Insulin-sparing effect of hydroxychloroquine in diabetic rats is concentration dependent

1999 ◽  
Vol 77 (2) ◽  
pp. 118-123 ◽  
Author(s):  
Jaber Emami ◽  
Hertzel C Gerstein ◽  
Franco M Pasutto ◽  
Fakhreddin Jamali
Keyword(s):  
Therapeutic Potential ◽  
Serum Insulin ◽  
Serum Glucose ◽  
Diabetic Rats ◽  
Type I ◽  
Time Curve ◽  
Insulin Metabolism ◽  
Glucose Levels ◽  
Percent Change ◽  
Glucose Challenge

To study the effect of hydroxychloroquine (HCQ) on glucose and insulin homeostasis, healthy rats were dosed with160 mg·kg-1·day-1 of HCQ orally, and streptozocin-induced diabetic rats received 80, 120, and 160 mg·kg-1·day-1 of HCQ, while controls received normal saline. Ten days after treatment with HCQ, healthy animals were challenged intravenously with insulin or glucose, while diabetic rats were given only an i.v. injection of insulin. In healthy rats, the areas within and under the glucose concentration - time curve following insulin and glucose challenge were estimated. In diabetic animals, the areas under the curve for both the percent change in serum glucose from baseline (AUG) and the percent change in serum insulin from baseline (AUI) were used as pharmacodynamic end points. In healthy rats, HCQ did not influence fasting serum glucose concentrations or glycemic profiles following i.v. administration of glucose or insulin. In diabetic rats, AUG and AUI were increased dependent on blood HCQ concentrations. The normal homeostatic mechanisms responsible for insulin-glucose regulation may compensate for possible HCQ-induced reduction of insulin metabolism in healthy rats. The HCQ dose- or concentration-effect relationships for glucose and insulin were linear over the range of HCQ concentrations tested. It is concluded that HCQ significantly elevated insulin blood concentration resulting in reduced glucose levels in a concentration-dependent fashion in diabetic rats. HCQ may have therapeutic potential in the treatment of type I and type II diabetes.Key words: hydroxychloroquine, enantiomers, insulin, glucose, diabetes, pharmacokinetics.

Comparative evaluation of atenolol and metoprolol on cardiovascular complications associated with streptozotocin-induced diabetic rats

2007 ◽  
Vol 85 (8) ◽  
pp. 831-836 ◽  
Author(s):  
Shraddha V. Bhadada ◽  
Ramesh K. Goyal
Keyword(s):  
Heart Rate ◽  
Serum Insulin ◽  
Cardiovascular Complications ◽  
Serum Glucose ◽  
Diabetic Rats ◽  
Diabetic Patients ◽  
Cardiac Tissues ◽  
Insulin Levels ◽  
Beneficial Effects ◽  
Glucose Levels

Recently, various clinical studies have indicated that lipophilic β-blockers reduce the coronary mortality in diabetic patients; however, systematic studies have not been reported. The objective of the present investigation was to compare the effects of chronic treatment with metoprolol and atenolol on cardiovascular complications in streptozotocin (STZ)-induced diabetic rats. Injection of STZ produced hyperglycemia, hypoinsulinemia, hyperlipidemia, increased blood pressure, cardiac hypertrophy, reduction in heart rate, and structural alterations in cardiac tissues. Metoprolol and atenolol effectively prevented the development of hypertension in diabetic rats. Metoprolol treatment produced a slight but significant reduction in serum glucose levels with elevation in serum insulin levels, while atenolol produced a slight increase in glucose levels but no effect on insulin levels. Moreover, neither metoprolol nor atenolol treatment reduced the elevated cholesterol levels in diabetic rats. Metoprolol treatment significantly prevented STZ-induced increase in triglyceride levels, but atenolol failed to produce this effect. Metoprolol exhibited a minimal improvement in STZ-induced bradycardia, whereas atenolol produced a further reduction in heart rate. Histological examination showed metoprolol treatment also prevented STZ-induced hypertrophy and some of the alterations in cardiomyocytes. In conclusion, our data suggest that metoprolol has some beneficial effects over atenolol with respect to cardiovascular complications associated with diabetes mellitus.

