还原型谷胱甘肽在预防糖尿病大鼠勃起功能障碍中的研究

The effect of reduced-glutathione on preventing erectile dysfunction in diabetic rats

目的探讨还原型谷胱甘肽(GSH)在预防糖尿病大鼠勃起功能障碍中的作用。方法通过腹腔注射链脲佐菌素65mg/kg建立糖尿病大鼠模型,然后随机分成DM组和DM+GSH组,DM+GSH组每天肌肉注射GSH200mg/kg。10周后观察大鼠勃起功能,并获取海绵体组织检测其谷胱甘肽、一氧化氮合酶(NOS)与丙二醛(MDA)水平,用TUNEL法检测细胞凋亡。结果成功建立糖尿病大鼠模型。与未注射GSH的DM组相比,DM+GSH组和正常对照组(C组)勃起功能更好,勃起率分别是20%,62.5%和100%。GSH水平DM+GSH组和C组明显比DM组高,其3组含量每克蛋白分别是(75.83±15.62)、(61.47±8.65)和(35.03±12.29)mg(P<0.05);NOS水平在DM+GSH组每毫克蛋白为(133.9±31.9)U,与正常对照组每毫克蛋白为(142.2±31.2)U相当,但较DM组每毫克蛋白为(58.4±18.9)U高(P<0.05);MDA含量在DM组每毫克蛋白为(3.71±0.62)nmol,明显高于正常对照组和DM+GSH组(P<0.05),这两组每毫克蛋白为(2.08±0.34)nmol和(2.44±0.28)nmol;细胞凋亡率在DM组、DM+GSH组和C组的分别是(22.6±3.6)%、(10.8±1.7)%和(7.2±2.1)%(P<0.05)。结论还原型谷胱甘肽对糖尿病大鼠阴茎组织有较好的抗氧化作用,能减少细胞凋亡,对延缓糖尿病性ED的发生有一定的作用。

Objective To investigate the effect of reduced-glutathione on preventing erectile dysfunction in diabetic rats. Methods Male adult Sprague-Dawley rats were induced for diabetes by an intraperitoneal injection of streptozotocin, then randomly divided into DM group and DM＋GSH group. The rats in DM＋GSH group were treated with GSH at a dosage of 200mg/kg through a intramuscular injection every day. Ten weeks later the erectile function of all these rats were evaluated,and their penises harvested. The GSH, NOS and MDA level in corpus cavernosum were measured;and TUNEL assay was used to analyse the penile cells for apoptosis. Results The diabetic rat model was successfully established. The erectile function was much better in normal control group（group C, 100%）and DM＋GSH group（62.5%） than DM group （20%）, P〈0.05. The glutathione level in DM group was significantly decreased （35.03±12.29）mg/g prot, compared to group C （61.47±8.65）mg/g prot and DM＋GSH group （75.83±15.62）mg/g prot, P〈0.05. The NOS level was approximately equal in DM＋GSH group（133.9±31.9）Uhng prot and group C （ 142.2±1.2）U/mg prot, both much higher than in DM group （58.4±18.9）Uhng prot, P〈0.05. The malondialdehyde content in corpus cavemosum was markedly increased in DM group （3.71±0.62）nmol/mg prot, compared to group C （2.08±0.34）nmol/mg prot and DM＋GSH group （2.44±0.28）nmol/mg prot, P〈0.05. TUNEL showed significantly differences in apoptosis in these groups, and the apoptosis rate in DM group, DM＋GSH group and group C were （22.6±3.6）%, （10.8±1.7）% and （7.2±2.1）%, respectively. Conclusion The reduced-glutathione has the effect of antioxidation on diabetic rats＇ penis tissues,which can decrease the apoptosis of corpus cavernosum cells, and may play some role in delaying the onset of diabetic erectile dysfunction.