The effects of exercise on vascular responses in TYPE I diabetic rats

Diabetes Mellitus is a metabolic disorder with multi-ethiologic nature characterized by the defects in insulin production and the effects of insulin or both, leading disorders in carbohydrate, fat, and protein metabolism. Diabetes causes dysfunctions and damages in different tissues in the long-term. It is known that exercise has beneficial effects on the pathologies associated with diabetes. This study was aimed to evaluate the effects of moderate swimming exercise on vascular responses in type-1 diabetic rats. The totally 36 male adult Wistar Albino rats were used in this study. The groups in the experiment were generated as diabetes, diabetes+exercise, exercise and control. Streptozotocin (50 mg/kg, intraperitoneally) was given to induce type 1 diabetes. The rats in group diabetes+exercise and exercise only were subjected to 1 h swimming exercise for 4 weeks after streptozotocin injection. The initial and final blood glucose levels and weekly body weight were measured. In vitro thoracic aorta responses were recorded at the end of the experiment. A reduction in body weight of type-1 diabetic rats was determined from week 1 to week 4 (p<0,001). Blood glucose levels were significantly (p<0,001) greater in both diabetic groups than in controls and group exercise, but swimming exercise did not affect blood glucose levels of diabetic rats. No differences between groups were found in the response of thoracic aorta to norepinephrine and sodium nitroprusside. It was determined that highest relaxation response to acetylcholine was observed in control and this response gradually decreased in group diabetes + exercise, group exercise, and group diabetes. These differences were significant in the concentration of 10-7,10-6 and 10-5 mM of acetylcholine (p<0,05, p<0,05, p<0,01, respectively). In conclusion, it was observed that 4-week moderate swimming exercise regimen corrected endothelium-dependent relaxation responses in type-1 diabetic rats.