (21% kJ-fat diet) was replaced with the substitute supplemented with linoleic acid (2% kJ-fat diet), rats increased food intake so that there was no effect on energy intake, body weight, body composition or serum lipid profile. Rats fed a diet containing 10% corn oil and 30% Crisco vegetable shortening (63% kJ-fat diet) became obese and hyperinsulinemic. When half (51% kJ-fat diet) or all (30% kJ-fat diet) of the Crisco was replaced with the fat substitute, the rats increased food intake and were fatter than controls but less obese than rats fed the 63% kJ-fat diet. Hepatic lipid oxidation and ketone synthesis were proportional to the percentage of dietary energy as fat. Adipocyte de novo lipid synthesis was inhibited by 51% kJ-fat and 63% kJ-fat diets. Partial or total replacement of Crisco prevented the hyperinsulinemia observed in 63% kJ-fat rats, suggesting a protective effect against the development of insulin resistance with diet-induced obesity.

Topics: Animals; Blood Glucose; Body Composition; Body Weight; Dietary Fats; Energy Intake; Fatty Acids; Female; Food, Formulated; Glycogen; Insulin; Lipid Metabolism; Liver; Rats; Rats, Inbred Strains

Prolonged exposure (4 weeks) to 6.72 ppb of the organochlorine insecticide endosulfan induced disturbances in the blood and organ chemistry values of a common fish, Barbus conchonius. In blood the total lipids, cholesterol, and proteins were decreased in comparison to unexposed controls, while the free fatty acids (FFA), glucose, total phosphorus, and lactate were increased. Total lipids, FFA, and proteins were augmented in liver; cholesterol, in liver and ovary; and phosphorus and glycogen, in skeletal muscles. Compared to the controls, a decrease was seen in the total lipids (skeletal muscles and ovary), glycogen (liver, brain, and heart), and cholesterol (testes). Hyperlipemia, hyperproteinemia, and hyperlactemia persisted during a recovery period of 1 week in clean water following endosulfan poisoning.

Topics: Animals; Blood Glucose; Blood Proteins; Body Weight; Cholesterol; Endosulfan; Fatty Acids, Nonesterified; Fishes; Glucose; Glycogen; Lactates; Lipid Metabolism; Lipids; Liver; Muscular Diseases; Organ Size; Phosphorus; Proteins

The purpose of the present study was to compare the carbohydrate use of insulin-resistant obese Zucker rats with that of their lean littermates during steady-state exercise. Obese and lean rats were randomly assigned to a sedentary group or to a run group in which rats ran at 72-73% of their maximal O2 consumption, with the duration of exercise set to require an energy expenditure of 2.1-2.2 kcal. During the run the respiratory exchange ratio was significantly higher in the obese than in the lean rats [0.94 +/- 0.01 (SE) and 0.86 +/- 0.01, respectively], which indicate that the obese rats required 54% more carbohydrate than the lean rats. Total muscle glycogen utilization in the soleus, plantaris, and red and white gastrocnemius was not different between groups. Obese rats had total liver glycogen values five times greater than those of lean rats (833.38 +/- 101.4 and 152.8 +/- 37.5 mg, respectively) and utilized twice as much liver glycogen as their lean littermates (193.5 and 90.4 mg, respectively). The obese rats exhibited higher blood glucose and insulin concentrations than the lean rats during the run. These findings indicate that, despite their characteristic insulin resistance, the obese Zucker rats had a greater dependency on carbohydrate as a substrate during exercise than their lean littermates and that the major source of this carbohydrate was liver glycogen.

Topics: Animals; Body Weight; Glycogen; Liver; Liver Glycogen; Muscles; Obesity; Organ Size; Oxygen Consumption; Physical Exertion; Rats; Rats, Zucker; Reference Values; Respiration

The effect of a continuous infusion of norepinephrine (NE) on glucose disposal in vivo was examined in conscious restrained rats using the euglycemic-hyperinsulinemic clamp technique. NE, 1,000 micrograms.kg-1.day-1 (130 nmol.kg-1.h-1) or vehicle (CO) was infused for 10 days in adult male Sprague-Dawley rats using subcutaneously implanted osmotic minipumps. Body weight and food intake were similar in both groups of animals throughout the study. Fasting basal plasma glucose and insulin concentrations were similar in both groups. However, basal hepatic glucose production (HGP) was increased by NE treatment (9.03 +/- 0.63 vs. 13.20 +/- 1.15 mg.kg-1.min-1, P less than 0.05, CO vs. NE, respectively). Insulin infusions of 2, 6, and 200 mU.kg-1.min-1 suppressed HGP to the same degree in both groups. During 2, 6, and 200 mU.kg-1.h-1 insulin infusions the glucose disposal rate was 65, 60, and 13% greater in NE-treated animals than in controls. Acute beta-adrenergic blockade with propranolol infused at 405 nmol.kg-1.h-1 during the glucose clamps did not normalize glucose disposal. These results demonstrate that chronic NE infusion is associated with increased basal glucose turnover and increased insulin sensitivity of peripheral tissues.

Topics: Animals; Blood Glucose; Body Weight; Feeding Behavior; Glucose; Glucose Clamp Technique; Glycogen; Glycogen Synthase; Insulin; Insulin Infusion Systems; Liver; Liver Glycogen; Male; Muscles; Norepinephrine; Propranolol; Rats; Rats, Inbred Strains; Reference Values

Previous studies have shown that dietary provision of carbohydrate can alter cardiac isomyosin distribution in hormonally deficient rats. The main objective of this study was to determine if varying the heart's potential to utilize carbohydrate for energy provision can influence the cardiac isomyosin expression in normal weanling rats. Animals were assigned to one of five groups according to dietary and/or metabolic treatment: (1) mixed-control--(M); (2) high carbohydrate--(H); (3) low carbohydrate--(L); (4) mixed-diet supplemented with oxfenicine, a cardiospecific fatty acid oxidation inhibitor--(MO); and (5) high carbohydrate diet supplemented with oxfenicine--(HO). The results show that 4 weeks of dietary manipulations aimed to either increase or decrease carbohydrate supply to the heart, failed to induce any alterations in either cardiac myosin ATPase activity or isoenzyme pattern. However, extremes in carbohydrate provision altered the metabolic properties of both heart and skeletal muscle. A low carbohydrate diet increased 3-hydroxyacyl CoA dehydrogenase (P less than 0.05) and citrate synthase activities (P less than 0.05) and decreased glycogen content in both heart and soleus muscle; whereas, a high carbohydrate diet, in conjunction with oxfenicine, tended to increase hexokinase activity in these same tissues. These alterations provide indirect evidence that the contributions of both fat and carbohydrate to the energy balance of the heart and skeletal muscle were altered by the imposed dietary interventions. Collectively, these results suggest that although the substrate utilization patterns of the normal weanling heart can be modified via dietary manipulation, such shifts do not exert any regulatory influence on cardiac isomyosin expression.

Topics: Adenosine Triphosphatases; Animals; Biomarkers; Blood Glucose; Body Weight; Carbohydrate Metabolism; Carbohydrates; Diet; Energy Metabolism; Fatty Acids; Female; Glycogen; Heart; Isoenzymes; Liver; Muscles; Myocardium; Myofibrils; Myosins; Organ Size; Rats; Rats, Inbred Strains

Diets high in saturated fat and simple carbohydrate result in an insulin-resistant state, while training increases insulin sensitivity. Insulin resistance was induced by feeding a high-fat, high-sucrose (HFS) diet to 4-week-old female Sprague-Dawley rats. A control diet (low-fat, complex-carbohydrate) was fed to another group for comparison. During the 4-week dietary treatment, half of each group was trained by treadmill running (2 h day-1, 6 days week-1m 30 m min-1, 0% grade). At the end of this 4-week experimental period, hindquarter perfusions were performed at either basal (0) or maximal (100 nM) insulin concentrations to determine glucose uptake, glycogen synthesis, total glycogen content and the activity of several enzymes. Insulin (100 nM) significantly increased glucose uptake and glycogen synthesis in all four groups (CON-UN, CON-TR, HFS-UN, HFS-TR, where CON, UN and TR refer to control, untrained and trained respectively). HFS feeding significantly decreased (P less than 0.002) glucose uptake (mumol g-1 h-1) with maximal insulin stimulation, while training significantly increased uptake (P less than 0.01) at both insulin concentrations. Glycogen synthesis was also increased by training (P less than 0.05) at both insulin concentrations, but accounted for only 25-28% of the glucose uptake. Although training improved the insulin resistance caused by the HFS diet, glucose uptake in the HFS-TR group was still significantly lower than the CON-TR group. Changes in glycogen synthesis are not great enough to account for the decrease or increase in glucose uptake found in the HFS-fed or trained animals.

Topics: Animals; Body Weight; Dietary Carbohydrates; Dietary Fats; Dose-Response Relationship, Drug; Female; Glucose; Glycogen; Hexokinase; Insulin; Insulin Resistance; Phosphofructokinase-1; Physical Conditioning, Animal; Rats; Rats, Inbred Strains

The effect of 10 wk endurance swim training on 3-O-methylglucose (3-MG) uptake (at 40 mM 3-MG) in skeletal muscle was studied in the perfused rat hindquarter. Training resulted in an increase of approximately 33% for maximum insulin-stimulated 3-MG transport in fast-twitch red fibers and an increase of approximately 33% for contraction-stimulated transport in slow-twitch red fibers compared with nonexercised sedentary muscle. A fully additive effect of insulin and contractions was observed both in trained and untrained muscle. Compared with transport in control rats subjected to an almost exhaustive single exercise session the day before experiment both maximum insulin- and contraction-stimulated transport rates were increased in all muscle types in trained rats. Accordingly, the increased glucose transport capacity in trained muscle was not due to a residual effect of the last training session. Half-times for reversal of contraction-induced glucose transport were similar in trained and untrained muscles. The concentrations of mRNA for GLUT-1 (the erythrocyte-brain-Hep G2 glucose transporter) and GLUT-4 (the adipocyte-muscle glucose transporter) were increased approximately twofold by training in fast-twitch red muscle fibers. In parallel to this, Western blot demonstrated a approximately 47% increase in GLUT-1 protein and a approximately 31% increase in GLUT-4 protein. This indicates that the increases in maximum velocity for 3-MG transport in trained muscle is due to an increased number of glucose transporters.

Topics: 3-O-Methylglucose; Animals; Blood Glucose; Body Weight; Carbon Radioisotopes; Electron Transport Complex IV; Female; Glycogen; Heart; Liver Glycogen; Methylglucosides; Monosaccharide Transport Proteins; Muscle Contraction; Muscles; Organ Size; Physical Conditioning, Animal; Radioisotope Dilution Technique; Rats; Rats, Inbred Strains; Reference Values

It is well accepted that exercise endurance is directly related to the amount of carbohydrate stored in muscle and that a low carbohydrate diet reduces glycogen storage and exercise performance. However, more recent evidence has shown that when the organism adapts to a high fat diet endurance is not hindered. The present study was designed to test that claim and to further determine if animals adapted to a high fat diet could recover from exhausting exercise and exercise again in spite of carbohydrate deprivation. Fat-adapted (3 to 4 weeks, 78% fat, 1% carbohydrates) rats (FAT) ran (28 m/min, 10% grade) as long as carbohydrate-fed (69% carbohydrates) animals (CHO) (115 v 109 minutes, respectively) in spite of lower pre-exercise glycogen levels in red vastus muscle (36 v 54 mumols/g) and liver (164 v 313 mumols/g) in the FAT group. Following 72 hours of recovery on the FAT diet, glycogen in muscle had replenished to 42 mumols/g (v 52 for CHO) and liver glycogen to 238 mumols/g (v 335 for CHO). The animals were run to exhaustion a second time and run times were again similar (122 v 132 minutes FAT v CHO). When diets were switched after run 1, FAT-adapted animals, which received carbohydrates for 72 hours, restored muscle and liver glycogen (48 and 343 mumols/g, respectively) and then ran longer (144 minutes) than CHO-adapted animals (104 minutes) that ate fat for 72 hours and that had reduced glycogen repletion. We conclude that, in contrast to the classic CHO loading studies in humans that involved acute (72 hours) fat feedings and subsequently reduced endurance, rats adapted to a high fat diet do not have a decrease in endurance capacity even after recovery from previous exhausting work bouts. Part of this adaptation may involve the increased storage and utilization of intramuscular triglycerides (TG) as observed in the present experiment.

Topics: Adaptation, Physiological; Animals; Blood Glucose; Body Weight; Dietary Carbohydrates; Dietary Fats; Fatty Acids, Nonesterified; Glycogen; Lactates; Lactic Acid; Liver Glycogen; Male; Muscles; Physical Endurance; Physical Exertion; Rats; Rats, Inbred Strains; Time Factors

The influence of the maternal thyroid status on the fetal and neonatal myocardial protein, carbohydrate and lipid metabolism was studied in rats. The neonates born of hypothyroid mothers could not survive beyond 8 days after birth. The offsprings born of hypothyroid mothers showed growth retardation, decreased level of heart mitochondrial protein, reduced myocardial free fatty acid (FFA) oxidation at birth and afterwards, low glucose oxidation by the heart at later fetal stages, and afterwards, despite low heart glycogen reserve, glucose oxidation was high. The offsprings born of hyperthyroid mothers showed stimulation in overall growth, increased myocardial FFA oxidation and increased 14C-glucose incorporation into glycogen as well as increased myocardial glucose oxidation during fetal stages. Results indicate that maternal thyroid hormones play an important role in the metabolic control of fetuses and neonates.

Topics: Animals; Animals, Newborn; Body Weight; Female; Fetal Heart; Glucose; Glycogen; Hyperthyroidism; Hypothyroidism; Lipid Metabolism; Maternal-Fetal Exchange; Pregnancy; Pregnancy Complications; Proteins; Rats; Rats, Inbred Strains; Thyroid Gland; Thyroxine

Subjective fatigue was quantified before and 20 days after uncomplicated elective abdominal surgery in 12 patients and compared with changes in heart rate, enzyme activities and skeletal muscle substrates before and after bicycle exercise for 10 min at 65 per cent of patients' preoperative maximum work capacity. Fatigue increased from a mean(s.e.m.) preoperative level of 2.5(0.5) arbitrary units to 4.6(0.5) on postoperative day 20 (P less than 0.01). Body-weight, triceps skinfold thickness and arm circumference decreased postoperatively (P less than 0.02). Postoperative values of muscle enzyme activities indicative of oxidative phosphorylation capacity (citrate synthase and 3-OH-acyl coenzyme A dehydrogenase) were lower than preoperative values (P less than 0.05). Lactate dehydrogenase was unaltered and resting values of muscle glycogen and adenosine triphosphate were higher after operation (P less than 0.05). In response to exercise, heart rate, muscle glucose, glucose-6-phosphate and lactate increased (P less than 0.05), while muscle glycogen and creatine phosphate decreased (P less than 0.05). Increase in postoperative fatigue correlated with the increase in heart rate (P less than 0.05), while no significant correlations were found between fatigue and muscle parameters. Our results suggest that lack of exercise and malnutrition may be of importance in the decrease in work capacity and in fatigue after operation.

Topics: Abdomen; Adenosine Triphosphate; Adult; Arm; Body Weight; Citrate (si)-Synthase; Exercise; Exercise Test; Fatigue; Fatty Acid Desaturases; Female; Glycogen; Heart Rate; Humans; L-Lactate Dehydrogenase; Lactates; Male; Middle Aged; Muscles; Phosphocreatine; Postoperative Complications; Skinfold Thickness

Results of hindlimb suspension and space flight experiments with rats examine the effects of weightlessness simulation, weightlessness, and delay in postflight recovery of animals. Parameters examined were body mass, protein balance, amino acid metabolism, glucose and glycogen metabolism, and hormone levels. Tables show metabolic responses to unweighting of the soleus muscle.

Topics: Ammonium Chloride; Animals; Body Weight; Corticosterone; Female; Glucose; Glycogen; Hindlimb Suspension; Insulin; Muscle Proteins; Muscle, Skeletal; Muscular Atrophy; Rats; Rats, Sprague-Dawley; Space Flight; Weightlessness; Weightlessness Simulation

In natural conditions young rabbit nurses once a day and therefore ingests the whole of his daily caloric intake during a single meal. The present work investigates glucose homeostasis during perinatal period in young rabbit by assessing blood glucose and glycogen stores before and after one single meal. Ponderal data, glycogen and blood metabolites were determined in 1-4 day- and 17-21 day-old rabbits before suckling and at different times (1, 3, 6, 9, 24, 48, 72 h) after controlled suckling. In "young" and "old" rabbits hepatic glycogen stores were exhausted after 48 and 72 h of fast. Within the first hours following milk ingestion, muscle and carcass glycogen did not vary until 9 h in the "young" and until 24 h in the "old" without notable variation of glycemia. From 24 to 72 h young rabbits were in a fasting period with low hepatic glycogen and a decrease of muscle and carcass glycogen, but glycaemia decreased only slightly at 48 and 72 h in "young" and at 72 h in "old" As blood alanine was decreased, it appears that gluconeogenesis was effective and that alanine-glucose and Cori cycles were operating in these conditions.

Topics: Aging; Alanine; Animals; Animals, Newborn; Animals, Suckling; Blood Glucose; Body Weight; Glycogen; Homeostasis; Ketone Bodies; Kinetics; Liver; Muscles; Myocardium; Rabbits

Two groups of young male OF-1 mice were fed for 60 days with cafeteria or, as controls, with standard pellet diet respectively. At that time, both groups were daily treated with hexadecane (HDK) on the skin. HDK induced a drastic body weight loss much higher in cafeteria than control mice. White adipose tissue were exhausted after 4 days of treatment in controls but not after 10 days in cafeteria ones. HDK resulted in mobilization of liver glycogen in both groups while muscle glycogen decreased slightly in the end. Hexadecane treatment did not result in massively enhanced nitrogen metabolism, as the actual oxidation of amino acids decreased considerably as indicated by the low levels of plasma urea. The results could be explained by powerful and lasting effects of hexadecane on thermogenesis and metabolic reserve balance. The use of this material for pharmacological manipulation of body weight appeared difficult.

Topics: 3-Hydroxybutyric Acid; Adipose Tissue; Adipose Tissue, Brown; Alkanes; Amino Acids; Ammonia; Animals; Blood Glucose; Body Weight; Diet; Energy Metabolism; Glycogen; Hydroxybutyrates; Lipids; Liver; Male; Mice; Muscles; Organ Size; Urea

Post-exercise ketosis is known to be suppressed by physical training and by a high carbohydrate diet. As a result it has often been presumed, but not proven, that the development of post-exercise ketosis is closely related to the glycogen content of the liver. We therefore studied the effect of 1 h of treadmill running on the blood 3-hydroxybutyrate and liver and muscle glycogen concentrations of carbohydrate-loaded trained (n = 72) and untrained rats (n = 72). Resting liver and muscle glycogen levels were 25%-30% higher in the trained than in the untrained animals. The resting 3-hydroxybutyrate concentrations of both groups of rats were very low: less than 0.08 mmol.l-1. Exercise did not significantly influence the blood 3-hydroxybutyrate concentrations of trained rats, but caused a marked post-exercise ketosis (1.40 +/- 0.40 mmol.l-1 h after exercise) in the untrained animals, the time-course of which was the approximate inverse of the changes in liver glycogen concentration. Interpreting the results in the light of similar data obtained after a normal and low carbohydrate diet it has been concluded that trained animals probably owe their relative resistance to post-exercise ketosis to their higher liver glycogen concentrations as well as to greater peripheral stores of mobilizable carbohydrate.

Topics: 3-Hydroxybutyric Acid; Acidosis; Animals; Body Weight; Dietary Carbohydrates; Glycogen; Hydroxybutyrates; Ketone Bodies; Ketosis; Liver Glycogen; Malate Dehydrogenase; Male; Muscles; Physical Conditioning, Animal; Physical Exertion; Rats

We examined whether chronic exercise prevents insulin resistance developing in the high-fat-fed (HFF) rat, a model that otherwise develops profound peripheral insulin resistance. Insulin action (euglycemic clamp plus 2-[3H]deoxy-D-glucose-[14C]glucose tracer technique) was examined after 3 wk in sedentary control and sedentary or wheel cage exercise-trained HFF rats. At the whole body level, a reduction in peripheral insulin potency in HFF rats was prevented by concomitant chronic exercise; the 30-40% reduction in insulin-stimulated whole body net glucose utilization in sedentary HFF rats was abolished. Responses in individual muscles, however, suggested that the chronic exercise effect may be a compensation for, rather than a correction of insulin resistance induced by a high-fat diet; in six of eight muscles examined it produced an upward additive shift rather than a left shift in insulin dose response. Chronic exercise increased both muscle glycolytic flux and glycogen storage rates in the HFF rats, suggesting that glucose transport may be involved. We conclude that increased physical activity is beneficial in counteracting high-fat diet-induced insulin resistance. Different processes appear to be involved in the development of diet-induced insulin resistance in muscle and its amelioration by regular exercise.

Topics: Animals; Blood Glucose; Body Weight; Dietary Fats; Glycogen; Glycolysis; Insulin; Insulin Resistance; Liver Glycogen; Male; Muscles; Organ Specificity; Physical Conditioning, Animal; Physical Exertion; Rats; Rats, Inbred Strains; Reference Values

To investigate insulin action in muscle and adipose tissue in hepatic cirrhosis, a recently described animal model was used. Dimethylnitrosamine administration induced histologically proven cirrhosis. Contrary to expectation, muscle strips from cirrhotic rats displayed increased insulin sensitivity both with respect to glycogen synthesis (ED50 0.11 +/- 0.01 vs 0.23 +/- 0.04 nmol/l; p less than 0.03) and glucose oxidation (ED50 0.36 +/- 0.07 vs 0.97 +/- 12 nmol/l; p less than 0.02). As the cirrhotic rats had failed to gain weight normally, it is postulated that a state of relative starvation accounted for the enhanced insulin sensitivity. These data demonstrate that the severe insulin resistance characteristically associated with cirrhosis is reversible. Control of nutritional state in future studies upon DMNA induced cirrhosis should permit detailed examination of the cellular mechanisms controlling insulin sensitivity in hepatic cirrhosis.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Glycogen; In Vitro Techniques; Insulin; Liver; Liver Cirrhosis, Experimental; Liver Function Tests; Muscles; Organ Size; Rats; Rats, Inbred Strains

Young Osborne-Mendel rats were given different diets ad libitum for 6 weeks. Food was either a purified powder with sucrose (15%) or commercial pellets, and drink was either distilled water or a sugar-containing (6%) sport-drink with or without added fluoride (F), magnesium (Mg) or both. Despite differences in the energy density of the diets, daily intakes were the same in terms of metabolisable energy and resulted in equal weight gains for all groups. Interscapular brown fat hypertrophied in response to powdered food, while both sugar-containing food and sport-drink were effective in accumulating white fat. When exposed to cold air at -20 degrees C for 2-4 h, most of the rats were able to maintain normothermia. Only the rats fed pelleted food and given distilled water were less resistant to cold than the others. After exposure to cold, the reserves of muscle glycogen were least in those rats having the poorest performance in the cold. In contrast, the stores of liver glycogen, plasma glucose and adrenal ascorbic acid were associated with pelleted food, rather than with the exposure to cold or type of drink. It is concluded that the presence of purified, simple sugars, either in food or drink, is the most likely explanation of the results obtained. The F and Mg supplements to the sport-drink did not modify the parameters measured.

Topics: Adipose Tissue; Adrenal Glands; Animals; Body Temperature Regulation; Body Weight; Dietary Carbohydrates; Female; Fluorides; Glycogen; Magnesium; Male; Muscles; Organ Size; Rats

The effects of 12 wk of endurance training at 70% peak O2 consumption (VO2) were studied in 10 elderly (65.1 +/- 2.9 yr) and 10 young (23.6 +/- 1.8 yr) healthy men and women. Training had no effect on weight or body composition in either group. The elderly had more adipose tissue and less muscle mass than the young. Initial peak VO2 was lower in the elderly, but the absolute increase of 5.5-6.0 ml.kg-1.min-1 after training was similar for both groups. Muscle biopsies taken at rest showed that, before training, muscle glycogen stores were 61% higher in the young. Before training, glycogen utilization per joule during submaximal exercise was higher in the elderly. Glycogen stores and muscle O2 consumption increased significantly in response to training in the elderly only. After training, the proportion of energy derived from whole body carbohydrate oxidation during submaximal exercise declined in the young only. The absolute changes that training produced in peak VO2 were similar in both age groups, but the 128% increase in muscle oxidative capacity was greater in the elderly, suggesting that peripheral factors play an important role in the response of the elderly to endurance exercise.

Topics: Adult; Aged; Aging; Blood Pressure; Body Composition; Body Weight; Energy Metabolism; Female; Glycogen; Heart Rate; Humans; Male; Middle Aged; Muscles; Oxygen Consumption; Physical Education and Training; Physical Endurance

We compared the effects of three different anesthetics (halothane, ketamine-xylazine, and diethyl ether) on arterial blood gases, acid-base status, and tissue glycogen concentrations in rats subjected to 20 min of rest or treadmill exercise (10% grade, 28 m/min). Results demonstrated that exercise produced significant increases in arterial lactate concentrations along with reductions in arterial Pco2 (PaCO2) and bicarbonate concentrations in all rats compared with resting values. Furthermore, exercise produced significant reductions in the glycogen concentrations in the liver and soleus and plantaris muscles, whereas the glycogen concentrations found in the diaphragm and white gastrocnemius muscles were similar to those found at rest. Rats that received halothane and ketamine-xylazine anesthesia demonstrated an increase in Paco2 and a respiratory acidosis compared with rats that received either anesthesia. These differences in arterial blood gases and acid-base status did not appear to have any effect on tissue glycogen concentrations, because the glycogen contents found in liver and different skeletal muscles were similar to one another cross all three anesthetic groups. These data suggest that even though halothane and ketamine-xylazine anesthesia will produce a significant amount of ventilatory depression in the rat, both anesthetics may be used in studies where changes in tissue glycogen concentrations are being measured and where adequate general anesthesia is required.

Topics: Acid-Base Equilibrium; Animals; Body Weight; Ether; Ethyl Ethers; Female; Glycogen; Halothane; Ketamine; Liver Glycogen; Muscles; Oxygen Consumption; Physical Exertion; Rats; Rats, Inbred Strains; Thiazines; Xylazine

Circulating somatomedin activity reflects the presence of both somatomedins and somatomedin inhibitors, factors which antagonize the growth-promoting actions of somatomedins. Although both are regulated by nutrition, somatomedin inhibitors respond more rapidly than somatomedins to refeeding in fasted animals. To explore the role of the liver in such responses, release of somatomedin activity and somatomedin inhibitor activity was assessed during perfusion of livers from normal, fasted, and fasted-refed rats. Size-exclusion high-performance liquid chromatography (HPLC) revealed that liver perfusates contain both somatomedin and somatomedin inhibitor activity of apparent molecular weight (mol wt) comparable to that found in the circulation (approximately 7,000 and approximately 30,000, respectively), as well as activity of apparently higher wt. In subsequent studies, responses to nutrition were evaluated as fluctuations in bioactivity only of mol wt comparable to that found in the circulation. Release of both somatomedin and somatomedin inhibitor activity was progressive over at least two hours of recirculating perfusion. Perfusates of livers from normal fed rats had somatomedin activity (stimulation of cartilage SO4 uptake) 94 +/- 19% above buffer (P less than .01), which fell to undetectable levels after three days of fasting. With refeeding, perfusate somatomedin activity rose within three hours to approximately 25% of levels in fed rats, but did not become significant until after 12 hours (29 +/- 7%, P less than .02). Perfusates of livers of fed rats also contained somatomedin inhibitor activity (42 +/- 10% inhibition of cartilage stimulation by normal serum), which rose after three days of fasting to 114 +/- 22% (P less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Fasting; Food; Glycogen; Hydrogen-Ion Concentration; Kinetics; Liver; Male; Molecular Weight; Nutritional Status; Perfusion; Rats; Rats, Inbred Strains; Somatomedins

Liver and kidney carbohydrate metabolism was investigated in rats treated with daily doses of 15 mg/kg body weight cyclosporin A (CyA) for 2 and 8 weeks or of 50 mg/kg body weight CyA for 2 weeks. The higher dosage caused significantly reduced liver glycogen and liver glycogen synthetase activity (of both active I-form and total enzyme activity), whereas the activity of the glycogen-degrading enzyme phosphorylase (active a-form and total activity) remained unchanged. Plasma glucose and glucagon levels, as well as blood ketone bodies of these animals, increased significantly and plasma insulin decreased. In contrast, kidney glycogen and glucose content were higher in rats treated with 50 mg CyA, probably due to enhanced ketone body utilization. Reduced liver glycogen synthetase activity was also found in rats treated with 15 mg CyA. Our data suggest that hypoinsulinemia, induced by CyA, might be a contributing factor to the hyperglycemia, which is mainly due to inhibition of liver glycogen synthesis.

Topics: Animals; Body Weight; Carbohydrate Metabolism; Cyclosporins; Glycogen; Kidney; Liver; Mitochondria; Rats; Rats, Inbred Strains

Topics: Amylases; Animals; Body Temperature Regulation; Body Weight; Glycogen; Heart; In Vitro Techniques; Male; N-Acetylneuraminic Acid; Physical Conditioning, Animal; Pilocarpine; Rats; Rats, Inbred Strains; Saliva; Sialic Acids; Submandibular Gland

The developmental growth of the rat placenta was investigated between days 14 and 21 of gestation in normal control, gestational-diabetic, established-diabetic, and insulin-maintained-diabetic mothers. While established-diabetic mothers were hyperglycemic for 2 wk before and throughout the pregnancy, gestational-diabetic mothers were only hyperglycemic for the second half of pregnancy. Daily insulin replacements successfully restored normoglycemia. The wet weight and protein content of control placentas increased linearly between days 14 and 21. Although placentas from diabetic animals were initially smaller, placentomegaly was found at full term. Placental glycogen concentrations were also markedly increased in all diabetic animals. These changes were largely prevented by insulin replacement. The changes in placental size during normal development and in association with the diabetic state were explained by measuring placental rates of protein turnover (in vivo). In normal placentas, protein synthetic and degradative rates progressively declined over the last week of gestation. Because synthesis rates were unchanged in placentas of diabetic mothers, it appears that the differences in placental size primarily arise from alterations in protein degradation.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; DNA; Female; Gestational Age; Glycogen; Organ Size; Placenta; Pregnancy; Pregnancy in Diabetics; Proteins; Rats; RNA

1. The effects of cadmium on consumption, assimilation rates and biochemical parameters of Daphnia magna were determined. 2. The consumption and assimilation rates of 14 days 1.0 ppb Cd treated animals tended to decrease slightly, the decline of these rates at 5.0 ppb Cd (14 days), however, was highly significant (P less than 0.001). 3. The assimilation efficiencies of daphnids exposed to cadmium did not significantly differ from control. 4. No notable changes in the biochemical composition of daphnids could be noticed after 7, 14 and 21 days of cadmium exposure. 5. It seems as if not one metabolic process in particular was depressed due to cadmium, but metabolic activities seemed to be inhibited on the whole. 6. Results are discussed in relation with data of a previous study on the reproduction of D. magna under cadmium stress.

