dinoprost and Hyperglycemia

Topics: Biomarkers; Diabetes Mellitus; Diabetic Angiopathies; Diabetic Neuropathies; Dinoprost; Electron Transport; Endothelial Cells; Glycation End Products, Advanced; Humans; Hyperglycemia; Mitochondria; NADPH Oxidases; Oxidative Stress; Polymers; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Superoxides

Long-term vascular complications still represent the main cause of morbidity and mortality in diabetic patients. Although randomized long-term clinical studies comparing the effects of conventional and intensive therapy have demonstrated a clear link between hyperglycemia and the development of complications of diabetes, they have not defined the mechanism through which excess glucose results in tissue damage. Evidence has accumulated indicating that oxidative stress may play a key role in the etiology of diabetic complications. Isoprostanes are emerging as a new class of biologically active products of arachidonic acid metabolism of potential relevance to human vascular disease. Their formation in vivo seems to reflect primarily, if not exclusively, a nonenzymatic process of lipid peroxidation. Enhanced urinary excretion of 8-iso-PGF(2alpha) has been described in association with both type 1 and type 2 diabetes mellitus, and correlates with impaired glycemic control. Besides providing a likely noninvasive index of lipid peroxidation in this setting, measurements of specific F(2) isoprostanes in urine may provide a sensitive biochemical end point for dose-finding studies of natural and synthetic inhibitors of lipid peroxidation. Although the biological effects of 8-iso-PGF(2alpha) in vitro suggest that it and other isoeicosanoids may modulate the functional consequences of lipid peroxidation in diabetes, evidence that this is likely in vivo remains inadequate at this time.

Topics: Animals; Antioxidants; Arachidonic Acids; Arteriosclerosis; Biomarkers; Coronary Disease; Diabetes Complications; Diabetes Mellitus; Dietary Supplements; Dinoprost; F2-Isoprostanes; Humans; Hyperglycemia; Lipid Peroxidation; Oxidative Stress; Protein Isoforms; Vitamin E

To investigate the effect of initial insulin dosage on blood glucose (BG) dynamics, β-cell protection, and oxidative stress in type 1 diabetes mellitus.. Sixty newly diagnosed type 1 diabetes mellitus patients were randomly assigned to continuous subcutaneous insulin infusions of 0.6 ± 0.2 IU/kg/d (group 1), 1.0 ± 0.2 IU/kg/d (group 2), or 1.4 ± 0.2 IU/kg/d (group 3) for 3 wk. BG was monitored continuously for the first 10 d and the last 2 d of wk 2 and 3. A total of 24-hour urinary 8-iso-PGF2α was assayed on days 8, 9, and 10. The occurrence and duration of the honeymoon period were recorded. Fasting C-peptide and glycosylated hemoglobin (HbA1c) were assayed after 1, 6, and 12 months of insulin treatment.. BG decreased to the target range by the end of wk 3 (group 1), wk 2 (group 2), or wk 1 (group 3). The actual insulin dosage over the 3 wk, frequency of hypoglycemia on wk 1 and 2, and median BG at the end of wk 1 differed significantly, but not 8-iso-PGF2α and the honeymoon period in the three groups. No severe hypoglycemia event was observed in any patient, but there was significant difference in the first occurrence of hypoglycemia.. Differences in initial insulin dosage produced different BG dynamics in wk 1, equivalent BG dynamics on wk 2 and 3, but had no influence on short- and long-term BG control and honeymoon phase. The wide range of initial insulin dosage could be chosen if guided by BG monitoring.

Topics: Biomarkers; Blood Glucose; C-Peptide; Child; Diabetes Mellitus, Type 1; Dinoprost; Dose-Response Relationship, Drug; Female; Follow-Up Studies; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Infusion Systems; Insulin Secretion; Insulin-Secreting Cells; Male; Monitoring, Ambulatory; Oxidative Stress

To test the effect of normoglycemia and glucagon-like peptide-1 (GLP-1), alone or in combination, on the possible normalization of endothelial function in type 1 diabetes.. Fifteen people with type 1 diabetes participated in three experiments: reaching and maintaining normoglycemia for 4h; reaching and maintaining hyperglycemia plus GLP-1 infusion for 4h; and reaching and maintaining normoglycemia for 4h with simultaneous infusion of GLP-1.. Both normoglycemia and GLP-1 infusion restored endothelial function and decreased and plasma 8-iso prostaglandin F2α levels. However, only the combination of normoglycemia and GLP-1 was able to normalize endothelial function.. This study confirms that long-lasting hyperglycemia in type 1 diabetes induces a permanent alteration which contributes to maintaining endothelial dysfunction even when glycemia is normalized, and that in the presence of normoglycemia, GLP-1 can contribute to normalizing endothelial function.

Topics: Adult; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 1; Dinoprost; Endothelium, Vascular; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Infusions, Parenteral; Male; Oxidative Stress; Vascular Diseases; Young Adult

Hypoglycemia produces thrombosis activation, but little attention has been paid to the effects of hyperglycemia following recovery from hypoglycemia on thrombosis activation.. In both twenty-two healthy subjects and twenty-one matched persons with type 1 diabetes, recovery from a 2-h induced hypoglycemia was obtained by reaching normo-glycemia or hyperglycemia for another 2 h. After this, normal glycemia was maintained for the following 6 h. Hyperglycemia after hypoglycemia was also repeated with the concomitant infusion of vitamin C. In both controls and people with diabetes, the recovery with normo-glycemia was accompanied by a significant improvement of Von Willebrand factor (vWF), prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin III-complexes (TAT), P-selectin, plasminogen activator inhibitor-1 (PAI-1), nitrotyrosine and 8-iso-prostaglandin F2α (8-iso-PGF2α) (p < 0.01 vs hypoglycemia for all the parameters), all directly affected by hypoglycemia itself (p < 0.01 vs baseline for all the parameters). On the contrary, the recovery with hyperglycemia after hypoglycemia worsens all these parameters (p < 0.01 vs normoglycemia for all the parameters), an effect persisting even after the additional 6 h of normo-glycemia. The effect of hyperglycemia following hypoglycemia was partially counterbalanced when vitamin C was infused (p < 0.01 vs hyperglycemia alone for all the parameters), suggesting that hyperglycemia following hypoglycemia may activate thrombosis through the oxidative stress production.. This study shows that, in type 1 diabetes as well as in controls, the way in which recovery from hypoglycemia takes place could play an important role in favoring the activation of thrombosis and oxidative stress, widely recognized cardiovascular risk factors.

