ACTA ENDOCRINOLOGICA (BUC)

Objective. Cardiovascular disorders in diabetes condition arise from increased oxidative stress. Both regular mild exercise and testosterone influence on body’s antioxidant system in diabetes. In this study, we evaluated treatment of testosterone and voluntary exercise, alone or together on oxidative stress in the heart and blood of diabetic rats. Methods. Type 1 diabetes was induced by intraperitoneal injection of 50 mg/kg of streptozotocin in rats. Sixty three rats have been divided into eight groups as follows: Diabetes, diabetes+ testosterone, diabetes+ exercise, diabetes+ testosterone+ exercise, diabetes+ castration, diabetes+ castration+ testosterone, Diabetes+ castration+ exercise, Diabetes+ castration+ exercise+ testosterone. Type 1 diabetes was induced by intraperitoneal injection of 50 mg/ kg of streptozotocin in the male Wistar rats and after a week, castration was performed. After 42 days of treatment with testosterone (2 mg/kg/day) or voluntary exercise alone or in combination, SOD, GPX and CAT activities and MDA levels were measured in the blood and heart tissue samples in the groups of study. In the end of study, SOD, GPX and CAT activities and MDA levels were measured in blood and heart tissue samples in the groups of study. Results. SOD, GPX and CAT activities significantly (p<0.05) increased in groups that treated either testosterone or exercise and MDA level significantly (p<0.01) decreased in the blood and heart tissue of diabetic and castrated diabetic rats. Simultaneously, treatment with testosterone and exercise had a synergistic effect on antioxidant enzymes level in diabetic and diabetic castrated rats. In the castrated animals with diabetes, SOD, GPX and CAT activities significantly decreased (p<0.05) and MDA levels significantly increased (p<0.05) in blood and heart tissue. Conclusion. Voluntary exercise and testosterone alone or together heightened body’s antioxidant system and were able to reduce the MDA levels in blood and heart of diabetic and castrated diabetic rats.

Methods. Ninety Wistar male rats were used in this study. Type 1 diabetes was induced by i.p injection of 50 mg/kg of streptozotocin in all animals. After 42 days of treatment with testosterone (2mg/kg/day) or voluntary exercise alone or in combination, the heart of the rats has been removed and MicroRNA was extracted from the heart using miRCURYTM RNA isolation kit. Results. Our results showed that either testosterone or exercise increased miRNA-126 expression levels in the heart of diabetic rats. Treatment of diabetic rats with testosterone and exercise at the same time had a synergistic effect on miRNA-126 levels in the heart. Furthermore, in castrated diabetes group, miRNA-126 levels were significantly decreased in heart, whereas either testosterone treatment or exercise training enhanced expression of this miRNA. Also, simultaneous treatment of castrated diabetic rats with testosterone and exercise had an additive effect on miRNA-126 expression levels. Conclusion. This study showed that testosterone and exercise promote an increase in the expression of miRNA-126 in the heart tissue and this may be related to cardiac angiogenesis. These results may indicate that testosterone and exercise can help to prevent progression of diabetic cardiomyopathy due to impaired angiogenesis in the heart.