Topics: Animals; Body Weight; Cadmium; Daphnia; Environmental Exposure; Feeding Behavior; Glycogen; Lipid Metabolism; Proteins; Reproduction; Time Factors; Water Pollutants; Water Pollutants, Chemical

Irradiation with fractionated doses is a specific form of stress and the data concerning these problems are topical for recent radiobiology, radiology and oncology. Interest in this present paper is focused on tissue glycogenesis and lipogenesis from U-14C-glucose in vivo in rats irradiated with fractionated doses of 2.39 Gy once a week. Analyses were done after 1-6 fractions, up to total accumulated doses of 2.39, 4.78, 7.17, 9.76, 11.95 and 14.34 Gy, which means LD50/30 for this experimental model. Fractionated irradiation of rats led to glycogen deposition and increased incorporation of 14C-glucose into the liver, heart and skeletal muscles, but not into brain glycogen. The ascertained changes were not dose-dependent. 14C-glucose was incorporated into the liver and adipose tissue lipids to a small extent, and synthesis of liver cholesterol increased only after the 5th and 6th fractions. A decreased concentration of hepatic lipids, especially of cholesterol, was observed from the 3rd to the 6th fractions.

Topics: Adipose Tissue; Animals; Body Weight; Brain; Cholesterol; Fatty Acids; Gamma Rays; Glucose; Glycogen; Heart; Lipids; Liver; Male; Muscles; Organ Size; Radiation Dosage; Rats; Rats, Inbred Strains

Glycogen nephrosis, i.e. the Armanni-Ebstein lesion which manifests itself by intracellular accumulation of beta-glycogen has been studied in two groups of streptozotocin diabetic rats and compared to controls. One diabetic group was left untreated and the other diabetic group received pancreatic islet transplantation after 4 weeks duration of diabetes. The kidneys were studied after another 4 week period with normoglycemia. In the non-transplanted diabetic animals glycogen containing tubules comprised 43% of the distal tubule length in the cortex but in the transplanted animals no abnormal, glycogen containing cells could be recovered at the light microscope level. Measurements of the total distal tubule length in the non-transplanted diabetic animals showed that the distal tubules increased in length by 24%. In the transplanted diabetic animals distal tubule length remained the same as in the non-transplanted diabetic animals in spite of normalization of the tubular morphology. This finding could possibly be responsible for the incomplete normalization of kidney weight after treatment.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Female; Glycogen; Islets of Langerhans Transplantation; Kidney; Kidney Tubules; Nephrosis; Organ Size; Rats; Rats, Inbred Lew

The effects of obesity, weight reduction, and physical condition on the concentrations of glucose-6-phosphate (G-6-P) and glycogen, and the activities of glycogen synthase (GS) and lactate dehydrogenase (LD) were determined in resting vastus or gastrocnemius muscles of 40 healthy subjects. In obese women the activity of GS was 50% (P less than 0.05) lower than in lean women with similar levels of glycogen and G-6-P, whereas no difference was found in the activity of LD. Calorie restriction induced a 4.5% (P less than 0.05) decrease in body weight from 82.5 kg corresponding to a 3.2% (P less than 0.05) decrease in body mass index from 30.9 kg m-2. The total and fractional activities of glycogen synthase were increased by 50% (P less than 0.05), whereas muscle glycogen content was reduced by 40% (P less than 0.05). The G-6-P concentration and the activity of LD remained unchanged. In well-trained young men the concentrations of G-6-P and glycogen were, respectively, 250% (P less than 0.05) and 50% (P less than 0.05) higher than in non-trained. The fractional and total activities of GS were 90% (P less than 0.05) and 50% (P less than 0.05) higher, respectively, and the total activity of LD was only half (P less than 0.05) that of non-trained subjects. In conclusion, physical training enhances the activity of GS, despite a concomitantly increased glycogen content, and thus seems to exert a more efficient stimulus on glycogen synthase than weight reduction. It is indicated that physical training may provide a clinically important contribution to blood glucose reduction in hyperglycaemic conditions.

Topics: Body Weight; Diet, Reducing; Dietary Carbohydrates; Female; Glycogen; Humans; Lactates; Male; Middle Aged; Muscles; Obesity; Physical Education and Training

Metabolic costs of growth and maintenance were determined from the relationship M (metabolism) = m + nG (growth), where m is the metabolic rate at the feeding level at which growth is zero. In the past, the slope n was interpreted as indicating the metabolic costs of growth, and the costs of maintenance that arise with the increase in body mass were disregarded. These costs are included in n. In female toads, Bufo bufo, feeding at different rates, the uncorrected value of n was 0.44, when metabolism and growth were expressed as kJ kJ-1. After correction for increased metabolic maintenance expenditure with increased body mass, the value became 0.35, indicating that the physiological costs of growth were equivalent to about one-third of the body mass deposited. Metabolic costs of growth accounted for 80% of the increase in metabolism with growth, leaving 20% for costs of maintenance. At maximum growth rate the metabolic costs of growth amounted to about 60% of the total metabolism, total mass-specific metabolic rate being 2.5 times the rate at zero growth. The physiological costs of growth in young toads were compared with the costs in teleosts. Recalculation of published data on the relationship between metabolism and growth in the African catfish Clarias lazera indicated that the metabolic costs of growth amounted to about 28% of body mass deposited. The costs represented about 80% of the increase in metabolism with growth. The physiological costs of growth are several times higher than the net biochemical costs of synthesis of the macromolecules constituting the increase in body mass.

Topics: Animal Feed; Animals; Body Constitution; Body Weight; Bufo bufo; Catfishes; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Eating; Energy Metabolism; Female; Glycogen; Lipid Metabolism; Mathematics; Oxygen Consumption; Proteins

Our purpose was to test the significance of exhaustive training in aerobic or endurance capacity. The extent of adaptations to endurance training was evaluated by assessing the increase in physical performance capability and oxidative markers in the organs of rats trained by various exercise programs. Rats were trained by treadmill running 5 days.week-1 at 30 m.min-1 for 8 weeks by one of three protocols: T1-60 min.day-1; T2-120 min.day-1; and T3-120 min.day-1 (3 days.week-1) and to exhaustion (2 days.week-1). Groups T2 and T3 ran for longer than T1 in an endurance exercise test (P less than 0.05), in which the animals ran at 30 m.min-1 to exhaustion; no difference was observed between groups T2 and T3. All 3 trained groups showed a similar increase (20-27%) in the fast-twitch oxidative-glycolytic (FOG) fibers with a concomitant decrease in the fast-twitch glycolytic (FG) fiber population in gastrocnemius (p less than 0.05). The capillary supply in gastrocnemius increased with the duration of exercise (p less than 0.05): no difference was found between groups T2 and T3. Likewise, no distinction was seen between groups T2 and T3 in the increase in succinate dehydrogenase activity in gastrocnemius and the heart. These results suggest that the maximal adaptive response to endurance training does not require daily exhaustive exercise.

Topics: Animals; Body Weight; Capillaries; Glycogen; Male; Muscles; Osmolar Concentration; Physical Conditioning, Animal; Physical Endurance; Rats; Succinate Dehydrogenase

Topics: Aedes; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Carbohydrates; Female; Glycogen; Lipids; Wings, Animal

This study was undertaken to determine the effects of increased substrate availability (glycogen + plasma fatty acids) by glucocorticoids on energy metabolism during exercise to exhaustion. Female rats received a single subcutaneous injection of cortisol acetate (CA) (100 mg.kg body wt-1) 21 h before treadmill running (30.8 m/min). At the start of exercise in the CA-treated rats, plasma fatty acids and liver glycogen were increased by 40%. Glycogen levels were also increased by CA treatment in slow-twitch soleus (61%), fast-twitch white vastus (38%), and fast-twitch red vastus lateralis (85%) muscles. Exercise time to exhaustion was increased by CA treatment (114 +/- 5 vs. 95 +/- 6 min, P less than 0.05). During the exercise, total glycogen depletion was greater in the CA-treated than in the control animals, whereas estimated relative rates of carbohydrate utilization (R = 0.90) were similar. However, while running the CA-treated group consumed 11% more O2 than the controls (P less than 0.05). These results show that a single injection of glucocorticoids is capable of improving endurance. Yet the increased O2 uptake during exercise may have minimized the impact of the initial increased availability of carbohydrates and fatty acids in prolonging exercise capacity. This decreased running economy by the CA-treated runners may be secondary to alterations in energy production or utilization.

Topics: Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Energy Metabolism; Fatty Acids, Nonesterified; Female; Glucocorticoids; Glycogen; Heart; Hydrocortisone; Lactates; Liver; Liver Glycogen; Muscles; Myocardium; Organ Size; Oxygen Consumption; Physical Exertion; Rats; Rats, Inbred Strains

The influence of a regimen designed to lower the muscle glycogen content on the capacity to perform a single brief isometric contraction has been studied. Eight male subjects performed a single exhausting isometric contraction of the knee extensor muscles at a tension corresponding to 60% of maximum voluntary contraction (MVC). This was followed by prolonged cycling exercise at a work rate equivalent to approximately 75% of maximum oxygen uptake in order to reduce the muscle glycogen content. A diet low in carbohydrate was consumed for the remainder of this day in order to retard the resynthesis of muscle glycogen. The isometric contraction at 60% of MVC was repeated on the following day. Endurance time on the first day was 53.8 +/- 8.4 s (mean +/- SD); this was reduced (45.8 +/- 12.1 s; p less than 0.02) on the second day. From previously published data on rates of muscle glycogen utilisation during isometric exercise, it seems probable that insufficient glycogen is available in the muscle under the low carbohydrate condition to enable maximum performance to be achieved.

Topics: Adult; Body Weight; Dietary Carbohydrates; Energy Metabolism; Glycogen; Humans; Isometric Contraction; Lactates; Male; Muscle Contraction; Muscles; Physical Endurance; Physical Exertion; Time Factors

The effect of repetitive alternance of 3 days fasting and 3 days refeeding on morphological and biochemical ability to perform exercise was investigated in adult male rats. At the end of 10 wk of chronic intermittent fasting, the rats had consumed 20% less food but were able to maintain their initial body weight. Intermittent fasted rats (IF) had significantly lower carcass fat but had maintained the percent contribution of proteins to total carcass weight. The relative mass of liver, heart, kidney, and muscles was not affected by such dietary manipulation. Both glycolytic and oxidative enzyme capacities were reduced in IF rat muscles. In response to exercise (2 h of swimming), control rats displayed hypoglycemia, whereas IF rats were able to maintain plasma glucose level in spite of a reduced energy supply from liver (low glycogen stores) and adipose tissue (low plasma free fatty acid levels). This had been obtained by accumulating glycogen and triglycerides in muscles and by deriving energy for muscular contraction from the in situ breakdown of these energetic substrates. In addition, although IF rats displayed a markedly reduced liver protein content, the liver exercise-induced protein breakdown was abolished in these animals.

Topics: Acclimatization; Animals; Blood Glucose; Body Weight; Citrate (si)-Synthase; Eating; Fasting; Glycogen; L-Lactate Dehydrogenase; Liver; Male; Muscles; Organ Size; Physical Exertion; Rats; Rats, Inbred Strains; Reference Values; Triglycerides

1. Male broiler chickens were killed at various times up to 36 h after withdrawal of food; hepatic and muscle glycogen concentrations and pH were compared with those of control birds given continuous access to food and water. 2. Liver glycogen was reduced to negligible concentrations (less than 1 mg/g) within 6 h of food deprivation and the initial pH was elevated. 3. Withdrawal of food had no effect on glycogen concentrations in the m. pectoralis superficialis (PS) but reduced them in the m. biceps femoris (BF); the reduction was significant after 12 h. Ultimate pH was elevated by fasting in the BF, but not the PS.

Topics: Animals; Body Weight; Chickens; Fasting; Glycogen; Liver Glycogen; Male; Muscles

The effect of maternal diabetes on functional and biochemical maturation of the fetal lung was studied in a rabbit model. Pregnancy was initiated only after diabetes had been established. Both the pregnant doe and its fetuses were hyperglycemic. For comparison, the fetal heart and liver were also studied. In the diabetic group, the DNA content was lower in the fetal heart and lung while the protein content was higher in all three tissues. The glycogen levels were higher only in the fetal lung. Glycogen synthase was higher in the fetal lung and heart while phosphorylase activity was higher in all three tissues from the diabetic group. The activities of key enzymes involved in glycolysis were not affected. No difference was observed in the concentration of total phospholipids or in the ability of the airway fluid to reduce surface tension. In contrast, fetal lungs from diabetic does did not expand as well as the controls and retained less air on deflation. These findings suggest that the utilization of glycogen in fetal lungs from the diabetic does was not complete and that the increased incidence of respiratory distress in infants of diabetic mothers may not be due to a lack of surfactant.

Topics: Animals; Blood Glucose; Body Weight; Bronchoalveolar Lavage Fluid; Diabetes Mellitus, Experimental; Embryonic and Fetal Development; Female; Glycogen; Liver; Liver Glycogen; Lung; Lung Compliance; Myocardium; Organ Size; Phospholipids; Pregnancy; Pregnancy in Diabetics; Rabbits

Cyproterone acetate (1 mg/kg b.w. per day; oral) in combination with testosterone enanthate (2 mg/kg b.w. 15 days; i.m.) was administered for 60 and 90 days into adult male langur monkeys (Presbytis entellus entellus, Dufresne). Testicular weight and volume were reduced significantly. Spermatogenesis was suppressed but the interstitial cells appeared normal. Seminiferous tubules and Sertoli cell nuclear diameters were reduced significantly. The indices of testicular steroidogenesis, i.e. testicular total proteins, sialic acid, RNA and fructose showed a fall. On the contrary, cholesterol, total lipids, glycogen and phosphatases increased after treatment. Libido was not affected. Cessation of treatment resulted in a resumption of all the variables to normal levels within 90 days. The results reveal a reversible inhibition of testicular steroidogenesis which ultimately resulted in the disruption of spermatogenesis, a definite index of sterility. It is further emphasized that simultaneously administered testosterone enanthate maintains androgenicity.

Topics: Animals; Body Weight; Cercopithecidae; Cholesterol; Contraceptive Agents, Male; Cyproterone; Cyproterone Acetate; Glycogen; Libido; Lipids; Male; Phosphoric Monoester Hydrolases; Testis; Testosterone

Intra-lake variations in physiological parameters, representing haematology, plasma ion composition and carbohydrate metabolism, were investigated in perch (Perca fluviatilis), inhabiting a comparatively unpolluted lake. Provided the perch were subjected to a standardized procedure for capture, handling, recovery after capture, and sampling, only few and minor differences were observed in 21 parameters investigated when 3 groups were compared to a control group of perch. It is concluded that the experimental design used is suitable for the examination of the physiological status of perch in the field.

Topics: Animals; Body Weight; Electrolytes; Female; Genetic Variation; Glycogen; Organ Specificity; Perches; Perciformes; Sweden

1. Glycogen concentrations in Richardson's ground squirrels of the weight-loss phase were 1/4-1/2 those in animals of the weight-gain phase. White adipose lipid content was similar in animals in the two phases when total body weight was similar. 2. Specific activity of 14C in muscle glycogen of fed, starved and refed ground squirrels in the weight-loss phase was similar to that in starved weight-gain phase animals. Activity in adipose lipids of fed, starved, and refed ground squirrels in the weight-gain phase was 5-8 times greater than that in the same nutritional states in weight-loss phase animals. 3. In addition to a voluntary reduction in food intake, a depressed synthetic activity in lipids and glycogen may account in part for the rapid decrease in body weight during the weight-loss phase of the circannual cycle.

Topics: Adipose Tissue; Animals; Body Weight; Glycogen; Lipid Metabolism; Male; Muscles; Periodicity; Sciuridae; Starvation

We showed previously that cardiac function was depressed in rabbits subjected to 6 weeks of protein depletion and was restored after 4 weeks of protein refeeding. To identify nutritional or metabolic factors that underlie cardiac dysfunction, we assessed the nutritional status and myocardial content of energy-providing substrates in three groups of rabbits: group I served as control; group II was fed a protein-free diet; and group III was fed a protein-free diet and then repleted. Animal weights were 2.73 +/- 0.22 kg in group I, 1.92 +/- 0.28 kg in group II, and 2.78 +/- 0.12 kg in group III. Serum albumin concentrations decreased from 3.70 +/- 0.12 g/dl in group I to 2.81 +/- 0.10 g/dl in group II, and returned to normal (3.71 +/- 0.11 g/dl) in group III. The heart weights; myocardial contents of water, nitrogen (N), total fat, and glycogen; skeletal muscle N concentrations; and liver N contents were measured. Protein depletion produced a reduction in total cardiac mass due to decreased nitrogen and glycogen contents, but there was an increased fat content. Comparison with other organs suggests that cardiac muscle plays a role in energy homeostasis, undergoing glycogenolysis and proteolysis similar to those of liver and skeletal muscle. Protein repletion restored normal mass of the heart, but not of the liver. We conclude that adequate nutrition may be important in maintaining cardiac function.

Topics: Animals; Body Water; Body Weight; Female; Glycogen; Heart; Lipid Metabolism; Liver; Male; Muscles; Myocardium; Nitrogen; Organ Size; Protein-Energy Malnutrition; Rabbits; Serum Albumin

The effects produced in offspring by corticosterone treatment to breeder quail were investigated. The breeders received corticosterone orally every day during 7 days. The total dose administered was 3.15 mg/quail/7 days. The quail from treated breeders have a decreased rate of body growth during the experimental period. The studied metabolic and nutritives parameters were smaller than the control group, however, the relative indices were similar. The breeders treated with corticosterone produce quail smaller than controls, but the pattern during the growth period is similar, there it can be observed by the same relative indices.

Topics: Animals; Body Weight; Corticosterone; Coturnix; Eating; Glycogen; Liver; Nitrogen; Organ Size; Quail; Reproduction; Uric Acid

The effects of the non-selective beta-adrenergic blocking agent propranolol (known for its anti-lipolytic activity) on body composition were investigated in growing male rats on normal unrestricted diet (N = 7) and on diet restriction (N = 7, 95% of controls). Three animals in each group were injected i.p. with 30 mg propranolol per kg body weight (bw) dissolved in saline, 5 days/week. This dose attenuates exercising heart rate by 25% and exercise training-induced enzyme activity. The remaining animals received saline. Fat, glycogen, moisture and non-ether extractable residue were determined in the homogenized residue of the whole animal. After 9 weeks on the experimental regimen, bw gain was significantly lower in the diet restricted rats, whereas propranolol had no effect on the bw gain. The percentage of fat, moisture and non-ether extractable residue were unchanged by either propranolol or diet restriction. However, glycogen content was significantly lower in the beta-blocked rats either with or without diet restriction. These data indicated that neither beta-adrenergic blockade nor minimal diet restriction influences the percentage body fat, whereas body glycogen content is decreased under both conditions.

Topics: Adipose Tissue; Animals; Body Weight; Food Deprivation; Glycogen; Male; Propranolol; Rats; Rats, Inbred Strains

The effect of both physiological and pharmacological doses of estradiol on exercise performance and tissue glycogen utilization was determined in oophorectomized estradiol-replaced (ER) rats. Doses of beta-estradiol 3-benzoate (0.02, 0.04, 0.1, 0.2, 1, 2, 4, or 10 micrograms.0.1 ml of sunflower oil-1.100 g body wt-1) were injected 5 days/wk for 4 wk. Controls were sham injected (SI). After treatment, the animals were run to exhaustion on a motorized treadmill. ER animals receiving the 0.02-microgram dose ran significantly longer and completed more total work than the SI group. ER animals receiving doses of greater than or equal to 0.04 microgram ran longer and performed more work than the 0.02-microgram group. At exhaustion, myocardial glycogen content was significantly decreased in animals that were ER with less than or equal to 0.1 microgram, whereas those replaced with doses greater than 0.1 microgram utilized significantly less glycogen. With the 10-micrograms dose no significant decrease in heart glycogen content was observed at exhaustion. A submaximal 2-h run significantly reduced glycogen content in heart, red and white portions of the vastus lateralis, and the livers of SI animals. The latter effect was attenuated in skeletal muscle and liver, and there was no effect in the hearts of the ER animals receiving 2 micrograms. These data indicate that estradiol replacement in oophorectomized rats influenced myocardial glycogen utilization during exhaustive exercise and spared tissue glycogen during submaximal exercise. These glycogen sparing effects may have contributed to the significant improvements in exercise performance observed in this study.

Topics: Animals; Body Weight; Dose-Response Relationship, Drug; Estradiol; Female; Glycogen; Myocardium; Organ Size; Ovariectomy; Physical Exertion; Rats; Rats, Inbred Strains; Uterus

The cellularity and histochemistry of the semitendinosus muscle was studied in lean and obese pigs at 14 days of age. Muscles from lean animals had lower (P less than .05) muscle weights and minimum fiber diameters and had reduced (P less than .05) percentages of dry matter and protein when contrasted to obese muscles. Concentrations of RNA and glycogen were independent of animal strain but DNA levels were severely depressed (P less than .01) in obese muscle. Histochemistry for lipid, NADH-TR, acid ATPase, esterase and glycogen (PAS) indicated no strain effects. Regardless of strain, sections from larger animals showed histochemical patterns indicative of more mature muscles. These studies demonstrate abnormalities in muscle cellular characteristics in the young obese animal. Furthermore, these abnormalities may accelerate muscle maturation and hasten the fattening phase of growth.

Topics: Adenosine Triphosphatases; Adipose Tissue; Animals; Body Weight; Esterases; Glycogen; Histocytochemistry; Lipid Metabolism; Muscle Proteins; Muscles; NADH Tetrazolium Reductase; Nucleic Acids; Obesity; Swine

The pattern of pancreatic islet lysosomal enzyme activities was investigated in adult obese mice (aged 5-7 months), old obese mice (aged 9-17 months) and aged-matched old "obese" mice suffering from excessive weight loss. A series of lean NMRI mice of comparable age was included as controls. It was observed that the islet activity of the glucose producing glycogenolytic hydrolase, acid amyloglucosidase, was excessively high in the adult obese mouse, being about 10 times higher than in the adult lean mouse. This high activity was reduced by about 65% in the islets of old obese mice and by about 80% in old mice suffering from weight loss. When glycogen and maltose were compared as substrates for the alpha-1,4-glucoside splitting activity, the ratio, glycogen splitting/maltose splitting activity in adult obese mice (1.68) showed amyloglucosidase predominance, whereas the ratio in old obese mice (0.67), and in old mice suffering from weight loss (0.79) revealed a significant change in this relation. The extremely elevated plasma insulin levels in the adult obese mice were reduced by about 65% in old obese mice and by about 95% in old mice with excessive weight loss and thus displaying the same pattern as islet amyloglucosidase activity. Further, in normoglycemic obese mice a highly significant correlation (r = 0.85; p less than 0.001) was found between islet acid amyloglucosidase activity and the actual insulin secretory rate as reflected by the plasma insulin concentrations. The activity of islet N-acetyl-beta-D-glucosaminidase showed an activity pattern opposite to that of acid amyloglucosidase.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acetylglucosaminidase; Acid Phosphatase; Aging; Animals; Blood Glucose; Body Weight; Cathepsin D; Glucan 1,4-alpha-Glucosidase; Glucuronidase; Glycogen; Insulin; Islets of Langerhans; Liver; Lysosomes; Maltose; Mice; Mice, Obese; Substrate Specificity

Effects of intraportal influsion of glucagon in vehicle concurrent to feeding on meal pattern were studied in rats with reference to the changes of glycogen content in the liver. The feeding of the animal was monitored by an eatometer in the test chamber. The removal of a Noyes peller, 45 mg, in the food trough activated both a food dispensor to deliver another one and an infusion pump to infuse fluid into the hepatoportal vein at a rate of 0.35 ml/min for 30 sec. The infusion pump was on active state 23 hr/day for consecutive 15 days with a sequence: saline from 1st to 5th day, glucagon in saline (3 micrograms/ml) from 6th to 12th day, and again saline from 13th to 15th day. During the experiment, 7 groups of 5 rats in each were sacrificed at different times for determination of the glycogen content of the liver and the glucose level in the hepatic and hepatoportal veins. The data of 10 rats that proceeded up to the 12th day of infusion and those of 5 that continued to complete the whole course of 15 days infusion were used for analysis of meal pattern. The results revealed that the food intake was uniformly depressed during the period of glucagon administration and that the reduced food intake was totally accounted for by the premature termination of meals. The hepatic glycogen was depleted with glucagon initially but tended to come back with time. However, hepatic hyperglycemia was maintained without abating.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Feeding Behavior; Glucagon; Glycogen; Liver Glycogen; Male; Portal Vein; Rats; Rats, Inbred Strains; Satiation

1. The effects of 'cafeteria feeding' on primiparous Wistar rats during lactation have been studied by measuring circulating levels of glucose, amino acids, lactate, urea and ammonia as well as glycogen levels in liver and muscle. 2. No significant changes in glucose levels were observed despite alterations in blood glucose compartmentation. 3. Compared with controls, the dams given the cafeteria diet had higher liver glycogen stores which were more easily mobilized at the peak of lactation. 4. Rats given the cafeteria diet showed a lower amino acid utilization than controls and adequately maintained circulating levels, as determined by the lower circulating levels of ammonia and urea. 5. No significant differences in body-weight were observed in the period studied despite increasing dam weight after weaning in the cafeteria-fed group. 6. The size of pups of cafeteria-fed dams was greater than that of controls, and the differences were marked after weaning, when the metabolic machinery of the cafeteria pup maintained high protein accretion and body build-up using fat as the main energy substrate characteristic of the preweaning stage. The controls, however, changed to greater utilization of amino acids as an energy substrate and adapted to high-protein (low-biological-quality) diets with a significantly different pattern of circulating nitrogen distribution.

Topics: Amino Acids; Animals; Animals, Suckling; Blood Glucose; Blood Urea Nitrogen; Body Weight; Diet; Energy Metabolism; Female; Glycogen; Humans; Lactates; Lactation; Liver Glycogen; Muscles; Organ Size; Pregnancy; Rats; Rats, Inbred Strains; Urea

After 36% of hepatic mass removal , rainbow trout recovered its initial liver weight in 20-30 days, i.e., with a regeneration rate clearly lower than in mammals. During early regeneration process hematocrit index and hemoglobin content were slightly decreased, but both parameters rapidly reached their normal values. The evolution of both glycaemia and hepatic glycogen content supported the idea of the existence of a late regeneration wave, which, in this case, could begin at about the 20th post-operative day.

Topics: Animals; Blood Glucose; Body Weight; Glycogen; Hematocrit; Hemoglobins; Hepatectomy; Liver; Liver Regeneration; Salmonidae; Trout

Topics: Animals; Body Weight; Dose-Response Relationship, Radiation; Electromagnetic Fields; Electromagnetic Phenomena; Female; Glycogen; Male; Pregnancy; Radar; Rats; Regression Analysis; Reproduction; Time Factors; USSR

Current knowledge about the thermic effects of exercise in lean and obese subjects and the relationships between exercise and food intake, resting metabolic rate, and dietary-induced thermogenesis were reviewed. Studies of the effects of carbohydrate restriction during low calorie diets on the capacity to perform physical exercise and of the effects of weight reduction with or without the addition of physical training on the metabolic abnormalities of non-insulin-dependent diabetes mellitus are also described. The metabolic efficiency of physical work is normal in obesity, total energy expenditure is increased because of increased body mass, and increased energy expenditure is not necessarily matched by a compensatory increase in caloric intake. Thus, increased physical activity can be expected to result in negative energy balance in obese subjects. It is not clear whether exercise increases resting metabolic rate, but there is considerable evidence that exercise may potentiate the thermic effect of food in lean subjects and that this response may be blunted in the obese. The capacity to perform moderate-intensity exercise during carbohydrate-restricted, low calorie diets is maintained after a period of adaptation, but the capacity for high-intensity exercise (greater than 70% VO2max) is decreased unless adequate carbohydrate is provided to maintain muscle glycogen stores. The major effect of the addition of a program of physical training to dietary restriction and weight reduction in the treatment of non-insulin-dependent diabetes mellitus is an increase in peripheral sensitivity to insulin, primarily due to increased non-oxidative glucose disposal in muscle tissue.