Topics: Adult; Antithrombin III; Ascorbic Acid; Blood Glucose; Diabetes Mellitus, Type 1; Dinoprost; Endothelium, Vascular; Female; Healthy Volunteers; Humans; Hyperglycemia; Hypoglycemia; Male; Oxidative Stress; P-Selectin; Peptide Fragments; Peptide Hydrolases; Plasminogen Activator Inhibitor 1; Protein Precursors; Prothrombin; Thrombosis; von Willebrand Factor; Young Adult

To test the hypothesis that the simultaneous administration of GLP-1 and insulin may increase their vasodilatory, antiinflammatory, and antioxidant action in type 2 diabetes.. In two groups of persons with type 2 diabetes, two sets of experiments were performed. The first group had two normoglycemic-normoinsulinemic clamps with or without GLP-1 and two normoglycemic-hyperinsulinemic clamps with or without GLP-1. The second group had two hyperglycemic-normoinsulinemic clamps and two hyperglycemic-hyperinsulinemic clamps with or without GLP-1.. During the normoglycemic-hyperinsulinemic clamp, flow-mediated dilatation (FMD) increased, while soluble intercellular adhesion molecule (sICAM-1), plasma 8-iso-prostaglandin F2α (8-iso-PGF2α), nitrotyrosine, and interleukin (IL)-6 decreased compared with normoglycemic-normoinsulinemic clamp. Similar results were obtained with the infusion of GLP-1 during the normoglycemic-normoinsulinemic clamp. The combination of hyperinsulinemia and GLP-1 in normoglycemia was accompanied by a further FMD increase and sICAM-1, 8-iso-PGF2α, nitrotyrosine, and IL-6 decrease. During the hyperglycemic-normoinsulinemic clamp, FMD significantly decreased, while sICAM-1, 8-iso-PGF2α, nitrotyrosine, and IL-6 significantly increased. When hyperglycemia was accompanied by hyperinsulinemia or by the simultaneous infusion of GLP-1, these phenomena were attenuated. The simultaneous presence of hyperinsulinemia and GLP-1 had an increased beneficial effect.. Our results show that the combination of insulin and GLP-1 is more effective than insulin or GLP-1 alone in improving endothelial dysfunction, inflammation, and oxidative stress in type 2 diabetes.

Topics: Anti-Inflammatory Agents; Antioxidants; Diabetes Mellitus, Type 2; Dinoprost; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hyperinsulinism; Hypoglycemic Agents; Insulin; Interleukin-6; Male; Middle Aged; Oxidative Stress; Vasodilator Agents

It has been reported that hyperglycemia following hypoglycemia produces an ischemia-reperfusion-like effect in type 1 diabetes. In this study the possibility that GLP-1 has a protective effect on this phenomenon has been tested.. 15 type 1 diabetic patients underwent to five experiments: a period of two hours of hypoglycemia followed by two hours of normo-glycemia or hyperglycemia with the concomitant infusion of GLP-1 or vitamin C or both. At baseline, after 2 and 4 hours, glycemia, plasma nitrotyrosine, plasma 8-iso prostaglandin F2alpha, sCAM-1a, IL-6 and flow mediated vasodilation were measured.. After 2 h of hypoglycemia, flow mediated vasodilation significantly decreased, while sICAM-1, 8-iso-PGF2a, nitrotyrosine and IL-6 significantly increased. While recovering with normoglycemia was accompanied by a significant improvement of endothelial dysfunction, oxidative stress and inflammation, a period of hyperglycemia after hypoglycemia worsens all these parameters. These effects were counterbalanced by GLP-1 and better by vitamin C, while the simultaneous infusion of both almost completely abolished the effect of hyperglycemia post hypoglycemia.. This study shows that GLP-1 infusion, during induced hyperglycemia post hypoglycemia, reduces the generation of oxidative stress and inflammation, improving the endothelial dysfunction, in type 1 diabetes. Furthermore, the data support that vitamin C and GLP-1 may have an additive protective effect in such condition.

Topics: Adult; Antioxidants; Ascorbic Acid; Biomarkers; Blood Glucose; Diabetes Mellitus, Type 1; Dinoprost; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Inflammation; Inflammation Mediators; Infusions, Parenteral; Intercellular Adhesion Molecule-1; Interleukin-6; Male; Oxidative Stress; Reperfusion Injury; Time Factors; Treatment Outcome; Tyrosine; Vasodilation; Young Adult

Nitric oxide plays a pivotal role in regulating vascular tone. Different studies show endothelial function is impaired during hyperglycemia. Dark chocolate increases flow-mediated dilation in healthy and hypertensive subjects with and without glucose intolerance; however, the effect of pretreatment with dark chocolate on endothelial function and other vascular responses to hyperglycemia has not been examined. Therefore, we aimed to investigate the effects of flavanol-rich dark chocolate administration on (1) flow-mediated dilation and wave reflections; (2) blood pressure, endothelin-1 and oxidative stress, before and after oral glucose tolerance test (OGTT). Twelve healthy volunteers (5 males, 28.2±2.7 years) randomly received either 100 g/d dark chocolate or flavanol-free white chocolate for 3 days. After 7 days washout period, volunteers were switched to the other treatment. Flow-mediated dilation, stiffness index, reflection index, peak-to-peak time, blood pressure, endothelin-1 and 8-iso-PGF(2α) were evaluated after each treatment phase and OGTT. Compared with white chocolate, dark chocolate ingestion improved flow-mediated dilation (P=0.03), wave reflections, endothelin-1 and 8-iso-PGF(2α) (P<0.05). After white chocolate ingestion, flow-mediated dilation was reduced after OGTT from 7.88±0.68 to 6.07±0.76 (P=0.027), 6.74±0.51 (P=0.046) at 1 and 2 h after the glucose load, respectively. Similarly, after white chocolate but not after dark chocolate, wave reflections, blood pressure, and endothelin-1 and 8-iso-PGF(2α) increased after OGTT. OGTT causes acute, transient impairment of endothelial function and oxidative stress, which is attenuated by flavanol-rich dark chocolate. These results suggest cocoa flavanols may contribute to vascular health by reducing the postprandial impairment of arterial function associated with the pathogenesis of atherosclerosis.

