triolein and Body-Weight

In vitro, the inhibition by epsilon-polylysine depends on how the substrate is presented to the lipase. We therefore examined whether epsilon-polylysine can interact with the lipid emulsion and prevent lipase activity in digestive organs. To confirm lipase inhibition by epsilon-polylysine, a (14)C-trioleoylglycerol emulsion with or without epsilon-polylysine was orally administered to rats, and the radioactive lipid distribution determined at regular intervals. The radioactive plasma lipid was decreased, and radioactive fecal lipid was increased by the administration of epsilon-polylysine. The peak of radioactive lipids in the intestine was delayed by the administration of epsilon-polylysine. We used 20-week-old rats as a model for the middle-aged and elderly to test the effect of epsilon-polylysine on the body weight increase. epsilon-Polylysine significantly prevented any elevation in body weight and weight of the liver and epididymal adipose tissues. These data show that epsilon-polylysine inhibited the lipase activity in the digestive organ and had an anti-obesity function in the middle-aged rats.

Topics: Animals; Body Weight; Fatty Acids; Gastric Mucosa; Hydrolysis; Intestinal Mucosa; Intestines; Lipase; Lipid Metabolism; Male; Pancreas; Polylysine; Rats; Rats, Wistar; Stomach; Triolein

Trans-11 vaccenic acid (VA) is the predominant trans isomer in ruminant fat and a major precursor to the endogenous synthesis of cis9,trans11-conjugated linoleic acid in humans and animals. We have previously shown that 3-wk VA supplementation has a triglyceride (TG)-lowering effect in a rat model of dyslipidemia, obesity, and metabolic syndrome (JCR:LA-cp rats). The objective of this study was to assess the chronic effect (16 wk) of VA on lipid homeostasis in both the liver and intestine in obese JCR:LA-cp rats. Plasma TG (P < 0.001), total cholesterol (P < 0.001), LDL cholesterol (P < 0.01), and nonesterified fatty acid concentrations, as well as the serum haptoglobin concentration, were all lower in obese rats fed the VA diet compared with obese controls (P < 0.05). In addition, there was a decrease in the postprandial plasma apolipoprotein (apo)B48 area under the curve (P < 0.05) for VA-treated obese rats compared with obese controls. The hepatic TG concentration and the relative abundance of fatty acid synthase and acetyl-CoA carboxylase proteins were all lower (P < 0.05) in the VA-treated group compared with obese controls. Following acute gastrointestinal infusion of a VA-triolein emulsion in obese rats that had been fed the control diet for 3 wk, the TG concentration was reduced by 40% (P < 0.05) and the number of chylomicron (CM) particles (apoB48) in nascent mesenteric lymph was reduced by 30% (P < 0.01) relative to rats infused with a triolein emulsion alone. In conclusion, chronic VA supplementation significantly improved dyslipidemia in both the food-deprived and postprandial state in JCR:LA-cp rats. The appreciable hypolipidemic benefits of VA may be attributed to a reduction in both intestinal CM and hepatic de novo lipogenesis pathways.

Topics: Acetyl-CoA Carboxylase; Animals; Apolipoprotein B-48; Body Weight; Chylomicrons; Diet; Emulsions; Energy Intake; Fatty Acid Synthases; Infusions, Parenteral; Lipogenesis; Liver; Lymph; Obesity; Oleic Acids; Organ Size; Rats; Rats, Inbred Strains; Triglycerides; Triolein

Differential meal fat uptake into adipose tissue depots may be a determinant of body fat distribution.. We used the meal fat tracer/adipose tissue biopsy approach to compare the effects of meal fat content on the fat uptake into visceral and upper and lower body subcutaneous fat depots in 21 premenopausal women. [(3)H]triolein was used to trace the fate of fatty acids from a normal-fat or high-fat meal.. The proportion of dietary fat uptake into the three depots did not differ between meals; visceral fat accounted for only approximately 5% of meal fat disposal irrespective of visceral fat mass. For the women consuming the normal-fat meal, the uptake of meal fatty acid into femoral fat (milligrams meal fat per gram lipid) increased as a function of leg fat mass (r = 0.68, P < 0.05), which we interpret as increased efficiency of uptake. The opposite pattern was seen in omental fat with the normal-fat meal and in all depots after the high-fat meal. For both meals, approximately 40% of meal fat was oxidized ((3)H(2)O production) after 24 h.. We conclude that greater thigh adipose tissue in women is associated with greater efficiency of meal fat storage under conditions of energy balance, whereas the opposite is seen with visceral fat. These findings imply that different mechanisms may regulate fatty acid uptake in different depots, which may in turn impact on body fat distribution.