Vildagliptin/pioglitazone combination improved the overall glycemic control in type I diabetic rats

2018 ◽  
Vol 96 (8) ◽  
pp. 710-718 ◽  
Author(s):  
Amir Mohamed Abdelhamid ◽  
Rania Ramadan Abdelaziz ◽  
Hatem Abdelrahman Ali Salem
Keyword(s):  
Glycemic Control ◽  
Type I Diabetes ◽  
Serum Insulin ◽  
Immunohistochemical Analysis ◽  
Diabetic Rats ◽  
Suboptimal Control ◽  
Type I ◽  
Β Cells ◽  
Treatment Regimens ◽  
Glucose Levels

Type I diabetes (TID) is generally assumed to be caused by an immune associated, if not directly immune-mediated, destruction of pancreatic β-cells. In patients with long-term diabetes, the pancreas lacks insulin-producing cells and the residual β-cells are unable to regenerate. Patients with TID are subjected to a lifelong insulin therapy which shows risks of hypoglycemia, suboptimal control and ketosis. In this study, we investigated the potential role of vildagliptin (Vilda) alone or in combination with pioglitazone (Pio), as treatment regimens for TID using streptozotocin (STZ)-induced TID model in rats. Daily oral administration of Vilda (5 mg/kg) alone or in combination with Pio (20 mg/kg) for 7 weeks significantly reduced blood glucose levels and HbA1c. It increased serum insulin levels and decreased serum glucagon. It also showed a strong antioxidant activity. Immunohistochemical analysis showed a marked improvement in β-cells in treated groups when compared with the diabetic group, which appeared in the normal cellular and architecture restoration of β-cells in the islets of Langerhans. Vilda alone or in combination with Pio has the ability to improve the overall glycemic control in type I diabetic rats and may be considered a hopeful and effective remedy for TID.

Hepatoprotective effects of selenium during diabetes in rats

2015 ◽  
Vol 35 (2) ◽  
pp. 114-123 ◽  
Author(s):  
C Zou ◽  
Q Qiu ◽  
H Chen ◽  
L Dou ◽  
J Liang
Keyword(s):  
Enzyme Activities ◽  
Serum Insulin ◽  
Serum Glucose ◽  
Diabetic Rats ◽  
Total Glutathione ◽  
Insulin Levels ◽  
Glucose Levels ◽  
Selenium Treatment ◽  
Male Wistar Rats

The present study investigated the hepatoprotective role of selenium during alloxan-induced diabetes in rats. Male Wistar rats were divided into four groups, namely, normal control, selenium treated, diabetic, and selenium-treated diabetic. Diabetes was induced in the animals by injecting alloxan intraperitoneally at a dose rate 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. The effects of different treatments were studied on various parameters in rat liver, which included serum glucose levels, serum insulin levels, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lipid peroxidation (LPO), glutathione reduced (GSH), oxidized glutathione (GSSG), total glutathione (TG), superoxide dismutase (SOD), catalase (CAT), glutathione reductase, glutathione peroxidase, metallothionein (MT), and histoarchitecture. A significant increase in the serum glucose levels, LPO levels, and in enzyme activities of ALP, ALT, and AST was observed in diabetic rats which, however, got decreased significantly upon supplementation with selenium. On the contrary, decreased enzyme activities of GSSG, SOD, and CAT and depressed levels of GSH as well as serum insulin levels were observed in diabetic rats which got improved following selenium supplementation. Interestingly, MT levels were increased both in diabetic and selenium-treated diabetic rats. Further, marked alterations in histoarchitecture were seen in diabetic rats with the prominent features being congestion in sinusoids, lipid accumulation, and centrilobular hepatocyte degeneration. However, selenium treatment to diabetic rats showed overall improvement in the hepatic histoarchitecture.

