AB096. Taurine supplementation improves erectile function in rats with streptozotocin-induced type 1 diabetes via amelioration of penile fibrosis and endothelial dysfunction

OBJECTIVE: For patients with diabetes, erectile dysfunction (ED) is common and greatly affects quality of life. However, these patients often exhibit a poor response to first-line oral phosphodiesterase type 5 inhibitors. The aim of this study was to investigate whether taurine, a sulfur-containing amino acid, affects diabetic ED (DED). METHODS: Type 1 diabetes mellitus was induced in male rats using streptozotocin. After 12 weeks, an apomorphine test was conducted to confirm DED. Only rats with DED were administered taurine or vehicle for four weeks. Age-matched nondiabetic rats were administered saline intraperitoneally for four weeks. Erectile function was evaluated by electrical stimulation of the cavernous nerve. Histologic and molecular alterations of the corpus cavernosum also were analyzed. RESULTS: Erectile function was significantly reduced in the diabetic rats compared with in the nondiabetic rats, and was ameliorated in the diabetic rats treated with taurine. The corpus cavernosum of the rats with DED exhibited severe fibrosis and decreased smooth muscle content. Deposition of extracellular matrix proteins was increased in the diabetic rats, while expression of endothelial nitric oxide synthase/cyclic guanosine monophosphate/nitric oxide pathway–related proteins was reduced. Taurine supplementation restored erectile response as well as histologic and molecular alterations. CONCLUSIONS: Taurine supplementation improves erectile function in rats with DED probably by potential antifibrotic activity. This finding provides evidence for a potential new therapy for DED.