Topics: Acute Disease; Adult; Blood Pressure; Cacao; Dinoprost; Endothelin-1; Endothelium, Vascular; Female; Flavanones; Glucose Tolerance Test; Humans; Hyperglycemia; Insulin Resistance; Insulin-Secreting Cells; Male; Pulse Wave Analysis

Chronic hyperglycemia is a major contributor to in vivo platelet activation in diabetes mellitus.. To evaluate the effects of acarbose, an alpha-glucosidase inhibitor, on platelet activation and its determinants in newly diagnosed type 2 diabetic patients.. Forty-eight subjects (26 males, aged 61 +/- 8 years) with early type 2 diabetes (baseline hemoglobin A(1c) < or = 7% and no previous hypoglycemic treatment) were randomly assigned to acarbose up to 100 mg three times a day or placebo, and evaluated every 4 weeks for 20 weeks. The main outcome measures were urinary 11-dehydro-thromboxane (TX)B(2) (marker of in vivo platelet activation) and 8-iso-prostaglandin (PG)F(2alpha) (marker of in vivo lipid peroxidation) excretion rate, 2-h postprandial plasma glucose (PPG) after a test meal, and assessment of glucose fluctuations by mean amplitude of glycemic excursions (MAGE).. Baseline measurements revealed biochemical evidence of enhanced lipid peroxidation and platelet activation. As compared with the placebo group, patients treated with acarbose had statistically significant reductions in urinary 11-dehydro-TXB(2) and 8-iso-PGF(2alpha) excretion rate as early as after 8 weeks and at each subsequent time point (between-group P < 0.0001 at 12, 16 and 20 weeks), following earlier decreases in PPG and MAGE. Multiple regression analyses in the acarbose group revealed that PPG was the only significant predictor of 11-dehydro-TXB(2) urinary excretion rate (beta = 0.39, P = 0.002) and MAGE the only predictor of 8-iso-PGF(2alpha) urinary excretion rate (beta = 0.42, P = 0.001).. Postprandial hyperglycemia is associated with enhanced lipid peroxidation and platelet activation in early type 2 diabetes. A moderate decrease in PPG achieved with acarbose causes time-dependent downregulation of these phenomena, suggesting a causal link between early metabolic abnormalities and platelet activation in this setting.

Topics: Acarbose; Aged; Arginine; Biomarkers; Blood Glucose; C-Reactive Protein; CD40 Ligand; Diabetes Mellitus, Type 2; Dinoprost; Double-Blind Method; Enzyme Inhibitors; Female; Glycated Hemoglobin; Glycoside Hydrolase Inhibitors; Humans; Hyperglycemia; Hypoglycemic Agents; Italy; Lipid Peroxidation; Male; Middle Aged; P-Selectin; Platelet Activation; Postprandial Period; Thromboxane B2; Time Factors; Treatment Outcome

Serum carotenoids are commonly used as biomarkers of fruit and vegetable (F/V) intake in the general population. Although hyperglycemia induces oxidative stress, it is unknown whether this pathway is associated with lower serum carotenoid concentrations in individuals with type 1 diabetes. Consequently, the utility of serum carotenoids as markers of F/V intake in individuals with type 1 diabetes is unclear.. The study objectives were: 1) to investigate the relationship of glycemic control, oxidative stress, dietary carotenoid and F/V intake with serum carotenoid concentrations in youth with type 1 diabetes and 2) to determine whether glycemic control or oxidative stress moderates the association of carotenoid and F/V intake with serum carotenoids.. The study participants were youth with type 1 diabetes (n=136; age range: 8 to 16.9 years; diabetes duration ≥1 year; glycated hemoglobin: 5.8% to 11.9%) enrolled in a nutrition intervention trial from 2010 to 2013 at a tertiary diabetes center in Boston, MA.. Serum carotenoids (total carotenoids and α-carotene, β-carotene, lycopene, β-cryptoxanthin, and lutein+zeaxanthin).. Regression analyses were used to estimate the association of glycemic control, oxidative stress, F/V and carotenoid intake with serum carotenoids, as well as the role of glycemic control and oxidative stress in moderating diet-serum carotenoid associations.. Greater F/V intake (β=0.35, P<0.001) and carotenoid intake (β=0.28, P<0.01) were associated with higher total serum carotenoids, and no moderation by glycemic control or oxidative stress was observed. Greater hyperglycemia, as indicated by lower 1,5-anhydroglucitol (β=0.27, P<0.01), was related to lower serum carotenoids; however, glycated hemoglobin was not associated with serum carotenoids. 8-Iso-prostaglandin F2α was not associated with glycemic control or serum carotenoids.. Findings support the validity of serum carotenoids as markers of F/V and carotenoid intake in youth with type 1 diabetes.

Topics: Adolescent; Biomarkers; Boston; Carotenoids; Child; Deoxyglucose; Diabetes Mellitus, Type 1; Diet Records; Dinoprost; Female; Fruit; Glycated Hemoglobin; Humans; Hyperglycemia; Male; Oxidative Stress; Regression Analysis; Vegetables

Hypertension is a major cause of stroke, and diabetes can increase incidence of this disease. We determined the role played by central angiotensin-(1-7) [Ang-(1-7)] pathway in modulating spontaneously hypertension with diabetic hyperglycemia.. Western Blot analysis and ELISA were used to determine the protein expression of Ang-(1-7) and its signal pathway Mas-R-nNOS in the cerebral cortex and hippocampus of spontaneously hypertensive rats (SHR) and control animals. In a subset of animals, diabetic hyperglycemia was induced by systemic injection of streptozotocin (STZ). We analyzed a relationship between the levels of central Ang-(1-7) and plasma brain natriuretic peptide (BNP) indicating a risk of ischemic stroke. We further examined the effects of Ang-(1-7) on arterial blood pressure.. Our findings demonstrated for the first time that administration of STZ 1) attenuates the levels of Ang-(1-7) in the cerebral cortex and hippocampus, which are closely linked to plasma BNP; and 2) leads to downregulation of central Ang-(1-7)-Mas-R-nNOS pathways. Notably, STZ has greater effects in SHR. Additionally, inhibition of oxidative stress can largely improve downregulation of Ang-(1-7) in diabetic SHR. Moreover, central stimulation of Ang-(1-7) pathway or a blockade of oxidative stress improves systolic blood pressure in diabetic SHR.. The Ang-(1-7) signaling pathway is engaged in the adaptive mechanisms associated with diabetic hypertension, suggesting that enhancing Ang-(1-7)-Mas-R-nNOS system is likely to be beneficial in preventing against cardiovascular and cerebrovascular dysfunction and vulnerability related to spontaneously hypertension, particularly to diabetic hypertension.

