胰岛素对糖尿病大鼠阴茎内nNOS神经纤维的影响

目的探讨糖尿病性阴茎勃起功能障碍（ED）的发病机制及胰岛素的治疗作用。方法注射链脲佐菌素建立糖尿病（DM）大鼠模型，胰岛素治疗组于成模后注射胰岛素。7周和12周后注射阿扑吗啡（APO）进行大鼠阴茎勃起功能实验，取大鼠阴茎和血浆，用ABC免疫组织化学法观察nNOS神经纤维的变化。测定血浆NOS活性。结果（1）与对照组相比，DM组大鼠阴茎勃起次数明显减少;胰岛素治疗后症状缓解;（2）与对照组相比，DM组血浆NOS活性明显增高;DM组血浆NOS活性与病程延长呈负相关;与DM组比较，胰岛素治疗组血浆NOS活性明显降低;（3）与对照组相比，DM组阴茎内nNOS阳性神经纤维明显减少;与DM组比较，胰岛素治疗组nNOS阳性神经纤维表达增加。结论糖尿病性ED阴茎内nNOS阳性纤维的数量及光密度随DM病程的延长而下降;早期给予胰岛素治疗可预防糖尿病大鼠ED的出现及阴茎内nNOS含量的下降。

Effect of insulin on the treatmenl of rats with diabetic erectile dysfunction

Objective To study the pathogenesis mechanism of diabetic mellitus(DM)erectile dysfunction and treatment effects by insulin for rat model.Methods Rats were induced DM by injecting streptozotocin.Seven weeks and twelve weeks later,experiment of penis erectile function was detected by injecting apomorphine.The nNOS nerve fibers in penis were showed by means of ABC immunohistochemistry.The plasma NOS activity was determined.Results(1)Compared with control and insulin-treated group rats,the erection times of DM rats penis were signifi-cantly decreased.(2)The plasma NOS activity level in diabetic rats was higher than control group.The plasma NOS activity level in twelve weeks DM rats was lower than seven weeks.The plasma NOS activity level in insulin-treated diabetic rats was lower than DM group.(3)Compared with control and insulin-treated group rats,there was significant difference of nNOS nerve fibers in penis of DM rats,and they were significantly decreased for twelve weeks DM rats.The expression of nNOS nerve fibers in penis of insulin-treated diabetic rats was higher than DM group.Conclusion The appearance of erectile dysfunction caused by diabetes mellitus is accompanied by the decrease of NO in penis.Early treatment with insulin can prevent the decrease of penile nNOS in DM rats.