Effect of Pregabalin on Erectile Function and Penile NOS Expression in Rats with Streptozotocin-Induced Diabetes

Objectives: To investigate the effect of pregabalin on erectile function and on the penile expression of nitric oxide synthase (NOS) isoforms in diabetic rat models. Methods: Male Sprague-Dawley rats were injected with streptozotocin to induce diabetes mellitus. The rats with blood glucose levels above 300 mg/dL were selected for the study. Those were randomly divided into 2 groups (N = 10 per group): i) EDDM (erectile dysfunction diabetes mellitus) group fed with saline and ii) EDDM + Pregabalin treated group receiving pregabalin (10 mg/k/day) by intragastric administration. 10 animals served as a control group and received no streptozotocin. 4 weeks later, the erectile function of the rats was assessed by recording frequency of erection after subcutaneous apomorphine (80 ug/kg) injection. Superoxide anion generation and the expression of mRNA of nNOS and eNOS were evaluated in corpora cavernosum tissue. Results: Penile erection, the expression of both nNOS, eNOS and superoxide generation were significantly decreased in pregabalin treated group compared to control group. Conclusion: Treatment with pregabalin for 4 weeks decreases superoxide production but cannot improve erectile dysfunction in diabetic rats probably by inhibiting Ca-2(+) channel-mediated NOS activation.