Topics: Animals; Basal Metabolism; Blood Glucose; Body Composition; Body Temperature Regulation; Body Weight; Diabetes Mellitus; Diet, Reducing; Energy Intake; Energy Metabolism; Feeding Behavior; Female; Glucose Tolerance Test; Glycogen; Humans; Male; Muscles; Obesity; Physical Endurance; Physical Exertion; Rats; Time Factors

Changes in body weight, feed intake, hepatic cellularity, and intermediary metabolism were assessed in the mature male (450 g) rat following 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) administration. All animals were schedule-fed (8-hr feeding period/24 hr) and treated with a single oral dose of either TCDD (75 micrograms/kg) or vehicle. Blood and tissues were sampled 16 to 18 hr following the end of the feeding period on 2, 4, 6, and 8 days post-treatment. Mature rats treated with TCDD exhibited a slight but progressive reduction in both body weight and feed intake throughout the 8-day experimental period. An increase in liver mass that was apparent at 2 days and plateaued by 4 days after TCDD treatment was associated with a decrease in the concentration of DNA per gram of wet liver. However, the total liver content of DNA in TCDD-treated rats remained similar to pair-fed animals. Thus, TCDD treatment produced liver enlargement in the mature rat that was the result of hepatocellular hypertrophy and not an increase in cell number. Hepatic glycogen content in TCDD-treated rats was threefold higher than their pair-fed counterparts at 2 to 6 days post-treatment, and this augmentation would account, in part, for the hypertrophy of the liver cell found after administration of TCDD. Plasma glucose and lactate concentrations were similar in TCDD-treated and pair-fed rats, suggesting that the Cori cycle remained unaltered following TCDD administration. Likewise, heart and gastrocnemius glycogen concentrations were similar in all experimental groups. Urinary excretion of urea, ammonia, and creatinine was comparable in TCDD-treated rats and their pair-fed counterparts, indicative of a nitrogen balance that was not disturbed by TCDD. Plasma glutamine concentrations in TCDD-treated rats tended to be reduced and were significantly lower at Day 6 post-treatment when compared to those of pair-fed counterparts, suggestive that amino acid release from muscle was not enhanced in TCDD-treated rats. Likewise, plasma concentrations of branched-chain amino acids, which are metabolized to a large extent in muscle, tended to be lower on Day 6 following TCDD treatment. Yet at Day 6 post-treatment, the circulating concentrations of amino acids that are metabolized by the liver were elevated in TCDD-treated animals. TCDD administration also resulted in an increase in total hepatic protein concentration which was evident at 4 days and increased progressively at 6 and 8 days post-tre

Topics: Administration, Oral; Alanine; Amino Acids; Analysis of Variance; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Dioxins; DNA; Energy Intake; Glutamine; Glycogen; Heart; Ketone Bodies; Lactates; Lipid Metabolism; Liver; Male; Myocardium; Organ Size; Polychlorinated Dibenzodioxins; Proteins; Rats; Rats, Inbred Strains

Growth and development of the mammary gland of ewe lambs was characterized by changes of various biochemical constituents. Mammary glands were removed from 49 ewe lambs ranging between 1 and 18 mo of age, weighed before and after trimming, and samples of the trimmed glands were fat extracted and dried. The dried fat-free tissues were weighed, ground, and analyzed for nucleic acids, nitrogen, sodium, potassium, and chloride contents. Fresh samples were used for glycogen determination. Trimmed weight of mammary glands increased rapidly after the 9th mo of age. The pattern was similar for nucleic acid content of mammary glands. Dry matter and fat contents of mammary glands increased up to the 9th mo, fat decreased thereafter, and dry matter remained constant. Protein content was low up to the 9th mo and increased thereafter. Sodium and glycogen content in mammary glands increased, but potassium decreased linearly from 1 to 18 mo of age. Allometric growth of mammary tissue started at about 3 mo of age, before onset of puberty at 8 mo of age, but intense mammary metabolic activity started only after the ewe attained puberty.

Topics: Aging; Animals; Body Weight; DNA; Female; Glycogen; Lipid Metabolism; Mammary Glands, Animal; Organ Size; Potassium; Proteins; RNA; Sexual Maturation; Sheep; Sodium

Twenty four male Sprague-Dawley rats, 35 days old, were randomly assigned to one of four groups: 2 resting control groups and 2 swimming groups. The sea level-control and the sea level-swimming groups were housed 5 weeks at 1,011 hPa (760 mmHg) while the hypoxic control and swimming groups were housed for 1 week at 678 hPa, followed by 4 weeks at 611 hPa. The swimming rats were subjected to a swimming program of 30 min, 6 days/week for 5 weeks. Both hypoxia groups developed significantly higher Hb and Hct levels than the sea level groups. The glycogen content in the extensor digitorum longus (EDL) and the deep portion of the vastus lateralis (DVL) muscles of the sea level-swimming group were significantly greater as compared to the hypoxia swimming group. The succinate dehydrogenase (SDH) activity in the sea level-control group was significantly lower in the EDL muscle than in the 3 other groups, and in the DVL muscle lower than that of the sea level-swimming group. Histochemically, hypoxia and swimming training induced significant increases in the fast-twitch-oxidative-glycolytic (FOG) fibers (6-11%) in soleus muscle, and decreases in the slow-twitch-oxidative (SO) fibers. The EDL muscles had significantly higher percentages of FOG fibers in the hypoxia and swimming groups than in the sea level-control group. On the basis of the present study it seems probable that hypoxia is a triggering factor for the conversions of muscle fiber types and the increase in oxidative capacity.

Topics: Acclimatization; Aging; Animals; Atmospheric Pressure; Blood Proteins; Body Weight; Glycogen; Hematocrit; Hemoglobins; Hypoxia; Male; Muscle Development; Muscles; Myocardium; Phosphofructokinase-1; Physical Exertion; Rats; Rats, Inbred Strains; Succinate Dehydrogenase; Swimming

Castanospermine, an inhibitor of alpha-glucosidase activity, was injected into rats to determine its effects in vivo. Daily injections of alkaloid, at levels of 0.5 mg/g of body weight, or higher, for 3 days decreased hepatic alpha-glucosidase to 40% of control values, whereas alpha-glucosidase in brain was reduced to 25% of control values and that in spleen and kidney was reduced to about 40%. In liver, both the neutral (pH 6.5) and the acidic (pH 4.5) alpha-glucosidase activities were inhibited, but the former was more susceptible. On the other hand, beta-N-acetylhexosaminidase activity was elevated in the livers of treated animals, whereas beta-galactosidase activity was unchanged and alpha-mannosidase activity was somewhat inhibited. Livers of treated animals were examined by light and electron microscopy and compared to control animals to determine whether changes in morphology had occurred. In treated animals fed normal rat chow, the hepatocytes were smaller in size and simplified in structure, whereas the high-glucose diet lessened these alterations. Furthermore, in those animals receiving castanospermine at 1.0 mg or higher per g of body weight for 3 days, there was a marked decrease in the amount of glycogen in the cytoplasm, while a large number of lysosomes were observed that were full of dense, granular material. That this dense material was indeed glycogen was shown by the fact that it disappeared when blocks of fixed tissue were pretreated with alpha-amylase. Glycogen levels in liver, as measured either colorimetrically or enzymatically, were somewhat depressed at the higher levels of castanospermine.

Topics: Alkaloids; Animals; Body Weight; Female; Glucosidases; Glycogen; Glycoside Hydrolase Inhibitors; Indolizines; Liver; Liver Glycogen; Microscopy, Electron; Rats; Tissue Distribution

Biochemical and morphologic maturation of fetal rat lung was studied in pregnant, diabetic rats with different levels of glucose intolerance (sub-, mildly, and severely diabetic). Fetuses were almost normoglycemic and hyperinsulinemic in subdiabetic rats, both hyperglycemic and hyperinsulinemic in mildly diabetic rats, and hyperglycemic but hypoinsulinemic in severely diabetic rats. A similar delay in type II pneumocyte differentiation and a similar decrease of disaturated phosphatidylcholine (DSPC) content in lung tissue and broncho-alveolar material recovered by lung lavage occurred in the fetuses of the three diabetic groups, independently of the severity of diabetes. Phosphatidylglycerol (PG) was decreased in fetuses from severely diabetic rats only. DSPC appeared specifically affected in fetuses of sub- and mildly diabetic groups, whereas in those of severely diabetic groups, DSPC alterations accompanied a variety of abnormalities including whole lung hypoplasia and hypotrophy and decreases of sphingomyelin, unsaturated PC, and lysoPC. The mechanisms leading to abnormal lung development could therefore be different in fetuses of sub- and mildly diabetic rats on one hand and fetuses of severely diabetic rats on the other. Since hyperinsulinemia was the prominent feature of fetal "milieu intérieur" in subdiabetic rats, this study presents arguments gained from in vivo experiments for an implication of hyperinsulinemia in lung developmental retardation due to maternal diabetes. However, the decrease of PG seems to depend on increased blood glucose level in itself. Diminished lung glycogen breakdown and decreased lung triglyceride content, more pronounced in fetuses of sub- and mildly diabetic rats than in those of severely diabetic rats, suggest that in the former, the decrease of DSPC biosynthesis could be due to decreased availability of substrates because of abnormal glycogen utilization. Fetuses from sub- and mildly diabetic rats constitute experimental models most closely resembling the human fetus of the diabetic mother with respect to circulating glucose and insulin. They appear therefore more adequate for elucidating the mechanisms of abnormal lung development in the diabetic pregnancy. In contrast, fetuses from severely diabetic rats associate very high blood glucose levels and hypoinsulinemia, which are features closer to those of adult diabetic subjects than to those of the human fetus of the diabetic mother.

Topics: 3-Hydroxybutyric Acid; Animals; Blood Glucose; Body Weight; DNA; Female; Fetal Blood; Fetal Organ Maturity; Glycogen; Hydroxybutyrates; Insulin; Lipid Metabolism; Lung; Organ Size; Phospholipids; Pregnancy; Pregnancy in Diabetics; Proteins; Rats; Rats, Inbred Strains

The effects of experimental diabetes on cardiac function and ultrastructure were studied in rats that had been diabetic for 6-24 wk. Experimental diabetes was produced by the intravenous (i.v.) injection of 65 mg/kg streptozocin (STZ) into rats 42-43 days old. Diabetic rat hearts perfused at 15 cm H2O on the working heart apparatus demonstrated depressed cardiac function (i.e., lower left ventricular pressure and +/- dP/dt) at 6, 12, and 24 wk of diabetes. Electron microscopic analysis of ventricular myocardium revealed increased lipid deposition from 6 to 24 wk of diabetes and progressive deterioration of the myocardial cell integrity at 12 and 24 wk of diabetes. This deterioration was characterized by loss of contractile protein, vacuolization (swollen sarcoplasmic reticulum), myelin formations, myocytolysis, and contracture bands. These alterations paralleled the depression of cardiac function at 12 and 24 wk of diabetes. There was, however, depressed function at 6 wk of diabetes but no observable alterations in myocardial ultrastructure. Therefore, experimental diabetes produced ultrastructural alterations in the rat heart that manifested themselves only after a demonstrable depression in cardiac function.

Topics: Animals; Blood Glucose; Body Weight; Cytoskeleton; Diabetes Mellitus, Experimental; Glycogen; Heart; Insulin; Male; Microscopy, Electron; Mitochondria, Heart; Myelin Sheath; Myocardium; Organ Size; Rats; Rats, Inbred Strains; Sarcoplasmic Reticulum

It has previously been suggested that exercise training leads to increased whole body insulin sensitivity. However, the specific tissues and metabolic pathways involved have not been examined in vivo. By combining the euglycemic clamp with administration of glucose tracers, [3H]2-deoxyglucose (2DG), [14C]glucose, and [3H]glucose, in vivo insulin action at the whole body level and within individual tissues has been assessed in exercise-trained (ET, running 1 h/d for 7 wk) and sedentary control rats at four insulin doses. Whole body insulin sensitivity was significantly increased in ET. In addition, the skeletal muscles, soleus, red and white gastrocnemius, extensor digitorum longus (EDL), and diaphragm all showed increased sensitivity of insulin-stimulated 2DG uptake with training. With the exception of EDL, no significant difference in insulin-mediated glycogen synthesis between control and ET could be found. Therefore, the increased insulin-induced 2DG uptake observed in muscle following training is apparently directed towards glucose oxidation. In ET animals, adipose tissue exhibited a significant increase in insulin-mediated 2DG uptake and [14C]glucose incorporation into free fatty acids but there was no difference from control in any parameters measured in lung or liver. EDL and white gastrocnemius, which are not primarily involved during exercise of this type, also demonstrated increased insulin sensitivity following training. In conclusion, exercise training results in a marked increase in whole body insulin sensitivity related mainly to increased glucose oxidation in skeletal muscle. This effect may be mediated by systemic as well as local factors and is likely to be of therapeutic value in pathological conditions exhibiting insulin resistance.

Topics: Adipose Tissue; Animals; Body Weight; Corticosterone; Deoxyglucose; Glucose; Glycogen; Hexokinase; Insulin; Isotope Labeling; Lipid Metabolism; Lung; Male; Mathematics; Muscles; Myocardium; Physical Exertion; Rats; Rats, Inbred Strains

To isolate and demonstrate the effect of insulin on pulmonary surfactant in vivo, islet cell hyperplasia and hyperinsulinemia were produced in fetal rabbits by the litter reduction technique without concomitant hormonal or metabolic changes in mother or fetus. This produced fetuses which were heavier than controls (37.1 vs. 31.5 g), with two-fold higher insulin levels (48.1 vs. 24.3 microU/ml). The fetal weight correlated directly with the insulin level, while the L/S ratio was found to correlate inversely with the insulin level. This inhibitory effect may be mediated by any of several mechanisms which await further investigation.

Topics: Animals; Body Weight; Disease Models, Animal; Female; Fetus; Glucose; Glycogen; Insulin; Macaca mulatta; Phosphatidylcholines; Pregnancy; Pulmonary Surfactants; Rabbits; Rats; Sphingomyelins

The effect of work-induced hypertrophy (without any concomitant change in circulating parameters) on skeletal muscle metabolism was studied in lean mice and in gold-thioglucose-obese mice. Soleus muscle was functionally overloaded in one leg by tenotomy of gastrocnemius muscle 4 days before muscle isolation, muscle in the other leg being used as control. Basal deoxyglucose uptake and glycolysis were markedly increased in overloaded muscles compared with control muscles, together with a ten-fold increase in fructose 2-6 bisphosphate content. In the presence of maximally effective insulin concentrations, deoxyglucose uptake and glycolysis were identical in overloaded and control muscles of lean mice, while the effects of overload and insulin were partly additive in muscles of gold-thioglucose-obese mice. The sensitivity to insulin and insulin binding to muscles were not modified in overloaded muscles. Insulin-stimulated glycogenogenesis was decreased by about 50% probably due to a lower amount of glycogen synthase in overloaded than in control muscles. Thus, in muscles of gold-thioglucose-obese mice work-induced hypertrophy increased the response to maximal insulin concentrations without modifying the altered insulin sensitivity and decreased insulin binding.

Topics: Animals; Aurothioglucose; Body Weight; Deoxyglucose; Fructosediphosphates; Glycogen; Glycolysis; Hypertrophy; Insulin; Insulin Resistance; Male; Mice; Muscles; Obesity; Physical Exertion

High L-thyroxine (T4) and cortisol doses given to rats during the first 8 days of life and on the first day only respectively, produce decrease of body and brain weight and perturbances to brain energy substrates, i.e. glucose and ketone bodies. The same alterations are found in the undernourished rats from the prenatal period. The pituitary GH and TSH is decreased in the T4- and cortisol-injected animals. The plasma ACTH is decreased in the treated cortisol animals at 8, 12 and 22 days of life. The pituitary TSH content is reduced with respect to controls in the undernourished animals from 14 to 70 days of life. From the exposed experiments we suggest an alteration in the hypothalamic-pituitary complex in T4- and cortisol-treated rats, and describe the similarities between the three experimental models.

Topics: Aging; Animals; Animals, Newborn; Blood Glucose; Body Weight; Brain; Corticosterone; Female; Food Deprivation; Glycogen; Growth Hormone; Hydrocortisone; Ketone Bodies; Lactates; Lactic Acid; Liver; Organ Size; Pituitary Gland; Pregnancy; Rats; Rats, Inbred Strains; Thyrotropin; Thyrotropin-Releasing Hormone; Thyroxine

This study compared glycogen depletion in active skeletal muscle after light and moderate exercise in both cold and comfortable ambient conditions. Twelve male subjects (Ss) were divided into two groups equally matched for the submaximal exercise intensity corresponding to a blood lactate concentration of 4 mM (W4) during cycle exercise. On two separate days Ss rested for 30 min at ambient temperatures of either 9 degrees C or 21 degrees C, with the order of temperature exposure being counter-balanced among Ss. Following rest a tissue specimen was obtained from the m. vastus lateralis with the needle biopsy technique. Six Ss then exercised on a cycle ergometer for 30 min at 30% W4 (range = 50 - 65 W) while the remaining group exercised at 60% W4 (range = 85 - 120 W). Another biopsy was taken immediately after exercise and both samples were assayed for glycogen content. Identical procedures were repeated for the second environmental exposure. No significant glycogen depletion was observed in the Ss exercising at 30% W4 in 21 degrees C, but a 23% decrease (p = 0.04) was observed when the same exercise was performed at 9 degrees C. A 22% decrease (p = 0.002) in glycogen occurred in the 60% W4 group at 21 degrees C, which was not significantly different from that observed during the same exercise at 9 degrees C. The results suggest that muscle substrate utilization is increased during light exercise in a cold environment as compared to similar exercise at a comfortable temperature, probably due to shivering thermogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Blood Glucose; Body Height; Body Temperature; Body Weight; Cold Temperature; Glycogen; Heart Rate; Humans; Lactates; Male; Muscles; Oxygen Consumption; Physical Exertion; Pulmonary Gas Exchange; Rectum; Self Concept

Topics: Adult; Aged; Body Weight; Diagnosis, Differential; Extracellular Space; Female; Glucose; Glycogen; Humans; Hypernatremia; Intracellular Fluid; Kidney Concentrating Ability; Male; Middle Aged; Vasopressins; Water Loss, Insensible

Effect of training on basal metabolism in rats by means of long-term exercise loaded at a moderate intensity were studied. The Wistar-strain male rats were carefully bred at the room temperature of 23.0 +/- 1 degree C and humidity of 60%. The first physical training was carried out by motor driven treadmill for 8 weeks at a speed of 25 m/min for less than 15 min once daily and 6 times in a week after 4 weeks of birth. Continuously, the second training was carried out for 15 months at the same load of one time per week. Running ability and the recovery of glycogen in exhausted skeletal muscles on period of the first training, loaded from 4 weeks to 12 weeks after birth. There was no change on the basal metabolism between the trained and sedentary control rats. In general, the basal metabolism significantly fell by aging, for instance, 24 months rat's basal metabolism was 63% of 3-4 months rat's. The second training repressed a decline of running ability and rose the recovery of muscle glycogen in rats, though training could not be stopped lowering of basal metabolism in aged rats.

Topics: Aging; Animals; Basal Metabolism; Body Weight; Energy Metabolism; Glycogen; Male; Muscles; Oxygen Consumption; Physical Exertion; Rats; Rats, Inbred Strains

In order to clarify the conclusion that the change of basal metabolism affected by physical training, effect of endurance training for 8 weeks on basal metabolism of young adult rats were investigated. Results are as follows. Endurance training increased significantly running ability of rats, for instance the running time at a speed of 25 m/min on the control and training groups were 53.7 +/- 18.8 min, 232.8 +/- 32.8 min, respectively. The ratio of soleus's weight to the body weight in trained rats was high significantly (p less than 0.05). The glycogen contents of trained rats under the condition of feeding have higher than the control rats. Especially, glycogen contents of the soleus and red-gastrocnemius significant increased (p less than 0.05), and liver glycogen content under the same condition increased significantly (p less than 0.02). The oxygen consumption in trained rats increased significantly compared with control rats (p less than 0.03). The basal metabolism of trained rats showed 1.24-fold increase compared with those of control (p less than 0.02). Oxygen consumption of sliced ventricle in trained rats increased significantly (p less than 0.03), it's rate was 118% of control. However those of other tissues did not change significantly.

Topics: Animals; Basal Metabolism; Body Weight; Glycogen; Kidney; Liver; Male; Muscles; Organ Size; Oxygen Consumption; Physical Conditioning, Animal; Physical Endurance; Rats; Rats, Inbred Strains; Spleen

The effect of gestational hypothyroidism on some maternal and foetal metabolites were studied on pregnant rats after 24 h fasting. Thyroidectomy induced a decrease in body weight in the pregnant rats. Their foetuses showed lower weights than the controls. No difference was found in circulating glucose levels in the thyroidectomized pregnant rats, although an increase was found in their foetuses. Hepatic glycogen and total serum lipids decrease in hypothyroid pregnant rats. Cholesterol concentration increases as a result of hypothyroidism. However, foetuses coming from thyroidectomized mothers show an increase in their total lipid levels. Hypothyroidism in pregnant rats affects foetal development and metabolic changes are greatly manifested in the starved condition.

Topics: Animals; Blood Glucose; Body Weight; Cholesterol; Female; Fetal Blood; Glycogen; Hypothyroidism; Lipids; Liver; Pregnancy; Pregnancy Complications; Rats; Rats, Inbred Strains

Ewes carrying twin fetuses were maintained during late pregnancy on a uniformly high plane (n = 22), a uniformly low plane (LP) (n = 24) or a low plane increasing to a high plane (n = 14) of nutrition. Seven ewes at each nutritional level were killed at 142 days of gestation and the liver and muscle glycogen and body lipid concentrations of the fetuses were determined. The rest of the ewes lambed naturally at about 145 days and the colostrum yields were obtained by hand milking after oxytocin injections during the first 18 hours after birth. The lactose, lipid and protein concentrations of colostrum were determined. Undernutrition in the LP group did not apparently affect the body concentrations of available glycogen, reduced available body lipid by about 47 per cent and reduced the lactose, lipid and protein available in colostrum during the first 18 hours by about 50 per cent. Refeeding previously underfed ewes to a high plane during the last five to 10 days of pregnancy did not improve the available reserves of glycogen or lipid in the lambs but did increase the yields of colostral constituents by about 30 per cent. The relative contributions of body reserves and colostral constituents to the maintenance of high, medium and low metabolic rates in lambs from different groups was assessed. It was concluded that under normal field conditions refeeding undernourished ewes during the last weeks of pregnancy would improve only marginally the survival potential of the lambs and that most lambs would be compelled to draw on their body glycogen reserves in order to maintain heat production during the first 18 hours after birth, even when they consumed all the available colostrum.

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Weight; Colostrum; Energy Metabolism; Female; Fetus; Glycogen; Humans; Lactose; Lipid Metabolism; Pregnancy; Pregnancy, Animal; Pregnancy, Multiple; Sheep; Twins

The effect of excess vitamin A on glycogen metabolism in the submandibular salivary gland, as compared to that in liver was studied. Contrary to what has been previously reported for the liver, either using from 1 to 6 X 15 000 or 2 X 30 000 U.I. vitamin A, the glycogen content in the submandibular salivary gland was lower in the hypervitaminotic rats. The total phosphorylase activity was reduced in the groups receiving lower vitamin A doses.

Topics: Animals; Body Weight; Glycogen; Hypervitaminosis A; Liver; Liver Glycogen; Male; Phosphorylase a; Phosphorylases; Rats; Rats, Inbred Strains; Submandibular Gland; Vitamin A

Rats were fed on a diet containing 1% beta-guanidinopropionic acid (GPA), a creatine substrate analogue, for 6-10 weeks to deplete their muscle of creatine. This manipulation was previously shown to give a 90% decrease in [phosphocreatine] in skeletal and cardiac muscle and a 50% decrease in [ATP] in skeletal muscle only. Maximal activities of creatine kinase and of representative enzymes of aerobic and anaerobic energy metabolism were measured in the superficial white, medial and deep red portions of the gastrocnemius muscle, in the soleus and plantaris muscle and in the heart. Fast-twitch muscles were smaller in GPA-fed animals than in controls, but the size of the soleus muscle was unchanged. The activities of aerobic enzymes increased by 30-40% in all fast-twitch muscle regions except the superficial gastrocnemius, but were unchanged in the soleus muscle. The activities of creatine kinase and phosphofructokinase decreased by 20-50% in all skeletal-muscle regions except the deep gastrocnemius, and the activity of glycogen phosphorylase generally paralleled these changes. There were no significant changes in the activities of any of the enzymes measured in the heart. The glycogen content of the gastrocnemius-plantaris complex was increased by 185% in GPA-fed rats. The proportion of Type I fibres in the soleus muscle increased from 81% in control rats to 100% in GPA-fed rats, consistent with a previous report of altered isometric twitch characteristics and a decrease in the maximum velocity of shortening in this muscle [Petrofsky & Fitch (1980) Pflugers Arch. 384, 123-129]. We conclude that fast-twitch muscles adapt by a combination of decreasing diffusion distances, increasing aerobic capacity and decreasing glycolytic potential. Slow-twitch muscles decrease glycolytic potential and become slower, thus decreasing energy demand. These results suggest that persistent changes in the [phosphocreatine] and [ATP] are alone sufficient to alter the expression of enzyme proteins and proteins of the contractile apparatus, and that fibre-type-specific thresholds exist for the transformation response.

Topics: Animals; Body Weight; Creatine; Glycogen; Guanidines; In Vitro Techniques; Male; Mitochondria, Muscle; Muscles; Myocardium; Organ Size; Oxygen Consumption; Propionates; Rats; Rats, Inbred Strains

The exhaust gas induces a stressing action, similar to classical type agression: activation of the pituitary adrenal-axis, with increase of relative adrenal weight, and of the rate of corticosterone production. After chronic exposure, deep metabolic changes appear, which reflect an accentuated state of exhaustion of the organism. Moreover perturbation of spermatogenesis with azoospermia is noted. Thus exhaust gas is to be considered as a very potent toxic agent.

Topics: Adrenal Cortex; Animals; Blood Proteins; Body Weight; Carbon Monoxide; Corticosterone; Glycogen; Growth; Lipids; Liver; Male; Metabolism; Organ Size; Rats; Rats, Inbred Strains; Vehicle Emissions

Glycogen content in the liver, skeletal muscle and heart has been determined in Sprague-Dawley (SD) and Wistar (W) rats and in tricoloured (T) and albino Dunkin Hartley (DH) guinea-pigs. The 12-week-old animals were studied under non-fasted or control conditions (N) and after 48 hr of fast (F48). Hepatic glycogen was higher in DH guinea-pigs (95.6 +/- 3.8 mg g-1) than in W (77.2 +/- 5.3 mg g-1) and SD (80.2 +/- 2.3 mg g-1) rats under N conditions. Mean values for the two strains were slightly higher in guinea-pigs than in rats. After fasting, hepatic glycogen was almost exhausted in the two species but was higher in W (1.5 +/- 0.08 mg g-1) and T (1.5 +/- 0.2 mg g-1) than in SD and DH (0.6 +/- 0.1 mg g-1). The content of glycogen in the anterior muscles of the thigh was comparable in the two strains of rat and guinea-pig, but was twice as high in the guinea-pigs (DH:15.1 +/- 0.6; T: 16.4 +/- 0.7 mg g-1) as in the rats (SD: 8.1 +/- 0.2; W: 7.1 +/- 0.5 mg g-1) under N conditions. In F48 animals, muscular glycogen decreased by 41-46% (rats) and 38-39% (guinea-pigs). Hepatic and extra-liver glycogen stores were calculated and found higher in the guinea-pigs than in the rats. The total utilization during fasting was larger in the guinea-pigs (6140 mg/kg body wt) than in the rats (4500 mg/kg body wt).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Fasting; Food; Glycogen; Guinea Pigs; Liver Glycogen; Male; Muscles; Myocardium; Rats; Rats, Inbred Strains; Time Factors

A combination of danazol (15 mg/kg b.w./day; oral) plus TE (5 mg/kg b.w./15 days; i.m.) was investigated for reversible inhibition of testicular function in rabbit. Testicular histology and biochemistry were studied before, during (30, 60 & 75 days) treatment and 120 days of recovery. A conspicuous decrease in testicular weight and volume with slight increase in body weight was observed. Gradual decrease in spermatogenesis accompanied with reduced tubular diameter and nuclei diameter of Leydig and Sertoli cells was observed. A significant elevation in testicular cholesterol, total lipids, glycogen and phosphatases with depleted concentrations of total proteins, RNA and fructose was noticed. Sialic acid did not change significantly. Libido was not affected. All parameters returned to normal level after 120 days of recovery. In conclusion, the combination therapy induced reversible inhibition of spermatogenesis without loss of libido.

Topics: Animals; Body Weight; Danazol; Glycogen; Libido; Lipids; Male; Pregnadienes; Rabbits; Spermatogenesis; Testis; Testosterone

Intermittent high altitude hypoxia (8 hours a day, 5 days a week, stepwise up to the altitude of 7000 m, total number of exposures 24) induced in male and female rats, chronic pulmonary hypertension and right ventricular hypertrophy. No significant sex differences were found in both these parameters. A significant sex difference was demonstrated in the resistance of the cardiac muscle to acute anoxia in vitro: the myocardium of control female rats proved to be significantly more resistant to oxygen deficiency. Intermittent altitude hypoxia resulted in significantly enhanced resistance in both sexes, yet the sex difference was maintained. Sex differences were further observed in the growth response of experimental animals to the acclimatization process. Whereas the body weight of male rats exposed to intermittent altitude hypoxia was significantly lower, hypoxic females had body weights comparable to those of control animals.

Topics: Altitude; Animals; Body Weight; Cardiomegaly; Female; Glycogen; Hemodynamics; Hemoglobins; Hypertension, Pulmonary; Hypoxia; Male; Myocardial Contraction; Myocardium; Rats; Rats, Inbred Strains; Sex Factors

We hypothesize that training results in a faster and greater repletion of glycogen in skeletal muscles of normal and diabetic rats. Normal male Sprague-Dawley rats (100-140 g) were divided into two groups--one to train by treadmill running for 10 wk and the other to remain sedentary. Forty-eight hours after the last training session the rats of both groups were exercised to exhaustion. One subgroup of each was fed oral glucose (3 g/kg) at exhaustion and killed 60 min later. The other was killed at exhaustion. The glycogen concentration of soleus, plantaris, and red and white gastrocnemius was determined in all rats. The trained group had higher glycogen levels after glucose feeding in all muscles (P less than 0.002) and repleted their muscle glycogen more rapidly (P less than 0.05). However, in diabetic rats (45 mg streptozotocin/kg body wt) the trained and sedentary rats have similar glycogen levels and glycogen repletion rates in all muscles. Compared with the normal trained rats, the diabetic trained rats had slower glycogen repletion rates (P less than 0.05).