Effects of cortisol and progesterone on insulin binding and lipogenesis in adipocytes from normal and diabetic rats

1985 ◽  
Vol 106 (2) ◽  
pp. 225-231 ◽  
Author(s):  
A.-M. Mendes ◽  
R. J. Madon ◽  
D. J. Flint
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Insulin Receptor ◽  
Body Weight Gain ◽  
Serum Insulin ◽  
Insulin Binding ◽  
Serum Glucose ◽  
Diabetic Rats ◽  
Receptor Concentration

ABSTRACT Cortisol implants in normal and diabetic rats reduced body weight, adiposity, insulin receptor concentration and both basal and insulin-stimulated rates of lipogenesis in isolated adipocytes, whilst insulin sensitivity was unchanged. In normal but not diabetic rats these changes were accompanied by increased serum glucose and insulin concentrations. In contrast, progesterone implants in normal and diabetic rats increased body weight gain, adiposity, insulin receptor concentration and both basal and insulin-stimulated rates of lipogenesis in adipose tissue, again without affecting insulin sensitivity. Progesterone did not affect serum insulin concentrations in normal or diabetic rats but accelerated the decline in serum glucose concentrations which occurred during an overnight fast in diabetic rats. The results suggest that (1) cortisol inhibits lipogenesis in adipose tissue without affecting insulin sensitivity, (2) cortisol reduces insulin binding in adipose tissue without a requirement for hyperinsulinaemia, which might itself indirectly lead to down-regulation of the insulin receptor, and (3) in diabetic rats progesterone stimulates lipogenesis in adipose tissue without any increase in food intake or serum insulin concentrations suggesting that progesterone may have a direct anabolic role in adipose tissue. J. Endocr. (1985) 106, 225–231

Hypothalamic noradrenergic and sympathoadrenal control of glycemia after stress

1989 ◽  
Vol 256 (2) ◽  
pp. E231-E235
Author(s):  
G. A. Smythe ◽  
W. S. Pascoe ◽  
L. H. Storlien
Keyword(s):  
Insulin Release ◽  
Acute Stress ◽  
Serum Insulin ◽  
Elevated Serum ◽  
Serum Glucose ◽  
Neural Pathways ◽  
Swim Stress ◽  
Insulin Levels ◽  
Glucose Levels ◽  
Positive Correlations

Central noradrenergic pathways play a significant role in mediating blood glucose levels after neuroglycopenia. To further investigate hypothalamic noradrenergic neuronal activity (NNA) and sympathoadrenal influences in glucoregulation, we studied the effects of acute stress on glycemia and insulin release in normal and adrenalectomized (ADRX) rats. Within 5 min of exposure of rats to ether or cold-swim stress, significant positive correlations were evident between hypothalamic NNA and serum glucose levels (r = 0.70, P less than 0.001; at 15 min r = 0.78, P less than 0.0001). Five minutes after stress in the intact rat, insulin release was inhibited and serum insulin levels inversely correlated to hypothalamic NNA (r = 0.45, P less than 0.05). This relationship between insulin and NNA was no longer present 15 min after stress, but the levels of insulin remained inappropriately low with respect to the elevated serum glucose levels (approximately 30% above basal). Blockade of sympathetic noradrenergic pathways by treatment of intact rats with guanethidine prevented the rise in glucose after cold-swim stress but did not prevent the inhibition of insulin release. Fifteen minutes after exposure of ADRX rats to cold-swim stress their hypothalamic NNA and serum glucose levels were similar to intact animals. However, in contrast to their intact counterparts, serum insulin levels were significantly elevated (P less than 0.01). These data are consistent with central noradrenergic neural pathways directly mediating hepatic glucose release and indirectly inhibiting pancreatic insulin release via activation of adrenal medullary catecholamines.

scholarly journals Endothelial dysfunction precedes hypertension in diet-induced insulin resistance

1998 ◽  
Vol 275 (3) ◽  
pp. R788-R792 ◽  
Author(s):  
Prasad V. G. Katakam ◽  
Michael R. Ujhelyi ◽  
Margarethe E. Hoenig ◽  
Allison Winecoff Miller
Keyword(s):  
Insulin Resistance ◽  
Endothelial Dysfunction ◽  
Serum Insulin ◽  
Serum Glucose ◽  
Mesenteric Arteries ◽  
Control Group ◽  
Sprague Dawley ◽  
Insulin Resistant ◽  
Glucose Levels

