Vitamin E (α-tocopherol) supplementation enhances nitric oxide production in penile tissue of diabetic rats

OBJECTIVE To investigate the effects of 0.1% and 2% vitamin E (alpha-tocopherol) supplementation on the expression of nitric oxide (NO) in penile tissue of rats with experimentally induced diabetes mellitus (DM). MATERIALS AND METHODS In all, 30 male rats were divided into six groups: normoglycaemic (NG), NG treated with 0.1% vitamin E (NGE1), NG treated with 2% vitamin E (NGE2), DM, DM treated with 0.1% vitamin E (DME1), and DM treated with 2% vitamin E (DME2). After 120 days the rats were killed, and penile tissue was collected and processed for neuronal NO synthase (nNOS) immunohistochemistry to determine areas of nNOS-immunoreactive varicosities. RESULTS nNOS-immunoreactive varicosities in DME2 rats were similar to those of controls (NG) and controls supplemented with vitamin E (NGE1 and NGE2). Varicosity sizes in the NGE1 group were similar to the DM rats with no vitamin E supplementation. CONCLUSION Supplementation with 2% vitamin E had a positive effect on areas of nNOS-immunoreactive varicosities of penile tissue in DM rats.