Topics: Animals; Body Weight; Diabetes Mellitus, Experimental; Glucose Tolerance Test; Glycogen; Male; Motor Activity; Muscles; Rats; Rats, Inbred Strains; Reference Values; Rest; Streptozocin

It has been reported that sand rats, naturally feeding on low-caloric-value plants containing a high concentration of salt, become obese and develop hyperglycemia when fed on a standard laboratory diet. The aim of this study was to examine the long-term effects of a synthetic-chow diet on the metabolic pattern of the diabetic syndrome in a large group of sand rats. While a few animals had a fulminant reaction with markedly decreased glucose tolerance, low plasma insulin levels, and death within 3-4 wk, most sand rats developed obesity and elevated plasma insulin levels. From the third month and forward, 40% of sand rats presented with a diabetic syndrome with hyperinsulinemia, hyperglycemia, markedly decreased glucose tolerance, and insulin resistance. This diabetic syndrome can be compared with maturity-onset (type II) diabetes. When this synthetic-chow diet was given for more than 6 mo, the majority of animals lost considerable weight and showed a major depletion of fat stores. Serum immunoreactive insulin levels fell, while blood glucose rose to above 500 mg/dl with glycosuria and ketonuria. The elevated triglyceride content of plasma and the lipid deposits in the liver were greatly augmented, and no glycogen was present. Animals developed frank insulin-dependent diabetes, and diabetic animals not treated with insulin died in diabetic coma with presumed ketoacidosis. The disease was essentially confined to sand rats showing abnormal glucose tolerance, even before eating laboratory chow. This observation suggests a genetic factor. Thus, the sand rat appears to be a potentially interesting model for investigation of both maturity-onset and insulin-dependent diabetes.

Topics: Animal Feed; Animals; Arvicolinae; Blood Glucose; Body Weight; Diabetes Mellitus; Disease Models, Animal; Energy Intake; Female; Glucose Tolerance Test; Glycogen; Glycosuria; Insulin; Ketone Bodies; Liver; Male

The effect of strenuous exercise on lipoprotein level and composition as well as on lipoprotein lipase activity (LPLA) and glycogen stores in skeletal muscle was studied in 16 healthy young men after military field maneuvers. Body weight was reduced by 1 kg after the maneuvers and was gradually restored during a 5-day recovery phase. Glycogen levels were reduced by 50% and LPLA increased threefold immediately after the exercise, and neither were restored until 3-5 days of recovery. Serum triglycerides were decreased by about 50% after 1 day of recovery and the cholesterol concentration in high-density lipoproteins increased but only immediately after exercise. In contrast, the apolipoproteins A-I and A-II, the main protein constituents, were both decreased and remained so for 3-5 days. The results indicate that significant alterations of plasma lipoprotein level and composition as well as of muscle metabolism occur after prolonged physical exertion and that some changes are still evident after 5 days of recovery.

Topics: Adult; Apolipoprotein A-I; Apolipoprotein A-II; Apolipoproteins A; Body Weight; Cholesterol, HDL; Dietary Carbohydrates; Energy Metabolism; Glycogen; Humans; Lipoprotein Lipase; Lipoproteins; Lipoproteins, HDL; Lipoproteins, LDL; Lipoproteins, VLDL; Male; Muscles; Physical Exertion; Time Factors; Triglycerides

The effect of progressive moderate exercise on body weight gain, visceral and muscle protein stores, and thyroid hormone levels during an 8-day refeeding period after 65 h of starvation was studied in 2-month-old male Sprague-Dawley rats. Twenty-four animals were divided into three groups and acclimated for 5 days while being fed with ordinary Purina Chow. After the fasting phase, a group of rats was killed in order to provide base-line information concerning fasting-induced changes in body composition; a sedentary group was fed Purina Chow ad libitum; and a treadmill-exercised group was pair fed with the sedentary rats. During the refeeding phase, the exercised animals regained significantly less weight than the sedentary animals (p less than 0.001), but the two groups did not differ significantly with respect to visceral, muscle, eviscerated carcass, and skin protein. Total body fat content was lower in the exercised than the sedentary group. The thyroid hormone levels were not significantly different for the two refed groups. These results indicate that exercise during refeeding may alter the pattern of body weight gain during refeeding after fasting such that the replenishment of adipose tissue stores is reduced without compromising the restoration and growth of lean tissue.

Topics: Adipose Tissue; Animals; Body Weight; Fasting; Food; Glycogen; Liver; Male; Muscles; Organ Size; Physical Exertion; Proteins; Rats; Rats, Inbred Strains; Thyroid Hormones; Tissue Distribution

This study examined how the duration of experimentally induced diabetes affects myocardial metabolism. Both acutely (2-day) and chronically (30-day and 90-day) streptozocin (STZ)-diabetic rats exhibited hyperglycemia and hyperketonemia, while hyperlipemia was evident only in the chronically diabetic rats. The activity of succinate dehydrogenase was lower, whereas that of 3-hydroxyacyl-CoA-dehydrogenase was higher in the hearts of chronically diabetic rats. Although myocardial concentrations of glucose-6-phosphate, glycogen, and triacylglycerols were elevated in diabetes, the patterns of alterations differed between acute and chronic diabetes. The fructose-1,6-diphosphate/fructose-6-phosphate ratio declined progressively after STZ administration, which was not accompanied by a reciprocal increase in citrate levels, although citrate concentrations were elevated. Impaired glucose oxidation was more severe in the freshly isolated heart cells from 30-day than from 2-day diabetic rats. For a given substrate concentration, the oxidation rates of palmitate and 3-hydroxybutyrate were markedly reduced in myocytes from 30-day diabetic rats. However, they were similar to or even higher than the rates found in their control counterparts under conditions that reflected the respective in vivo concentrations of the substrates. Incubating isolated myocytes from 2-day diabetic rats in the presence of insulin only partially restored the impaired glucose oxidation. Insulin administered to the animals 4 h before the experiments restored the impaired glucose oxidation by the cells. Insulin in vitro or single injection in vivo had little or no effect on glucose oxidation in isolated myocytes from 30-day diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Citrates; Citric Acid; Diabetes Mellitus, Experimental; Glycogen; Hexosephosphates; Hydroxybutyrates; Male; Myocardium; Organ Size; Oxygen Consumption; Rats; Rats, Inbred Strains; Substrate Specificity; Time Factors; Triglycerides

The effects of reduced maternal placental blood flow on the growth and development of the fetal guinea pig have been studied by unilateral ligation of the uterine artery at day 30 of pregnancy. Fetal guinea pigs were investigated about 20 or 30 days later. In about one-third of cases fetal death occurred, in another third fetuses less than 60% of normal weight were observed and in the remainder all fetuses were in the normal weight range. In the growth retarded fetuses prenatal growth occurred at about 50% of the rate in control. There was no postnatal 'catch up' as growth still remained lower than in controls. Restricted fetal growth affected particularly development of the visceral tissues in which case size declined in proportion to body weight. Brain and adrenal by comparison were less affected as their contribution to total body weight increased, but even so in the severely retarded fetuses the mass of both fell. The responses of the liver were in general consistent with a delay in the pattern of development. Thus DNA, RNA, protein and haematopoietic cell content changes occurred later than normal. In contrast an enhanced deposition of glycogen was apparent in the liver of the growth-retarded fetus. The results indicate some of the ways in which nutritional deprivation of the fetuses leads to reprogramming of growth and maturation of selected fetal tissues to allow non-essential changes to await more favourable times.

Topics: Animals; Animals, Newborn; Arteries; Body Weight; Female; Fetal Proteins; Fetus; Glycogen; Growth; Guinea Pigs; Hematocrit; Ligation; Liver; Maternal-Fetal Exchange; Nucleic Acids; Organ Size; Placenta; Pregnancy; Triglycerides; Uterus

Glycogen level in and size of pinealocytes of the feral, white-footed mouse Peromyscus leucopus, were studied by a semiquantitative histochemical method to determine whether seasonal changes exist in them under natural conditions, what temporal pattern they exhibit, and whether 24-hour changes in these parameters exist in different seasons, as shown in the laboratory dd-mice. Marked seasonal changes were seen in both glycogen levels and nuclear densities (ANOVA p less than 0.005). The size of pinealocytes at 09:00 to 10:00 showed one peak (and nadir) seasonal change, with the smallest size in winter (December and February) and a larger size in warmer seasons, with the maximum value in July. Glycogen level in pinealocytes at 09:00 to 10:00 showed bimodal seasonal changes, with lower levels in fall and spring and higher levels in winter and summer. In fall, a circadian trend in glycogen level in pinealocytes was seen, with a higher level at the end of the light period. In winter, the glycogen levels were very high at 09:00, 13:00, 17:00, and 21:00 examined and showed dampening of time-of-day differences. On the other hand, the size of pinealocytes followed a time-of-day change (P less than 0.005), being largest at 13:00 and smallest at 21:00. Thus, marked changes in quantitative structure and chemical activities, suggesting changes in functional activity, in pinealocytes were noted especially in severe, cold winter.

Topics: Acclimatization; Animals; Body Weight; Female; Glycogen; Male; Peromyscus; Pineal Gland; Seasons; Sex Factors

Diet in itself cannot provide fitness or championship form, but a poor diet can ruin both. Optimal nutrition is a basic component of training that is necessary for the development and maintenance of top physical performance. Appropriate application of recent research findings can have a beneficial impact on exercise performance.

Topics: Adult; Body Weight; Child; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Drinking; Exercise Therapy; Glycogen; Humans; Minerals; Nutritional Requirements; Physical Education and Training; Physical Exertion; Sports; Vitamins

Starting at 6 weeks of age, male Fischer 344 rats were provided five different dietary regimens: group 1, fed ad libitum; group 2, restricted to 60% of the food intake of group 1; group 3, restricted to 60% of the food intake of group 1 until 6 months of age and then fed ad libitum; group 4, fed ad libitum until 6 months of age and then restricted to 60% of the food intake of group 1; group 5, given the same caloric intake as group 1 but 60% of the protein intake. The weight of the liver was maintained at about 2.5% of body weight over the wide range of body weight, age (6 through 30 months of age) and diets of this study. Liver cholesterol concentration increased with age in the rats of group 1 but not in the other groups; the hepatic cholesterol concentration was lower in the rats of groups 2 and 4 than in the others. The liver microsomal 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase activity was higher in 4-month-old rats than in rats 12 months of age and older; also, the microsomal activity from group 2 and group 4 rats was higher than that from rats of the other groups. Liver triglyceride levels increased with age in groups 1, 2, 3 and 5 but not in group 4. At all ages, postabsorptive (15 h without food) hepatic glycogen concentrations were much higher in groups 2 and 4 than in the other groups. Liver phospholipid concentration was not affected by age or diet. Basal adenylate cyclase activity in liver homogenates increased with age in all but group 4, but hormone-stimulated adenylate cyclase activity was little affected by age or diet. The age-related hepatic changes in lipids and in hormone responsiveness noted in the present study were much less marked than those previously found in blood and adipose tissue.

Topics: Adenylyl Cyclases; Aging; Animals; Body Weight; Cholesterol; Diet; Dietary Proteins; Food Deprivation; Glycogen; Hydroxymethylglutaryl CoA Reductases; Liver; Male; Organ Size; Rats; Rats, Inbred F344; Triglycerides

Glucagon has been shown to lower blood lipids and to decrease food intake and body weight in short-term studies in man and animals. There is evidence of decreased secretion of glucagon in human obesity. The Zucker obese rat suffers from a genetic type of obesity and has an absolute reduction in circulating glucagon concentration. The effect of long-term administration of glucagon on the body weight in obese Zucker rats was studied. Glucagon caused a marked (-20%) reduction of body weight in obese Zucker rats with no change in feed intake. Urine glucose, urea nitrogen, creatinine, and ketone content, as well as serum triglyceride, cholesterol, alkaline phosphatase, creatinine, and insulin levels remained unchanged. Weights of perirenal fat, kidneys, and heart also remained unchanged. However, glucagon injection in obese Zucker rats caused significant decrease in serum glucose, and increases in SGOT, liver weight, and liver lipid and glycogen content. Further investigations are needed concerning the safety of chronic glucagon administration for weight control.

Topics: Adipose Tissue; Animals; Aspartate Aminotransferases; Blood Glucose; Body Weight; Glucagon; Glycogen; Lipid Metabolism; Liver; Obesity; Organ Size; Rats; Rats, Zucker

1. Levels of glycogen and fat in the liver showed a diurnal difference, being higher at dusk than at dawn during the post- and premigratory periods. 2. Fat level increased by at least more than double from its lowest in the postmigratory period (August) to highest towards migration time (21-30 April) at both dawn as well as dusk. 3. With the steady increase in liver fat, there was a gradual decrease in liver glycogen up to about the middle of April and a slight increase thereafter. 4. RQ values obtained for liver and pectoralis muscle slices in vitro at postmigration (August) indicated lipid utilization. Those for the premigratory period indicated hyperlipogenesis, while towards migration time the values denoted carbohydrate catabolism and sparing of lipid.

Topics: Animals; Birds; Body Weight; Circadian Rhythm; Glycogen; India; Lipid Metabolism; Liver; Muscles; Seasons

The influence of streptozotocin-induced maternal diabetes on choline phosphate cytidylyltransferase activity (EC.2.7.7.15) glycogen content and disaturated phosphatidyl choline in fetal lung was studied between 19 and 21 days of gestation. In this experimental model, induction of maternal diabetes two days after mating, resulted in fetal hyperglycemia and hyperinsulinemia; the fetuses were neither macrosomic nor showed any evidence of fetal growth retardation. The glycogen content of lungs on days 19 and 20, but not on day 21 of gestation was significantly higher in fetuses of diabetic rats than in controls. The pulmonary cytosol cytidylyltransferase activity was similar in the two groups of fetuses on days 19 and 20. On day 21 of gestation the enzyme activity was significantly lower in fetuses of diabetic rats than in those of controls. On day 21 of gestation and in newborns of diabetic mothers, although there was no difference in the total pulmonary phospholipids, the levels of disaturated phosphatidyl cholines were significantly lower than in controls.

Topics: Animals; Blood Glucose; Body Weight; Choline-Phosphate Cytidylyltransferase; Diabetes Mellitus, Experimental; Female; Fetal Blood; Gestational Age; Glycogen; Insulin; Lung; Maternal-Fetal Exchange; Nucleotidyltransferases; Phosphatidylcholines; Pregnancy; Pregnancy in Diabetics; Rats; Rats, Inbred Strains; Streptozocin

Diabetes was induced in 3 pregnant sows by administration of alloxan tetrahydrate (50 mg/kg body weight) at the 60th-70th day of gestation. Body weight, concentration of glycogen in liver, heart and skeletal muscle, weight of liver, heart, pancreas, thyroid gland and adrenal glands as well as plasma concentrations of glucose, fructose and insulin (IRI) were determined immediately after birth in the piglets of diabetic sows (4 litters). Furthermore, the plasma glucose and insulin reactions to and intravenous bolus injection of glucose (0.5 g/kg) were examined 4-8 hours and 6-7 days after birth. The results were compared with the values obtained from the offspring of 4 normal litters. Newborn piglets of diabetic sows showed a significantly increased absolute and relative weight of liver as well as a significant increase in the relative weight of heart, thyroid gland and pancreas. The concentration of glycogen in heart and skeletal muscle as well as the amount of glycogen in liver/kg body weight were significantly elevated. Furthermore, we found significantly higher plasma glucose values in the offspring of alloxan treated sows, while there were no differences in plasma insulin and fructose levels. When compared to normal piglets, the diabetic piglets displayed an impaired insulin response and glucose tolerance after a bolus injection of glucose. The results obtained suggest considerable differences in the fetal development and pancreatic function during a diabetic pregnancy in different species.

Topics: Animals; Animals, Newborn; Blood Glucose; Body Composition; Body Weight; Diabetes Mellitus, Experimental; Female; Glucose; Glycogen; Insulin; Pancreas; Pregnancy; Pregnancy in Diabetics; Swine

Topics: Anemia, Hypochromic; Body Weight; Diet; Diet Fads; Eating; Energy Metabolism; Female; Glycogen; Humans; Male; Nutritional Physiological Phenomena; Physical Education and Training; Sports Medicine

Twelve crossbred barrows from four litters (average initial body weight of 21 kg) were used to examine the relationship between acetate and glucose metabolism in pigs. The treatments were the addition of acetate in the form of triacetin to the basal diet at 0, 5 and 10% of the metabolizable energy intake. In the immediate postprandial period, the administered acetate decreased the venous plasma glucose concentration linearly (P less than .05) and increased linearly the venous plasma concentrations of lactate (P less than .01) and ketone bodies (P less than .001). There was a linear increase in the glycogen content of the liver (P less than .001), heart (P less than .001) and femoral muscle (P less than .01), as the level of acetate intake was increased. In the remote postprandial period (12 h after the last meal), glucose, which was considered to have been derived from hepatic glycogen storage, became the dominant blood metabolite in place of the acetate administered with the diet. This led to the reduction in hepatic production of endogenous acetate, arterial acetate concentration and in acetate utilization in the hind limb. Hepatic urea production was also decreased. Thus, there was a reciprocal change in acetate and glucose metabolism.

Topics: Acetates; Acetic Acid; Animals; Blood Glucose; Body Weight; Diet; Glucose; Glycogen; Ketone Bodies; Lactates; Lactic Acid; Liver Glycogen; Male; Swine; Triacetin

Topics: Animals; Body Weight; Female; Glucose Tolerance Test; Glycogen; Hypoxia; Insulin Resistance; Muscles; Rats

Topics: Animals; Animals, Newborn; Body Weight; Chlorphentermine; Glycogen; Lung; Male; Organ Size; Phentermine; Phospholipids; Piperazines; Rats; Rats, Inbred Strains

Changes induced in liver and striated muscle glycogen and glycogen enzymes (glycogen synthetase, glycogen phosphorylase and alpha-amylase) by hypothyroidism and hyperthyroidism in rats have been determined. There were no changes in liver glycogen synthetase, phosphorylase and amylase activities in the hypothyroid group. Hyperthyroid rats showed lower liver glycogen synthetase, phosphorylase a and amylase activities. In muscle, hypothyroid rats had lower phosphorylase activity. In the hyperthyroid group glycogen synthetase was increased.--The results presented do not completely agree with the glycogen levels found in both tissues studied, and they are obviously more related to other factors such as glucose availability. It can be concluded that under the conditions studied, the glycogen enzyme levels could not alone explain the variations of glycogen levels.

Topics: Amylases; Animals; Blood Glucose; Body Weight; Glycogen; Glycogen Synthase; Hyperthyroidism; Hypothyroidism; Liver; Liver Glycogen; Male; Muscles; Phosphorylases; Rats; Rats, Inbred Strains

The effects of maternal treatment with ritodrine, a beta 2-adrenergic agonist, on the biochemical development of fetal brain were studied in an animal model. Pregnant rats were treated with long and short dosage schedules. Fetuses were delivered by hysterotomy 4 h after the last dose. No differences in the fetal brain content of protein, DNA, glycogen, cholesterol or beta-adrenergic receptors were found. In this animal model, using relatively high maternal doses of ritodrine, there were no apparent effects on the fetal brain biochemical indices measured, suggesting a relatively high efficacy to toxicity ratio of ritodrine for brain development.

Topics: Animals; Body Weight; Brain; Brain Chemistry; Cholesterol; DNA; Female; Fetus; Glycogen; Myelin Basic Protein; Nerve Tissue Proteins; Organ Size; Pregnancy; Propanolamines; Rats; Receptors, Adrenergic, beta; Ritodrine

Rats fed a copper-poor diet were found to have a reduced plasma insulin response to an oral glucose load in comparison with rats fed a copper-supplemented diet. In addition, the increment in plasma glucose above the fasting level at 60 min and at 120 min was significantly higher in rats maintained on the copper-poor diets. In vitro glucose incorporation into diaphragm glycogen and into epididymal fat-pad lipids was stimulated greater than twofold by the addition of 100 micrograms/ml CuCl2 to the incubation medium. In tissues of streptozotocin-diabetic rats, the stimulatory effect of copper on glucose incorporation in vitro was also noted, but was significantly smaller. These results indicate that glucose utilization by peripheral tissues and insulin release may be added to the many vital functions for which copper is essential.

Topics: Animals; Body Weight; Copper; Diabetes Mellitus, Experimental; Epididymis; Female; Glucose; Glycogen; Insulin; Male; Rats; Streptozocin

The effect of different dosages of streptozotocin (STZ) on selected rat tissue enzyme activities and glycogen concentration were investigated. The rats were administered STZ intravenously at 60 (STZ-60), 80 (STZ-80), 100 (STZ-100), and 150 (STZ-150) mg/kg body weight. They were used 3 weeks postinjection. Mortality prior to kill occurred only in the STZ-100 and STZ-150 rats. All diabetic rats showed reduced growth rate, hyperglycemia, hypoinsulinemia, and hyperlipemia. Phosphofructokinase (PFK) and succinate dehydrogenase (SDH) activities were significantly reduced in the red gastrocnemius muscle of all diabetic rats, and in the white gastrocnemius and soleus of STZ-100 and STZ-150 groups. PFK activity in the heart remained unaltered, but SDH activity was below normal. Liver SDH activity was not affected by insulin deficiency. Glycogen content was markedly increased in the heart and decreased in the liver of all diabetic rats. Glycogen content in the skeletal muscle was similar to the controls, except for the lower values in the soleus of STZ-100 and STZ-150 rats. When STZ-80 and STZ-150 rats were given insulin therapy, the STZ-80 rats showed a greater response to the treatment. Despite similar levels of plasma immunoreactive insulin among all groups of diabetic rats, the STZ-100 and STZ-150 rats had higher mortality, greater loss in body weight, and alterations in enzyme activities and glycogen content in the tissues studied.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Enzymes; Glycogen; Insulin; Lipids; Male; Organ Size; Rats; Rats, Inbred Strains; Streptozocin

Topics: Animals; Animals, Newborn; Blood Glucose; Body Weight; Cyclic AMP; Diabetes Mellitus, Experimental; Epinephrine; Female; Glycogen; Insulin; Liver; Norepinephrine; Pancreas; Pregnancy; Pregnancy in Diabetics; Prenatal Exposure Delayed Effects; Rats; Rats, Inbred Strains

Previous studies suggest that fast-twitch skeletal muscle overloaded by surgical removal of synergists contains a greater percent of slow-twitch fibers than normal muscle. Therefore we examined subcellular systems known to represent biochemical properties of slow-twitch skeletal muscle by measuring myosin ATPase, Ca2+ regulation of myofibril ATPase, Ca2+ uptake of sarcoplasmic reticulum (SR), and marker enzymes of glycogenolysis in normal soleus (NS) and in normal (NP) and surgically overloaded (OP) plantaris muscles of adult female rats. The OP muscles were 65% larger than NP muscles (P less than 0.001). Specific activity of myosin and myofibril ATPase was approximately 25% lower in OP compared with NP muscle (P less than 0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of myosin revealed the presence of more slow and less fast myosin light-chain components in OP muscles. Although SR of NP muscle took up more Ca2+ than OP muscle during the initial for both groups. Marker regulatory enzymes of glycogenolysis collectively were reduced by 40% in OP compared with NP muscle (P less than 0.001). Collectively the data are consistent with the concept that some muscle fiber types were converted from "fast" to "slow" in the OP muscle.

Topics: Adenosine Triphosphatases; Animals; Body Weight; Calcium; Female; Glycogen; Histocytochemistry; Leg; Muscle Proteins; Muscles; Myofibrils; Myosins; Organ Size; Rats; Rats, Inbred Strains; Sarcoplasmic Reticulum

The respiratory exchange and urinary nitrogen excretion of 6 healthy male subjects (age 21 +/- 1 yr; body weight 70 +/- 2 kg; means +/- SD) were followed for 10 hr after ingestion of a large amount of carbohydrates (CHO) in the form of bread, jam, and fruit juice, equivalent to 479 g of starch. Peak values for blood glucose (6.6 +/- 0.6 mM; mean +/- SEM) and plasma insulin (139 +/- 26 microU/ml) were reached after 90 min at which time the nonprotein respiratory quotient (NP-RQ) had risen to 0.97. During the next 8 hr glucose levels remained near 5.5 mM while insulin declined gradually to 22 +/- 7 microU/ml. The average NP-RQ remained in the range of 0.91 to 0.98, though individual values exceeding 1.0 for very short periods were observed. The increase in energy expenditure above basal rates corresponded to a specific dynamic action (SDA) of 5.9 +/- 0.6%. Assuming the CHO load to be completely absorbed after 5 hr, and allowing for glucose oxidation calculated from the gas exchange data, the glycogen content of the subject's body tissue had then increased by 408 +/- 19 g. During the 10 hr after the meal, 133 g CHO, 17 g fat and 29 g protein were oxidized, providing respectively 66%, 19% and 15% of caloric expenditure, and leaving a gain in glycogen stores estimated at 346 +/- 12 g. The data imply that: (1) The capacity for glycogen storage in man in larger than generally believed, and (2) Fat synthesis from CHO will not exceed fat oxidation after one high-carbohydrate meal, even if it is uncommonly large. When a single high-carbohydrate meal is consumed, dietary CHO merely has the effect of reducing the rate of fat oxidation. These findings challenge the common perception that conversion of CHO to fat is an important pathway for the retention of dietary energy and for the accumulation of body fat.

Topics: Adult; Basal Metabolism; Blood Glucose; Body Weight; Calorimetry; Dietary Carbohydrates; Fatty Acids, Nonesterified; Glycogen; Humans; Insulin; Lipids; Male; Oxygen Consumption; Sodium Chloride

Nine male subjects performed continuous incremental exercise on a bicycle ergometer pedaling at 50 and 90 rpm in a normal glycogen state (NG) and at 50 rpm in a glycogen-depleted state (GD) to determine if alterations in pedaling frequency and muscle glycogen content would affect their "anaerobic thresholds." Ventilatory [T(vent)] and lactate [T(lac)] thresholds were identified as the points after which expired minute volume and blood lactate began to increase nonlinearly as a function of work rate. The GD protocol elicited a significant divergence between the two thresholds shifting the T(vent) to a lesser and the T(lac) to a greater work rate relative to the NG state. When the pedaling frequency was increased to 90 rpm in the NG condition, the T(lac) was shifted to a lesser work rate relative to the 50-rpm NG condition. A correlation of only 0.71 was obtained between subjects' T(vent) and T(lac). In subjects of less than 70 kg body wt, the T(lac) came at a work rate 400 kg.m.min-1 less than in subjects of greater than 80 kg body wt despite equivalent O2 uptake. The observation that the T(vent) and T(lac) could be manipulated independently of each other reveals limitations in using the T(vent) to estimate the so-called anaerobic threshold.

Topics: 3-Hydroxybutyric Acid; Acid-Base Imbalance; Adult; Anaerobiosis; Analysis of Variance; Blood Glucose; Body Weight; Carbon Dioxide; Differential Threshold; Glycogen; Humans; Hydroxybutyrates; Lactates; Lactic Acid; Male; Metabolism; Oxygen Consumption; Physical Exertion; Respiration

The role of the adrenergic system in regulating glycogenolysis during exercise was studied in rats. Alterations in the adrenergic system were produced by injections of 6-hydroxydopamine (6-OHD), surgical removal of the adrenal medulla (ADMX), or the combination of ADMX and 6-OHD injection. Exercise was treadmill running at 22 m/min for 60 min. Colonic temperature averaged 2.8 degrees C higher in the exercised than control rats. Exercise reduced the glycogen of the liver and skeletal muscles of all groups. The glycogen concentrations of the soleus and red portion of the gastrocnemius muscles of the ADMX and ADMX-6-OHD groups were about 3.8 and 2.5 times higher after exercise than those of the normal-exercised rats. Glycogen depletion of the white portion of the gastrocnemius muscle was similar for all exercised groups. 6-OHD treatment depleted the catecholamines of the myocardium. These results demonstrate that glycogen depletion during exercise occurs in rats devoid of adrenergic control. However, differences between types of skeletal muscle suggest that factors other than the adrenergic system may be involved in controlling glycogen metabolism during exercise.

Topics: Adrenal Medulla; Animals; Body Temperature; Body Weight; Female; Glycogen; Hydroxydopamines; Liver Glycogen; Muscles; Oxidopamine; Physical Exertion; Rats; Rats, Inbred Strains; Sympathectomy, Chemical; Sympathetic Nervous System

125 rats which were divided into five groups were deprived of food or given orally D- (a potent inhibitor for L-asparaginase) and/or L-aspartic acids (Asp) for one week. The body weights before and at the end of the experiment were determined as well as post mortem the weights of brain, liver and kidneys, their protein contents, and the liver triglyceride and glycogen contents. D- and D+L-Asp caused significant decreases in the weights of body and liver, and in daily fluid intake; in addition liver and kidney protein, and liver triglyceride and glycogen contents were found to be lower than control. On the other hand, the food-deprived group which was subjected to more or less the same body weight loss due to food deprivation showed only a decrease in the liver triglyceride content. Since D-amino acids cause naloxone reversible analgesia which is, thus, considered as an involvement of endorphinergic system and of vasopressin, the effects of D-Asp were attributed to the changes in the availability of opioids and vasopressin, which simultaneously have an effect on each other as well as an effect of the release of ACTH. L-Asp appeared to antagonize the effects of D-Asp. Because L-Asp antagonizes the acute and chronic effects of morphine, including that on L-asparaginase activity, the hypothesis is proposed that the antagonizing effects of L-Asp observed may be caused at the level of L-asparaginase activity.

