The investigation of effects vitamin D and vitamin E on apoptosis at experimental diabetic rat testes tissue

Diabetes mellitus (DM) is a chronic metabolic disease characterized by microvascular and macrovascular complications. In diabetic men, apoptosis increases in testicular germ cells and testicular dysfunction occurs, due to increased oxidative stress. In recent years, vitamin D has been shown to have antioxidative effects. Vitamin E is an antioxidant that is very important, creates a first line of defense against lipid peroxidation.In this study, protective effects of vitamin D and vitamin E on apoptotic changes of the rat testicular tissue in streptozotocin (STZ) induced experimental model of diabetes were investigated.Twenty-eight Wistar albino male rats, aged 9 weeks were used. The experimental animals were divided into 4 groups that have 7 animals in each group. No application made to the control group (group 1). 50 mg/kg single-dose STZ was intraperitoneally (i.p) induced to other 3 groups by dissolving on the 0,1 M sodium-citrate buffer (pH: 4,5). After diabetes occured, the diabetic group (Group II) did not receive any medication. Vitamin D (50 IU/kg/day) was given to DM + vitamin D group (Group III) and vitamin E (500 IU/kg/day) was given to DM + vitamin E group (Group IV), orally for 9 weeks. Rats were decapitated at the end of the experiment and testicular tissues were removed. The testicular tissues were stained with Haematoxylin-Eosin and TUNEL.In diabetic group, weights of testis, cauda epididimis and ventral prostat, count and motility of sperm (p<0.01), weights of epididimis and seminal vesicules were significantly less than control group (p<0.001). In DM + vitamin D group and DM + vitamin E group, there was a significant increase in the weight of testis and sperm motility (p<0.01) and weight of epididimis compared to diabetic group (p<0.001). In histological examinations of diabetic group, there were atrophic tubules, marked edema, vascular congestion, decrease in number of germ cells and some disorganised areas. But in DM + vitamin D group and DM + vitamin E group, there were similar histological findings with control group. Diabetic group had a significant increase in apoptotic index with TUNEL staining (p<0.05). There was a significant reduction in apoptotic index in DM + vitamin D group and DM + vitamin E group compared to diabetic group (p<0.05).As a result, showing the protective effects of vitamin D and vitamin E against the oxidative stress due to DM, new treatment approaches may be useful in order to prevent complications of diabetes.Key words: Diabetes mellitus, vitamin D, vitamin E, apoptosis, testis.