Topics: Adipose Tissue; Biological Transport; Body Weight; Dietary Fats; Fatty Acids; Female; Humans; Polycystic Ovary Syndrome; Premenopause; Radioisotope Dilution Technique; Sterilization, Tubal; Triolein; Tritium

In the present study the effects of dietary fat with defined fatty acids on lecithin:cholesterol acyltransferase (LCAT) and apoA-1, the two components of HDL that play a major role in reverse cholesterol transport (RCT), were examined. In addition, the expression of scavenger receptor B1 (SR-B1), the receptor involved in the uptake of HDL core lipids, was also determined under the same conditions in rats fed semisynthetic diets supplemented with triolein (TO), tripalmitin (TP) or menhaden oil (MO). Serum LCAT activity [ micro mol CE/(L.h)] was significantly (P < 0.05) higher in rats fed TO (33 +/- 4) compared with those fed TP (23 +/- 3) or MO (21 +/- 1). The levels of hepatic LCAT mRNA and hepatic SR-B1 receptor protein did not differ between rats fed TP and MO. The triolein diet, on the other hand, increased the induction of hepatic LCAT mRNA and hepatic SR-B1 receptor protein 1.5- to 2-fold. Serum HDL cholesterol concentrations differed among all groups and were 1.30 +/- 0.08, 1.17 +/- 0.10 and 0.91 +/- 0.06 mmol/L for TO-, TP- and MO-fed rats, respectively. Serum apoA-1 levels were significantly higher in TO-fed rats than in the other two groups. The data indicate that TO increases the secretion of HDL and its components (apoA-1 and LCAT), and stimulates the production of hepatic SR-B1 receptor protein. Overall, these results suggest that triolein may promote RCT and thus retard the development of atherosclerosis.

Topics: Animals; Apolipoprotein A-I; Body Weight; CD36 Antigens; Dietary Fats; Fish Oils; Gene Expression; Lipoproteins, HDL; Liver; Male; Membrane Proteins; Phosphatidylcholine-Sterol O-Acyltransferase; Rats; Rats, Sprague-Dawley; Receptors, Immunologic; Receptors, Lipoprotein; Receptors, Scavenger; RNA, Messenger; Scavenger Receptors, Class B; Triglycerides; Triolein

The aim of the present study was to determine the effects of dietary proteins on the oxidation of dietary carbohydrate and lipids in type II diabetic mice. KK-A(y) strain mice were provided free access to a high fat diet (30% of energy as fat) for an initial 4-wk period to induce diabetes. To reduce body weight gain, the mice were subsequently fed restrictive isoenergetic and isonitrogenous diets (35% of energy as protein and 5% as fat) based on either casein or soy protein isolate hydrolysate (SPI-H) for 4 wk. To measure exogenous carbohydrate and lipid oxidation, the mice were fed a diet containing (13)C-glucose or (13)C-triolein while they were in a respiratory chamber for 72 h. Postprandial energy expenditure was higher in the SPI-H than in the casein group; this difference was due to an increase in postprandial exogenous and endogenous carbohydrate oxidation. There were no differences in 24-h energy expenditure between dietary groups. Oxidation of exogenous carbohydrate tended to be higher (P = 0.054) in the SPI-H group during the 24 h of measurement. Fecal excretion of (13)C-glucose was lower but the excretion of lipid was higher in mice fed the SPI-H diet than in casein-fed mice. These results indicate that in type II diabetic mice, dietary SPI-H not only inhibits the absorption of dietary lipids and increases the absorption of dietary carbohydrates but also augments postprandial energy expenditure, which is accompanied by a postprandial increase in oxidation of dietary carbohydrates.

Topics: Animals; Body Weight; Carbon Isotopes; Caseins; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Energy Intake; Energy Metabolism; Feces; Intestinal Absorption; Male; Mice; Oxidation-Reduction; Soybean Proteins; Triolein

Fatty acid bile acid conjugates (FABACs) are a new family of synthetic molecules designed to solubilize biliary cholesterol. They were shown to prevent and dissolve cholesterol gallstones in inbred C57L/J mice fed a lithogenic, high-fat diet (HFD). In these mice, fatty liver was observed in the controls but not in the FABAC-treated ones. The present study was designed to study the effect of FABAC (arachidyl-amido-cholanoic acid) on diet-induced fatty liver in rats, hamsters, and mice. The fatty liver score (on a scale of 0-4 by light microscopy) was 4.0 in control hamsters and 0.3 in the FABAC-fed hamsters (P <.001). In mice it was 1.5 and 0.4, respectively (P <.01). The lipid/protein ratio in the liver was 1.3 +/- 0.44 (mg lipid/mg protein) in control rats and 0.66 +/- 0.04 in the FABAC group (P =.001) after 14 days. In hamsters it was 1.41 +/- 0.27 and 1.11 +/- 0.20, respectively (P =.03), after 21 days. In Imperial Charles River (ICR) mice the ratio was 0.34 +/- 0.10 and 0.17 +/- 0.07 (P =.03), respectively, after 24 days. Liver fat concentration, measured as mg lipid/g liver tissue, decreased similarly by FABAC feeding. The decrease in liver fat affected mainly the triglyceride levels. FABAC-fed animals gained weight similarly to the controls. Triglyceride absorption was unaffected by FABAC supplementation. In conclusion, oral FABAC therapy prevents/reduces the development of fatty liver in animals consuming a HFD.