Topics: Animals; Aspartic Acid; Body Weight; Eating; Glycogen; Metabolism; Morphine; Narcotics; Organ Size; Proteins; Rats; Stereoisomerism; Triglycerides

To assess whether placental DNA, glycogen, and fat are affected by diabetes mellitus and whether the changes correlate with the disturbance in maternal fuels, placentas were examined at delivery in women with normal carbohydrate metabolism, gestational diabetes mellitus, and Classes B to F diabetes and in rats rendered diabetic by the administration of streptozotocin 2 weeks before mating. Plasma glucose values during late pregnancy were higher in patients with Classes B to F diabetes than in the patients with gestational diabetes mellitus so that they were judged to have more severe metabolic disturbances; rats were also divided into groups with "mild" or "severe" diabetes on the basis of blood sugar. In rats, as in humans, diabetes tended to increase placental mass, DNA, glycogen, and lipids. However, the relative changes in glycogen and fat exceeded the alterations in mass and DNA, especially in those with more severe diabetes, so that a true increase in glycogen and fat per placental cell may have occurred. Thus, placental glycogen/DNA and placental triglycerides/DNA significantly exceeded control values in patients with Classes B to F diabetes and in rats with severe diabetes but not in women with gestational diabetes mellitus or rats with mild diabetes. Total placental triglycerides and total placental glycogen were significantly correlated (r = 0.952; p less than 0.001) in rats with experimental diabetes, which suggests that these alterations in placental composition during late pregnancy may share communal dependencies.

Topics: Animals; Blood Glucose; Body Weight; Cholesterol; Diabetes Mellitus, Experimental; DNA; Female; Glycogen; Humans; Insulin; Lipids; Organ Size; Placenta; Pregnancy; Pregnancy in Diabetics; Rats; Triglycerides

Topics: Animals; Body Weight; Female; Fetal Resorption; Glycogen; Organ Size; Pregnancy; Pregnancy, Animal; Proteins; Pseudopregnancy; Rats; Rats, Inbred Strains; Rotenone; Uterus

In the analysis of weight loss in cancer patients, consideration must be given to decreased caloric intake, increased caloric expenditure and abnormal losses of calories. When these factors do not adequately explain the degree of weight loss, this may be due to a specific loss of lean body mass, as the caloric density of muscle is much less than that of fat. The key enzyme for the protection of lean body mass in hypocaloric states is pyruvate dehydrogenase (PDH). During fasting, fast oxidation in host tissues leads to inactivation of PDH, preventing irreversible loss of pyruvate precursors which would have to be replaced by protein breakdown. A tumor in which PDH activity remains high in the fasting state would cause loss of lean body mass in the host. This report suggests that this phenomenon may be important in certain patients with cancer cachexia.

Topics: Amino Acids; Body Weight; Cachexia; Carbohydrate Metabolism; Energy Intake; Energy Metabolism; Glycogen; Humans; Lipid Metabolism; Neoplasms; Proteins; Pyruvate Dehydrogenase Complex

The purpose of this investigation was to determine whether adenosine 3',5'-cyclic monophosphate (cAMP) content is increased in vivo in the heart as a result of exercise at a time when there is rapid cardiac glycogen utilization. Rats were run to exhaustion on a treadmill for a period of 164.5 +/- 9.5 min. Blood norepinephrine and epinephrine were significantly elevated approximately 2.5-fold above resting levels at the end of the treadmill run. Myocardial glycogen was reduced by 54.7% at exhaustion compared with control values. Myocardial cAMP was significantly elevated 88% above control levels as a result of the run. Associated with the depletion of myocardial glycogen and the elevation of cAMP was an activation of phosphorylase to its a form. These data suggest that myocardial glycogen metabolism during exercise is, in part, mediated by hormonal influences that are associated with increases in cAMP.

Topics: Animals; Body Temperature; Body Weight; Catecholamines; Cyclic AMP; Fatigue; Glycogen; Heart; Male; Myocardium; Phosphorylase a; Physical Exertion; Rats; Rats, Inbred Strains

The effects of chronic ethanol ingestion on a preparation of liver glycogen phsophorylase have been studied. A coupled assay in the direction of glycogenolysis was used. In the absence of AMP, a significant decrease in specific activity was observed in both males (19%) and females (30%). AMP additions stimulated phosphorylase activity and completely obliterated the ethanol-induced decreases in both sexes of animal. Kinetic studies, done in the absence of AMP, showed that only the apparent Vmax had been altered by ethanol. These data suggest that decreases in liver glycogen after chronic ethanol ingestion may not be related to the specific activity of glycogen phosphorylase. Using both glucose and caffeine as negative effectors, addditional studies demonstrated that the inhibitory effects of caffeine had been altered by ethanol in both males and females and that the inhibitory effects of glucose had been altered only in females. Even though the specific activity for phosphorylase did not directly implicate this enzyme in the ethanol-induced decrease in liver glycogen stores, the latter data regarding glucose and caffeine suggest that chronic ethanol ingestion has altererd this enzyme and that differences exist between males and females.

Topics: Adenosine Monophosphate; Alcoholism; Animals; Body Weight; Caffeine; Fasting; Female; Glycogen; Humans; Kinetics; Liver; Male; Phosphorylases; Rats; Sex Factors

Topics: Body Weight; Diabetes Mellitus; Energy Metabolism; Glycogen; Humans; Male; Muscles; Oxygen Consumption; Physical Exertion

Eight untrained, obese females (greater than 30% body fat), ages 25-33 yr, were studied before, at 1 wk, and after 6 wk while taking either of two 830-kcal/d diets: carbohydrate-containing (CC) group (n = 4): 35% protein, 29% fat, 36% carbohydrate-restricted (CR) group (n = 4): 35% protein, 64% fat, 1% carbohydrate. Endurance, at approximately 75% of VO2max (maximum oxygen uptake) on a cycle decreased from base line by 50% at 1 and 6 wk in the CR group, but there was no change in the CC group. Preexercise muscle glycogen (vastus lateralis) did not change significantly in the CC group, but was decreased by 49% in the CR group after 1 wk, and by 51% after 6 wk. There was a close correlation between percent decrease in resting muscle glycogen and percent decrease in endurance (r = 0.79, P less than 0.01). The mean fasting and exercise plasma glucose concentration was lower in the CR group than in the CC group after 6 wk, but no subject became hypoglycemic during exercise. Serum FFA, lactate, pyruvate, beta-hydroxybutyrate, acetoacetate, insulin, and glucagon changed similarly in the two groups during exercise at base line, 1 and 6 wk. Glycerol concentration was higher in the CR group during exercise only after 6 wk. Increases in serum lactate concentrations, and a mean exercise respiratory quotient of 0.93 suggested that cycle exercise at approximately 75% VO2max used predominantly glucose as a fuel.. Resting muscle glycogen and endurance, during cycle exercise at approximately 75% VO2max, were maintained during a 36% carbohydrate, 830-kcal/d diet. In contrast, significant decreases, occurred in resting muscle glycogen and endurance, during similar exercise, after 6 wk of a 1% carbohydrate, 830-kcal/d diet.

Topics: Adult; Body Weight; Dietary Carbohydrates; Energy Metabolism; Glycogen; Humans; Muscles; Obesity; Physical Exertion

A series of experiments were conducted with turkey poults to ascertain the effects of supplemental chromium or excess of nicotinic acid on growth and carbohydrate metabolism. A 23% protein starter diet was selected to emphasize the effect of chromium under basal, starvation for 48 hr, and refeeding periods. Thirty percent protein diets were also used to determine if the effects were compounded by protein levels. Supplemental chromium (20 ppm) significantly increased (P less than .05) weight at 3 weeks of age of poults consuming 23% protein diets, while an additional 250 ppm of nicotinic acid had little effect on poult weight at 3 weeks (P greater than .05). Supplemental chromium did not increase (P greater than .05) feed consumption of poults consuming both 23 and 30% protein diets. Supplemental chromium increased liver glycogen at 3 weeks of age and following refeeding after the 48 hr fast (P less than .05). Blood glucose was significantly affected by starvation-refeeding (P less than .05) but was not affected by either chromium or nicotinic acid. Supplemental chromium increased (P less than .01) active glycogen synthetase, while nicotinic acid increased (P less than .01) active phosphorylase at both protein levels. Synthetase was not decreased by starvation but was increased (P less than .01) by refeeding regardless of protein level fed. Phosphorylase was not affected by a starvation-refeeding regimen. Chromium supplementation increased in the vitro incorporation of (14C) glucose into glycogen during basal, starvation and refeeding periods (P less than .01), again, regardless of protein level.

Topics: Animal Feed; Animals; Body Weight; Chromium; Glucose; Glycogen; Liver; Niacin; Nicotinic Acids; Starvation; Turkeys

We tested the hypothesis that maternal diabetes is associated with a decreased ability of the newborn to tolerate hypoxia by measuring the time to last gasp of rabbit pups born to diabetic and control does and placed in 100% N2. Rabbits were made diabetic by injection of 100 mg/kg alloxan i.v. The alloxan-treated mothers had significantly elevated blood glucose during pregnancy and at delivery (132 vs. 90 mg/dl, p less than 0.001). Pups were delivered at 30 day's gestation by hysterectomy under local anesthesia. Half of each litter were immediately sacrificed and the remaining pups placed in 100% Ns. The pups from the alloxan-treated mothers showed a higher pre-asphyxial mean blood glucose (97 vs. 73 mg/dl, p less than 0.025) and a lower mean survival time (18.4 vs. 21.1 min, p less than 0.005).

Topics: Animals; Animals, Newborn; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Female; Fetal Blood; Glycogen; Heart; Hypoxia; Male; Myocardium; Organ Size; Pregnancy; Pregnancy in Diabetics

Topics: Animals; Bacterial Vaccines; Blood Glucose; Body Weight; Cathepsin D; Cathepsins; Glycogen; Liver; Methylcholanthrene; Mice; Mice, Inbred C57BL; Muscles; Myocardium; Propionibacterium acnes; Sarcoma, Experimental

Topics: Adipose Tissue; Animals; Body Weight; Diet; Energy Intake; Female; Glucose; Glycogen; Hypothalamus; Liver; Liver Glycogen; Obesity; Rats

The effect of a 48 hr fasting period on liver and muscle glycogen was studied in rats and guinea pigs. Total content of glycogen in the liver was similar in both species of fed animals and was totally exhausted after the fasting period. Muscle glycogen was twice as high in fed guinea pigs as in fed rats. The loss during fasting in guinea pigs was also twice that in rats. The differences in glycogen stores may explain the different metabolic response to fasting previously observed in the two species : hypoglycemia and decreased glucose production in fasted rats and constancy of these parameters in fasted guinea pigs.

Topics: Animals; Body Weight; Fasting; Glycogen; Guinea Pigs; Liver Glycogen; Male; Muscles; Organ Size

In the past three decades, wheelchair sports have become an international reality. Disabled athletes are exercising their right to accept the challenges and risks taken by able-bodied athletes. Marathon racing over a 26-mile, 385-yard course is the latest and most strenuous of the wheelchair athletic events. The small amount of available research data on wheelchair sports has been summarized, as well as some relevant data from exercise physiology studies on able-bodied subjects. Physicians and other health professionals who work with disabled people should be knowledgeable about the risks and benefits of wheelchair sports. Much more basic research is needed to improve the safety, training techniques, and performance of wheelchair athletes.

Topics: Athletic Injuries; Body Weight; Capillaries; Dehydration; Energy Metabolism; Female; Glycogen; Humans; Hypothermia; Male; Muscles; Oxygen Consumption; Paraplegia; Sports; Sports Medicine; Wheelchairs

The effect of long-term treatment with fencamfamine on swimming endurance and availability of metabolic substrates was investigated in mice. Fencamfamine (14 micrograms/g per day orally for 6 weeks) reduced maximum swimming capacity by more than 40%. This effect could not be attributed to motor incoordination or a diminution of pre-swimming levels of metabolic substrates such as liver and muscle glycogen or blood glucose and non-esterfied fatty acids. However, during swimming the hepatic and muscular glycogen stores were depleted more rapidly in the fencamfamine-treated animals. Thus it appears that fencamfamine leads more rapidly to a shortage of combustible substrates in the swimming animals.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Temperature; Body Weight; Central Nervous System Stimulants; Drinking Behavior; Fatty Acids, Nonesterified; Feeding Behavior; Glycogen; Liver Glycogen; Male; Metabolism; Mice; Muscles; Norbornanes; Physical Endurance; Swimming

Effects of cyproterone acetate, a synthetic steroidal compound, on the reproductive organs of female rats have been investigated. This agent causes reduction in ovarian weights indicative of suppression of pituitary gonadotrophins. Oestrogenic nature of cyproterone acetate was investigated in intact and ovariectomized animals taking uterine weight, vaginal keratinization and other oestrogen sensitive biochemical parameters. Cyproterone acetate in ovariectomized animals induced vaginal keratinization, increase in uterine weight and uterine protein, RNA, glycogen and sialic acid contents. These effects were parallel to the effect of oestradiol dipropionate in ovariectomized animals, thus indicating oestrogenic activity cyproterone acetate. The histological and biochemical parameters lead to the conclusion that cyproterone acetate possessed antifertility property due to its inherent oestrogenic nature.

Topics: Adrenal Glands; Animals; Body Weight; Castration; Cyproterone; Estradiol; Female; Fertility; Glycogen; Organ Size; Ovary; Proteins; Rats; RNA; Sialic Acids; Uterus; Vagina

Swimming endurance and availability of metabolic substrates (blood glucose and nonesterified fatty acids [NEFA], liver and muscle glycogen, body fat) were studied in mice treated with 10 microgram/g methamphetamine/day for 6 weeks. At the end of the 6-week treatment, motor coordination of the methamphetamine-treated animals was much better than that of controls, and swimming capacity tended to increase. While swimming, mice treated with methamphetamine mobilized more glycogen from the hepatic stores and utilized glucose more effectively. Their NEFA levels in blood were higher than those of controls. There was no difference in the muscular glycogen content.

Topics: Animals; Blood Glucose; Body Weight; Drinking Behavior; Fatty Acids, Nonesterified; Feeding Behavior; Glycogen; Liver Glycogen; Male; Metabolism; Methamphetamine; Mice; Motor Activity; Muscles; Physical Exertion; Swimming; Time Factors

In Experiment 1 a double-phase test diet (high-protein low-carbohydrate phase (HP): 5 days, high-carbohydrate phase (HC): 2 days) was compared to a normal diet by measuring all-out performance in rats trained by steady or interval swimming exercise. The tests carried out on the 8th day showed the swimming performance to be improved to a similar extent by the two training procedures, to be further improved by the test diet in the exercised animals; changes in liver glycogen, blood glucose and serum corticosterone reflected especially in the influence of exercise which in some cases was potentiated by the test diet. In Experiment 2 the 5 days of high protein intake were treated separately from the effect of the double-phase test diet as a whole in order to study the mechanism. These aminals were exercised by treadmill running of 7 days. Cytochrome P450 content of the liver rose under the effect of exercise as well as the HP phase, thus supplying additional evidence for the enzyme inducer effect of physical exertion. Glycogen decreased both in the muscle and liver during the HP phase and returned to normal after the HC phase. Liver glycogen rose to an even higher level than normal in the trained groups, but muscle glycogen values remained lower, this may be related to the shortness of training and to an accelerated rate of turnover. High protein intake associated with a depletion of carbohydrate stores was found to have an effect of its own which, when followed by replenishment of calories reserves, might be used to advantage in improving physical performance.

Topics: Animals; Blood Glucose; Body Weight; Corticosterone; Cytochrome P-450 Enzyme System; Dietary Carbohydrates; Dietary Proteins; Glycogen; Liver; Liver Glycogen; Muscles; Physical Conditioning, Animal; Physical Endurance; Rats; Swimming

Studies were carried out on adult rats of Wistar strain. Six weeks after postpubertal gonadectomy some of the orchiectomized rats were injected with a single dose of testosterone cypionate and ovari-ctomized rats with estradiol cypionate (17 beta-cyclopentyloproprionate esters of testosterone or estradiol). The control rats were sham operated. Investigations were carried out 8 weeks after surgery. Absolute and relative adrenal weight is lower in the male than in the female rat. Orchiectomy increases these weights while testosterone restores them to their normal level. Ovariectomy has no effect on the weight of adrenal, estradiol, however, increases the relative weight of the gland. The adrenal cortex of the adult female is wider than in the adult male rat and in female gland sudanophobic zone is lacking. Orchiectomy leads to the broadening of the adrenal cortex and testosterone replacement has an opposite effect. Ovariectomy has no effect on the structure of adrenal cortex and estradiol replacement resulted in the narrowing of zona glomerulosa. There were no differences in the nuclear-cytoplasmic ratio of zona glomerulosa cells in male and Female rats and neither gonadectomy nor gonadal hormone replacement has no effect on this parameter. The nuclear-cytoplasmic ratio of zona fasciculata cells in the male is markedly higher than in female. Orchiectomy lowers this ratio and testosterone restores it to the normal level. Neither ovariectomy nor estradiol replacement has effect on the nuclear-cytoplasmic ratio of zona fasciculata cells. Similar changes as those in the zona fasciculata were observed in zona reticularis cells. Among the oxidoreductases studied, the most marked sex differences were found in alpha-glycerophosphate dehydrogenase activity. In control female rats an intense reaction for this enzyme is observed in broad band of cells of the zona fasciculata interna, while in male rats only individual cells showed this reaction. In orchiectomized rats the reaction for this enzyme is similar as in control female rats and testosterone restores it to normal. Ovariectomy has no effect on localisation of reaction while after estradiol replacement reaction was more intense. Regarding the remaining oxidoreductases studied, in the adrenal cortex of rats of both sexes no marked differences were observed in localization, however, intensity of reaction depended upon applied experimental conditions. More distinct sex differences were observed in topochemistry of

Topics: Adrenal Cortex; Adrenal Glands; Animals; Body Weight; Castration; Cell Nucleus; Cytoplasm; Esterases; Estradiol; Female; Glycogen; Male; Organ Size; Oxidoreductases; Rats; Sex; Testosterone

The effects of voluntary exercise on the growth, glycogen of muscle and lipid contents of the liver and serum of mice fed different levels of dietary protein were investigated. In both the exercise and non-exercise groups, body weight gains were significantly greater in the 20% and 30% protein diet groups than in the 6% and 4% protein diet groups. After 6 weeks of age, it was shown that the amount of voluntary exercise by the 6% and 4% protein diet groups was greater than that by the 20% and 30% protein diet groups. As for hematological status, the raising of hemoglobin levels due to increasing dietary protein levels was further exaggerated by voluntary exercise. Hematocrit values rose with the increase in dietary protein levels. However the effect of exercise on hematocrit values was not clear. Liver glycogen levels, which were elevated with the increase in dietary protein levels, rose further due to exercise, though no changes were observed in muscle glycogen due to dietary protein levels and exercise. The lipid contents of the liver in all groups tended to be lower in exercise groups compared with non-exercise groups and it was observed that the high levels of dietary protein depressed the increase in liver lipids. Liver triglyceride levels of all groups fed the dietary protein levels except for the 20% casein diet group decreased due to voluntary exercise, and liver triglyceride levels were also lowered as dietary protein levels increased. The levels of serum triglyceride of all groups decreased due to voluntary exercise. This phenomenon was most remarkable in rats fed a 6% casein diet. The tendency for serum cholesterol levels to decrease due to exercise. However it was not further influenced by voluntary exercise in the 4% casein diet group.

Topics: Animals; Body Weight; Dietary Proteins; Feeding Behavior; Glycogen; Hematocrit; Lipids; Liver; Male; Mice; Muscles; Organ Size; Physical Exertion

The effects of training were investigated in male Sprague Dawley rats group (N), fed ad libitum, by measuring the weight increase and food intake of the animals, biochemical parameters (myocardial triglycerides and glycogen levels), mechanical and metabolic properties of the heart, and adrenergic reactions to swimming stress. An other group of rats remaining sedentary served as control (T). Conditioned rats had been submitted to a one hour test swim 6 days a week for 9 weeks. Gradually additional weights were fixed to the thorax. At the end of training, the load reached 6% of the body weight. Both groups were sacrified by decapitation at the same time, thirty hours after the last swimming session. The study of mechanical performances and metabolic properties was achieved with isolated working heart preparation. Adrenergic reactions of swimming stress were evaluated from plasma, heart and adrenal catecholamine concentrations.

Topics: Animals; Body Weight; Diet; Eating; Energy Intake; Epinephrine; Glycogen; Myocardium; Norepinephrine; Rats; Swimming; Triglycerides

Repeated injections of rat with 1-thyroxine (50 microgram/kg daily for 5 five-day weeks) retarded the weight gain of the animals and increased the absolute and relative size of the heart, adrenals and interscapular brown adipose tissue. In the myocardium and thigh muscle, thyroxine treatment resulted in elevated activity of oxidative enzymes, succinate dehydrogenase, malate dehydrogenase and citrate synthase, while the activities of glycolytic enzymes remained unchanged. Glycogen content of the heart was decreased following thyroxine regime. In the brown fat, on the other hand, thyroxine injections resulted in a reduction of the activity of oxidative enzymes. This reduction can be accounted for by the decreased protein (enzyme) content of the tissue due to deposition of fat. Furthermore, thyroxine treatment delayed the body cooling of the rats swimming in water at 25 degrees C and enhanced hyperthermic response to injected noradrenaline. All these changes, which were not observable in rats treated with daily alprenolol (20 mg/kg) injections, were as pronounced in rats injected with alprenolol together with thyroxine as in rats injected with thyroxine only. It is concluded that beta blockers do not antagonize the metabolic changes due to hyperthyroidism.

Topics: Adipose Tissue; Adrenergic beta-Antagonists; Alprenolol; Animals; Body Temperature; Body Weight; Cold Temperature; Glycogen; Injections, Subcutaneous; Male; Muscles; Myocardium; Organ Size; Physical Exertion; Rats; Thyroxine

An experimental protein-calorie malnutrition was produced in weanling Sprague-Dawley rats. The model resembles human malnutrition with respect to weight loss, inanition, angular stomatitis, anemia, lymphopenia, hypoproteinemia with hypoalbuminemia, and marked thymic involution. In addition, systemic invasion by gram-negative rods was documented. However, no edema was produced, and animals did not survive for longer than six weeks on the protein-deficient diet. One percent glycogen was found to be a satisfactory nonprotein stimulus for induction of a peritoneal exudate consisting primarily of young macrophages. Electron microscopy showed that morphologic events of phagocytosis and degranulation proceeded normally in macrophages from protein-deficient animals. In addition, cell surface receptors for IgG were preserved under these experimental conditions. These data indicate that weanling rats may be employed as a small animal model for servere, fulminant protein-calorie malnutrition in humans.

Topics: Animals; Ascitic Fluid; Binding Sites, Antibody; Body Weight; Disease Models, Animal; Glycogen; Hexosephosphates; Immunoglobulin G; Macrophages; Male; Neutrophils; Phagocytosis; Protein-Energy Malnutrition; Rats; Receptors, Antigen, B-Cell

Topics: Amino Acids; Animals; Body Weight; Eels; Energy Metabolism; Gills; Glucose-6-Phosphatase; Glycogen; Hypophysectomy; Liver; Muscles; Nitrogen; Oxygen Consumption; Pituitary Gland

Spontaneously hypertensive rats and normotensive Kyoto Wistar controls were divided into 3 groups of 10 animals each and treated with phenoxybenzamine (5 mg/kg once daily), propranolol (25 mg/kg twice daily) or saline (once daily). After 5 weeks the in vitro incorporation of D-[U-14C]-glucose into aortic lipids and glycogen was measured in the presence and absence of insulin (1 mU/ml). In both normotensive and hypertensive rats treated with propranolol 14C-incorporation into triglycerides was reduced. Furthermore, insulin significantly stimulated 14C-incorporation into triglycerides, phospholipids and glycogen in propranolol-treated hypertensive rats. This effect was not statistically significant (0.05 less than p less than 0.1) in propranolol-treated normotensives. Phenoxybenzamine treatment did not significantly modify aortic lipogenesis or glycogen synthesis from glucose. Chronic propranolol treatment of spontaneously hypertensive rats resulted in aortic tissue becoming sensitized to insulin. Possible mechanisms and explanations for this are discussed.

Topics: Animals; Aorta; Blood Pressure; Body Weight; Chromatography, Thin Layer; Drug Interactions; Glucose; Glycogen; Hypertension; In Vitro Techniques; Insulin; Male; Phospholipids; Propranolol; Rats; Receptors, Adrenergic; Triglycerides

Kangaroo rats deprived of food ran themselves to death in 48 h in wheel cages. Despite the loss of 14.5% of body weight the ratio of water to protein was the same after the run as it was in control rats. Metabolic measurements at rest and in the running wheel and weight loss in the 48-h run were used to estimate fuels used and water expended. Two-thirds of the initial amount of fat and 9% of the protein were metabolized. The terminal mean percentage of body fat was about twice that observed in rats trapped in the spring of 1967, when seed production was low: death in the 48-h run could not have been due to depletion of body fat alone. The powerful activity drive seen in hungary kangaroo rats presumably is intensified in dry years when food is scarce and may deplete their reserves enough to result in death from starvation.

Topics: Animals; Body Composition; Body Water; Body Weight; Dipodomys; Female; Food Deprivation; Glycogen; Lipids; Male; Motor Activity; Oxygen Consumption; Proteins; Rodentia

Rat aorta responds to refeeding after a fast in a manner similar to adopose tissue and liver by developing an enhanced capacity for lipogenesis and glycogen synthesis from glucose. The in vitro incorporation of D-U-14C-glucose into aortic triglycerides and glycogen was two- to four-fold higher in rats refed for three to five days after a three day fast than in ad libitum fed controls. Insulin significantly stimulated this incorporation only during refeeding for three days after a three-day fast. The glycogen synthesizing system appeared to be stimulated and to become sensitive to insulin earlier in the refeeding process than did the lipogenic system. The in vitro incorporation of 14C-glucose into aortic phospholipids was less affected by the nutritional state of the animal, and was not stimulated by insulin at any stage of the experiment. Possible mechanisms for the development of insulin supersensitivity and the implications for lipid accumulation in the artery wall are discussed.

Topics: Animals; Aorta; Body Weight; Fasting; Glucose; Glycogen; In Vitro Techniques; Insulin; Lipids; Male; Phospholipids; Rats; Triglycerides

Goldfish (Carassius auratus) were exercised continuously for periods of 28 days at swimming speeds of 1.5, 3.0 and 4.5 body lengths per second and their rates of growth were determined. Changes in muscle fibre size were examined, as were changes which occurred in the concentrations of the major chemical constituents of these cells. These fish, typical of the carp family in that they are found only in still or slowly moving water, did not adapt well to the flowing water environment at any swimming speed. They often grew less than the controls, although consuming much more food. Changes in the composition of the muscle fibres indicated that excess food was not being stored, and also indicated that the major fuel for swimming at all speeds was glycogen. The fish survived well at high speeds and it was suggested that this was due to the ability of the species to metabolize glycogen anaerobically without the production of lactic acid.

Topics: Animals; Body Weight; Cyprinidae; Glycogen; Goldfish; Lipid Metabolism; Locomotion; Muscle Proteins; Muscles; Physical Conditioning, Animal

Topics: Anemia, Hypochromic; Body Weight; Child; Child Nutritional Physiological Phenomena; Diet; Female; Glycogen; Humans; Iron; Male; Physical Exertion; Sports; Sports Medicine; Washington

Cerebral oxidative metabolism during intrauterine growth retardation was investigated utilizing a pregnant-rat model. Dams were subjected to unilateral uterine artery ligation on the 17th day of gestation. At term, they were sacrificed by decapitation and the fetuses delivered by cesarean section. Body and brain weights of fetuses from ligated uterine segments were smaller than those of offspring from nonligated horns of the experimental rats or those from sham-operated dams. Blood glucose at birth was reduced by 25% in growth-retarded fetuses. Cerebral oxidative metabolites, including glycogen, glucose, lactate, ATP, and phosphocreatine, were not different from control levels. These findings suggest that neither tissue hypoxia nor deficient glucose delivery to brain can account for the stunted cerebral growth observed in fetuses following uterine artery ligation.

Topics: Adenosine Triphosphate; Animals; Body Weight; Brain; Female; Fetal Growth Retardation; Fetal Hypoxia; Glucose; Glycogen; Lactates; Organ Size; Oxygen Consumption; Phosphocreatine; Pregnancy; Rats

Fetuses of nine gilts were decapitated (D) in utero and fetuses of eight gilts were sham operated (C) at 43 to 47 days of pregnancy. At 110 days, one fetus from each gilt was studied. Heart, liver, kidney, thyroid and body weights were recorded. Thyroids were evaluated for the degree of colloid accumulation and height of the follicular epithelium. Blood glucose, lactate, triglycerides and creatine phosphokinase activity were determined. Longissimus muscle glycogen was evaluated histochemically. Longissimus muscle total phosphorylase, phosphorylase a, G-6-PDH and SDH activity and glycogen were determined biochemically. The D fetuses were hairless, edematous, devoid of adrenal glands and unaffected by maternal anesthesia. Results indicate that the fetal pig pituitary gland is not required for continued fetal growth, but is necessary for normal organ and endocrine gland development. Fetal decapitation caused delayed maturation of the longissimus muscle with little change in anaerobic glycolytic capacity but decreased aerobic glycolytic capacity accompanied by increased activity of the pentose shunt.

Topics: Animals; Blood Glucose; Body Weight; Creatine Kinase; Female; Fetus; Glucosephosphate Dehydrogenase; Glycogen; Hypophysectomy; Lactates; Muscle Proteins; Muscles; Organ Size; Phosphorylases; Pregnancy; Succinate Dehydrogenase; Swine; Triglycerides

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Female; Fetus; Glycogen; Insulin; Liver; Liver Glycogen; Muscle Development; Muscles; Pregnancy; Pregnancy in Diabetics; Swine; Swine Diseases

The availability and utilization of B-hydroxybutyrate as an alternate oxidative fuel during fasting hypoglycemia has been examined in the rat conceptus at 18 and 20 days gestation. A 48-hr maternal fast between days 16 and 18 or 18 and 20 resulted in a 50% fall in fetal glucose levels and a marked rise in B-hydroxybutyrate, i.e., 30-fold at 18 and 60-fold at 20 days. Tissue concentrations of B-hydroxybutyrate or acetoacetate did not exceed extracellular levels. Placenta, fetal brain, carcass, and liver all oxidized 14C-labeled B-hydroxybutyrate to 14CO2 when incubated in vitro in the presence of B-hydroxybutyrate. Highest rates of oxidation were apparent in the placenta, followed by brain, liver, and carcass. The D isomer of B-hydroxybutyrate appeared to be oxidized preferentially by all tissues studied. Despite levels of 3-ketoacid CoA transferase and acetoacetyl CoA thiolase lower at 18 than at 20 days, rates of oxidation in individual tissues incubated under identical concentrations of substrate were similar at both times. In liver and brain, increasing rates of 14CO2 generation proportionate to graded concentrations of B-hydroxybutyrate in vitro indicated that such rates were probably determined by substrate availability. B-hydroxybutyrate oxidation in extrahepatic fetal tissues was unaffected by maternal fasting. By contrast, fetal liver derived from fasted mothers generated significantly less 14CO2 from B-hydroxybutyrate than livers from fed mothers. It has been suggested that capabilities for ketone utilization are widespread in tissues of the conceptus, and that such utilization may fulfill in part the oxidative demands for continued anabolic growth during fasting hypoglycemia in the mother.

