Kanwar Y S, Rosenzweig L J
Kidney Int. 1982 Apr;21(4):565-74. doi: 10.1038/ki.1982.63.
Changes in the permeability of the glomerular capillary wall (GCW) to native ferritin (NF), following detachment of the visceral epithelium from the glomerular basement membrane (GBM) were investigated. Detachment was induced by either perfusing kidneys with highly purified neuraminidase or by the induction of nephrosis through administration of puromycin aminonucleoside (PAN). Both experimental treatments resulted in marked glomerular ultrastructural changes which were characterized by focal detachment of the visceral epithelium from the GBM, replacement of the normal pattern of interdigitating foot processes with flattened expanses of continuous epithelium at certain areas of the GCW, and a generalized loss of sialic acid-rich epithelial cell cost in areas where the epithelium was detached as well as where it remained adherent. These changes were more frequent and prominent in the paramesangial regions of the glomeruli. When experimentally treated kidneys were perfused with NF, the tracer leaked into the urinary spaces in those areas of the GBM where the epithelium was detached. By contrast, in those areas of the GCW where the epithelium remained adherent, the tracer localized within the GBM mainly at the level of the lamina rara interna (LRI), and none of it appeared in the urinary spaces. Nephrotic and neuraminidase control kidneys were ultrastructurally normal, NF localizing mainly in the inner layers of the GBM. These data are consistent with the idea that the firm attachment of the epithelial foot processes to the GBM plays a vital role in determining the permselectivity properties of the GCW to plasma macromolecules.
研究了肾小球毛细血管壁（GCW）对天然铁蛋白（NF）的通透性变化，这些变化发生在内脏上皮从肾小球基底膜（GBM）脱离之后。通过用高度纯化的神经氨酸酶灌注肾脏或通过给予嘌呤霉素氨基核苷（PAN）诱导肾病来诱导脱离。两种实验处理均导致明显的肾小球超微结构变化，其特征为内脏上皮从GBM局灶性脱离，在GCW的某些区域，正常的指状足突模式被连续上皮的扁平区域所取代，并且在上皮脱离以及仍保持粘附的区域中，富含唾液酸的上皮细胞覆盖物普遍丧失。这些变化在肾小球的系膜旁区域更为频繁和明显。当用NF灌注经实验处理的肾脏时，示踪剂在GBM上皮脱离的那些区域漏入尿腔。相比之下，在GCW上皮保持粘附的那些区域，示踪剂主要定位在GBM的内疏松层（LRI）水平，并且没有示踪剂出现在尿腔中。肾病和神经氨酸酶对照肾脏在超微结构上是正常的，NF主要定位在GBM的内层。这些数据与以下观点一致，即上皮足突与GBM的牢固附着在决定GCW对血浆大分子的选择通透性特性方面起着至关重要的作用。
