硫化氢对1型糖尿病大鼠肾诱导型一氧化氮合酶的影响

Effect of hydrogen sulfide on inducible nitric oxide synthase in kidneys of Type 1 diabetic rats

目的:观察硫化氢(hydrogen sulfide,H_2S)对1型糖尿病大鼠肾诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)的影响。方法:将32只雄性SD大鼠随机分为4组(n=8):正常对照(NC)组、糖尿病(DM)组、糖尿病治疗(NaHS+DM)组和NaHS对照(NaHS)组。采用腹腔注射55 mg/kg链脲佐菌素复制1型糖尿病大鼠模型。造模成功后,NaHS+DM组和NaHS组大鼠腹腔注射56μmol/kg NaHS溶液进行干预治疗。8周后,分别测定各组大鼠血清和肾组织中总一氧化氮合酶(total nitric oxide synthase,T-NOS)、iNOS活性和一氧化氮(NO)水平;测定肾组织中谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活性;采用透射电镜观察肾皮质超微结构变化;Western印迹检测肾组织iNOS蛋白表达。结果:与NC组相比,NaHS组各项指标间差异均无统计学意义(P>0.05),而DM组大鼠血清和肾组织中T-NOS,iNOS活性和NO水平均显著增高(P<0.01);肾组织GSH-Px活性明显下降(P<0.01)。电镜观察显示DM组大鼠肾小球基底膜增厚、系膜基质增多,足突融合;iNOS蛋白表达明显升高。与DM组相比,NaHS+DM组血清和肾T-NOS,iNOS活性和NO水平明显下降(P<0.01),GSH-Px活性明显升高(P<0.01),肾超微结构损伤明显减轻,iNOS蛋白表达显著降低(P<0.01)。结论:H2S对1型糖尿病大鼠肾损伤具有保护作用,其机制可能与下调iNOS活性和蛋白表达,降低肾NO生成相关。

Objective： To investigate effects of hydrogen sulfide （HzS） on inducible nitric oxide synthase （iNOS） in kidneys of Type 1 diabetic rats.Methods： Thirty-two male SD rats were randomly divided into four groups： A normal control （NC） group, a diabetes mellitus （DM） group, a Naris （NaHS＋DM） group, and a Naris control （NariS） group （n=8 per group）. Type 1 diabetes was induced by a single intraperitoneal injection of streptozotocin （55 mg/kg）. After successful establishment of models, the rats in NaHS＋DM and Naris groups were injected with Naris solution （56 μmol/kg） intraperitoneally. Eight weeks later, the activities of total nitric oxide synthase （T-NOS） and iNOS, as well as the level of nitric oxide （NO） were detected in serum and renal tissues, respectively. The activity of glutathione peroxidase （GSH-Px） was determined in renal tissues. The ultrastructures of renal tissues were observed by transmission electron microscope. The protein expression of iNOS in renal tissues was detected by Western blot. Results： Compared with the NC group, there was no significant difference in the various indexes in the Naris group （P〉0.05）. However, in the DM group, the activities of T-NOS and iNOS, and the level of NO were all increased significantly in serum and renal tissues, while the activity of GSH-Px was decreased in renal tissues. Under the electronic microscope, the thickening of the glomerular capillary basement membrane, the proliferation of mesangial matrix, and the foot fusion were observed. The protein expression ofiNOS was increased obviously in renal tissues in the DM group （P〈0.01）. Compared with the DM group, the activities of T-NOS and iNOS and the level of NO were all decreased in serum and renal tissues, while the activity of GSH-Px was increased in renal tissues in the NaHS＋DM group （P〈0.01）. The renal ultrastructural damages were ameliorated obviously. The protein expression ofiNOS was decreased significantly （P〈0.01）. Conclusion： H2S exerts a protective effect on kidney injury in type 1 diabetic rats. The mechanism might be related to inhibition of iNOS activity and protein expression, in turn leading to reduction of NO content in renal tissues.