Topics: Acetyl-CoA C-Acetyltransferase; Animals; Blood Glucose; Body Weight; Brain; Carbon Dioxide; Fasting; Female; Fetal Blood; Fetus; Gestational Age; Glycogen; Hydroxybutyrates; In Vitro Techniques; Keto Acids; Ketones; Liver; Liver Glycogen; Organ Size; Oxidation-Reduction; Placenta; Pregnancy; Pregnancy, Animal; Rats; Sulfurtransferases

Mice on an atherogenic diet for 40 days show a decrease in brain content of catecholamines, cyclic AMP and in dopamine degradation, and modification of the glycolytic pathway. The metabolic changes are paralleled by changes in behaviour, i.e. decrease in spontaneous motor activity and in conditioning avoidance response. The decrease in dopamine degradation and in behaviour parameters is partly due to the propylthiouracil present in the diet. Endovenous treatment with sonicated dispersions of bovine brain phospholipids induces a modification in the parameters of behaviour and metabolism. The possibility is discussed that some of the defects arising during the atherogenic diet are related with the establishment of a hypoxic state.

Topics: Animals; Avoidance Learning; Behavior, Animal; Blood Glucose; Body Weight; Brain; Catecholamines; Cattle; Cholesterol, Dietary; Cyclic AMP; Diet, Atherogenic; Dopamine; Glycogen; Homovanillic Acid; Hypoxia; Lactates; Mice; Motor Activity; Phospholipids; Propylthiouracil; Pyruvates

Topics: Adipose Tissue, Brown; Adrenalectomy; Animals; Body Temperature Regulation; Body Weight; Glucagon; Glycogen; Lipid Metabolism; Male; Organ Size; Rats; Thyroidectomy

Topics: Adenosine Triphosphate; Animals; Body Weight; Carbohydrate Metabolism; Ethanol; Fructose-Bisphosphate Aldolase; Fructosephosphates; Glucose; Glucosephosphates; Glycogen; Lung; Male; Pyruvates; Rats

1. Foetal hypophysectomy or bilateral adrenalectomy, carried out in utero at about 100 or 125 days gestation respectively, increased the length of gestation in sheep. It was confirmed that pregnancy was not prolonged significantly if hypophysectomy or adrenalectomy was carried out on one of a pair of twins. The hypophysectomized foetus was, however, smaller and the adrenalectomized foetus larger, than the unoperated twin. 2. In about half of the previously operated foetuses intravascular catheters were inserted into both mother and foetus, either at about 125 days, for a comparison with normal catheterized foetuses, or during the post-mature period. Both adrenalectomized and hypophysectomized foetuses appeared to have little resistance to stress or infection and the majority survived only 1-2 weeks after the insertion of catheters. 3. Maternal peripheral plasma oestrogen, progesterone and corticosteroid concentrations did not appear to be altered by either foetal hypophysectomy or adrenalectomy and were maintained in the normal range during prolonged gestation. 4. Foetal plasma oestrogen concentrations were significantly lower after hypophysectomy or adrenalectomy than values found in control lambs. Plasma progesterone values were low in all three groups of foetuses. 5. Plasma corticosteroid concentrations after foetal hypophysectomy (12-6 ng/ml.) or adrenalectomy (14-7 ng/ml.) were in the same range as the values for control lambs before the pre-partum rise (14-6 ng/ml.). However, there was a small but significant maternal-to-foetal plasma corticosteroid gradient in the two operated groups whereas this difference was not found in the control animals. 6. Tissue glycogen concentrations were measured in non-catheterized adrenalectomized and hypophysectomized foetuses. In these two groups, whether examined before 149 days or after prolonged gestation, liver glycogen concentrations were 30-40% of those in non-catheterized control foetuses at term. In other respects there was little apparent difference between adrenalectomized and control foetuses. 7. Hypophysectomized foetuses had significantly higher glycogen concentrations in heart, skeletal muscle and lung compared with control or adrenalectomized lambs. Plasma glucose and fructose values were also low in this group compared with control foetuses.

Topics: Adrenal Cortex Hormones; Adrenal Glands; Adrenalectomy; Animals; Body Weight; Estrogens; Female; Fetus; Gestational Age; Glycogen; Hypophysectomy; Organ Size; Pituitary Gland; Pregnancy; Progesterone; Sheep

Topics: Aging; Alkaline Phosphatase; Animals; Body Weight; Cell Division; Decidua; DNA; Estradiol; Estrogens; Female; Glycogen; Mice; Mice, Inbred C57BL; Organ Size; Pharmaceutical Vehicles; Pregnancy; Progesterone; Proteins; Receptors, Estrogen; Uterus

Fasting plasma immunoreactive insulin levels increased with age in hyperinsulinemic Koletsky obese rats, being almost four times as high as in lean siblings at 3 mo (40 +/- 5 muU/ml) and rising steadily to 82 +/- 4 muU/ml at 6 mo (about seven times higher than lean siblings). Restricting the food intake of the obese rats markedly reduced but did not normalize the hyperinsulinemia, which in these rats was accompanied by normal plasma glucose concentrations. The incorporation in vivo of D-U-14C-glucose into tissue lipids and glycogen was measured 1 hr after the intravenous injection of 1 g glucose (containing 100 muDi D-U-14C-glucose) per kg body weight in obese rats eating ad libitum, obese rats after 3 mo on a restricted food intake, and lean siblings. All tissues (heart, diaphragm, skeletal muscle, and adipose tissues and liver) of obese rats exhibited a significantly greater lipogenesis from glucose than those of lean siblings. Dietary restriction of the obese rats reduced the 14C incorporation into lipid to levels not significantly different from lean controls in all tissues except skeletal muscle and liver, where, although greatly reduced, lipogenesis was still significantly higher than in lean rats. Glycogen synthesis tended to be greater in all tissues of obese rats than in lean animals. Dietary restriction of obese rats did not greatly affect glycogen synthesis.

Topics: Animals; Blood Glucose; Body Weight; Carbon Radioisotopes; Diet, Reducing; Female; Glucose; Glycogen; Insulin; Lipids; Male; Obesity; Rats; Rats, Inbred Strains

Topics: Animals; Body Weight; Cardiac Output; Coronary Disease; Epinephrine; Glycogen; Heart; Injections, Subcutaneous; Lactates; Muscle Proteins; Myocardium; Organ Size; Perfusion; Rats

The flank gland becomes functional by about the 9th day after parturition and exhibits a secretory rhythm with a nocturnal peak. Lipids constitute the major biochemical constituent of the total solids. Relatively, cholesterol, ascorbic acid and alkaline phosphatase contents of the flank gland were much higher than those of the control skin samples. Disc electrophoretic pattern of glandular secretion reveal that male and female shrews have 6 & 8 protein fractions respectively. The flank gland was observed to be androgen-dependent in male shrews. Ethological observations indicate that secretions of this gland are used for marking purposes.

Topics: Age Factors; Alkaline Phosphatase; Animals; Ascorbic Acid; Body Weight; Castration; Cholesterol; Female; Glycogen; Lipid Metabolism; Male; Minerals; Organ Size; Phospholipids; Proteins; Sebaceous Glands; Sebum; Shrews; Skin

Serial frozen sections of longissimus dorsi muscles from twelve Canadian Yorkshire breed pigs at different live weights (13-86 kg) were stained for glycogen by the periodic acid-Schiff (PAS) reaction and reacted for NAD tetrazolium reductase to determine the mitochondrial content of muscle fibres. Sections from muscles taken immediately post mortem and at 5 hr post mortem were compared and the patterns of glycogenolysis in high, intermediate and low mitochondrial content fibres were assessed on the basis of the percentage of initially PAS-positive fibres which became PAS-negative 5 hr post mortem. This form of assessment was necessary because not all fibres were PAS-positive immediately post mortem. In smaller pigs, only a few muscle fibres depleted their stainable glycogen by 5 hr and most of these fibres had a high mitochondrial content. In larger pigs, most or all initially PAS-positive fibres became PAS-negative 5 hr post mortem. Fibres with a low mitochondrial content accounted for most of the glycogenolysis detected histochemically in larger animals. The overall percentage of PAS-positive fibres was related to glycogen concentration (mg/g), r = 0.52, P less than 0.025, when samples with all PAS-positive fibres were excluded.

Topics: Animals; Body Weight; Castration; Female; Glycogen; Histocytochemistry; Male; Muscles; Postmortem Changes; Staining and Labeling; Swine

Adrenal glands of eight Indian species of birds, namely Columba livia, Passer domesticus, Corvus splendens, Acridotheres tristis, Acridotheres ginginianus, Milvus migrans, Francolinus pondicerianus and Bubulcus ibis were examined during the sexually active and inactive phases of their annual reproductive cycles. Excepting A ginginianus and M. migrans, among members of either sex of the remaining six species the weight of the adrenal gland increases during the period of sexual activity. Histologically, the interrenal tissue of these birds could be divided into a peripheral subcapsular zone and a central zone. The cytochemical content of these two zones varies between sexual activity and inactivity. In sexually active birds of both sexes, interrenal cells of the central zone exhibit an increased concentration of alkaline phosphatase, glycogen, acid mucopolysaccharides and gross lipids, while in the subcapsular interrenal cells there is a prominent increase of ascorbic acid content. Cytochemical contents of chromaffin cells remain unchanged except acid phosphatase, which increases during the sexually active phase.

Topics: Acid Phosphatase; Adrenal Glands; Alkaline Phosphatase; Animals; Ascorbic Acid; Birds; Body Weight; Female; Glycogen; Glycosaminoglycans; Lipid Metabolism; Male; Organ Size; Reproduction; Seasons; Species Specificity

The effects of control, dilute, and low-protein duets on organ development were evaluated in infant rhesus monkeys. Both experimental duets resulted in growth failure of the cerebral hemisphere, lung, liver, kidney, and muscle and, with few exceptions, in their total organ contents of water, protein, lipid, glycogen, DNA, and RNA. Calculation of the various ratios for biochemical indices per mg of DNA indicates that with the exception of increased glycogen:DNA ratios in lung of animals fed the dilute diet, increased lipid:DNA ratios in liver, and reduced glycogen:DNA ratios in muscle of animals fed the low-protein diet, all other biochemical profiles of the cellular populations of organs were comparable to control values. Accordingly, the small organ size and reduced organ content of the various biochemical indices of growth appear primarily due to the reduced cellular populations of these organs. The reduced cellular populations reflect failure of the normal miotic processes of infancy to occur, with or without loss of cells already present at the onset of the malnutrition phase. If no cell loss is involved, it is speculated that normal indices of organ growth may still be possible through the processes of "catch up" growth which accompany nutritional rehabilitation.

Topics: Age Factors; Animals; Animals, Newborn; Body Water; Body Weight; DNA; Glycogen; Haplorhini; Lipid Metabolism; Macaca; Macaca mulatta; Nutrition Disorders; Organ Size; Protein Deficiency; Proteins; RNA

In the range-finding test, 6 groups of 4 male and 4 female weanling rats were given dietary levels of 0, 0.1,0.5, 2.5, 12.5 and 250 ppm methylmercury chloride (MeHgCl) for 2 weeks. Signs of central nervous system toxicity, weight loss and high mortality appeared at 250 ppm but not at lower levels. No haematological changes were observed at 0.1-12.5 ppm. The relative weights of the liver in females on 2.5 and 12.5 ppm and of the kidneys in females on 12.5 ppm were significantly increased; the effects in males were less marked. Total mercury concentration in the kidneys increased proportionally with increasing dietary levels of MeHgCl. In the short-term test, 5 groups of 15 male and 10 female weanling rats were given dietary levels of 0, 0.1, 0.5, 2.5 and 25 ppm MeHgCl for 12 weeks. Toxic signs, weight loss and restricted food intake were observed at 25 ppm starting from week 9 onwards. Haematological, serum enzyme and urinalysis changes were seen at 25 ppm. Liver microsomal enzyme activity was increased non-significantly and liver glycogen was depressed at 25 ppm. Organ weight changes were evident at 25 ppm and histological changes seen in the spleen, kidneys, brain, spinal cord and peripheral nerves were confined to the 25 ppm level. Histochemical changes in kidney enzymes occured at 2.5 and 25 ppm. Hg concentrations in blood, hair, kidneys, liver and brain were higher at 12 weeks than 6 weeks and generally increased with increasing MeHgCl level in the diet.

Topics: Animals; Body Weight; Diet; Feeding Behavior; Female; Glycogen; Growth; Hemoglobins; Male; Methylmercury Compounds; Microsomes, Liver; Organ Size; Rats

Articular chondrocytes of achondroplastic mice (cn/cn) resemble ultrastructurally those of their non-achondroplastic siblings (Cn/Cn or Cn/cn), except for premature deposition of glycogen and a tendency to undergo regression. The latter may be slight or extreme. The ultimate cause of the vulnerability of the chondrocytes and the cause of the heterogeneity of the reaction could not be determined with the method employed. Nevertheless, increased vulnerability accounts for cell death under conditions which are usually not injurious, and which may be either physiologic or altered by endogenous or exogenous factors.

Topics: Achondroplasia; Animals; Body Weight; Cartilage, Articular; Collagen; Endoplasmic Reticulum; Femur Head; Glycogen; Golgi Apparatus; Mice; Mice, Inbred Strains; Mitochondria

The effect of the anaesthetic procedures and of the sex, age and weight of each patient on glucose uptake and glycogen content of human skeletal muscle has been studied in vitro in the presence and absence of insulin. Statistical analysis indicated that the relationships between age and both glucose uptake and the response to insulin were significant, older patients in general having higher uptakes. The blucose uptake was highly correlated with the three obesity indices (ponderal index, body mass index and percentage of the ideal weight). The anaesthetic agents had no significant effect on glucose uptake. The choice of premedication appeared to have a small effect on the basal glucose uptake level, but as the choice of premedication was also age related and age itself was a significant factor, this effect may not be of importance. It is concluded that the age and the degree of obesity of the patients ought to be taken into account when studying samples of human muscle.

Topics: Adult; Age Factors; Aged; Anesthesia; Atropine; Body Weight; Female; Glucose; Glycogen; Humans; Male; Meperidine; Middle Aged; Muscles; Papaverine; Preanesthetic Medication; Scopolamine; Thiopental

Weanling male Sprague-Dawley rats received bilateral electrolytic lesions in the dorsomedial hypothalamic area by means of a direct cathodal current. Sham-operated rats served as controls. Ponderal and linear growth, obesity index, food intake, and several indices of intermediary metabolism of adipose tissue and muscle were measured. Cathodal lesions, as did anodal lesions reported on previously resulted in retardation of body weight, length, and food intake, while the obesity index remained in the normal range. Similarly, the metabolic data in adipose tissue and muscle are comparable to those from experiments in which dorsomedial lesions were placed by anodal current: incorporation of glucose into CO2 lipid, and glycogen of muscle tissue (diaphragm) were similar in DMN-lesioned rats and controls. The difference between anodal and cathodal lesions in this hypothalamic syndrome is a delay in the onset of hypophagia until about 30 days after the hypothalamic operation. The data support the concept that lesions in the hypothalamus, in general, exert their effect by destruction of neuronal assemblies, i.e., nerve cells and/or fiber tracts passing through the lesioned area.

Topics: Adipose Tissue; Animals; Animals, Newborn; Body Weight; Carbon Dioxide; Diaphragm; Feeding Behavior; Glucose; Glycogen; Growth Disorders; Hypothalamus; Hypothalamus, Middle; Insulin; Lipid Metabolism; Male; Muscles; Proteins; Rats; Syndrome

The purpose of this investigation was to examine the effects of training either once or three times/day on the principal stages of skeletal muscle. The experiments were carried out on male albino rats fed either 3 or 5 times/day a diet containing 20% protein. Experimental animals swam either once or 3 times/day, 6 days/week for 10 weeks with weights attached. The total duration of daily activity was equal for both groups and at 10 weeks each animal was swimming for 60 min/day with 3% of his body weight attached. All the animals were examined at rest after the 10-week training programs. The adequacy of the weight-loading and training schedules was estimated by body weight dynamics and such energy metabolites as creatine phosphate and glycogen. Skeletal muscle RNA and protein synthesis were studied by means of 14C-orotic acid and 14C-leucine incorporation, respectively. Quadriceps and gastrocnemius muscles were used for analysis in all experiments. It was found that the increase in the number of daily training sessions resulted in an increased content and intensity of synthesis of skeletal muscle proteins as evidenced by an increase in the content of amino acids in the muscle, an increased synthesis of both microsomal and ribosomal RNA, an increased stability of (poly-A)-containing messenger RNA, and an increased synthesis of all skeletal muscle protein fractions: myofibrillar, sarcoplasmic, and myostromal.

Topics: Animals; Body Weight; Glycogen; Leucine; Male; Microsomes; Muscle Proteins; Muscles; Orotic Acid; Phosphocreatine; Physical Exertion; Rats; RNA; RNA, Messenger; RNA, Ribosomal; Swimming

Topics: Animals; Blood Glucose; Body Weight; Chromium; Dose-Response Relationship, Drug; Energy Metabolism; Female; Fertility; Genetics; Glycogen; Male; Nutritional Requirements; Physical Exertion; Pregnancy; Pregnancy Complications; Pregnancy, Animal; Rats; Sex Factors

Bilateral electrolytic lesions were placed in the dorsomedial hypothalamic nuclei (DMN) of weanling male Sprague-Dawley rats. Sham-operated rats served as controls. After 22 days on lab chow and tap water ad libitum, the animals were injected with U-14 C-alanine 0.167 muC/mu moles intraperitoneally (5 muC and 30 mu moles/100 gm body weight) and sacrificed 2 hr later. There was no significant difference, in the incorporation of the label into total lipid, free fatty acids, glycogen, or tissue protein of both liver and diaphragm, between the DMN-lesioned and the sham-operated rats. Similarly, there was no significant difference in the incorporation into plasma glucose or protein. It is concluded that in spite of profound alterations in both ponderal and linear growth and food intake, there is no disruption of normal gluconeogenesis in the weanling rat with DMN lesions.

Topics: Alanine; Animals; Animals, Newborn; Blood Glucose; Body Weight; Diaphragm; Fatty Acids, Nonesterified; Feeding Behavior; Gluconeogenesis; Glycogen; Growth Disorders; Hypothalamus; Lipid Metabolism; Liver; Male; Muscles; Proteins; Rats

Topics: Animals; Blood Glucose; Body Weight; Glycogen; Glycolysis; In Vitro Techniques; Lactates; Male; Nutritional Physiological Phenomena; Oxygen Consumption; Rats; Submandibular Gland

Maternal hypothyroidism in rats has been shown previously to result in alterations of maternal, placental, and fetal metabolism. Maternal treatment with 2 IU GH/day for three days prior to autopsy (on the 22nd day of pregnancy) corrected many of the observed alterations of carbohydrate metabolism in hypothyroidism. The maternal and fetal liver glycogen concentrations and the fetal serum glucose levels of the hypothyroid animals were elevated significantly by the GH treatment. In most cases, the utilization of a [1-14C]glucose tracer dose was returned to normal by GH treatment. These results suggest that the impairment of fetal metabolism occurring in maternal hypothyroidism may be due in part to insufficient maternal GH secretion. However, GH alone in the absence of sufficient thyroid hormones did not totally correct all of the observed fetal abnormalities.

Topics: Animals; Blood Glucose; Body Weight; Female; Fetus; Glucose; Glycogen; Growth Hormone; Hypothyroidism; Liver; Liver Glycogen; Maternal-Fetal Exchange; Muscles; Organ Size; Parathyroid Glands; Placenta; Pregnancy; Rats; Thyroidectomy

The in vivo incorporation of radioactivity from [U-14C]glucose was reduced in undernourished rat pups at ages 6, 10, and 17 days for brain lipids, and at age 10 days for brain amino acids. Brain glucose concentrations were lower at age 20 days (controls 1.58 +/- 0.26 vs. test 1.14 +/- 0.07 mumol/g) but other alterations in brain glucose, glycogen, ATP, or phosphocreatine concentrations were not found. Brain mitochondrial glutamate dehydrogenase activity was 21% and 30% lower in undernourished animals at ages 10 and 20 days, respectively. Brain mitochondrial and supernatant isocitrate dehydrogenase activities and pyruvate kinase activity were similar for undernourished and control animals. Brain glycogen levels were 2-4 times higher in late fetal and newborn control animals (13.6 and 15.3 mumol/g) than in older animals (4.2-5.7 mumol/g). Brain glucose, ATP, and phosphocreatine levels increased from the 15-day fetus to the newborn, but thereafter showed no further increase.

Topics: Adenosine Triphosphate; Amino Acids; Animals; Body Weight; Brain; Glucose; Glutamate Dehydrogenase; Glycogen; Lipid Metabolism; Mitochondria; Nutrition Disorders; Organ Size; Phosphocreatine; Rats

Topics: Body Weight; Child; Diet Fads; Female; Glycogen; Humans; Male; Nutrition Disorders; Nutritional Physiological Phenomena; Obesity; Physical Fitness; Sports Medicine; Starvation

Serial sections of longissimus dorsi and rectus femoris muscles from 15 Yorkshire breed pigs (live weights 24-46 and 49-139 kg) were stained for glycogen (PAS) and a mitochondrial enzyme (NAD tetrazolium reductase). Muscle fibres with a low mitochondrial content in both muscles were more frequently PAS-positive than fibres with a high or intermediate mitochondrial content. However, some pigs had all their muscle fibres PAS-positive while one pig with a high post-mortem muscle pH had all rectus femoris fibres PAS-negative. Relative to lighter weight pigs, longissimus dorsi muscles of heavy pigs tended to have less fibres with a high mitochondrial content and less fibres with a positive PAS reaction. Compared to longissimus dorsi muscles, rectus femoris muscles had more fibres with a high mitochondrial content and less with a positive PAS reaction. All fibres in both muscles became PAS-negative with an accompanying decrease in pH by 24 hr post-mortem. Fibres from longissimus dorsi muscles frequently had PAS-positive sarcoplasmic cores between their myofibrils. Heavy pigs tended to have larger cores (up to a mean maximum diameter of 13.4 mum), more fibres with cores, and more cores per fibre. The pigs involved exhibited no other ante- or post-mortem muscle abnormalities.

Topics: Animals; Body Weight; Glycogen; Histocytochemistry; Mitochondria, Muscle; Muscles; Staining and Labeling; Swine

The effect of clofibrate (CPIB) on lipid metabolism was studied in male rats rendered diabetic by intravenous injection of 80 mg/kg of streptozotocin. After 1 wk, the rats received by gastric intubation 242 mg/kg/day of CPIB for 7 days. Liver lipid concentration remained unchanged in experimental diabetes and after treatment with CPIB; however, due to decreased liver weight, total liver lipids were lower in diabetic rats. Elevation of cholesterol, phospholipids, and triglycerides in the serum of diabetic rats was reversed by CPIB treatment. Hepatic cholesterol synthesis in diabetic rats was suppressed to approximately 1/10 of that in normal rats. Treatment with CPIB abolished this residual cholesterogenic activity. Diabetes had no effect on intestinal cholesterol synthesis; a slight increase was noted after CPIB treatment. Basal and norepinephrine-induced lipolysis in fat pads was elevated in diabetic rats; CPIB had no effect on these changes. The data show that the elevated serum lipids in diabetic rats are lowered by treatment with C-IB. It was concluded that the hypocholesterolemic activity of clofibrate in rats is not caused by its suppression of hepatic cholesterol synthesis.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Cholesterol; Clofibrate; Diabetes Mellitus; Eating; Fatty Acids, Nonesterified; Glycogen; Intestinal Mucosa; Lipid Metabolism; Lipoproteins, HDL; Liver; Male; Phospholipids; Rats; Streptozocin; Triglycerides

Topics: Adaptation, Physiological; Adipose Tissue; Animals; Blood Glucose; Body Weight; Female; Glycogen; Lipid Metabolism; Liver; Liver Glycogen; Muscles; Organ Size; Ovary; Oviducts; Rana catesbeiana; Seasons; Time Factors

An effort was made to determine to what degree the hyperinsulinemia found in the genetically obese Zucker rat is the result of the carbohydrate content of the diet. When Zucker obese rats are fed precisely the same amount of carbohydrate as lean controls and allowed to become obese by drinking vegetable oil, their pancreatic islets still release 59% more insulin than do those from lean controls. When their diet contains even more carbohydrate, fed from weaning, and they become equivalently obese, their islet insulin release is increased by an additional 46%. An obese Zucker rat fed a high-carbohydrate diet possesses muscle sensitivity to insulin and enlarged adipocytes undergoing active lipogenesis. A rat becoming equivalently obese on a high-fat diet has an absence of insulin sensitivity in muscle and diminished lipogenesis in adipocytes. Clearly, the composition of the diet plays an important role in the metabolic consequences of obesity, but neither diet nor changes in peripheral glucose metabolism can completely explain the hyperinsulinemia.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Composition; Body Weight; Carbon Dioxide; Cell Count; Dietary Carbohydrates; Dietary Fats; Glucose; Glycogen; Insulin; Insulin Secretion; Islets of Langerhans; Obesity; Rats; Triglycerides

The effects of hypophysectomy and short-term GH replacement on insulin release and on some aspects of glucose metabolism in isolated rat islets of Langerhans were investigated. The effects on body, pancreas and adrenal gland weights, and on the levels of blood plasma constituents were also measured. Three to four weeks after hypophysectomy the early and late phases of insulin release from islets incubated with high concentrations of glucose, but not with low concentrations of glucose or with xylitol, leucine, arginine, tolbutamide, citrate or butyrate, were significantly lowered. Short-term GH replacement partially reversed the depression in glucose-stimulated insulin release. This reversal effect was not dependent on the increase in body weight of rats after GH replacement when the fall in adrenal gland but not in pancreas weight was also reversed. Nine out of the 12 plasma constituents measured, including glucose, were maintained in the control range of levels, but albumin, inorganic phosphate and urea nitrogen levels were altered after hypophysectomy or GH replacement. Three to four weeks after hypophysectomy, total glucose oxidation and glucose utilization by the islets were slightly depressed. Hypophysectomy appeared to slow down glucose 6-phosphate utilization in the islets. However, the functional capacity of the glucose phosphorylating, glucose-6-phosphate and 6-phosphogluconate dehydrogenase activities were not changed. Short-term GH replacement caused improvements in these islet functions.

Topics: Adrenal Glands; Animals; Arginine; Blood Urea Nitrogen; Body Weight; Butyrates; Cattle; Citrates; Eating; Glucose; Glycogen; Growth Hormone; Hypophysectomy; In Vitro Techniques; Insulin; Insulin Secretion; Islets of Langerhans; Leucine; Male; Organ Size; Pancreas; Phosphates; Pituitary Gland; Rats; RNA; Serum Albumin; Time Factors; Tolbutamide; Xylitol

Weaning female Sprague-Dawley rats were exposed to 2.76 or 4.15 G for periods ranging from 2 to 20 wk. The isolated diaphragm tissues from these rats were studied in vitro to determine the uptake of glucose and its utilization to CO2 and glycogen. The diaphragm muscle tissues obtained from centrifuged rats showed higher rates of glucose uptake and 14CO2 production from [U-14C]glucose than those obtained from noncentrifuged controls, but no significant differences in the rate of incorporation of [U-14C]glucose into glycogen were observed. Rats centrifuged for 12 wk at 4.15 G continued to show an increase in diaphragm tissue glucose uptake for periods up to 2 wk after return to normal gravity. The stimulating effect of insulin on the uptake of glucose and its incorporation into glycogen was much higher in the diaphragms of centrifuged rats. From the results of this study, it is concluded that one of the adaptive responses of rats to chronic centrifugation is an increase in glucose metabolism of their muscle tissues.

Topics: Adaptation, Physiological; Animals; Body Weight; Carbon Dioxide; Centrifugation; Diaphragm; Female; Glucose; Glycogen; Gravitation; Insulin; Muscles; Rats; Stimulation, Chemical; Time Factors

Topics: Amino Acids; Animals; Blood Proteins; Body Weight; Diet; Dietary Carbohydrates; DNA; Female; Glycogen; Liver; Liver Glycogen; Microsomes; Microsomes, Liver; Muscles; Myocardium; Organ Size; Polyribosomes; Protein Biosynthesis; Rats; Ribosomes; RNA; Spleen; Threonine

The incorporation of -14C FROM [1-14C]palmitate into blood glucose and liver and kidney glycogen in postnatal mice has been studied. Incorporation of -14C FROM [1-14C]palmitate into blood glucose and hepatic glycogen is relatively high in suck ling mice. Incontrast, the incorporation into kidney glycogen is low in suckling mice and high in adults. The study indicates the possible utilization of palmitate for glucose synthesis.

Topics: Aging; Animals; Blood Glucose; Body Weight; Glycogen; Kidney; Liver; Mice; Organ Size; Organ Specificity; Palmitic Acids; Time Factors

No relationship was apparent between the maximum thermogenic response of lambs to cold (summit metabolism) and the dissectable brown adipose tissue content, or the chemically extractable lipid content of the whole animal or the weight of various skeletal muscles. Correlations of summit metabolism with other parameters also suggested that the level of glucose, FFA and glycerol in the circulation, and the glycogen stores in liver and muscle, did not limit summit metabolism. However, significant correlations of summit metabolism with cardiac output and arteriovenous differences in oxygen content of blood focused attention on the possible role of the cardiovascular system and on the metabolic capability of the thermogenic tissues in determining summit metabolism.