Topics: Angiotensin I; Animals; Blood Pressure; Brain; Cyclic N-Oxides; Diabetes Mellitus, Experimental; Dinoprost; Heart Rate; Hyperglycemia; Natriuretic Peptide, Brain; Nitric Oxide Synthase Type I; Oxidative Stress; Peptide Fragments; Proto-Oncogene Mas; Proto-Oncogene Proteins; Rats, Inbred SHR; Rats, Inbred WKY; Receptors, G-Protein-Coupled; Signal Transduction; Spin Labels; Systole

Epidemiological evidence suggests that whole grain intake is associated with reduced risk of type 2 diabetes. However, studies of individual whole grains on the prevention of type 2 diabetes are lacking. The objective of the present study was to examine the effect of different whole grains on type 2 diabetes in an animal model of type 2 diabetes, the Goto-Kakisaki (GK) rat. GK rats were fed either a basal diet or a whole grain-containing diet for 5 months. Whole grain diets contained 65 % whole grain flours of wheat, barley, oats or maize. After 2 months of feeding, fasting plasma glucose concentrations were lower in the wheat, barley and oats groups, compared with the basal group, whereas glycated Hb was significantly greater in the wheat group compared with other groups. Feeding of whole barley and maize increased plasma C-peptide concentrations compared with whole wheat at 2 months. There was a trend in the improvement of insulin resistance with a consumption of barley and oats diets at 2 months (P = 0·06) compared with the basal diet. Oxidative stress markers, urinary thiobarbituric acid-reactive substances and 8-isoprostane, did not improve with whole grain intake at 2 months. At 5 months, whole grain diets did not differ from the basal diet in glycaemic control, insulin secretion, oxidative stress and preservation of pancreatic β-cell mass. These results suggest that the consumption of whole grains may offer modest benefit early in the development of type 2 diabetes, but this benefit is lost with further development of the disease.

Topics: Animals; Antioxidants; Biomarkers; C-Peptide; Diabetes Mellitus, Type 2; Dietary Fiber; Dinoprost; Disease Progression; Edible Grain; Food Handling; Functional Food; Glycated Hemoglobin; Hyperglycemia; Insulin Resistance; Insulin-Secreting Cells; Male; Oxidative Stress; Random Allocation; Rats; Rats, Mutant Strains; Rats, Wistar; Thiobarbituric Acid Reactive Substances

It is unknown whether glycaemic variability adds to the risk of microvascular complications of diabetes over and above the mean glucose value for a patient. We examined the effect of purposefully induced short-term glycaemic variability on oxidative stress markers. Eleven healthy subjects underwent three sequential glycaemic states; sustained hyperglycaemia, sustained euglycaemia and variable glycaemia, using glycaemic clamps for 3 h. Twenty-four hours urinary 8-isoprostane-PGF2α was measured before and after each glycaemic state to assess oxidative stress. The median and interquartile range of the urinary 8-iso-PGF2α in ng/24 h were (1373, 513), (996, 298) and (1227, 472) for the euglycaemic, hyperglycaemic and variable states, respectively. There was no significant difference in urinary isoprostanes between the three different states; mean ranks 20.9, 11.9 and 18.2 for the euglycaemic state, hyperglycaemic state and glycaemic variability state, respectively, p = 0.083. In conclusion, we did not see a significant increase in the urinary isoprostanes when glycaemic variability was induced under controlled conditions in healthy individuals.

Topics: Adult; Biomarkers; Blood Glucose; Dinoprost; Female; Humans; Hyperglycemia; Male; Oxidative Stress; Time Factors

Because pharmacotherapies in type 2 diabetes exert complex effects, we examined the different anti-diabetic strategies, especially the influence of insulin doses, on the activation of oxidative stress, a key player in atherosclerosis, ageing and the risk of cancer.. This observational study included 122 persons with type 2 diabetes, 61 treated with oral hypoglycaemic agents alone (group I), 61 treated with a combination of oral hypoglycaemic agents and insulin at either a low dose (<0.40 unit/kg/day, group IIa, n = 30) or high dose (≥0.40 unit/kg/day, group IIb, n = 31) of insulin. Oxidative stress was estimated from 24-h urinary excretion rates of 8-iso-prostaglandin F2α. Haemoglobin A(1c) (%) was also measured to assess overall diabetic control.. The 24-h excretion rates of 8-iso-prostaglandin F2α [median (range) pmol/mmol of creatinine] were much lower in group IIa [68 (32-220)] than in either group I [120 (26-329) p < 0.001] or group IIb [101 (30-289) p = 0.026]. Considering groups IIa and IIb as a whole, a significant and positive relationship (p = 0.021) was observed between insulin dose and 8-iso-prostaglandin F2α. Haemoglobin A(1c) was comparable in the three groups.. The main benefit of insulin therapy is the restoration and maintenance of near normal glycaemia. However insulin at elevated doses can promote oxidative stress which is thought to be an important mediator of some of the deleterious effects of insulin. Our study shows that the link between insulin action and oxidative stress in type 2 diabetes is complex and warrants further study.