Topics: Administration, Oral; Animals; Bile Acids and Salts; Body Weight; Cholic Acids; Cricetinae; Dietary Fats; Fatty Liver; Female; Liver; Male; Mesocricetus; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Mutant Strains; Rats; Rats, Wistar; Triglycerides; Triolein; Tritium

Essential fatty acid (EFA) deficiency induces fat malabsorption, but the pathophysiological mechanism is unknown. Bile salts (BS) and EFA-rich biliary phospholipids affect dietary fat solubilization and chylomicron formation, respectively. We investigated whether altered biliary BS and/or phospholipid secretion mediate EFA deficiency-induced fat malabsorption in mice. Free virus breed (FVB) mice received EFA-containing (EFA(+)) or EFA-deficient (EFA(-)) chow for 8 wk. Subsequently, fat absorption, bile flow, and bile composition were determined. Identical dietary experiments were performed in multidrug resistance gene-2-deficient [Mdr2((-/-))] mice, secreting phospholipid-free bile. After 8 wk, EFA(-)-fed wild-type [Mdr2((+/+))] and Mdr2((-/-)) mice were markedly EFA deficient [plasma triene (20:3n-9)-to-tetraene (20:4n-6) ratio >0.2]. Fat absorption decreased (70.1 +/- 4.2 vs. 99.1 +/- 0.3%, P < 0.001), but bile flow and biliary BS secretion increased in EFA(-) mice compared with EFA(+) controls (4.87 +/- 0.36 vs. 2.87 +/- 0.29 microl x min(-1) x 100 g body wt(-1), P < 0.001, and 252 +/- 30 vs. 145 +/- 20 nmol x min(-1) x 100 g body wt(-1), P < 0.001, respectively). BS composition was similar in EFA(+)- and EFA(-)-fed mice. Similar to EFA(-) Mdr2((+/+)) mice, EFA(-) Mdr2((-/-)) mice developed fat malabsorption associated with twofold increase in bile flow and BS secretion. Fat malabsorption in EFA(-) mice is not due to impaired biliary BS or phospholipid secretion. We hypothesize that EFA deficiency affects intracellular processing of dietary fat by enterocytes.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Transporters; Bile; Bile Acids and Salts; Body Weight; Carbon Radioisotopes; Cholestanetriol 26-Monooxygenase; Cholesterol 7-alpha-Hydroxylase; Cytochrome P-450 Enzyme System; Dietary Fats; Diterpenes; Enterocytes; Fatty Acids; Fatty Acids, Essential; Homozygote; Kinetics; Liver; Malabsorption Syndromes; Mice; Mice, Knockout; Oleic Acid; Phospholipids; Polyethylene Glycols; Retinyl Esters; RNA, Messenger; Steroid Hydroxylases; Triolein; Tritium; Vitamin A

Our previous work has shown that the lymphatic absorptions of lipids and lipid-soluble vitamins, retinol and alpha-tocopherol (alphaTP), are lowered markedly in rats fed a low-zinc (LZ) diet in parallel with lower lymphatic phospholipid outputs. Phosphatidylcholine (PC), when infused enterally, restored the absorptions of fat and retinol, but further lowered the absorption of alphaTP in rats fed the LZ diet. This study was conducted to determine whether a luminal infusion of lysophosphatidylcholine, a product of PC hydrolysis by pancreatic phospholipase A2 (PLA2), would simultaneously restore the absorptions of retinol and alphaTP in LZ rats. Rats were trained to consume two meals per day and were divided into two groups. One group was fed an AIN-93G diet containing a LZ (3.0 mg Zn/kg), and the other was fed the same diet, but containing adequate zinc (AZ; 30.0 mg Zn/kg) for 6 weeks. Rats with lymph cannula were infused at 3.0 ml/hr for 8 hr with a lipid emulsion containing retinol, alphaTP, and 14C-labeled triolein (14C-oleic acid) with or without 1-oleoyl-2-hydroxy phosphatidylcholine (lysoPC) in 24 ml of PBS (pH 6.5). When the lipid emulsion without lysoPC was infused, the absorptions of retinol and alphaTP were significantly lower in LZ rats (retinol, 13.2+/-1.5 nmol; alphaTP, 430.6+/-66.8 nmol) than in AZ rats (retinol, 18.2+/-1.0 nmol; alphaTP, 543.8+/-58.9 nmol). The lower absorptions of the vitamins in LZ rats occurred in parallel with a significant decrease in 14C-oleic acid absorption. When the emulsion containing lysoPC was infused, however, absorptions of the vitamins (retinol, 18.4+/-3.0 nmol; alphaTP, 777.2+/-92.1 nmol) in LZ rats were restored completely to the control levels (retinol, 20.4+/-2.8 nmol; alphaTP, 756.3+/-136.1 nmol). The results suggest that the luminal hydrolysis of PC to lysoPC by PLA2 may be impaired in LZ rats, resulting in impaired absorption of fat and the fat-soluble vitamins.

