AB140. Protective effects of insulin on erectile function in rats with streptozotocin-induced diabetes

OBJECTIVE: To investigate the therapeutic effects of insulin on erectile dysfunction (ED) in a rat model with streptozotocin-induced diabetes. MATERIALS AND METHODS: The diabetic erectile dysfunction (DMED) rat model was made by injecting the male 8-week-old Sprague-Dawley rats intraperitoneally with vehicle or freshly prepared 60 mg/kg streptozocin, and blood glucose level was measured in the later experiments. Then the rats were divided into three groups: the normal control group (N), the diabetes group (DM) and the diabetes plus insulin therapy group (DM + insulin). Eight weeks after STZ injection, the DM + insulin group were treated with 2-6 units of neutral protamine Hagedorn twice a day for 4 weeks through subcutaneous injection. After the final treatment, all rats were tested for erectile function by measuring the intracavernous pressure and mean arterial pressure (ICP/MAP), and the penile was harvested for histology study. RESULTS: Although the glycemic level was tightly controlled by insulin in the therapy group, ICP/MAP level was partially restored compared to the normal control group, so with the endothelial and smooth muscle contents and apoptosis index. CONCLUSIONS: Insulin could partially restore the erectile functions and pathology changes in the streptozotocin-induced diabetes rat model. Further studies are needed to investigate the underlying mechanisms in the processes of diabetic erectile dysfunction.