Topics: Aged; Body Mass Index; Caloric Restriction; Diabetes Mellitus, Type 2; Dinoprost; Dose-Response Relationship, Drug; Drug Therapy, Combination; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Oxidative Stress; Reproducibility of Results; Thiazolidinediones

Oxidative stress plays a leading role in the progression of diabetic secondary complications, e.g., of cardio-vascular illnesses. Physical activity has been shown to delay and even prevent the progression of type 2 diabetes by improving the antioxidative capacity and thereby decreasing systemic oxidative stress. Peroxiredoxins (PRDX) are important antioxidative components that are highly abundant in erythrocytes. The present study examines the influence of glycemic control and physical fitness on oxidative stress and the peroxiredoxin system in the erythrocytes of non-insulin-dependent type 2 diabetic men ( N=22, years=61 ± 10) at rest. Oxidative stress was measured by immunohistochemical stainings for 8-iso-prostaglandin-F2α (8-Iso-PGF) and the overoxidized form of peroxiredoxins (PRDX-SO (2-3)). Peroxiredoxin isoforms PRDX1 and PRDX2 were also quantified immunohistochemically. Physical fitness was determined during the WHO-step test. Regression analyses showed a positive relationship between 8-Iso-PGF plotted against HbA (1c) (hyperbolic curve (y=a+b/x), R (2)=0.346, P=0.013), a positive relationship between 8-Iso-PGF plotted against fasting glucose (hyperbolic curve (y=a+b/x), R (2)=0.440, P=0.003), as well as positive relationships between PRDX2 plotted against VO (2 peak) (S-curve (y=e(a+b/x)), R(2)=0.259, P=0.018) and between PRDX2 plotted against the workload corresponding to the 4 mmol/l blood lactate concentration (hyperbolic curve (y=a+b/x), R(2)=0.203, P=0.041). Further significant relationships were not found.. Poor glycemic control may increase oxidative stress in the erythrocytes of type 2 diabetic men. Good physical fitness seems to be associated with increased peroxiredoxin contents. Therefore, it can be speculated that physical training can contribute to the improvement of the erythrocyte peroxiredoxin system to counteract free radicals in type 2 diabetic patients.

Topics: Aged; Body Mass Index; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Dinoprost; Erythrocytes; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Lipid Peroxidation; Male; Middle Aged; Overweight; Oxidation-Reduction; Oxidative Stress; Peroxiredoxins; Physical Fitness

We examined whether type of diabetes and/or insulin treatment can modulate the impact of sustained hyperglycaemia and glycaemic variability as activators of oxidative stress.. This was an observational study in 139 patients with diabetes, 48 with type 1, 60 with type 2 treated by oral hypoglycaemic agents (OHAs) alone and 31 with type 2 treated with insulin plus OHAs. In addition, two groups of ten patients with type 2 diabetes were investigated either before and after introducing insulin treatment (add-on insulin group) or before and after add-on OHA therapy to metformin (add-on OHA group). Oxidative stress was estimated from 24 h urinary excretion rates of 8-isoprostaglandin F2alpha (8-iso-PGF2alpha). HbA(1c) was assessed and mean amplitude of glycaemic excursions (MAGE) was estimated by continuous monitoring.. The 24 h excretion rate of 8-iso-PGF2alpha (median [range] picomoles per millimole of creatinine) was much higher (p < 0.0001) in type 2 diabetes patients treated with OHAs alone (112 [26-329]) than in the type 1 diabetes group (65 [29-193]) and the type 2 diabetes group treated with insulin (69 [30-198]). It was associated with HbA(1c) (F = 12.9, p = 0.0008) and MAGE (F = 7.7, p = 0.008) in non-insulin-treated, but not in insulin-treated patients. A significant reduction in 24 h excretion rate of 8-iso-PGF2alpha from 126 (47-248) to 62 (35-111] pmol/mmol of creatinine was observed in the add-on insulin group (p = 0.005) but not in the add-on OHA group.. In type 1 and type 2 diabetes, insulin exerts an inhibitory effect on oxidative stress, a metabolic disorder that is significantly activated by sustained hyperglycaemia and glucose variability in non-insulin-treated type 2 diabetes.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dinoprost; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Insulin; Male; Middle Aged; Oxidative Stress

The effect of glucose excursions on oxidative stress is an important topic in diabetes research. We investigated this relationship by analyzing markers of oxidative stress and glycemic data from a continuous glucose monitoring system (CGMS) in 30 individuals with normal glucose regulation (NGR), 27 subjects with impaired glucose regulation (IGR), and 27 patients with newly diagnosed type 2 diabetes (T2DM). We compared the mean amplitude of glycemic excursion (MAGE), mean postprandial glucose excursion (MPPGE), and mean postprandial incremental area under the curve (IAUC) with plasma levels of oxidative stress markers 8-iso-PGF2α, 8-OH-dG, and protein carbonyl content in the study subjects. Patients with T2DM or IGR had significantly higher glucose excursions and plasma levels of oxidative stress markers compared to normal controls (P < 0.01 or 0.05). Multiple linear regression analyses showed significant relationships between MAGE and plasma 8-iso-PGF2α, and between MPPGE and plasma 8-OH-dG in patients with IGR or T2DM (P < 0.01 or 0.05). Furthermore, 2h-postprandial glucose level and IAUC were related to plasma protein carbonyl content in the study cohort including T2DM and IGR (P < 0.01). We demonstrate that glucose excursions in subjects with IGR and T2DM trigger the activation of oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Biomarkers; Blood Glucose; Cohort Studies; Deoxyguanosine; Diabetes Complications; Diabetes Mellitus, Type 2; Dinoprost; Female; Glucose Intolerance; Humans; Hyperglycemia; Hypoglycemia; Male; Middle Aged; Monitoring, Ambulatory; Oxidative Stress; Postprandial Period; Protein Carbonylation

Regulation of coronary function in diabetic hearts is an important component in preventing ischemic cardiac events but remains poorly studied. Exercise is recommended in the management of diabetes, but its effects on diabetic coronary function are relatively unknown. We investigated coronary artery myogenic tone and endothelial function, essential elements in maintaining vascular fluid dynamics in the myocardium. We hypothesized that exercise reduces pressure-induced myogenic constriction of coronary arteries while improving endothelial function in db/db mice, a model of type 2 diabetes. We used pressurized mouse coronary arteries isolated from hearts of control and db/db mice that were sedentary or exercised for 1 h/day on a motorized exercise-wheel system (set at 5.2 m/day, 5 days/wk). Exercise caused a approximately 10% weight loss in db/db mice and decreased whole body oxidative stress, as measured by plasma 8-isoprostane levels, but failed to improve hyperglycemia or plasma insulin levels. Exercise did not alter myogenic regulation of arterial diameter stimulated by increased transmural pressure, nor did it alter smooth muscle responses to U-46619 (a thromboxane agonist) or sodium nitroprusside (an endothelium-independent dilator). Moderate levels of exercise restored ACh-simulated, endothelium-dependent coronary artery vasodilation in db/db mice and increased expression of Mn SOD and decreased nitrotyrosine levels in hearts of db/db mice. We conclude that the vascular benefits of moderate levels of exercise were independent of changes in myogenic tone or hyperglycemic status and primarily involved increased nitric oxide bioavailability in the coronary microcirculation.