Topics: Animals; Body Weight; Carbon Radioisotopes; Duodenum; Infusions, Parenteral; Intestinal Absorption; Lymph; Lysophosphatidylcholines; Male; Phospholipases A; Phospholipases A2; Rats; Rats, Sprague-Dawley; Triolein; Vitamin A; Vitamin E; Zinc

We examined the effects of dietary fats with specific fatty acid compositions, on serum paraoxonase (PON1) activity in rats. Male adult Sprague-Dawley rats were divided randomly into four dietary groups. One group received the control diet [AIN 93M with soybean oil (5 g/100 g diet)], whereas the remaining three groups received the modified control diet supplemented with (15 g/100 g diet) triolein, tripalmitin or fish oil, respectively. After 20 d, blood was obtained after overnight food deprivation and PON1 activity was determined. Serum lipids and lipid components of lipoproteins were also determined. Serum PON1 activity [micromol/(L.min)] was significantly (P: < 0.05) higher in triolein (98 +/- 6) and lower in fish oil (41 +/- 4), compared with tripalmitin-fed rats (63 +/- 11). Serum PON1 activity in tripalmitin-fed rats was comparable to that of controls (67 +/- 9). Serum PON1 activity correlated significantly with serum lecithin:cholesterol acyltransferase (LCAT) activity (r = 0.77, P: < 0.001) and was transported in blood principally in association with the denser subfraction of HDL, very high density lipoprotein (VHDL; d > 1.15 kg/L). Serum PON1 activity correlated strongly with serum lipids as well as lipids of VLDL, HDL and its subfractions. Multiple linear regression analysis, however, showed a significant relationship of serum PON1 activity, principally with the phospholipids of VHDL (r = 0.47, P: < 0.002). These data suggest that the modulation of serum PON1 activity by dietary fat may be mediated via the effect of the specific fatty acids on the synthesis and secretion of VHDL, the subfraction of HDL that transports the majority of PON1 in the blood.

Topics: Animals; Aryldialkylphosphatase; Body Weight; Cholesterol; Dietary Fats; Esterases; Fasting; Fatty Acids; Fish Oils; Lipids; Lipoproteins; Lipoproteins, HDL; Lipoproteins, VLDL; Male; Phospholipids; Rats; Rats, Sprague-Dawley; Triglycerides; Triolein

An elevation of lipoprotein lipase (LPL) activity in adipose tissue is considered a possible cause of obesity. However, transgenic mice that overexpress the human LPL gene showed no increase in fat deposition as compared with controls. In the present study, we investigated effects of LPL on fat accumulation. Respiratory quotients and uptake of [3H] triolein by tissues (white and brown adipose tissue, and skeletal muscles) did not differ significantly for transgenic and non-transgenic mice. The mRNA levels of hormone-sensitive lipase (HSL) and HSL activity in adipose tissue during feeding were higher in LPL transgenic mice than in controls. Results suggest that the overexpression of LPL does not induce obesity by enhancing the hydrolysis of triglycerides in adipose tissue.

Topics: Adipose Tissue; Adipose Tissue, Brown; Animals; Blotting, Northern; Body Composition; Body Weight; Humans; Lipoprotein Lipase; Mice; Mice, Transgenic; Muscle, Skeletal; Oxygen Consumption; Recombinant Proteins; RNA, Messenger; Sterol Esterase; Triolein

