Effect of testosterone on pancreatic beta cells resistance and blood glucose control in diabetic male rats by streptozotocin

Diabetes mellitus (DM) is the most common carbohydrate metabolic disorder، with defective insulin secretory or insulin receptor function، or both. We examined the protective effect of testosterone against the destruction of pancreatic β-cells by streptozotocin (STZ).

This empirical cross-sectional research involved 56 adult male rats (mean wt 220 g) randomized to: group 1، food and water; group 2، olive oil injection; group 3، STZ-induced DM; group 4، castrated rats; group 5، gonadectomy + STZ; group 6، gonadal hormone + STZ; group 7، gonadal hormone + STZ + gonadal hormone. Testosterone enanthate was injected intramuscularly (50 mg/kg in group 6، 4 weeks before DM induction، and 50 mg/kg in group 7، 4 weeks before and 2 weeks after DM). Diabetes was induced by 60 mg/kg، intraperitoneal STZ (STZ; 20130 Sigma-Aldrich) in citrate buffer. Data were analyzed using SPSS16 software.

In groups 6 and 7 (testosterone) blood glucose was significantly lower than in groups 3 and 5 (P ≤ 0. 001). Groups 6 and 7 also had higher serum insulin concentrations (P ≤ 0. 05) and absolute numbers of islet cells compared to other groups (P≤ 0. 001).

Testosterone exerted a protective effect against early STZ-induced apoptotic damage to pancreatic β-cells.