Topics: Animals; Blood Glucose; Body Weight; Coronary Circulation; Coronary Vessels; Diabetes Mellitus, Type 2; Dinoprost; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelium, Vascular; Exercise Therapy; Hyperglycemia; Insulin; Mice; Microcirculation; Nitric Oxide; Oxidative Stress; Vasoconstriction; Vasoconstrictor Agents; Vasodilation; Vasodilator Agents

Glycemic disorders, one of the main risk factors for cardiovascular disease, are associated with activation of oxidative stress.. To assess the respective contributions of sustained chronic hyperglycemia and of acute glucose fluctuations to oxidative stress in type 2 diabetes.. Case-control study of 21 patients with type 2 diabetes (studied 2003-2005) compared with 21 age- and sex-matched controls (studied in 2001) in Montpellier, France.. Oxidative stress, estimated from 24-hour urinary excretion rates of free 8-iso prostaglandin F2alpha (8-iso PGF2alpha). Assessment of glucose fluctuations was obtained from continuous glucose monitoring system data by calculating the mean amplitude of glycemic excursions (MAGE). Postprandial contribution to glycemic instability was assessed by determining the postprandial increment of glucose level above preprandial values (mean postprandial incremental area under the curve [AUCpp]). Long-term exposure to glucose was estimated from hemoglobin A1c, from fasting glucose levels, and from mean glucose concentrations over a 24-hour period.. Mean (SD) urinary 8-iso PGF2alpha excretion rates were higher in the 21 patients with diabetes (482 [206] pg/mg of creatinine) compared with controls (275 [85] pg/mg of creatinine). In univariate analysis, only MAGE (r = 0.86; P<.001) and AUCpp (r = 0.55; P = .009) showed significant correlations with urinary 8-iso PGF2alpha excretion rates. Relationships between 8-iso PGF2alpha excretion rates and either MAGE or AUCpp remained significant after adjustment for the other markers of diabetic control in multiple linear regression analysis (multiple R2 = 0.72 for the model including MAGE and multiple R2 = 0.41 for the model including AUCpp). Standardized regression coefficients were 0.830 (P<.001) for MAGE and 0.700 (P = .003) for AUCpp.. Glucose fluctuations during postprandial periods and, more generally, during glucose swings exhibited a more specific triggering effect on oxidative stress than chronic sustained hyperglycemia. The present data suggest that interventional trials in type 2 diabetes should target not only hemoglobin A1c and mean glucose concentrations but also acute glucose swings.

Topics: Aged; Blood Glucose; Case-Control Studies; Chronic Disease; Diabetes Mellitus, Type 2; Dinoprost; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Linear Models; Male; Middle Aged; Oxidative Stress

Topics: Blood Glucose Self-Monitoring; Diabetes Complications; Diabetes Mellitus; Dinoprost; Glycated Hemoglobin; Humans; Hyperglycemia; Oxidative Stress

Heme oxygenase (HO-1) is a stress protein, which has been suggested to participate in defense mechanisms against glucose induced oxidative injury. The purpose of this study was to examine the role of human HO-1 in attenuating glucose-mediated oxidative stress. We investigated the effect of high ambient glucose (15, 33 and 66 mM) on HO-1 gene expression in endothelial cells grown in a serum deprived media compared to the effect of glucose on exponentially grown cells (10% FBS). High glucose at 15 and 33 mM caused significant inhibition of HO-1 protein and activity in G0/G1 and in cells exponentially grown. Glucose concentration at 66 mM caused a significant increase in HO-1. Addition of heme (10 microM) increased HO-1 protein and bilirubin formation in G0/G1, in a time dependent manner peaking at 16 h. Glucose attenuated heme mediated increase in HO-1 proteins. RT-PCR demonstrated that glucose decreased the levels of HO-1 mRNA in both G0/G1 or cells grown in 10% FBS. The rate of HO-1 induction in response to heme was several fold higher in serum-starved cells compared to cells cultured in 10% FBS. Cells exposed to high glucose for up to 24 h had a significant increase in cellular heme and potentiated heme-mediated increase in generation of superoxide anion and 8-epi-isoprostane PGF(2alpha). HO-1 gene transduction prevented glucose-mediated elevation of 8-epi-isoprostane PGF(2alpha). These results imply that expression of HO-1 in G0/G1 cells may be a key player in decreasing cellular heme, associated with increased generation of bilirubin, and in attenuating glucose mediated oxidative stress.

Topics: Cell Cycle; Cells, Cultured; Computer Systems; Culture Media, Serum-Free; Dinoprost; Endothelial Cells; G1 Phase; Glucose; Heme; Heme Oxygenase (Decyclizing); Humans; Hyperglycemia; Oxidative Stress; Resting Phase, Cell Cycle; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Superoxides

Heme oxygenase (HO)-1 represents a key defense mechanism against oxidative injury. Hyperglycemia produces oxidative stress and various perturbations of cell physiology. The effect of streptozotocin (STZ)-induced diabetes on aortic HO activity, heme content, the number of circulating endothelial cells, and urinary 8-epi-isoprostane PGF2alpha (8-Epi) levels in control rats and rats overexpressing or underexpressing HO-1 was measured. HO activity was decreased in hyperglycemic rats. Hyperglycemia increased urinary 8-Epi, and this increase was augmented in rats underexpressing HO-1 and diminished in rats overexpressing HO-1. The number of detached endothelial cells and O2- formation increased in diabetic rats and in hyperglycemic animals underexpressing HO-1 and decreased in diabetic animals overexpressing HO-1 compared with controls. These data demonstrate that HO-1 gene transfer in hyperglycemic rats brings about a reduction in O2- production and a decrease in endothelial cell sloughing. Upregulation of HO-1 decreases oxidant production and endothelial cell damage and shedding and may attenuate vascular complications in diabetes.