Lymphatic transport of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids given as trieicosapentaenoyl glycerol (TriEPA) and tridocosahexaenoyl glycerol (TriDHA) was compared with that of ethyl ester and free acid in rats cannulated with thoracic duct. Trioleoylglycerol (TO) served as a control. EPA and DHA, compared with oleic acid, were slowly transported in lymph irrespective of fat types administered. Total 24-h recovery of DHA in all fat types and ethyl EPA was significantly lower compared to that of oleic acid. Lymphatic recovery of EPA and DHA in rats given TriEPA and TriDHA was significantly higher at the first 3 h after the administration compared to those given as free acid or ethyl ester. The recovery in rats given free acid at a later stage (9-24 h) was higher than that of the other fat types. As a result, the 24-h recovery was comparable between triacylglycerol (TAG) and free acid, while it was significantly lower in ethyl ester. Although TriEPA and TriDHA were slowly hydrolyzed by pancreatic lipase in vitro compared with TO and TAGs rich in EPA or DHA at the second position, the hydrolysis rate at 60 min incubation was comparable among the TAGs examined. The hydrolysis rate of ethyl esters was extremely low even in 6 h incubation with lipase. These observations show that presence of EPA and DHA at the 1- and 3-positions of TAGs does not result in their lower recovery in lymph. Processes after lipolysis may be responsible for their low recovery in lymph. In a separate study, slower lymphatic recovery of DHA given as free acid than TriDHA was improved by the simultaneous administration of TO, but not by free oleic acid. The observations suggest that the slow recovery of free acid is caused by delayed TAG synthesis in mucosal cells and/or low micellar solubility of fatty acids in the intestinal lumen due to a limited supply of 2-monoacylglycerol (MAG). A large portion of EPA and DHA were recovered in lymph chylomicrons and very low density lipoproteins (VLDL, > 95%) and incorporated into TAG (84-92%) fraction in all fat types examined. Lymphatic recovery rate of simultaneously administered cholesterol was influenced by the fat types given.

Topics: Animals; Body Weight; Chylomicrons; Docosahexaenoic Acids; Eicosapentaenoic Acid; Esters; Intestinal Absorption; Lipase; Lymph; Lymphatic System; Oleic Acid; Oleic Acids; Phospholipids; Rats; Triglycerides; Triolein

Refeeding a chow meal containing [1-14C]triolein to food-restricted rats results in increased accumulation of [14C]lipid in carcass and epididymal adipose tissue and lower oxidation to [14C]CO2 compared to ad libitum-fed rats (Biochem. J. 285, 773-778, 1992). In the present experiments the effects of treatment with triiodothyronine (T3) for three days on lipid accumulation in refed food-restricted rats has been examined. T3 decreased accumulation of [14C]lipid in carcass and epididymal adipose tissue (32 and 77%, respectively) of food-restricted rats on refeeding the chow-[1-14C]triolein meal. This decreased accumulation of [14C]lipid was accompanied by increased [14C]CO2 production (77%) and decreased heparin-elutable lipoprotein lipase activity in the epididymal fat pad (90%) and subcutaneous adipose tissue (80%). Accumulation of [14C]lipid in the latter did not decrease significantly. In contrast, T3 treatment of ad libitum-fed rats increased [14C]lipid deposition in carcass (44%) and in subcutaneous adipose tissue (240%) on refeeding, when compared to untreated ad libitum rats. Lipoprotein lipase activity in the two adipose tissue depots of the refed ad libitum+T3 rats, however, decreased. Thus, the effects of T3 on [14C]lipid deposition are adipose-tissue-depot-specific and depend on the previous dietary intake (over 14 days) of the rat. T3-treatment increased the lipoprotein lipase activity released from perfused hearts to a similar extent in both food-restricted and ad libitum-fed rats compared to the corresponding untreated groups. The rates of lipogenesis in-vivo in liver, epididymal and subcutaneous adipose tissue of food-restricted rats refed chow were not altered by T3. It is concluded that the increased deposition of dietary lipid in the food-restricted rat can be partially reversed by treatment with T3, suggesting that the low-T3 state associated with this condition may be in part responsible.

Topics: Adipose Tissue; Animal Feed; Animals; Body Weight; Carbon Dioxide; Carbon Radioisotopes; Diet; Fatty Acids; Hyperthyroidism; Lipoprotein Lipase; Male; Myocardium; Oxidation-Reduction; Rats; Rats, Wistar; Tissue Distribution; Triiodothyronine; Triolein; Tritium

Meal-fed (3 h) rats had a decreased food intake, body weight and carcass fat compared with rats fed ad libitum. On refeeding a chow meal containing [1-14C]triolein, the production of 14CO2 was lower (45%) and the accumulation of carcass [14C]lipid higher (37%) in the meal-fed rats. There was higher lipoprotein lipase activity and greater accumulation of [14C]lipid in the epididymal and subcutaneous adipose-tissue depots of the meal-fed rats. In contrast, heparin-releasable lipoprotein lipase was not increased in perfused hearts of meal-fed rats on refeeding. Return of meal-fed rats to feeding ad libitum reversed these changes before the restoration of body weight or carcass fat. Evidence is presented that decreased dietary intake rather than meal pattern is an important determinant of the alterations in adipose lipid metabolism in the meal-fed rat in response to a meal.

