糖尿病大鼠阴茎海绵体GSH、GSSG和GSH/GSSG对eNOS表达的影响

The effect of GSH,GSSG and GSH/GSSG on eNOS expression in the penile corpus cavernosum of DMED rats

目的探究在糖尿病大鼠阴茎海绵体中还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)和GSH/GSSG对内皮型一氧化氮合酶(eNOS)表达的影响。方法 30只SD级8周龄健康雄性大鼠,8只作为正常对照组(C组),剩余22只作为糖尿病实验组(D组);D组大鼠高脂高糖喂养4周后腹腔注射链脲佐菌素(40mg/kg)建DM模型;C组大鼠未作特殊处理。继续喂养8周后,注射阿扑吗啡(apomorphine,APO),观察阴茎勃起情况;所有大鼠测定阴茎海绵体内压/平均颈动脉压(ICP_(max)/MAP)后处死,采集血液、阴茎组织,测定GSH、GSSG、睾酮含量,免疫组化和Western印迹法检测eNOS的表达。结果与C组相比较,D组大鼠阴茎组织中GSH含量、GSH/GSSG比值、eNOS含量明显降低(P<0.05),而GSSG的含量明显升高(P<0.05)。结论糖尿病大鼠阴茎海绵体中GSH和GSSG、GSH/GSSG影响eNOS的表达,在糖尿病性阴茎勃起功能障碍机制中起重要作用。

Objective To investigate effects of GSH, GSSG and GSH/GSSG on the expression of eNOS in the penile corpus cavernosum of DMED rats.Methods Thirty healthy male Sprague Dawley （SD） rats aged 8 weeks were randomly divided into the control group （C group, 8 rats） and diabetes mellitus （DM） model group（D group, 22 rats）. The rats in D group were fed with high calorie and high sugar diet for 4 weeks, then intraperitioneally injected with streptozotocin （STZ, 40mg/kg） to establish diabetes mellitus rat models. The rats in C group were given normal diet. At eighth weeks after STZ injection, the rats were injected with apomorphine, and their penile erections were observed to evaluate their erectile function. All rats were killed after detection of the maximal intracavernous pressure/mean arterial blood pressure（ICPmax/MAP） using electrostmulation, levels of GSH, GSSG and testosterone in plasma and penis were measured, and the expression of eNOS in the penile corpus cavernosum was examined by immunohistochemistry and Western blot.Results Compared with those of the controls （C group）, the expression levels of GSH, GSH/GSSG in the plasma and eNOS in the penile tissue of the model rats with diabetes mellitus were all decreased markedly（P〈0.05）, whereas GSSG level was significantly increased（P〈0.05）.Conclusion The low level of GSH and GSH/GSSG in the plasma and high concentration of GSSG in the penile corpus cavernosum of the diabetic rats will downregulate the expression of eNOS, which may be an important pathological mechanism for diabetes mellitus erectile dysfunction.