阿霉素肾病幼鼠肾组织足细胞蛋白podocin定位和半定量分析

Localization and semi-quantitive analysis of podocin in adriamycin neprosis of young rats

目的 探讨podocin在肾小球滤过膜中的定位及其在肾病综合征蛋白尿发生中的作用。方法 制备大鼠阿霉素肾病模型(肾病组)与正常对照组。进行对比观察。4周后测尿蛋白的变化,同时处死大鼠取肾皮质应用免疫组织化学方法定位及半定量分析研究各组肾组织中足细胞蛋白podo cin的异同。结果 podocin主要分布在肾小球上皮细胞足突裂隙隔膜的胞质面,小部分金颗粒偶可发现于离肾小球基底膜(GBM)稍远的足突细胞的表面,而在GBM、内皮细胞、系膜、包曼囊或肾小管均没有表达迹象。肾病组肾小球中podocin表达较正常对照组明显减少(P<0. 01 )。结论 podocin为肾小球上皮细胞裂孔隔膜上的主要结构蛋白;阿霉素肾病幼鼠肾小球podocin含量显著减少。

Objective To study the localization of podocin in glomerulus and its potential role in proteinuria occuring in nephrotic syndrome. Methods The study set up adriamycin nephropathic model of rats as nephropathic group and compared with that the normal control group.Four weeks later proteinuria were measured and all rats were killed. The renal cortex was taken for immunohischemical and semi-quantitive analysis. Results Podocin distributed at the base of the podocyte foot processes near the GBM.It primarily located at the cytoplasmic face of the plasma membrane adjacent to the filtration slits. Small clusters of particles of podocin were occasionally found along the surface of the foot processes with a distance from the GBM. No significant labelling was observed on the GBM orthe podocyte cell bodies. No labelling was detected on Bowmans capsule epithelia cells,endothelial or mesangial cells. At the end of the experiment, optical density (A) of each group were gained through Metaphorgh as following: normal control group: 0.298±0.041 4; nephropathic control group: 0.562±0.037 5. Compared with the nephropathic group,optical density was significantly different ( F=77.56, P <0.001).The staining intensity of podocin decreases prominently in nephropathic samples compared with normal control group. Conclusion Podocin is a major component of the slit diaphram; the concentration of podocin decreases prominently in nephropathic samples; it is possible that podocin plays an important role in the occurance of proteinuria in NS.