Distribution of endogenous albumin in the rat glomerulus: role of hemodynamic factors in glomerular barrier function.
Distribution of endogenous albumin in the rat glomerulus: role of hemodynamic factors in glomerular barrier function.
复制标题
大鼠肾小球内源性白蛋白的分布：血流动力学因素在肾小球屏障功能中的作用。
作者：
G. Ryan;M. Karnovsky
用免疫过氧化物酶超微结构技术，在正常和异常血流动力学条件下，大鼠肾小球内源性白蛋白的分布划定。麻醉的Munich-Wistar大鼠的浅表肾小球通过将戊二醛应用于肾表面而原位快速固定。固定的组织切片用与辣根过氧化物酶（HRP）缀合的抗大鼠白蛋白Fab片段处理，然后进行Graham-Karnovsky超微结构过氧化物酶定位程序。在正常血流过程中，白蛋白特异性的致密反应产物主要局限于肾小球毛细血管腔和内皮窗，仅在内层稀疏层中可检测到少量，在基底膜（GBM）或泌尿间隙中没有更深处。如果对皮质组织进行常规浸泡固定，或者如果在肾动脉结扎后原位进行固定，则在整个GBM和泌尿间隙中检测到反应产物。如果在结扎肾动脉和静脉（或动脉、静脉和输尿管）后进行原位固定，则在GBM中发现反应产物，并且在泌尿空间中发现非常大量的反应产物。如果肾蒂（动脉和静脉）闭塞5分钟后血流恢复10分钟，白蛋白的分布恢复正常。因此，肾小球屏障功能取决于正常血流条件的维持。
Using an ultrastructural immunoperoxidase technique, the distribution of endogenous albumin in the rat glomerulus was delineated under normal and abnormal hemodynamic conditions. Superficial glomeruli in anesthetized Munich-Wistar rats were rapidly fixed in situ by applying glutaraldehyde to the renal surface. Fixed tissue slices were treated with anti-rat albumin Fab fragments conjugated to horseradish peroxidase (HRP), and were then subjected to the Graham-Karnovsky ultrastructural peroxidase localization procedure. During normal blood flow, dense reaction product specific for albumin was largely confined to the glomerular capillary lumen and endothelial fenestrae, with only small amounts detectable in the lamina rara interna, and none deeper in the basement membrane (GBM) or in the urinary space. If cortical tissue was subjected to routine immersion fixation, or if fixation was performed in situ after ligation of the renal artery, reaction product was detected throughout the GBM and in the urinary space. If fixation was performed in situ after ligation of the renal artery and vein (or artery, vein and ureter), reaction product was found in the GBM and, in very large amounts, in the urinary space. If blood flow was restored for ten minutes after five minutes of renal pedicle (artery and vein) occlusion, the distribution of albumin returned to normal. Thus, glomerular barrier function depends upon the maintenance of normal blood flow conditions.