Topics: Adipose Tissue; Animals; Body Weight; Carbon Dioxide; Dietary Fats; Eating; Food; Food Deprivation; Insulin; Lipid Metabolism; Lipoprotein Lipase; Male; Oxidation-Reduction; Rats; Rats, Inbred Strains; Triolein

Oxidation in vivo of [14C]triolein to 14CO2 was significantly lower in obese (fa/fa) Zucker rats as compared with their lean (+/?) controls. In response to a 24 h starvation period, both lean and obese rats showed an enhanced rate of [14C]triolein oxidation. There were, however, no changes in the rate of intestinal absorption of [14C]triolein between the lean and obese animals. Conversely, the total tissular [14C]lipid accumulation was significantly higher in white adipose tissue, carcass and plasma in the obese animals, whereas that of brown adipose tissue was lower. This was associated with a marked hyperinsulinaemia and hypertriglyceridaemia in the fa/fa animals. Starvation dramatically decreased [14C]lipid accumulation in white adipose tissue of the lean Zucker rats, but had no effect in the obese rats. The lipogenic rate of the obese rats was significantly higher than that of lean rats in liver, white adipose tissue, skeletal muscle and carcass. Lipoprotein lipase activity (per g of tissue) was significantly lower in both white and brown adipose tissue of obese versus lean rats; however, total activity was higher in both tissues. Starvation significantly lowered perigenital-adipose-tissue lipoprotein lipase activity in the lean groups, and had no effect in the obese ones. These results demonstrate that the tissue capacity of exogenous lipid uptake is involved, but cannot be the only factor influencing the maintenance of obesity in these animals. Thus, in the adult fa/fa rat, the large increase in obesity is not solely dependent on a deviation of energy-producing substrate metabolism towards the storage of lipids in white fat. Other factors, such as a low rate of oxidation, a high lipogenic rate and decreased brown-adipose-tissue activity are involved in the perseverance of the obesity syndrome.

Topics: Animals; Body Weight; Fatty Acids, Nonesterified; Feeding Behavior; Glycerol; Insulin; Lipid Metabolism; Lipoprotein Lipase; Male; Obesity; Oxidation-Reduction; Rats; Rats, Zucker; Triglycerides; Triolein

The concentration of ethyl esters of fatty acids as well as the activity of the enzyme synthesizing these esters (fatty acid ethyl ester synthase) were determined in adipose tissue of rats ingesting ethanol (9-16 g/kg body weight/day) for different periods of time. After 10 and 17 weeks of ethanol exposure about 300 nmol of ethyl esters of oleic, palmitic, stearic, and linoleic acids were found per gram adipose tissue. The ethyl esters disappeared after 1 week of abstinence. Closer analyses, using radioactive ethanol, revealed a half-life of the esters of less than 24 hr. The bulk of the esters was found in a membrane preparation of isolated adipocytes. Hormone-sensitive lipase hydrolyzed emulsified ethyl oleate as efficiently as that of trioleoylglycerol, but in mixed ethyl oleate/trioleoyl glycerol particles the hydrolysis of ethyl oleate was slower, suggesting a decreased accessibility. Synthase activity was found in adipose tissue from rats not exposed to ethanol. It doubled after 10 and 17 weeks of ethanol and decreased with a half-life of at least a week after abstinence. It was concluded that ethyl esters of fatty acids are formed in rat adipose tissue as previously shown in other tissues. They seem to be stored mainly in membranous parts of the adipocytes. Synthase activity is induced by ethanol. The elevated activity has a longer half-life, and may be useful as an indicator of alcohol abuse.

Topics: Acyltransferases; Adipose Tissue; Alcoholism; Animals; Body Weight; Cell Membrane; Fatty Acids; Linoleic Acids; Male; Oleic Acids; Palmitic Acids; Rats; Rats, Inbred Strains; Stearic Acids; Triglycerides; Triolein

To confirm the hypotriglyceridemic effect of aluminum (Al), male weanling and adult Wistar rats were fed sucrose diets with the addition of aluminum hydroxide (Al(OH)3) or aluminum potassium sulfate (AlK(SO4)2) for 67 days. As in the foregoing report (C. Sugawara, N. Sugawara, H. Kiyosawa, and H. Miyake, Fundam. Appl. Toxicol. 10, 607-615), no Al-induced anemia or hypophosphatemia was observed and serum Al did not exceed 20 ng/ml. Serum triglyceride (TG) was decreased by aluminum. Serum TG was significantly correlated with the serum nonesterified fatty acid (NEFA) concentration in both the Young groups (R = 0.757, n = 22, p less than 0.01) and the Adult groups (R = 0.727, n = 19, p less than 0.01). Neither serum cholesterol nor phospholipids was affected by Al ingestion. Aluminum caused a decrease in hepatic glycogen in all groups, but the decrease was significant only in Adult groups. Glycerol tri[9,10(n)-3H]oleate was administered by gastric tube into rats fed for 81 days with experimental diets. In all the Al-treated groups serum 3H was significantly greater than in control groups at 3 hr after intubation. At 24 hr after intubation, serum 3H did not differ between Control and Al-treated groups. Total 3H at 24 hr found in serum, liver, and epididymal adipose tissue was not changed significantly by Al feeding. These effects were observed without measurable increase of Al in the serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Alum Compounds; Aluminum; Aluminum Hydroxide; Animals; Body Weight; Diet; Lipids; Liver; Liver Glycogen; Male; Rats; Rats, Inbred Strains; Sucrose; Tissue Distribution; Triglycerides; Triolein

