| Objectives: Impaired angiogenesis in cardiac tissue is a major complication of diabetes. This study was
aimed to evaluate the effects of testosterone and voluntary exercise on vascular endothelial growth factor-A
(VEGF-A), stromal cell-derived factor 1a (SDF-1a) and myocardial capillary density in heart of rats with
diabetes.
Methods: Type 1 diabetes was induced by intraperitoneal injection of 55 mg/kg of streptozotocin in 80
male Wistar rats. After 42 days of treatment with testosterone (2 mg/kg/day) or voluntary exercise alone
or in combination, angiogenesis was determined in the hearts by immunostaining for PECAM-1/CD31.
The expressions of VEGF-A and SDF-1a levels in heart were also determined by the ELISA method.
Results: Our results showed that capillary density, VEGF-A and SDF-1a levels in the heart were significantly
decreased in castrated rats with diabetes, whereas these effects were reversed by testosterone and
exercise. Furthermore, simultaneous treatment of castrated rats with diabetes with testosterone and exercise
had a synergistic effect on capillary density, VEGF-A and SDF-1a levels in the heart. In the group with
diabetes, either testosterone or exercise increased capillary density, VEGF-A and SDF-1a protein levels
in heart tissue. However, the effects of combination therapy in rats with diabetes with testosterone and
exercise on capillary density, VEGF-A and SDF-1a levels in the heart was synergistic.
Conclusions: Our findings suggest that testosterone and exercise can promote neoangiogenesis in rats with
diabetes and in castrated rats with diabetes. The proangiogenesis effect of testosterone and exercise is
associated with the enhanced expression of VEGF-A and SDF-1a in heart tissue. |