厄贝沙坦对糖尿病大鼠肾脏足细胞保护作用的研究

Protective effects of Irbersartan against podocyte injury in rats with early diabetic nephropathy

目的探讨厄贝沙坦对糖尿病大鼠尿蛋白以及足细胞、足突顶膜区主要的带负电荷跨膜蛋白Podocalyxin的影响。方法采用链脲佐菌素(streptozotocin STZ,65mg/kg)腹腔注射建立糖尿病大鼠模型。将30只雄性SD大鼠随机分为3组:正常组、糖尿病模型组和厄贝沙坦(ARB)治疗组。连续监测血糖8周,8周后处死各组大鼠的前一天行24小时尿蛋白定量和肾功检查了肾组织;处死大鼠后取行苏木素伊红染色(hematoxylin and eosin stain,HE)观察其病理变化;透射电镜观察足细胞、裂孔隔膜等变化。采用Western蛋白印迹从蛋白水平观察nephrin蛋白水平的表达。结果模型组大鼠镜下见肾小球体积增大,基底膜增厚(P<0.05)及系膜物质增多,足细胞与正常对照组比较明显减少(P<0.01),肾小球内可见散在炎细胞浸润。部分毛细血管腔受压变窄,部分肾小管上皮细胞胞浆疏松,轻度水肿。治疗组与模型组分别比较,肾小球基底膜未见明显增宽,足细胞数明显增加(P<0.05)。模型组大鼠血糖、24h尿蛋白、血肌酐水平明显升高,与对照组相比差异显著(P<0.05)。治疗组与模型组相比,上述生化指标均有所改善(P<0.05)。West-ern蛋白印迹结果表明,与正常组相比,模型组nephrin蛋白水平明显下降,经过厄贝沙坦干预后nephrin表达明显上调。结论厄贝沙坦能改善糖尿病肾病大鼠足细胞及肾脏的病理损害,显著减少糖尿病大鼠24h尿蛋白,上调nephrin的表达,具有一定的肾保护作用。

Objective To investigate the effects of Irbersartan on proteinuria and the mchanisms in rat model with Diabetic Nephropathy（DN）.Methods The Diabetic Nephropathy Rat Model was established by the injection of streptozotocin in abdominal cavity.30 healthy Sprague-Dawley male rats were randomly divided into 3 groups： the normal group,diabetic nephropathy group and Irbesartan treatment group.The blood glucose was monitored routinely.After eight weeks,rats from each group were killed.Twenty-four hours urine protein,serum creatine were measured at the end of the study.Renal pathological and podocyte changes were evaluated.The Protein of nephrin expression was assessed by western blot analysis.In diabetic nephropathy group,it is observed that the volume of renal glomerulus was inlarged,the basement membrane was thickening,and the mesenterium mass was increased.There were some inflammatory cells in renal glomerulus.Some capillary lumen became collapsed due to compression and some renal tubular epithelial cells was slightly edematus.Results The number of potocyte was decreased dramaticly in DM group compared wtih normal group（P0.01）.Compared to DM group,the basement membrane became thinning and the number of podocyte was increased in the treatment groups（P0.05）.In diabetic nephropathy group,Compared with the normal group,the twenty-four hours urine protein、serum creatine,serum glucose were raised significantly in the diabetic nephropathy group（P0.05） and treated group（P0.05）.Compared with the diabetic nephropathy group,the twenty-four hours urine protein,serum creatine,serum glucos were reduced significantly in treated group（P0.05）.The expression of nephrin decreased noticeably in diabetic nephropathy group.ARB treatment could significantly reverse the change.Conclusion ARB could enhanced the expression of nephrin and amendment pathological lesions of podocyte and nephron and obviously reduced the twenty-four hours urine protein in diabetic nephropathy rats.