Topics: Adipose Tissue, Brown; Animals; Blood Glucose; Body Weight; Cold Temperature; Fatty Acids, Nonesterified; Glycerol; Glycogen; Heart Rate; Liver Glycogen; Muscles; Oxygen Consumption; Respiration; Sheep; Time Factors

The tolerance of altitude-acclimatized (18,000 ft 4 wk) and unacclimatized rats to exercise at 5 degrees was determined. Fewer unacclimatized than acclimatized rats became fatigued during 9 hr of exercise in the cold. Normal body temperatures were maintained in both groups during 9 hr in the cold at rest, but after exercise unacclimatized rats became mildly hypothermic (body temperature 35 degrees) and acclimatized rats severely hypothermic (body temperature 27.9 degrees). Polycythemia (hematocrit 69) was produced during the altitude acclimatization. Altitude-acclimatized rats developed more severe hypoglycemia and lower liver glycogen and serum lactic acid concentrations after exercise than did controls. No pathological changes were found in resting altitude-acclimatized rats, but after exercise in the cold, a higher percentage of acclimatized than unacclimatized rats developed focal myocardial necrosis within 4 days. Reduced exercise tolerance is attributed to severe hypothermia with associated decreased metabolism, polycythemia, hypoglycemia, and a higher incidence of pathological changes in the cardiac and striated muscles.

Topics: Acclimatization; Altitude; Animals; Blood Glucose; Body Temperature; Body Weight; Cold Climate; Glycogen; Hematocrit; Lactates; Liver; Liver Glycogen; Male; Muscles; Myocardium; Physical Exertion; Rats; Time Factors

PCN, a microsomal enzyme inducer, given orally (10 mg in 1 ml water twice daily for 5 days), increased liver weight and mitotic activity in intact as well as in partially hepatectomized rats. Electron microscopy revealed SER proliferation in the hepatocytes of animals treated with PCN alone. Accumulation of SER membranes was also evident in the liver cell cytoplasm of untreated, partially hepatectomized rats; it was however, more pronounced in the hepatocytes of partially hepatectomized animals given PCN. These results indicate that the steriod has a marked effect on the regeneration rat liver.

Topics: Animals; Body Weight; Cell Division; Cytoplasmic Granules; Endoplasmic Reticulum; Female; Glycogen; Hepatectomy; Liver; Liver Regeneration; Organ Size; Pregnenolone Carbonitrile; Rats; Stimulation, Chemical; Time Factors

In the water-snake, Natrix piscator, the following are depressed by orchidectomy and restored to normal by testosterone treatment: glucose, free and esterified fatty acids and triglycerides in plasma, hepatic triglycerides, and total esterified fatty acids. The increase in hepatic free fatty acids and muscle glycogen was also reduced to the level found in intact snakes. Moreover, although castration had no effect, testosterone caused a significant increase in liver weight and plasma protein, and a significant decrease in free plasma cholesterol. Except for an increase in triglyceride content by high doses of the hormone, neither castration nor the administration of 5 mg testosterone had any significant effect on the free fatty acid and triglyceride content of the adipose tissue of the snakes.

Topics: Adipose Tissue; Animals; Blood Glucose; Blood Proteins; Body Weight; Castration; Cholesterol; Fatty Acids, Nonesterified; Glycogen; Liver; Liver Glycogen; Male; Muscles; Organ Size; Snakes; Testis; Testosterone; Triglycerides

Topics: Animals; Bile Ducts; Body Weight; Cyclopropanes; Fatty Acids; Fatty Acids, Unsaturated; Glycogen; Lipids; Liver; Organ Size; Salmonidae; Time Factors; Trout

Topics: Adipose Tissue; Animals; Blood Proteins; Body Weight; Cholesterol; Cholesterol Esters; Fatty Acids; Fatty Acids, Nonesterified; Glycogen; Kidney; Liver; Liver Glycogen; Muscles; Organ Size; Snakes; Thyroidectomy; Thyroxine; Triglycerides

Changing the qualitative and quantitative level of diet may affect the physiology of the insects. However only the total growth of the larvae is generally pointed out. Biochemical changes in undernourished larvae have been rarely investigated. For this purpose Bombyx mori larvae reared upon Spring leaves are compared to larvae reared upon Autumn leaves (poor nutritional value because of their Chemical composition). In both cases the analyses were carried out from the fourth larval ecdysis to the beginning of spinning. Three measurements indicate the development of larvae growth:--the mean weight of the larvae;--the fresh and dry weight of fat body;--the hemolymph volume.

Topics: Adipose Tissue; Animals; Body Weight; Bombyx; Diet; Energy Metabolism; Glycogen; Hemolymph; Larva; Lipid Metabolism; Nutrition Disorders; Seasons; Trehalose

A comparative study was made of the growth and of the influence of seasonal changes on nitrogen and carbohydrate metabolism of carp kept in batches in natural ponds. 10 Growth is active only in natural ponds. In batches where only industrial dried foods are used, no growth can be measured. 20 Activity of ribonucleic and protein metabolism is correlated with seasonal variations of water temperature in both conditions.

Topics: Animals; Body Height; Body Weight; Carps; Cyprinidae; DNA; Environment; Glycogen; Gonads; Lipids; Liver; Liver Glycogen; Muscles; Organ Size; Proteins; RNA; Seasons; Temperature

Thus far both the weanling rat ventromedial and dorsomedial syndrome have been investigated in only two and three-week studies. The present data are derived from a six-month study. Food intake and body weight and length changes were recorded weekly or bi-weekly and endocrine and metabolic parameters were assessed at sacrifice. Rats that had received ventromedial hypothalamic lesions shortly after weaning showed all the changes noted in previous short-term studies, i.e. normal body weight gains and food intake but increased carcass fat content. In addition, they manifested a slight hyperglycemia, normal free fatty acid levels and slowingdown of lipogenesis. Rats that had received dorsomedial lesions shortly after weaning also showed changes previously reported in short-term experiments. These include reduced ponderal and linear growth and food intake, but normal carcass composition and growth hormone levels. In addition, they showed a slight improvement of hypophagia with time, and at sacrifice hypoglycemia and low free fatty acid levels. Incorporation of glucose into fat pad glycogen and CO2 was decreased. In diaphragm, glucose incorporation was increased in both total lipid and fatty acids. The data demonstrate that both hypothalamic syndromes change with time, but not necessarily in a progressive manner. They also show that destruction of two so closely appositioned hypothalamic structures brings about entirely different and, in some parameters, opposite changes.

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Brain Mapping; Diaphragm; Fatty Acids; Fatty Acids, Nonesterified; Feeding Behavior; Glycogen; Growth; Growth Hormone; Hypothalamus; Insulin; Lipid Metabolism; Lipids; Male; Proteins; Rats; Time Factors

Two groups of rats were given, ad libitum, diets containing 20% fat for 4-5 weeks. The fat consisted of either long chain (LCT) or medium chain triglycerides (MCT). A third group of rats was given a low fat control diet. No difference in weight increase could be found between LCT and MCT rats. Total lipids and cholesterol concentrations in the plasma were the same whatever the diet. The high fat diets caused an increase in hepatic acetyl-CoA, citrate, malate and ketone body concentrations. Concentration of ketone bodies in the blood, however, decreased. No ketonuria occurred in any case. Hepatic levels of adenosine 5'-triphosphate, adenosine 5'-monophosphate and inoganic phosphate seemed higher in MCT rats than in LCT rats. The levels of these substrates were increased in both groups compared with the control group. LCT rats had hepatic (NS) and blood (HS) lactate and pyruvate concentrations below the corresponding figures for control rats. Hepatic and blood lactate concentrations in MCT rats were at least equal to or slightly higher (NS) than those of control rats. Hepatic glucose and glycogen and blood glucose concentrations were higher in rats given the high fat diet.

Topics: Acetyl Coenzyme A; Adenosine Monophosphate; Adenosine Triphosphate; Animals; Body Weight; Cholesterol; Citrates; Dietary Fats; Glucose; Glycogen; Ketone Bodies; Lactates; Lipids; Liver; Malates; Male; Phosphates; Pyruvates; Rats; Triglycerides

Topics: Animals; Body Weight; Dose-Response Relationship, Drug; Female; Glucagon; Glycogen; Lithium; Liver Glycogen; Muscles; Rats

Topics: Amides; Animals; Animals, Newborn; Body Weight; Ethanol; Female; Glycogen; Glycolates; Growth; Meclofenoxate; Muscle Development; Muscles; Organ Size; Palmitic Acids; Protein-Energy Malnutrition; Rats

Male rats rendered diabetic by the intravenous injection of streptozotocin (150mg/kg) were treated with a long-acting insulin for 1 week, then allowed to develop ketoacidosis. By using sampling techniques designed to avoid the use of anaesthesia and extended anoxic periods, sequential measurements of metabolic intermediates were made in blood, liver, cerebrospinal fluid and brain at 24h intervals after the last insulin injection. Measurements in blood and liver suggested a rapid increase in hepatic glycogenolysis and gluconeogenesis and peripheral-depot lipolysis between 24 and 48h after the last insulin injection, whereas blood and liver ketone-body and triglyceride concentrations rose more slowly. The changing metabolic patterns occurring with increasing time of insulin deprivation stress the importance of sequential compared with static measurements in experimental diabetes. Data are presented for brain metabolic intermediates in diabetic ketoacidosis, and support recent evidence that glucose plays a less important role in brain oxidative metabolism in ketotic states.

Topics: Animals; Antibodies; Blood Glucose; Body Weight; Brain; Diabetes Mellitus; Diabetic Ketoacidosis; Gluconeogenesis; Glycogen; Insulin; Ketone Bodies; Lipid Mobilization; Liver; Male; Organ Size; Radioimmunoassay; Rats; Streptozocin; Time Factors; Triglycerides

Topics: Animals; Antigens; Basement Membrane; Body Weight; Capillaries; Diabetic Retinopathy; Disease Models, Animal; Endothelium; Eye; Glycogen; Hyperglycemia; Inclusion Bodies; Injections, Intravenous; Insulin; Microscopy, Electron; Mitochondria; Plasma Cells; Polyuria; Rats; Retina; Retinal Vessels; Streptozocin; Time Factors; Trypsin

Topics: Animals; Body Weight; Cattle; Cyclic AMP; Cyclic GMP; Glycogen; Kinetics; L-Serine Dehydratase; Liver; Male; Organ Size; Phosphodiesterase Inhibitors; Rats; Structure-Activity Relationship; Theophylline; Vitamin E; Vitamin E Deficiency

Topics: Acid Phosphatase; Animals; Basement Membrane; Body Weight; Cell Differentiation; Cytoplasm; Cytoplasmic Granules; Endoplasmic Reticulum; Female; Fetus; Gestational Age; Glycogen; Golgi Apparatus; Male; Microscopy, Electron; Mitochondria; Phosphoric Monoester Hydrolases; Pituitary Gland; Rats; Regional Blood Flow

Topics: Biopsy; Body Weight; Cardiomyopathies; Glucosidases; Glycogen; Glycogen Storage Disease; Humans; Infant; Infant, Newborn; Liver; Muscles; Muscular Diseases; Prenatal Diagnosis; Skin

A combined ultrastructural and functional approach was employed to define the effects of duration of diabetes and of diet on various aspects of lipid metabolism in rats with severe streptozotocin (SZ)-induced insulin deficiency. Plasma triglyceride (TG) levels rose to a mean of 479 mg/100 ml 24 h after SZ administration in rats eating a fat-free, high carbohydrate diet as compared to a mean of 324 mg/100 ml in rats eating a high fat diet. These changes were associated with a commensurate increase in hepatocyte Golgi very low density lipoprotein (VLDL) content, but only a small increase in estimates of VLDL-TG secretion rate (post-Triton WR 1339 increment in plasma TG level). Although these findings are consistent with the thesis that VLDL-TG synthesis and secretion are increased 24 h after administration of SZ, it seemed unlikely that the observed increase in VLDL-TG secretion could entirely account for the severity of the hypertriglyceridemia. Thus, although lipoprotein removal rate was not measured directly, it was necessary to postulate that a defect in VLDL-TG removal was also present at this stage. Hypertriglyceridemia was still present 7 days later, only in this instance plasma TG levels were higher in rats eating the high fat diet (a mean of 589 mg/100 ml, as compared to 263 mg/100 ml). Rats with diabetes of 7-day duration had a 50% decrease in both TG entry rate and hepatocyte Golgi complex VLDL content, irrespective of diet. Thus, there was no evidence of increased VLDL-TG secretion in chronic insulin deficiency. In this instance, although not assessed directly, it was necessary to postulate that the hypertriglyceridemia in chronically insulin-deficient rats is due entirely to a defect in lipoprotein removal, involving both dietary and endogenous fat.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus; Diet; Dietary Carbohydrates; Fatty Acids, Nonesterified; Female; Glycogen; Golgi Apparatus; Insulin; Lipoproteins, VLDL; Liver; Microscopy, Electron; Rats; Streptozocin; Time Factors; Triglycerides

Topics: Animals; Blood Glucose; Body Weight; Carbohydrates; Caseins; Cellulose; Dietary Fats; Energy Metabolism; Fasting; Fatty Acids; Glucokinase; Gluconeogenesis; Glucose-6-Phosphatase; Glycogen; Growth; Ketones; Liver; Minerals; Rats; Starch; Vitamins; Zea mays

Topics: Age Factors; Amino Acids; Animal Nutritional Physiological Phenomena; Animals; Body Composition; Body Water; Body Weight; Brain; Chlorides; Diet; Eggs; Glutens; Glycogen; Lipid Metabolism; Lysine; Male; Muscle Proteins; Muscles; Nerve Tissue Proteins; Nitrogen; Nutrition Disorders; Organ Size; Potassium; Rats; Sodium; Water-Electrolyte Balance

Topics: Adult; Biopsy; Body Height; Body Weight; Glycogen; Heart Rate; Humans; Lactates; Leg; Male; Microscopy, Electron; Muscles; Myofibrils; Oxygen Consumption; Physical Exertion; Respiration; Spirometry; Time Factors; Vital Capacity

Topics: Animals; Behavior, Animal; Body Weight; Carbohydrates; Glycogen; Grasshoppers; Hemolymph; Insecticides; Lipids; Male; Neurosecretory Systems; Time Factors

Organ weights and blood parameters were measured in male and female Brattleboro rats with hereditary diabetes insipidus (DI) and in normal rats of the same strain, between 37 and 138 weeks old. Although differences in body weight between the homozygous DI and heterozygous normal rats accounted for differences in the weights of the heart and gonads, the weights of the spleen, liver and kidney were not solely body-weight dependent; there were significant sex and genotype differences in the mean weights of these organs. The liver, heart and gonads were the only organs showing age-dependent changes. No genotype-dependent differences were observed in the haematocrit and haemoglobin concentration, although there was a sex difference; the mean values of these parameters were higher in males. Plasma glucose concentrations were significantly lower in homozygous than in heterozygous rats; in the latter, plasma glucose concentration decreased with age. No significant changes occurred in the mean plasma concentrations of sodium or potassium with age or genotype. Total plasma lipids of heterozygous female rats showed both age- and genotype-dependent changes; this parameter reached a plateau at 90-100 weeks old, and was significantly higher in heterozygous females than in all other groups. Plasma proteins showed no age-dependent changes, but were of higher mean value in heterozygous than in homozygous rats and were greater in females than in males. Differences in blood parameters of homozygous and heterozygous Brattleboro rats are discussed in terms of differences in hormone concentrations.

Topics: Age Factors; Analysis of Variance; Animals; Blood Glucose; Blood Proteins; Body Weight; Diabetes Insipidus; Female; Genotype; Glycogen; Gonads; Heart; Hematocrit; Hemoglobins; Kidney; Lipids; Liver; Male; Organ Size; Potassium; Rats; Rats, Inbred Strains; Sex Factors; Sodium; Spleen

Topics: Adenosine Triphosphate; Adult; Atmosphere Exposure Chambers; Body Height; Body Weight; Carbon Dioxide; Glucose; Glucosephosphates; Glycogen; Heart Rate; Helium; Humans; Hyperbaric Oxygenation; Lactates; Male; Muscles; Nitrogen; Oxygen; Oxygen Consumption; Partial Pressure; Physical Exertion; Pyruvates; Time Factors

Topics: Adrenal Cortex Hormones; Adrenal Glands; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; DNA; Electrophoresis, Polyacrylamide Gel; Estradiol; Glycogen; Glycosuria; Growth Hormone; Hypophysectomy; In Vitro Techniques; Insulin; Islets of Langerhans; Liver; Male; Microscopy, Electron; Organ Size; Pituitary Gland; Rats; RNA; Seminal Vesicles

Topics: Age Factors; Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Birth Weight; Blood Glucose; Body Composition; Body Water; Body Weight; Chromatography, Gas; Elements; Fasting; Fatty Acids; Female; Glycogen; Lactation; Lipid Metabolism; Lipids; Pregnancy; Proteins; Swine

Topics: Adipose Tissue; Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diet; Energy Metabolism; Fatty Acids, Nonesterified; Food Deprivation; Glycogen; Lactates; Liver; Liver Glycogen; Male; Motor Activity; Muscles; Physical Exertion; Rats

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Carbon Radioisotopes; Dose-Response Relationship, Drug; Fatty Acids; Glucocorticoids; Glucose; Glycogen; Growth Hormone; Insulin; Insulin Resistance; Insulin Secretion; Lipid Metabolism; Male; Methylprednisolone; Proteins; Rats; Time Factors

Topics: Adipose Tissue; Animals; Biometry; Blood Glucose; Blood Proteins; Body Weight; Carbohydrate Metabolism; Cholesterol; Fatty Acids, Nonesterified; Glycogen; Kidney; Lipid Metabolism; Liver Glycogen; Muscles; Phospholipids; Proteins; Snakes; Temperature; Thyroid Gland; Thyroidectomy

Topics: Adult; Anaerobiosis; Blood; Blood Glucose; Body Weight; Diet; Dietary Carbohydrates; Glucosephosphates; Glycogen; Heart Rate; Hematocrit; Humans; Hydrogen-Ion Concentration; Lactates; Male; Oxygen Consumption; Physical Exertion; Potassium; Respiration; Sodium; Time Factors

Topics: Animals; Body Weight; Chickens; Cholesterol; Circadian Rhythm; Esters; Fatty Acids, Nonesterified; Glucose; Glycerides; Glycogen; Housing, Animal; Intestines; Lighting; Liver; Liver Glycogen; Male; Methods; Muscles; Myocardium; Noise; Organ Size; Pancreas; Spleen; Temperature

Topics: Adipose Tissue; Animals; Blood Chemical Analysis; Blood Glucose; Body Weight; Diet; Fatty Acids, Nonesterified; Glycogen; Lactates; Liver; Male; Muscles; Physical Exertion; Rats

Topics: Adenosine Triphosphate; Amino Acids; Animals; Body Weight; Brain; Brain Chemistry; Carbon Dioxide; Carbon Radioisotopes; Glucose; Glycogen; Hyperthyroidism; Hypothyroidism; Leucine; Lipids; Liver; Organ Size; Phosphocreatine; Rats; Time Factors

Topics: Animals; Animals, Newborn; Body Weight; Carbon Radioisotopes; Dactinomycin; Delivery, Obstetric; Enzyme Induction; Female; Gluconeogenesis; Glucose; Glycogen; Lactates; Liver; Phosphoenolpyruvate Carboxykinase (GTP); Pregnancy; Progesterone; Rats

Topics: Abortion, Spontaneous; Animals; Ascorbic Acid; Blood Glucose; Body Weight; Carbohydrates; Diet; Extraembryonic Membranes; Female; Fetus; Glycogen; Liver; Organ Size; Placenta; Pregnancy; Pregnancy, Animal; Rats; Time Factors; Uterus

Topics: Animals; Body Weight; Chlormadinone Acetate; Contraceptives, Oral; Female; Fetus; Gestational Age; Glycogen; Liver; Organ Size; Placenta; Pregnancy; Pregnancy, Animal; Pregnancy, Prolonged; Rabbits; RNA; Time Factors

Topics: Animals; Body Weight; Fatty Acids; Glycogen; Heart; Histocytochemistry; L-Lactate Dehydrogenase; Male; Myocardium; Photometry; Physical Exertion; Rats; Staining and Labeling; Succinate Dehydrogenase; Time Factors

Topics: Alanine; Animals; Antigens; Biological Transport; Blood Glucose; Body Weight; Carbon Radioisotopes; Chromatography, Paper; DNA; Fasting; Female; Gluconeogenesis; Glucose; Glycogen; Hypothyroidism; Insulin; Ketone Bodies; Lactates; Liver; Organ Size; Radioimmunoassay; Rats; Thyroid Function Tests; Thyroid Gland; Thyroidectomy; Time Factors

Topics: Adrenal Glands; Aging; Animals; Animals, Newborn; Blood Glucose; Blood Pressure; Body Temperature Regulation; Body Weight; Chlorisondamine; Cold Temperature; Epinephrine; Fatty Acids, Nonesterified; Glycerol; Glycogen; Liver; Metabolism; Muscles; Norepinephrine; Propranolol; Spectrometry, Fluorescence; Swine

Topics: Animals; Aspartate Aminotransferases; Blood Glucose; Blood Proteins; Body Weight; Chlorides; Cholesterol; Eels; Fatty Acids, Nonesterified; Glycerides; Glycogen; Hematocrit; Hemoglobinometry; Lactates; Liver; Liver Glycogen; Muscles; Organ Size; Phosphates; Seasons; Starvation

Topics: Animals; Body Weight; Carboxy-Lyases; Circadian Rhythm; Feeding Behavior; Food; Fructose-Bisphosphate Aldolase; Glucokinase; Glucosephosphate Dehydrogenase; Glycogen; Hexokinase; Light; Liver; Male; Ornithine; Proteins; Pyruvate Kinase; Rats; Tyrosine Transaminase

Topics: Acidosis; Animals; Blood Glucose; Body Weight; Carbon Dioxide; Diabetes Mellitus, Experimental; Gluconeogenesis; Glucosephosphate Dehydrogenase; Glycogen; Glycolysis; Hexokinase; Hydrogen-Ion Concentration; Intestinal Mucosa; Jejunum; Kidney; Kidney Cortex; Ligases; Liver; Malate Dehydrogenase; Male; Organ Size; Phosphofructokinase-1; Phosphogluconate Dehydrogenase; Pyruvate Kinase; Rats

Topics: Adenosine Triphosphatases; Animals; Body Weight; Carbohydrate Metabolism; Cardiac Output; Coronary Vessels; Energy Metabolism; Fatty Acids, Nonesterified; Glycogen; Heart; Hypoxia; Myocardium; Organ Size; Oxygen Consumption; Physical Conditioning, Animal; Physical Fitness; Rats; Regional Blood Flow

Topics: Animals; Biomphalaria; Body Water; Body Weight; Cell Nucleus; Connective Tissue Cells; Cytoplasmic Granules; Endoplasmic Reticulum; Epithelium; Female; Genitalia; Glycogen; Golgi Apparatus; Histocytochemistry; Inclusion Bodies; Lipoproteins; Lysosomes; Male; Microscopy, Electron; Mitochondria; Organ Size; Pigments, Biological; Polysaccharides; Starvation; Time Factors

Topics: Animals; Biometry; Body Weight; Cell Nucleus; Circadian Rhythm; Epithelial Cells; Glycogen; Inclusion Bodies; Kupffer Cells; Liver; Lysosomes; Male; Microbodies; Microscopy; Microscopy, Electron; Mitochondria, Liver; Phagocytosis; Rats; Starvation; Time Factors

Topics: Animals; Body Weight; Cytochrome P-450 Enzyme System; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Ethanol; Female; Glucose-6-Phosphatase; Glycogen; Male; Microsomes, Liver; Phenobarbital; Rats

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Cytoplasmic Granules; Endoplasmic Reticulum; Epididymis; Glycogen; Golgi Apparatus; Hypertrophy; Insulin; Islets of Langerhans; Male; Microscopy, Electron; Microtubules; Obesity; Organ Size; Rats; Time Factors; Triglycerides

Topics: Animal Nutritional Physiological Phenomena; Animals; Appetite Regulation; Behavior, Animal; Body Weight; Carbon Isotopes; Circadian Rhythm; Diet; Eating; Feeding Behavior; Food Deprivation; Glucose; Glycogen; Hunger; Hypothalamus; Insulin; Lipid Metabolism; Male; Rats; Satiation; Statistics as Topic

Topics: Age Factors; Animals; Body Weight; Castration; Epididymis; Glucosephosphate Dehydrogenase; Glycogen; Isocitrate Dehydrogenase; Male; Organ Size; Phosphogluconate Dehydrogenase; Rats; Testis

Topics: Alanine; Animals; Blood Glucose; Body Weight; Carbon Isotopes; Estradiol; Female; Gluconeogenesis; Glycogen; Insulin; Liver; Organ Size; Progesterone; Pyruvates; Rats

Topics: Age Factors; Aging; Animals; Ascorbic Acid; Body Weight; Glycogen; Lizards; Male; Muscle Proteins; Muscles; Species Specificity; Water

Topics: Animals; Blood Glucose; Body Weight; Ethanol; Glycogen; Heart; Male; Myocardium; Organ Size; Rats; Time Factors

Topics: Adult; Age Factors; Body Height; Body Weight; Glycogen; Humans; Male; Middle Aged; Muscles; Phospholipids; Sports; Triglycerides

Topics: Animals; Body Weight; Cell Nucleus; Circadian Rhythm; Darkness; Estrus; Female; Glycogen; Histocytochemistry; Light; Mice; Organ Size; Pineal Gland; Pregnancy; Uterus; Vaginal Smears

Topics: Adult; Basal Metabolism; Body Composition; Body Weight; Chronic Disease; Feeding Behavior; Female; Glycogen; Growth Disorders; Humans; Male; Motivation; Muscles; Nitrogen; Nutrition Disorders; Physical Exertion; Pregnancy; Psychosexual Development; Sleep; Sports Medicine; Twins; Wakefulness

Topics: Animals; Blood Glucose; Body Weight; Castration; Depression, Chemical; Estrogen Antagonists; Female; Glycogen; Liver; Organ Size; Ovary; Progesterone; Rats; Uterus

Topics: Animals; Blood Glucose; Body Weight; Cholesterol; Female; Fructosephosphates; Glucose; Glycerophosphates; Glycogen; Glycolysis; Hydrogen-Ion Concentration; Hypophysectomy; Lactates; Muscles; Phosphoenolpyruvate; Pituitary Gland; Postmortem Changes; Pyruvates; Swine; Time Factors

Topics: Animals; Blood Glucose; Body Weight; Breeding; Carbon Radioisotopes; Fasting; Female; Genetics; Gluconeogenesis; Glucose; Glucose Tolerance Test; Glycogen; In Vitro Techniques; Insulin; Liver; Male; Mice; Oxidation-Reduction; Pancreas; Retina

Topics: Aging; Animals; Blood Glucose; Body Weight; DNA; Fatty Acids; Female; Glycogen; Ketone Bodies; Lactation; Liver; Male; Organ Size; Pregnancy; Rats; Starvation; Time Factors

Topics: Adult; Biopsy, Needle; Blood Glucose; Blood Pressure; Body Weight; Depression, Chemical; Dietary Carbohydrates; Female; Glycogen; Humans; Liver; Male; Middle Aged; Pulse; Starvation; Stimulation, Chemical; Time Factors

Topics: Administration, Oral; Adrenal Glands; Animal Feed; Animals; Ascorbic Acid; Blood Glucose; Body Weight; Carbohydrate Metabolism; Chickens; Corticosterone; Female; Glycogen; Male; Organ Size; Poultry Diseases; Vitamin A; Vitamin A Deficiency

Topics: Adenosine Triphosphate; Animals; Body Weight; Creatine; Energy Metabolism; Glycogen; Growth; Heart Rate; Lactates; Liver Glycogen; Male; Muscles; Myoglobin; Organ Size; Oxygen Consumption; Phosphocreatine; Phosphorus; Physical Exertion; Pyruvates; Rats; Respiration; Stress, Mechanical

Topics: Anaerobiosis; Animals; Blood Glucose; Body Weight; Glycogen; Injections, Subcutaneous; Insulin; Lactates; Male; Metabolism; Mice; Muscles; Physical Exertion; Pyruvates; Rats

Topics: Analysis of Variance; Animals; Body Weight; Carbohydrate Metabolism; Cryptorchidism; Germ Cells; Glucose; Glycogen; Histocytochemistry; Lactates; Leydig Cells; Male; Oxygen Consumption; Proteins; Rats; Sertoli Cells; Testis; Time Factors

Topics: Adenosine Triphosphate; Adolescent; Blood Pressure; Blood Volume; Body Height; Body Weight; Carbon Dioxide; Cardiac Output; Child; Glucose; Glycogen; Heart Rate; Hemoglobins; Humans; Lactates; Male; Muscles; Oxygen; Oxygen Consumption; Phosphocreatine; Phosphofructokinase-1; Physical Education and Training; Physical Exertion; Potassium; Respiration; Succinate Dehydrogenase

Topics: Adrenal Glands; Adrenocorticotropic Hormone; Animals; Body Weight; Feeding Behavior; Female; Food Deprivation; Glycogen; Liver; Liver Glycogen; Male; Mammals; Muscles; Organ Size; Reptiles; Seasons

Topics: Adipose Tissue; Body Weight; Cholesterol; Electrophoresis, Paper; Fasting; Glycogen; Humans; Hyperlipidemias; Lipid Metabolism; Lipoproteins; Lipoproteins, LDL; Male; Muscles; Nicotinic Acids; Time Factors; Triglycerides; Ultracentrifugation

Topics: Acetanilides; Adrenergic beta-Antagonists; Amino Alcohols; Animals; Blood Glucose; Blood Pressure; Body Weight; Drug Antagonism; Fatty Acids, Nonesterified; Female; Glycogen; Heart Rate; Hypertrophy; Isoproterenol; Lactates; Muscles; Myocardium; Organ Size; Propranolol; Propylamines; Rats; Salivary Gland Diseases; Submandibular Gland; Sympatholytics

Topics: Adolescent; Age Factors; Birth Weight; Body Weight; Child; Child, Preschool; Female; Glycogen; Humans; Infant; Infant, Newborn; Infant, Premature; Kidney; Kidney Glomerulus; Kidney Pelvis; Kidney Tubules; Male; Sex Factors