Rats were fed linoleic acid from a safflower oil emulsion or triolein-supplemented total parenteral nutrition solutions by continuous intragastric infusion for 7 and 14 d. Biochemical signs of essential fatty acid deficiency (EFAD) developed in rats supplemented with triolein compared with those receiving linoleic acid, and the relationship between hepatic cholesterol esterification and the distribution of free cholesterol in plasma lipoproteins was investigated in the EFAD and control animals. Results indicate that hepatic triglyceride (TG) and cholesterol ester content are greater and plasma levels of TG and cholesterol are lower in triolein-supplemented groups. Hepatic accumulation of cholesterol esters is associated with an increase in hepatic acyl-CoA:cholesterol acyltransferase activity and also with plasma very low density lipoprotein (VLDL) and high-density lipoprotein (HDL), which contain a greater proportion of cholesterol esters. These data suggest that EFAD can be rapidly induced with continuous intragastric feeding and that hepatic accumulation of cholesterol esters and enrichment of VLDL and HDL with cholesterol esters are early indicators of EFAD in the rat.

Topics: Acyl Coenzyme A; Acyltransferases; Animals; Body Weight; Cholesterol; Cholesterol Esters; Fatty Acids; Fatty Acids, Essential; Lipoproteins; Liver; Male; Organ Size; Rats; Rats, Inbred Strains; Triglycerides; Triolein

Obese and lean male Zucker rats were fed ad libitum on diets containing either 50 (L) or 200 (H) g/kg diet of either triolein (T) or sunflowerseed oil (S). The specific activity of the hepatic microsomal delta 9 desaturase enzyme was depressed in both lean and obese rats fed the HS diet compared with the other three diets. The fatty acid composition of liver and subcutaneous white adipose tissue lipids were consistent with a lower delta 9 desaturation activity in rats fed the H diets, particularly for the HS diet. In both genotypes, microsomal delta 9 desaturase activity and the ratio of 16:1/(16:0 + 16:1) fatty acids in liver lipids were inversely related to the proportion of 18:2 in liver lipid. Plasma insulin concentrations and rates of glucose-stimulated insulin release in vivo were higher in obese rats compared with lean rats, and plasma insulin levels were higher in rats fed S compared with T. There was no relationship between delta 9 desaturase activity and either plasma insulin concentration or rates of insulin release in vitro. These findings suggest that hepatic delta 9 desaturase activity of Zucker rats is responsive to changes in the proportion of 18:2 in liver lipids but is not affected by changes in insulin secretion.

Topics: Animals; Body Weight; Dietary Fats; Fatty Acid Desaturases; Insulin; Insulin Secretion; Lipid Metabolism; Liver; Male; Microsomes, Liver; Oils; Organ Size; Plant Oils; Rats; Rats, Zucker; Sunflower Oil; Triolein

The aim of the present study was to evaluate whether treatment with ursodeoxycholic acid (UDCA) may affect the absorption of dietary fat in man. Fifteen healthy subjects volunteered for the study. They were treated with UDCA in a daily dose of 15 mg/kg body weight for 4 weeks. Before and during treatment fat absorption was measured with a 14C-triolein breath test. In addition, fasting serum bile acids were measured in 11 of the subjects. The maximum specific activity of 14CO2 was not significantly changed during the treatment period. However, the cumulative output of 14CO2 during a 6-h period was decreased by about 25% (p less than 0.03). Several subjects with decreased outputs also lost 1-2 kg of body weight during the study period. UDCA treatment raised the serum level of this bile acid from 0.18 +/- 0.11 mumol/l to 5.98 +/- 1.08 mumol/l. The concentrations of the other bile acids were not significantly changed. It is suggested that UDCA treatment may in some patients be associated with an impaired fat absorption. Whether this effect is of any clinical importance remains to be elucidated.

Topics: Adult; Bile Acids and Salts; Body Weight; Breath Tests; Deoxycholic Acid; Dietary Fats; Female; Humans; Intestinal Absorption; Lipids; Liver; Male; Triglycerides; Triolein; Ursodeoxycholic Acid

1. The pharmacokinetics of [14C]carbaryl administered intravenously and orally were studied in male rats whose reticuloendothelial system (RES) was inhibited by colloidal carbon or activated by glyceryl trioleate. 2. A time course for [14C]carbaryl blood concn. was fitted to a two-compartment open model following single intravenous administration. A single exponential decay was noted following intragastric administration. 3. The constant blood elimination of [14C]carbaryl decreased significantly in animals with the RES inhibited and increased in those whose RES was activated compared to control animals. 4. There was an increase in carbaryl concn. in the tissue compartment in animals with the RES activated, but no change in animals with the RES inhibited. 5. The equivalent [14C]carbaryl concn. of liver and lungs were decreased or increased in animals with the RES inhibited or activated respectively.

