Abstract: Objective: To observe the feature of glomerular endothelial function in rats with early diabetic nephropathy(DN),and evaluate the effect of reduced glutathione on glomerular endothelial function in diabetic rats.Methods: Streptozotocin(60mg/ kg) was injected into peritoneal cavity in the rats to establish animal DN model.The diabetic rats were randomly divided into DN model group and reduced glutathione treated group.Coherent kits were used to detect glomerular nitrogen monoxide(NO),the activity of glomerular endothelial nitric oxide synthase(eNOS),von Willebrand factor(vWF),urinary albumin(UA),superoxide dismutase(SOD),malondialdehyde(MDA) and glutathione peroxidase.Results: Compared with normal control group,glomerular NO,activities of glomerular eNOS were significantly decreased in early DN rats,while the level of vWF and UA significantly increased(P<0.01),and the level of UA was correlated with the level of glomerular vWF(P<0.05).Glomerular SOD,glutathione peroxidase significantly decreased in early DN rats,while MDA was significantly increased(P<0.01).Compared with DN model group,glomerular NO,activities of glomerular eNOS were significantly increased in early DN rats treated with reduced glutathione,while the level of vWF and UA were significantly decreased,and glomerular MDA was significantly increased in early DN rats treated with reduced glutathione(P<0.01).Conclusions: Glomerular endothelial function is indiscriminate in early DN rats,while the level of oxidative stress significantly increases.Reduced glutathione improves glomerular endothelial dysfunction in early DN rats,maybe through reducing oxidative stress.