Topics: Adenosine Triphosphate; Animals; Body Weight; Glycogen; Growth; Immobilization; Lactates; Male; Muscles; Organ Size; Oxygen Consumption; Phosphocreatine; Physical Exertion; Pyruvates; Rats

Topics: Adenosine Triphosphate; Adult; Body Height; Body Weight; Fatigue; Glycogen; Humans; Lactates; Male; Methods; Muscle Contraction; Muscles; Phosphocreatine; Physical Exertion; Posture; Thigh; Time Factors

Topics: Alanine Transaminase; Animals; Blood Chemical Analysis; Blood Proteins; Body Weight; Cholesterol; Chromatography, Gas; Eels; Glycogen; Hematocrit; Hemoglobins; Herbicides; Kinetics; Liver; Liver Function Tests; Muscles; Pentachlorophenol; Phenols; Seawater

Topics: Animals; Blood Glucose; Body Weight; Carbon Isotopes; Fatty Acids, Nonesterified; Female; Fetus; Glucose; Glycogen; Humans; Infant, Newborn; Injections, Intraperitoneal; Lipase; Nitrogen; Oleic Acids; Organ Size; Placental Lactogen; Pregnancy; Pregnancy, Animal; Rats; Triglycerides

Topics: Animals; Body Weight; Carbon Isotopes; Diaphragm; Fasting; Female; Glycogen; Injections, Intraperitoneal; Insulin; Male; Methods; Muscles; Nutritional Physiological Phenomena; Rats; Sex Factors

Topics: Adipose Tissue; Adult; Aged; Body Weight; Carbon Dioxide; Carbon Isotopes; Female; Glucose; Glycogen; Humans; Insulin; Insulin Resistance; Lipid Metabolism; Male; Middle Aged; Muscles; Obesity

Topics: Animals; Antigens; Blood Glucose; Blood Proteins; Body Weight; Carbon Isotopes; Diaphragm; Fatty Acids, Nonesterified; Female; Glucosamine; Glucose; Glycogen; Glycoproteins; Growth Hormone; Hyperpituitarism; In Vitro Techniques; Insulin; Ketone Bodies; Muscles; Neoplasms, Experimental; Organ Size; Pancreas; Rats; Valine

Topics: Adenosine Triphosphate; Animals; Blood Pressure; Body Weight; Cardiac Output; Coronary Circulation; Glycogen; Heart; Hypoxia; Lactates; Male; Myocardium; Oxygen; Oxygen Consumption; Partial Pressure; Phosphocreatine; Physical Education and Training; Pyruvates; Rats; Rats, Inbred Strains; Time Factors

Topics: Adipose Tissue; Animals; Body Weight; Carbohydrate Metabolism; Carbon Isotopes; Glucose; Glycogen; Hypothalamus; Lipid Metabolism; Male; Organ Size; Palmitic Acids; Rats; Triglycerides

Topics: Adipose Tissue; Animals; Animals, Newborn; Blood Glucose; Body Weight; Carbon Isotopes; Diet; Feeding Behavior; Glucose; Glycogen; Hypothalamus; Insulin; Lipid Metabolism; Liver; Male; Rats

Topics: Animals; Body Weight; Female; Glycogen; Larva; Male; Methods; Mice; Schistosoma mansoni; Schistosomiasis; Sex Factors

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Carbon Dioxide; Carbon Isotopes; Diaphragm; Diet; Epididymis; Glucose; Glycogen; Hyperglycemia; In Vitro Techniques; Insulin; Insulin Resistance; Male; Mice; Mice, Inbred Strains; Muscles; Obesity; Parabiosis; Triglycerides

Topics: Adipose Tissue; Body Weight; Carbon Dioxide; DNA; Fasting; Glucose; Glucose Tolerance Test; Glycogen; Humans; In Vitro Techniques; Insulin; Methods; Obesity; Stimulation, Chemical

Topics: Adenosine Triphosphate; Adolescent; Adult; Biopsy; Body Weight; Glycogen; Humans; Lactates; Male; Muscles; Oxygen Consumption; Phosphocreatine; Physical Education and Training; Physical Exertion; Skinfold Thickness; Spirometry; Time Factors

Topics: Animals; Animals, Newborn; Asphyxia Neonatorum; Blood Glucose; Body Weight; Female; Glycogen; Humans; Infant, Newborn; Kidney; Liver Glycogen; Lung; Macaca; Muscles; Myocardium; Organ Size; Pregnancy; Umbilical Arteries

1. The specific radioactivity of plasma l-lactate and the incorporation of (14)C into plasma d-glucose, liver glycogen and skeletal-muscle glycogen were measured as a function of time after the intraperitoneal injection of l-[U-(14)C]lactate into 2-, 10- and 30-day-old rats. 2. Between 15 and 60min after the injection of the l-[U-(14)C]lactate, the specific radioactivity of plasma lactate decreased with a half-life of 20-33min in animals at all three ages. 3. At all times after injection examined, the specific radioactivity of plasma glucose of the 2- and 10-day-old rats was at least fourfold greater than that of the 30-day-old rats. 4. Although (14)C was incorporated into liver glycogen the amount incorporated was always less than 5% of that present in plasma glucose. 5. The results are discussed with reference to the factors that may influence the rate of incorporation of (14)C into plasma glucose, and it is concluded that the rate of gluconeogenesis in the 2- and 10-day-old suckling rat is at least twice that of the weaned 30-day-old animal.

Topics: Age Factors; Animals; Animals, Newborn; Blood Glucose; Body Weight; Carbon Isotopes; Gluconeogenesis; Glycogen; Growth; Half-Life; Lactates; Liver Glycogen; Muscles; Organ Size; Rats; Rats, Inbred Strains; Time Factors

1. The specific radioactivity of plasma d-glucose and the incorporation of (14)C into plasma l-lactate, liver glycogen and skeletal-muscle glycogen was measured as a function of time after the intraperitoneal injection of d-[6-(14)C]glucose and d-[6-(3)H]glucose into newborn, 2-, 10- and 30-day-old rats. 2. The log of the specific radioactivity of both plasma d-[6-(14)C]- and d-[6-(3)H]-glucose of the 2-, 10- and 30-day-old rats decreased linearly with time for at least 60min after injection of labelled glucose. The specific radioactivity of both plasma d-[6-(14)C]- and d-[6-(3)H]-glucose of the newborn rat remained constant for at least 75min after injection. 3. The glucose turnover rate of the 30-day-old rat was significantly greater than (approximately twice) that of the 2- and 10-day-old rats. The relative size of both the glucose pool and the glucose space decreased with age. Less than 10% of the glucose utilized in the 2-, 10- and 30-day-old rats was recycled via the Cori cycle. 4. The results are discussed in relationship to the availability of dietary glucose and other factors that may influence glucose metabolism in the developing rat.

Topics: Age Factors; Animals; Animals, Newborn; Blood Glucose; Body Weight; Carbon Isotopes; Glucose; Glycogen; Growth; Lactates; Liver Glycogen; Muscles; Organ Size; Rats; Rats, Inbred Strains; Time Factors; Tritium

Topics: Adipose Tissue; Body Weight; Carbohydrate Metabolism; Carbon Dioxide; Carbon Isotopes; Cholesterol; Fasting; Glucose; Glucose Tolerance Test; Glycogen; Humans; Insulin; Lipid Metabolism; Lipids; Male; Middle Aged; Muscles; Oxygen Consumption; Physical Exertion; Physical Fitness; Succinate Dehydrogenase; Triglycerides

Topics: Amino Acids; Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Blood Proteins; Body Weight; Dietary Proteins; DNA; Fasting; Glycogen; Liver; Lysine; Male; Methionine; Muscles; Nutritional Requirements; Organ Size; Proteins; Rats; RNA

Topics: Adenosine Triphosphatases; Animals; Body Weight; Edema; Glucosyltransferases; Glycogen; Histocytochemistry; Immobilization; Kinesthesis; Male; Motor Activity; Movement; Muscles; Myofibrils; NAD; Oxidoreductases; Pinocytosis; Rats; Sarcoplasmic Reticulum; Space Flight; Succinate Dehydrogenase; Time Factors; Transferases

Topics: Animals; Body Weight; Dietary Carbohydrates; Fasting; Fatty Acids; Glucokinase; Glucose-6-Phosphatase; Glucosyltransferases; Glycogen; Hexokinase; Liver; Liver Glycogen; Male; Organ Size; Proteins; Rats; Water

Topics: Adenine Nucleotides; Barium; Body Weight; Chlorides; Fetus; Gestational Age; Glucagon; Glycogen; Humans; In Vitro Techniques; Insulin; Insulin Secretion; Islets of Langerhans; Ouabain; Pancreas; Potassium; Theophylline

Topics: Animals; Body Weight; Carbon Dioxide; Carbon Isotopes; Female; Fetus; Gestational Age; Glucose; Glycogen; Heart; In Vitro Techniques; Insulin; Lactates; Myocardium; Organ Size; Pregnancy; Rats

Topics: Body Height; Body Weight; Embryonic and Fetal Development; Female; Fetus; Glycogen; Humans; Nitrogen; Organ Size; Placental Lactogen; Pregnancy; Triglycerides

Topics: Animals; Body Weight; Carbohydrate Metabolism; Diptera; Fasting; Glycogen; Growth; Hexoses; Lipid Metabolism; Nitrogen; Sex Factors; Water

Topics: Animals; Body Weight; Cartilage; Citrates; Cortisone; Epiphyses; Feeding Behavior; Glucose; Glycogen; Injections, Subcutaneous; Metabolism; Oxidation-Reduction; Pentoses; Phosphorylases; Rats

Topics: Abnormalities, Drug-Induced; Alkaline Phosphatase; Animals; Ascorbic Acid; Body Weight; Corpus Luteum; Depression, Chemical; Embryo, Mammalian; Female; Fertility; Fetal Death; Gestational Age; Glycogen; Histocytochemistry; Nucleic Acids; Organ Size; Placenta; Placenta Diseases; Pregnancy; Rats; Tetracycline

Topics: Age Factors; Animals; Body Weight; Glycogen; Liver; Muscles; Phosphocreatine; Rats

Topics: Animal Feed; Animals; Body Weight; DDT; Estrus; Female; Glucose; Glycogen; Isomerism; Lactation; Lipids; Liver; Liver Glycogen; Milk; Organ Size; Ovary; Pregnancy; Reproduction; Sheep; Uterus; Water

Topics: Anesthesia, General; Anesthesia, Inhalation; Animals; Body Weight; Carbon Tetrachloride; Chloroform; Drug Synergism; Glycogen; Halothane; Hepatectomy; Lipid Metabolism; Liver; Male; Nitrogen; Nitrous Oxide; Preanesthetic Medication; Rats; Time Factors; Transaminases

Topics: Adipose Tissue; Animals; Animals, Newborn; Blood Glucose; Body Weight; Corticosterone; DNA; Drug Tolerance; Epinephrine; Fasting; Fatty Acids, Nonesterified; Glucose; Glycogen; Homeostasis; Insulin; Liver; Liver Glycogen; Metabolic Diseases; Muscles; Organ Size; Rats; RNA; Stress, Physiological; Swimming

Topics: Adenosine Triphosphate; Age Factors; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Weight; Fasting; Glycogen; Lactates; Lipids; Muscles; Phosphocreatine; Proteins; Swine; Water

Topics: Adult; Biopsy; Body Height; Body Weight; Fatigue; Fluorometry; Glycogen; Glycolysis; Humans; L-Lactate Dehydrogenase; Lactates; Muscles; Oxygen Consumption; Phosphocreatine; Physical Exertion; Potassium; Pyruvates; Sodium; Tissue Extracts; Water

Topics: Age Factors; Animals; Body Weight; Chickens; Depression, Chemical; DNA; Drug Antagonism; Electrophoresis; Estradiol; Estrogen Antagonists; Female; Glucose; Glycogen; Hyperplasia; Hypertrophy; Lipid Metabolism; Ovalbumin; Oviducts; Progesterone; Proteins; RNA; Time Factors

Topics: Adenosine Triphosphate; Aminobutyrates; Animals; Animals, Newborn; Aspartic Acid; Body Weight; Brain; Centrifugation; DNA; Fluorometry; Glucose; Glutamates; Glycogen; Lactates; Liver; Nerve Tissue Proteins; Nutrition Disorders; Phenylalanine; Phosphates; Phosphocreatine; Phosphorus; Rats; RNA; Spectrophotometry

Topics: Adenosine Triphosphate; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Catecholamines; Chickens; Glucosyltransferases; Glycogen; Lactates; Liver; Liver Glycogen; Pectoralis Muscles; Poultry Diseases; Vitamin A Deficiency

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Cholesterol; Chromatography, Gas; Creatinine; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Fatty Acids; Fatty Acids, Essential; Fatty Acids, Nonesterified; Glycogen; Growth; Insulin; Lipids; Liver Glycogen; Male; Muscles; Nitrogen; Rats; Starvation; Triglycerides

Topics: Animals; Body Weight; Fasting; Glycogen; Heart; Male; Myocardium; Organ Size; Physical Exertion; Rats; Swimming

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Carbon Dioxide; Carbon Isotopes; Diaphragm; Diet Therapy; Glucose; Glycogen; Hyperglycemia; In Vitro Techniques; Insulin; Insulin Resistance; Mice; Muscles; Obesity

Topics: Altitude; Animals; Blood Glucose; Blood Urea Nitrogen; Body Weight; Diaphragm; Disease Models, Animal; Glycogen; Hypoxia; Insulin; Lactates; Liver; Liver Glycogen; Male; Myocardium; Organ Size; Phenformin; Pyruvates; Rats

Topics: Acid-Base Equilibrium; Blood Transfusion; Body Surface Area; Body Weight; Child; Child, Preschool; Dehydration; Glycogen; Humans; Infant; Infant, Newborn; Infusions, Parenteral; Kidney; Pediatrics; Potassium; Sodium; Water; Water-Electrolyte Balance; Wounds and Injuries

Topics: Adenine Nucleotides; Adenosine Triphosphate; Animals; Animals, Newborn; Body Weight; Diet; Glucose; Glycogen; Growth; Growth Disorders; Hindlimb; Lactates; Male; Muscle Development; Muscles; Organ Size; Oxidoreductases; Pyruvates; Rats; Starvation

Topics: Adolescent; Bile; Body Weight; Carbohydrate Metabolism, Inborn Errors; Child; Child, Preschool; Cystic Fibrosis; Female; Galactosemias; Glycogen; Hepatitis A; Hepatolenticular Degeneration; Humans; India; Infant; Infant Nutritional Physiological Phenomena; Liver Diseases; Male; Tyrosine

Topics: Animals; Body Weight; Fasting; Glycogen; Hydrocortisone; Liver; Liver Glycogen; Male; Musculoskeletal System; Myocardium; Organ Size; Rats

Topics: Animals; Blood Cell Count; Blood Glucose; Blood Proteins; Body Weight; Cholestanes; Cholesterol; Endocrine Glands; Enzymes; Female; Glycogen; Hematocrit; Hemoglobins; Histocytochemistry; Invertebrate Hormones; Liver; Male; Metamorphosis, Biological; Nitrogen; Organ Size; Rats; Vaginal Smears

Topics: Age Factors; Amino Acids; Animals; Appetite; Body Composition; Body Weight; Deficiency Diseases; Diet; Dietary Proteins; Eggs; Glutens; Glycogen; Hematocrit; Liver; Liver Glycogen; Lysine; Male; Organ Size; Rats; Triticum

Topics: Adipose Tissue; Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Depression, Chemical; Diaphragm; Diet; Eating; Epididymis; Feeding Behavior; Glucose; Glucose Tolerance Test; Glycogen; In Vitro Techniques; Insulin; Male; Muscles; Rats; Time Factors

Topics: Adipose Tissue, Brown; Animals; Body Weight; Brain Chemistry; Chorionic Gonadotropin; Disease Models, Animal; Female; Fetus; Glycogen; Hydrogen-Ion Concentration; Hypoxia; Lactates; Lipids; Liver Glycogen; Myocardium; Organ Size; Placenta; Placenta Diseases; Pregnancy; Pregnancy, Prolonged; Rabbits

Topics: Animals; Blood Glucose; Body Weight; Carbon Dioxide; Carbon Isotopes; Fatty Acids; Fatty Acids, Nonesterified; Glucose; Glycogen; Hepatectomy; Liver; Liver Glycogen; Male; Muscles; Organ Size; Rats

Topics: Aging; Animals; Bile; Body Weight; Cell Nucleus; Cytoplasm; Gestational Age; Glycogen; Histocytochemistry; Karyometry; Liver; Mitosis; Organ Size; Rats; RNA

Topics: Animals; Body Weight; Cresols; Diet; Fats; Food Additives; Glycogen; Growth; Hepatomegaly; Hyperplasia; Hypertrophy; Liver; Male; Nitrogen; Nucleic Acids; Organ Size; Proteins; Rats; Water

Topics: Animals; Body Weight; Culex; Female; Glycogen

Topics: Adaptation, Physiological; Animals; Body Weight; Glycogen; Heart; Histocytochemistry; Liver; Liver Glycogen; Male; Myocardium; Organ Size; Physical Exertion; Rats; Swimming

Topics: Adult; Arm; Body Fluids; Body Weight; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Glycogen; Humans; Leg; Male; Muscles; Physical Exertion; Tritium; Water

Topics: Adolescent; Adult; Age Factors; Body Temperature; Body Weight; Diet; Female; Glycogen; Humans; Male; Middle Aged; Muscles; Oxygen Consumption; Physical Education and Training; Sports

Topics: Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Weight; Cyprinidae; Fasting; Glycogen; Hematocrit; Hemoglobins; Lactates; Liver; Muscles; Organ Size; Potassium; Pyruvates; Sodium; Water; Water-Electrolyte Balance

Topics: Age Factors; Aged; Arteriosclerosis; Blood Pressure; Body Weight; Carbohydrate Metabolism; Cholesterol; Fatty Acids, Nonesterified; Glucose Tolerance Test; Glycogen; Humans; Lipid Metabolism; Male; Middle Aged; Prediabetic State; Triglycerides; Uric Acid

Topics: Adipose Tissue; Animals; Body Weight; Carbohydrate Metabolism; Glycogen; Hemolymph; Insecta; Larva; Lipid Metabolism; Muscles; Organ Size; Starvation

Topics: Adrenal Glands; Animal Nutritional Physiological Phenomena; Animals; Behavior, Animal; Body Weight; Caseins; Corticosterone; Dietary Proteins; Feeding Behavior; Glycogen; Hypothalamus; Liver; Liver Glycogen; Male; Muscles; Rats; Rats, Inbred Strains

Topics: Aging; Animals; Body Weight; Carbohydrate Metabolism; Castration; Estradiol; Female; Glucose-6-Phosphate Isomerase; Glycogen; Organ Size; Ovary; Phosphofructokinase-1; Rats; Uterus

Topics: Age Factors; Animals; Body Weight; Germ Cells; Glycogen; Histocytochemistry; Male; Organ Size; Periodic Acid; Rats; Sertoli Cells; Testis

Topics: Animals; Blood Glucose; Body Weight; Corticosterone; Diabetes Mellitus, Experimental; Fatty Acids; Gluconeogenesis; Glucose; Glycogen; Glycolysis; Hyperglycemia; Liver; Male; Mice; Obesity; Oxidation-Reduction; Pyruvates; Radioactivity; Time Factors

Topics: Adipose Tissue; Animals; Basal Metabolism; Blood Glucose; Body Weight; Carbon Isotopes; Diet, Reducing; Female; Glucose; Glycogen; Hyperglycemia; Injections, Intravenous; Insulin; Mice; Muscles; Obesity

Topics: Aflatoxins; Animals; Body Weight; Chemical and Drug Induced Liver Injury; Glycogen; Liver Diseases; Male; Necrosis; Rabbits; Skin Absorption; Time Factors

Topics: Adrenal Glands; Alanine Transaminase; Alkaline Phosphatase; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Aspartate Aminotransferases; Body Weight; Brain; Catechols; Ceruloplasmin; Cholesterol; Flavonoids; Glycogen; Guinea Pigs; Kidney; Lipoproteins; Liver; Liver Glycogen; Male; Myocardium; Spleen

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Dietary Carbohydrates; Dietary Fats; Enzyme Activation; Fasting; Glucosyltransferases; Glycogen; Liver; Liver Glycogen; Male; Muscles; Organ Size; Phosphorus; Rats; Time Factors

Topics: Adrenalectomy; Animals; Body Weight; Castration; Electrophoresis; Glycogen; Isoenzymes; L-Lactate Dehydrogenase; Lactates; Male; Mice; Organ Size; Pituitary Gland; Proteins; Pyruvates; Thyroidectomy; Thyroxine

Topics: Adrenal Glands; Adrenalectomy; Animals; Blood Glucose; Body Weight; Calcium; Chlorides; Eels; Glycogen; Hydrocortisone; Liver Glycogen; Magnesium; Muscles; Potassium; Sodium

Topics: Animals; Body Weight; DNA; Female; Glucose; Glycogen; Lactates; Liver; Liver Glycogen; Lung; Male; Mice; Nicotiana; Organ Size; Oxygen Consumption; Plants, Toxic; Pyruvates; Ribose; RNA; Sex Factors; Smoking; Succinates

Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Diaphragm; Dietary Carbohydrates; Glucose; Glycogen; In Vitro Techniques; Insulin; Liver Glycogen; Pancreas; Rats

Topics: Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Body Temperature Regulation; Body Weight; Fasting; Glucose; Glycogen; Metabolism; Rectum; Swine

Topics: Acetates; Animals; Benzene Derivatives; Benzopyrenes; Body Weight; Cytochromes; Glycogen; Liver; Male; Methylcholanthrene; Microsomes; Morphinans; Organ Size; Phenobarbital; Rats; Stimulation, Chemical

Topics: Age Factors; Animals; Body Weight; Cricetinae; Glucosyltransferases; Glycogen; Male; Spermatozoa; Testis; Vas Deferens

Topics: Animals; Arachis; Body Weight; Caseins; Diet; Fasting; Glycine max; Glycogen; Lipid Metabolism; Liver; Male; Organ Size; Proteins; Rats; Time Factors

Topics: Acetoacetates; Animals; Ascorbic Acid Deficiency; Blood Glucose; Body Weight; Glucose-6-Phosphatase; Glucosyltransferases; Glycogen; Glycolysis; Guinea Pigs; Liver; Male; Organ Size; Phosphoglucomutase

Topics: Adrenal Glands; Animals; Body Weight; Caseins; Dietary Carbohydrates; Dietary Proteins; Enzyme Induction; Fructose; Fructose-Bisphosphatase; Glucokinase; Glucose; Glucose-6-Phosphatase; Glucose-6-Phosphate Isomerase; Glucosephosphate Dehydrogenase; Glycerolphosphate Dehydrogenase; Glycogen; Kidney; Liver; Liver Glycogen; Malate Dehydrogenase; Male; Organ Size; Phosphofructokinase-1; Phosphogluconate Dehydrogenase; Proteins; Pyruvate Kinase; Rats; Time Factors; Transferases

Topics: Acid Phosphatase; Animals; Blood Glucose; Body Weight; Diabetes Mellitus; Female; Glucose-6-Phosphatase; Glucosephosphate Dehydrogenase; Glucosyltransferases; Glycogen; Glycosuria; Guinea Pigs; Histocytochemistry; Hydrocortisone; Islets of Langerhans; L-Lactate Dehydrogenase; Male; Time Factors

Topics: Acclimatization; Adipose Tissue; Animals; Body Composition; Body Weight; Chorionic Gonadotropin; Female; Fetus; Glycogen; Liver; Mice; Myocardium; Organ Size; Placenta; Pregnancy; Pregnancy, Animal; Starvation; Temperature; Water

Topics: Animals; Blood Glucose; Body Weight; Dogs; Exercise Test; Female; Glucose; Glycogen; Hydrochloric Acid; Insulin; Liver; Male; Pargyline; Tolbutamide

Topics: Adaptation, Physiological; Animals; Aortic Coarctation; Body Weight; Glycogen; Male; Myocardium; Oxygen Consumption; Physical Exertion; Rats

Topics: Aging; Animals; Body Weight; Cell Membrane; Germ Cells; Glycogen; Histocytochemistry; Male; Mammals; Organ Size; RNA; Seasons; Testis

Topics: Animals; Body Temperature; Body Weight; Chlorpromazine; Endoplasmic Reticulum; Eulipotyphla; Female; Glycogen; Hibernation; Histocytochemistry; Hypothalamus; Male; Microscopy, Electron; Neurons; Phenothiazines; Rats; Seasons

Topics: Adrenalectomy; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Dogs; Glucose; Glycogen; Glycosuria; Hypoglycemia; Hypophysectomy; Injections, Intravenous; Insulin; Ketone Bodies; Melatonin; Peptides; Pineal Gland; Rabbits; Rats; Tissue Extracts; Urine

Topics: Animals; Body Composition; Body Weight; Carbon Isotopes; Cestoda; Chromatography, Thin Layer; Dietary Fats; Esterases; Fatty Acids; Fatty Acids, Essential; Glycogen; Linoleic Acids; Lipase; Lipid Metabolism; Male; Oleic Acids; Palmitic Acids; Phosphatidylcholines; Phosphatidylethanolamines; Phospholipids; Proteins; Rats; Spectrum Analysis; Starvation; Stearic Acids; Triglycerides

Topics: Amino Acids; Animals; Body Weight; Deficiency Diseases; Diet; Glycogen; Liver; Male; Nitrogen; Organ Size; Proteins; Rats; Threonine

Topics: Acceleration; Adaptation, Physiological; Animals; Body Weight; Glycogen; Male; Muscles; Poultry

Topics: Animals; Body Weight; Dietary Carbohydrates; Fructose; Galactose; Glucose; Glycogen; Hypophysectomy; Liver Glycogen; Muscles; Rats; Sodium Chloride; Sorbose; Water; Xylose

Topics: Adolescent; Adult; Body Composition; Body Weight; Carbon Dioxide; Dietary Proteins; Eating; Feces; Female; Glycogen; Humans; Male; Muscles; Nitrogen; Nutritional Physiological Phenomena; Oxygen Consumption; Respiration; Time Factors; Water-Electrolyte Balance

Topics: Animals; Body Weight; Carbon Isotopes; Female; Glucose; Glycogen; In Vitro Techniques; Male; Neoplasms, Experimental; Oxygen Consumption; Rats; Sarcoma, Yoshida

Topics: Animals; Blood Glucose; Body Weight; Delivery, Obstetric; Female; Glucose Tolerance Test; Glycogen; Linoleic Acids; Liver Glycogen; Muscles; Pregnancy; Pregnancy, Animal; Rats; Stearic Acids; Stomach; Uterus

Topics: Acetates; Adaptation, Physiological; Adipose Tissue; Animals; Body Weight; Carbon Isotopes; Diet; Digestive System Physiological Phenomena; Eating; Endocrine Glands; Fatty Acids; Female; Glycogen; Humans; Insulin; Lipid Metabolism; Lipids; Liver; Mice; Nutritional Physiological Phenomena; Phenylalanine; Probability; Rats; RNA; Statistics as Topic

Topics: Androsterone; Animals; Anticholesteremic Agents; Blood Proteins; Body Weight; Butyrates; Carbon Isotopes; Dogs; Glycogen; Haplorhini; Leucine; Liver; Male; Organ Size; Protein Biosynthesis; Proteins; Rats; Ribosomes; Thyroxine; Water

Topics: Animals; Body Weight; Glycogen; Hydrocortisone; In Vitro Techniques; Muscles; Oxygen Consumption; Rats

Topics: Animals; Body Weight; Carnitine; Citrates; Esterases; Fatty Acids; Glucose; Glycerides; Glycogen; Guinea Pigs; Hexosephosphates; Male; Myocardium; Organ Size; Pyruvates; Thyroxine

Topics: Adenine Nucleotides; Animals; Body Weight; Cholesterol; Creatine; Glycogen; Heart; Isoproterenol; Lactates; Myocardium; Necrosis; Organ Size; Phosphocreatine; Phospholipids; Propranolol; Rats; Triglycerides

Topics: Adrenal Cortex Hormones; Adrenal Glands; Adrenalectomy; Adrenocorticotropic Hormone; Amino Acids; Body Weight; Carbohydrate Metabolism; Fructose-Bisphosphatase; Gluconeogenesis; Glucose-6-Phosphatase; Glycogen; L-Lactate Dehydrogenase; Liver; Malate Dehydrogenase; Metabolism; Neoplasm Transplantation; Neoplasms, Experimental; Nitrogen; Organ Size; Orotic Acid; Pharmacology; Pituitary Neoplasms; Rats; Research; RNA

Topics: Anabolic Agents; Animals; Body Weight; Glycogen; Mice; Muscles; Organ Size; Pharmacology; Rats; Research; Steroids

Topics: Aging; Animals; Body Weight; Fasting; Female; Glycogen; Myocardium; Phosphates; Rats; Sex

Topics: Animals; Body Weight; Diaphragm; Glucose; Glycogen; Hepatectomy; In Vitro Techniques; Liver Regeneration; Muscles; Oxygen Consumption; Rats; Thalidomide

Topics: Animals; Body Weight; Chickens; Glycogen; Iodine Isotopes; Liver; Liver Glycogen; Metabolism; Pharmacology; Physiology; Poultry; Radiation Effects; Research; Thyroid Gland

Topics: Anura; Blood Glucose; Body Weight; Glucagon; Glycogen; Hepatectomy; Hyperglycemia; Hypophysectomy; Liver Glycogen; Metabolism; Muscles; Myocardium; Pancreas; Pancreatectomy; Pharmacology; Physiology; Research

Topics: Animals; Autonomic Nervous System; Body Weight; Carbohydrate Metabolism; Carbohydrates; Chromatography; Dogs; Epinephrine; Fatty Acids; Ganglia; Ganglia, Autonomic; Glycogen; Heart; Histamine; Lipase; Metabolism; Myocardium; Nitrogen; Norepinephrine; Phospholipids; Research; Sympathectomy; Ubiquinone