Topics: Animals; Aorta; Diabetes Mellitus, Experimental; Dinoprost; Endothelium, Vascular; Female; Gene Expression Regulation, Enzymologic; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Humans; Hyperglycemia; Immunohistochemistry; Male; Membrane Proteins; Organisms, Genetically Modified; Oxidative Stress; Pregnancy; Rats; Rats, Sprague-Dawley

The interaction between angiotensin-(1-7) [Ang-(1-7)] and bradykinin (BK) was studied in the isolated mesenteric arteriolar bed of control and diabetic rats perfused with either 5.5 or 22 mM of glucose. Prostanoids release after the administration of BK, Ang-(1-7) and Ang-(1-7)+BK was also studied. In control and diabetic preparations perfused with Krebs Henseleit solution with 5.5mM of glucose, Ang-(1-7) potentiates BK-induced vasodilation. On the other hand, the potentiating effect disappeared in control and diabetic preparations perfused with 22 mM of glucose. Prostaglandin F(2alpha) (PGF(2alpha)) release induced by BK and Ang-(1-7)+BK was increased in perfusates of diabetic preparations containing 22 mM of glucose. The release of thromboxane A(2) (TXA(2)) (measured as TXB(2)) or prostaglandin I(2) (PGI(2)) (measured as 6-keto-PGF(1alpha)) did not differ in control and diabetic preparations perfused with 5.5 and 22 mM of glucose. Our data allow us to suggest that hyperglycemia may be involved in the lack of potentiation in control and diabetic preparations; increase in PGF(2alpha) release, but not other cyclooxygenase products, may explain the absence of potentiation in diabetic preparations.

Topics: Angiotensins; Animals; Blood Glucose; Bradykinin; Dinoprost; Dinoprostone; Disease Models, Animal; Epoprostenol; Hyperglycemia; Male; Mesenteric Arteries; Prostaglandin-Endoperoxide Synthases; Protein Binding; Rats; Rats, Wistar; Thromboxane A2

Acute hyperglycemia in type 2 diabetes increases the generation of plasma 8-epi-prostaglandin F2 (8-epi-PGF2alpha) isoprostane, a sensitive direct marker of in vivo free radical oxidative damage to membrane phospholipids.. A total of 21 patients with type 2 diabetes underwent an oral 75-g glucose tolerance test. Plasma 8-epi-PGF2alpha isoprostane concentrations (by gas chromatography [GC]/mass spectrometry [MS]), intralymphocyte reduced-to-oxidized glutathione ratios, and plasma total antioxidant capacity were measured at baseline and 90 min after glucose loading.. Plasma 8-epi-PGF2alpha isoprostane concentrations rose significantly (P=0. 010) from 0.241 +/- 0.1 to 0.326 +/- 0.17 ng/l after 90 min. Intracellular oxidative balance and plasma antioxidant capacity did not change in either group.. Plasma concentrations of 8-epi-PGF2alpha isoprostane increase during acute hyperglycemia in type 2 diabetes, providing direct evidence of free radical-mediated oxidative damage and demonstrating a pathway for an association between acute rather than fasting hyperglycemia and macrovascular risk in type 2 diabetes.

Topics: Adult; Aged; Antioxidants; Blood Glucose; Cholesterol; Diabetes Mellitus, Type 2; Dinoprost; F2-Isoprostanes; Female; Free Radicals; Gas Chromatography-Mass Spectrometry; Glucose Tolerance Test; Glutathione; Glutathione Disulfide; Humans; Hyperglycemia; Lymphocytes; Male; Middle Aged

The aim of the present study was to investigate the effects of experimental diabetes and hyperglycaemia per se on the endothelium-dependent relaxation of isolated canine coronary arteries and to analyse the possible involvement of the cyclooxygenase pathway in the alterations induced by hyperglycaemia. Rings from the left anterior descending coronary arteries of 18 metabolically healthy, six alloxan-diabetic and six insulin-treated alloxan diabetic dogs were set up for isometric tension recording. Diabetic coronaries as well as healthy vessels subjected to in vitro hyperglycaemia (25.5 mmol L-1 glucose) showed impaired (P < 0.05) relaxation to acetylcholine (3 nmol L-1-10 micromol L-1) compared with normoglycaemic, i.e. metabolically healthy and insulin-treated diabetic controls, either before or after indomethacin (3 micromol L-1) administration. The maximal dilation elicited by acetylcholine was further decreased (P < 0.05) by the cyclooxygenase inhibitor in the diabetic coronaries only. Relaxation to sodium nitroprusside did not differ among groups. These results suggest that hyperglycaemia may result in impaired endothelium-dependent dilation of coronary arteries. Diminished relaxation of diabetic coronaries is worsened by the inhibition of the synthesis of vasodilator cyclooxygenase products.

Topics: Acetylcholine; Animals; Blood Glucose; Coronary Vessels; Cyclooxygenase Inhibitors; Diabetes Mellitus, Experimental; Dinoprost; Dogs; Endothelium, Vascular; Enzyme Inhibitors; Female; Hyperglycemia; In Vitro Techniques; Indomethacin; Male; Nitroarginine; Nitroprusside; Osmolar Concentration; Vasoconstriction; Vasodilation; Vasodilator Agents

We have concurrently investigated oxidant stress, glucose tolerance and glucose-stimulated insulin responses in the obese Zucker rat, a widely used model of insulin resistance. The plasma level of the lipid peroxidation product 8-epi-prostaglandin F2alpha, a sensitive in vivo marker of oxidant stress, was elevated approximately 5-fold in 13-week old obese relative to age-matched, insulin-sensitive lean Zucker rats. Supplementation of the diet with vitamin E (as (+)-alpha-tocopherol acetate, 0.5% w/w) for 4 weeks, reduced plasma 8-epi-prostaglandin F2alpha and concomitantly reversed glucose-stimulated hyperinsulinaemia in the obese Zucker rat without worsening glucose tolerance. We therefore provide evidence of oxidant stress, measured as elevated plasma 8-epi-prostaglandin F2alpha, for the first time in the obese Zucker rat which now provides a rationale for the beneficial effects of antioxidants on insulin action previously reported in this model of insulin resistance.