The insulin-resistant (IR) syndrome may be an impetus for the development of hypertension (HTN). Unfortunately, the mechanism by which this could occur is unclear. Our laboratory and others have described impaired endothelium-mediated relaxation in IR, mildly hypertensive rats. The purpose of the current study is to determine if HTN is most likely a cause or result of impaired endothelial function. Sprague-Dawley rats were randomized to receive a fructose-rich diet for 3, 7, 10, 14, 18, or 28 days or were placed in a control group. The control group received rat chow. After diet treatment, animals were instrumented with arterial cannulas, and while awake and unrestrained, their blood pressure (BP) was measured. Subsequently, endothelium-mediated relaxation to acetylcholine was determined (in vitro) by measuring intraluminal diameter of phenylephrine-preconstricted mesenteric arteries (∼250 μM). Serum insulin levels were significantly elevated in all groups receiving fructose feeding compared with control, whereas there were no differences in serum glucose levels between groups. Impairment of endothelium-mediated relaxation starts by day 14 [mean percent maximal relaxation (Emax): 69 ± 10% of baseline] and becomes significant by day 18 (Emax: 52 ± 11% of baseline; P < 0.01). However, the mean BP (mmHg) does not become significantly elevated until day 28 [BP: 132 ± 1 ( day 28) vs. 116 ± 3 (control); P < 0.05]. These findings demonstrate that both IR and endothelial dysfunction occur before HTN in this model and suggest that endothelial dysfunction may be a mechanism linking insulin resistance and essential HTN.

scholarly journals Effect of metformin on the expression of SNAER proteins in the skeletal muscle of rats with type 2 diabetes

2021 ◽  
pp. 270-278
Keyword(s):  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Body Weight ◽  
Serum Insulin ◽  
Serum Glucose ◽  
Snare Complex ◽  
Snare Proteins ◽  
Glucose Levels ◽  
Male Wistar Rats

Background and Aims: SNARE proteins are composed of a combination of SNAP-23, Stx-4, and VAMP-2 isoforms that are significantly expressed in skeletal muscle. These proteins control the transport of GLUT4 to the cell membranes. The modifications in the expression of SNARE proteins can cause Type 2 diabetes. The present study aimed to assess the effect of metformin on the expression of these proteins in rats. Materials and Methods: For the purpose of the study, 40 male Wistar rats were randomly selected. Streptozotocin and Nicotinamide were used for the induction of type 2 diabetes. The animals were assigned to five groups (n=8), including healthy and diabetic groups as control, as well as three experimental groups which were treated with different doses of metformin (100, 150, and 200 mg/kg body weight) for 30 days. The quantitative reverse transcription PCR (RT-qPCR) method was applied to evaluate the expression of SNARE complex proteins.. Results: Based on the results, metformin (100, 150, and 200 mg/kg body weight) decreased serum glucose levels and increased serum insulin levels. This difference in dose of 200 mg/kg body weight was statistically significant (P<0.05). Moreover, all three doses of metformin increased the expression of SNAP- 23, syntaxin-4, and VAMP-2 proteins in skeletal muscle tissue. Metformin at a dose of 200 mg/kg body weight demonstrated the most significant effects (P<0.05). Conclusion: As evidenced by the results of the current study, another anti-diabetic mechanism of metformin is to increase the expression of SNARE proteins, which effectively improves insulin resistance and lowers blood glucose.

Effects of Vitamin E on Serum Glucose Levels and Nephropathy in Streptozotocin-Diabetic Rats

2005 ◽  
pp. 268-272
Author(s):  
M. James C. Crabbe ◽  
B. Üstündag ◽  
M. Cay ◽  
M. Naziroglu ◽  
N. Ilhan ◽  
...  
Keyword(s):  
Vitamin E ◽  
Serum Glucose ◽  
Diabetic Rats ◽  
Glucose Levels ◽  
Streptozotocin Diabetic Rats

scholarly journals Influence of GABA and GABA-producing Lactobacillus brevis DPC 6108 on the development of diabetes in a streptozotocin rat model

2016 ◽  
Vol 7 (3) ◽  
pp. 409-420 ◽  
Author(s):  
T.M. Marques ◽  
E. Patterson ◽  
R. Wall ◽  
O. O’Sullivan ◽  
G.F. Fitzgerald ◽  
...  
Keyword(s):  
Body Weight ◽  
Serum Insulin ◽  
Lactobacillus Brevis ◽  
Diabetic Rats ◽  
Protective Effects ◽  
Sprague Dawley ◽  
Metabolic Markers ◽  
Glucose Levels ◽  
Intestinal Length ◽  
Sprague Dawley Rats