Topics: Animals; Body Weight; Carbaryl; Carbon; Kinetics; Liver; Lung; Male; Mononuclear Phagocyte System; Organ Size; Phagocytosis; Rats; Spleen; Triolein

1. The effect of oven-drying on the heat of combustion of rat carcasses was studied and found to produce losses of 10% of the original energy content. Oven-drying also produced a small loss of nitrogen. 2. A method of carcass preparation not involving oven-drying was tested and found to produce suitably homogeneous samples for analysis without any loss of energy.

Topics: Animals; Body Composition; Body Weight; Calorimetry; Diet; Energy Metabolism; Evaluation Studies as Topic; Freeze Drying; Hot Temperature; Nitrogen; Rats; Thermodynamics; Triolein

Topics: Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Body Weight; Carbon Radioisotopes; Dietary Fats; Dietary Proteins; Female; Fetus; Gastric Mucosa; Guinea Pigs; Intestinal Absorption; Intestinal Mucosa; Intestines; Jejunum; Lipid Metabolism; Oleic Acids; Organ Size; Pregnancy; Protein Deficiency; Reproduction; Triolein

Topics: Animals; Autoanalysis; Body Weight; Ethyl Ethers; Injections, Intraperitoneal; Liver; Male; Methods; Organ Size; Pentobarbital; Phospholipids; Propylene Glycols; Rats; Rats, Inbred Strains; Spectrometry, Fluorescence; Time Factors; Triglycerides; Triolein

Topics: Blood Cell Count; Body Weight; Digestion; Gastrectomy; Glucose Tolerance Test; Humans; Intestinal Absorption; Intestines; Iodine Radioisotopes; Oleic Acids; Serum Albumin; Serum Albumin, Radio-Iodinated; Triolein; Vitamin B 12; Xylose

Topics: Animals; Body Weight; Carbon Isotopes; Dogs; Intestinal Absorption; Intestine, Small; Nutrition Disorders; Oleic Acids; Postoperative Complications; Time Factors; Triolein

Topics: Body Weight; Celiac Disease; Humans; Hyperthyroidism; Iodine Isotopes; Oleic Acids; Triolein

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Weight; Bone and Bones; Calcium; Diet; Dietary Fats; Digestion; Feces; Feeding Behavior; Femur; Magnesium; Male; Palmitic Acids; Phosphorus; Rats; Stearic Acids; Triglycerides; Triolein

Topics: Acetates; Animals; Body Weight; Carbon Dioxide; Carbon Isotopes; Cocos; Diet; Dietary Fats; Fasting; Fatty Acids; Fatty Acids, Essential; Linoleic Acids; Lipids; Liver; Male; Mice; Mineral Oil; Oils; Oleic Acids; Time Factors; Triglycerides; Triolein; Zea mays

Topics: Animals; Body Weight; Cobalt Isotopes; Fats; Feces; Intestinal Absorption; Iodine Isotopes; Rabbits; Radiation Effects; Transaminases; Triolein

Topics: Animals; Body Weight; Dogs; Fats; Humans; Intestinal Absorption; Iodine Radioisotopes; Liver Cirrhosis; Nitrogen; Portacaval Shunt, Surgical; Proteins; Radiometry; Rats; Serum Albumin, Radio-Iodinated; Triolein

Topics: Adipose Tissue; Animals; Body Weight; Carbon Isotopes; Carotenoids; Intestinal Absorption; Liver; Male; Oleic Acids; Organ Size; Rats; Surface-Active Agents; Triolein; Vitamin A

Topics: Animals; Animals, Newborn; Body Weight; Dogs; Female; Gastrectomy; Growth; Lipid Metabolism; Nutritional Physiological Phenomena; Nutritional Sciences; Nutritional Status; Peptic Ulcer; Research; Triolein; Vagotomy

Topics: Alkaline Phosphatase; Blood; Body Weight; Calcium Metabolism Disorders; Calcium, Dietary; Celiac Disease; Creatine; Creatinine; Feces; Gastrectomy; Humans; Malabsorption Syndromes; Osteoporosis; Peptic Ulcer; Postgastrectomy Syndromes; Triolein; Urine

Topics: Body Weight; Caloric Restriction; Creatine; Creatinine; Dietary Fats; Feces; Iodine Isotopes; Lipid Metabolism; Metabolism; Minerals; Nitrogen; Proteins; Rats; Research; Triolein; Urine