Protective effects of hydrogen-rich saline against erectile dysfunction in a streptozotocin induced diabetic rat model.

PURPOSE: Hydrogen has antioxidative stress and anti-inflammatory effects. We investigated the effect of hydrogen on erectile dysfunction in streptozotocin induced diabetic rats. MATERIALS AND METHODS: Diabetes was induced in Sprague-Dawley® rats by a single intravenous injection of streptozotocin. Diabetic rats were then randomized to a diabetes mellitus group and to a diabetic group that received hydrogen saline. The latter 8 rats were fed saturated hydrogen saline (5 ml/kg per day) by intragastric administration for 8 weeks. At the end of week 8 erectile function was assessed by measuring the increase in intracavernous pressure after cavernous nerve electrostimulation. We measured nitric oxide synthase activity, and malondialdehyde, 8-hydroxydeoxyguanosine, and nitrite and nitrate in the corpus cavernosum. eNOS protein immunolocalization in cavernous tissues was detected by immunohistochemistry. eNOS, Bcl-2 and Bax protein expression was determined by Western blot. We determined eNOS, Bcl-2 and Bax mRNA using real-time reverse transcriptase-polymerase chain reaction. RESULTS: Oxidative stress is involved in the pathophysiological mechanism of erectile dysfunction. Maximum intracavernous pressure in diabetic rats decreased significantly compared to controls and increased significantly compared to untreated diabetic rats after hydrogen-rich saline treatment. Decreased nitric oxide synthase activity, nitrite and nitrate, and eNOS expression as well as increased 8-hydroxydeoxyguanosine and malondialdehyde were found in the diabetic group compared to controls. Hydrogen-rich saline improved nitric oxide synthase activity, and malondialdehyde, nitrite and nitrate, and 8-hydroxydeoxyguanosine levels in the diabetic rat corpus cavernosum. Decreased eNOS in diabetic rats was ameliorated by hydrogen-rich saline. Also, apoptosis in the diabetic rat corpus cavernosum was significantly enhanced compared with controls. Hydrogen-rich saline therapy may decrease apoptosis in cavernous tissues and it ameliorated erectile dysfunction in diabetic rats by inhibiting oxidative stress and apoptosis. CONCLUSIONS: Hydrogen-rich saline effectively improved erectile function in a streptozotocin induced diabetic rat model of erectile dysfunction.