The aim of this study was to investigate if dietary administration of γ-aminobutyric acid (GABA)-producing Lactobacillus brevis DPC 6108 and pure GABA exert protective effects against the development of diabetes in streptozotocin (STZ)-induced diabetic Sprague Dawley rats. In a first experiment, healthy rats were divided in 3 groups (n=10/group) receiving placebo, 2.6 mg/kg body weight (bw) pure GABA or L. brevis DPC 6108 (~109microorganisms). In a second experiment, rats (n=15/group) were randomised to five groups and four of these received an injection of STZ to induce type 1 diabetes. Diabetic and non-diabetic controls received placebo [4% (w/v) yeast extract in dH2O], while the other three diabetic groups received one of the following dietary supplements: 2.6 mg/kg bw GABA (low GABA), 200 mg/kg bw GABA (high GABA) or ~109 L. brevis DPC 6108. L. brevis DPC 6108 supplementation was associated with increased serum insulin levels (P<0.05), but did not alter other metabolic markers in healthy rats. Diabetes induced by STZ injection decreased body weight (P<0.05), increased intestinal length (P<0.05) and stimulated water and food intake. Insulin was decreased (P<0.05), whereas glucose was increased (P<0.001) in all diabetic groups, compared with non-diabetic controls. A decrease (P<0.01) in glucose levels was observed in diabetic rats receiving L. brevis DPC 6108, compared with diabetic-controls. Both the composition and diversity of the intestinal microbiota were affected by diabetes. Microbial diversity in diabetic rats supplemented with low GABA was not reduced (P>0.05), compared with non-diabetic controls while all other diabetic groups displayed reduced diversity (P<0.05). L. brevis DPC 6108 attenuated hyperglycaemia induced by diabetes but additional studies are needed to understand the mechanisms involved in this reduction.

Changes in Levels of Serum Insulin, C-Peptide and Glucose after Electroacupuncture and Diet Therapy in Obese Women

2006 ◽  
Vol 34 (03) ◽  
pp. 367-376 ◽  
Author(s):  
Mehmet Tuğrul Cabıoğlu ◽  
Neyhan Ergene
Keyword(s):  
Weight Loss ◽  
Serum Insulin ◽  
Diet Therapy ◽  
Serum Glucose ◽  
The Body ◽  
Obese Women ◽  
Diet Restriction ◽  
C Peptide ◽  
Glucose Levels ◽  
Restriction Group

Our purpose was to investigate the effects of electroacupuncture (EA) therapy on body weight and on levels of serum insulin, c-peptide and glucose in obese women. 52 healthy women were included in this study and were allocated into three groups: 1) Placebo EA group ( n = 15; mean age = 41.8 ± 4.6 and mean body mass index { BMI } = 33.2 ± 3.5); 2) EA group ( n = 20; mean age = 42.1 ± 4.4 and BMI = 35.9 ± 3.6) and 3) Diet restriction group ( n = 20; mean age = 42.9 ± 4.3 and BMI = 34.7 ± 2.7). EA was applied to the ear points Hunger and Shen Men on alternating days and to the body points LI 4, LI 11, St 36 and St 44 once a day for 30 minutes over 20 days. Diet restriction that entailed a 1450 kilocalorie (kcal) diet program was applied to the three groups for 20 days. An increase in weight loss was observed when weight loss in the EA group (p < 0.000) was compared to that in the diet restricted and placebo EA groups using the Tukey HSD test. There were increases in the serum insulin (p < 0.001) and c-peptide levels (p < 0.000) in the women treated with EA compared to those in the women treated with the placebo EA and diet restriction groups. A decrease was observed in the glucose levels (p < 0.01)in both the EA and diet restriction groups compared to those in the placebo EA group. Our results suggest that EA therapy is an effective method in treating obesity. EA therapy also helps serum glucose levels to decrease through the increase of serum insulin and c-peptide levels.

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