Topics: Animals; Blood Glucose; Body Weight; Dietary Supplements; Dinoprost; Hyperglycemia; Hyperinsulinism; Insulin; Insulin Resistance; Male; Obesity; Oxidative Stress; Rats; Rats, Zucker; Vitamin E

The relationship between high glucose concentrations and arachidonic acid metabolism in uterine tissue from control and diabetic ovariectomized rats was evaluated. Uterine tissue from diabetic rats produced amounts of PGE2 and PGF2 alpha similar to controls, while a lower production of 6-keto-PGF1 alpha (indicating the production of prostacyclin) and a higher production of TXB2 (indicating the generation of TXA2) was found in the diabetic group. A group of diabetic rats was treated with phlorizin to diminish plasma glucose levels. Phlorizin treatment did not alter production of PGE2, PGF2 alpha, and 6-keto-PGF1 alpha in the diabetic group. A diminished production of TXB2 was found in the treated diabetic uteri when compared to the non-treated diabetic group. Moreover, a positive correlation between plasma glucose levels and uterine TXB2 generation was observed. When control uterine tissue was exposed in vitro to high concentrations of glucose (22 mM) and compared to control tissue incubated in the presence of glucose 11 mM alterations in the generation of PGE2, PGF2 alpha, and 6-keto-PGF1 alpha were not found, but a higher production of TXB2 was observed and values were similar to those obtained in the diabetic tissue. Alteration in the production of the prostanoids evaluated were not observed when diabetic tissue was incubated in the presence of high concentrations of glucose. These results provide evidence of a direct relationship between plasma glucose levels and uterine production of TXA2.

Topics: Animals; Arachidonic Acid; Blood Glucose; Dinoprost; Dinoprostone; Female; Glucose; Hyperglycemia; In Vitro Techniques; Ovariectomy; Phlorhizin; Rats; Thromboxane A2; Thromboxane B2; Uterus

We investigated the effects of intraperitoneal administration of adrenoceptor antagonists to the hyperthermia and hyperglycemia induced by prostaglandin F2 alpha (50 micrograms) injected into the third cerebral ventricle in anesthetized rats. Phentolamine inhibited the hyperthermia and hyperglycemia induced by prostaglandin F2 alpha. Prazosin inhibited the hyperthermia induced by prostaglandin F2 alpha, while enhancing the hyperglycemia. Yohimbine inhibited the prostaglandin F2 alpha-induced hyperglycemia without an effect on the hyperthermia. Propranolol had no effect on either prostaglandin F2 alpha-induced hyperglycemia or hyperthermia. These observations suggest that the hyperglycemia induced by prostaglandin F2 alpha is regulated by alpha 2-adrenoceptor systems while the hyperthermia is regulated by alpha 1-adrenoceptor systems in rats.

Topics: Adrenergic alpha-Antagonists; Animals; Blood Glucose; Body Temperature; Dinoprost; Fever; Hyperglycemia; Injections, Intraperitoneal; Injections, Intraventricular; Male; Phentolamine; Prazosin; Propranolol; Rats; Rats, Wistar; Yohimbine

We studied the effects of the histamine H1 receptor antagonists diphenhydramine and pyrilamine, the H2 receptor antagonist ranitidine and the muscarinic receptor antagonist atropine injected into the third cerebral ventricle on prostaglandin F2 alpha (PGF2 alpha)-induced hyperglycemia in anesthetized fed rats. The concomitant injection of diphenhydramine (1 x 10(-8), 5 x 10(-8) mol) with 50 micrograms PGF2 alpha significantly suppressed the increase in hepatic plasma glucose concentrations induced by PGF2 alpha. The concomitant injection of 1 x 10(-8) mol pyrilamine with 50 micrograms PGF2 alpha did not suppress the above-mentioned parameter, while 5 x 10(-8) mol pyrilamine significantly suppressed it. Diphenhydramine suppressed the PGF2 alpha-induced hyperglycemia to a greater extent than did pyrilamine. In contrast, concomitant injection of the H2 receptor antagonist ranitidine (1 x 10(-8), 5 x 10(-8) mol) did not suppress the hyperglycemia induced by PGF2 alpha. The concomitant injection of 5 x 10(-8) mol diphenhydramine or pyrilamine with 50 micrograms PGF2 alpha significantly suppressed the increase in plasma epinephrine induced by PGF2 alpha, but the same dose of ranitidine had no effect. The concomitant injection of atropine (5 x 10(-8), 5 x 10(-7) mol) with 50 micrograms PGF2 alpha significantly suppressed the increase in hepatic plasma glucose and epinephrine induced by PGF2 alpha. These findings demonstrate that PGF2 alpha-induced hyperglycemia is mediated by the muscarinic receptors of cholinoceptive neurons and in part by H1 receptors in the central nervous system.

Topics: Animals; Atropine; Dinoprost; Diphenhydramine; Histamine H1 Antagonists; Hyperglycemia; Injections, Intraventricular; Male; Muscarinic Antagonists; Pyrilamine; Ranitidine; Rats; Rats, Wistar; Receptors, Muscarinic

We previously reported that intraventricular prostaglandins (PGs) produced hyperthermia and hyperglycemia in anesthetized rats. However, the relationship of them is little known. We examined the relationship between hyperthermia and hyperglycemia induced by intraventricular PGF2 alpha using curarized and adrenal demedullated rats. Iv curare completely prevented the PGF2 alpha-induced hyperthermia, but enhanced the hyperglycemic effect of PGF2 alpha. Adrenal demedullation completely prevented the hyperglycemia, but did not affect the hyperthermic effect of PGF2 alpha. To further assess the site of action concerned with PGF2 alpha-induced thermoregulation and glucoregulation in the central nervous system (CNS), we injected saline or PGF2 alpha into the preoptic area of the anterior hypothalamus (POA) in intact rats. After microinjection of PGF2 alpha into the POA, the rectal temperature rose, but the plasma glucose level did not increase significantly, as compared with saline-treated control rats. These results suggest that PGF2 alpha causes the central nervous system to produce hyperthermia via shivering, stimulated the somatic motor system, and to produce hyperglycemia by stimulating central sympathetic outflow to the adrenal medulla, but these operate independently under different neural regulation, and these sensitive sites are organically dissociated in the CNS.

Topics: Adrenal Medulla; Adrenalectomy; Animals; Blood Glucose; Body Temperature; Cerebral Ventricles; Curare; Dinoprost; Fever; Hyperglycemia; Injections, Intravenous; Injections, Intraventricular; Kinetics; Male; Rats; Rats, Inbred Strains