Fries J W, Sandstrom D J, Meyer T W, Rennke H G
Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
Lab Invest. 1989 Feb;60(2):205-18.
The effects of glomerular size and visceral epithelial cell integrity upon the development of progressive glomerulosclerosis was studied by superimposing renal ablation on adriamycin-induced nephropathy in rats. Adriamycin alone caused focal epithelial cell injury and proteinuria but minimal segmental glomerulosclerosis. In normal rats, renal ablation was accompanied by mild progressive proteinuria and glomerulosclerosis. However, renal ablation in rats with adriamycin nephropathy caused a dramatic increase in proteinuria and a disproportionately high frequency of segmental glomerulosclerosis. Accelerated glomerular injury after renal ablation in adriamycin-treated rats was associated with substantial glomerular hypertrophy with near doubling of the tuft volume. Morphometric and autoradiographic studies showed that compensatory glomerular hypertrophy occurs without a proportional increase in the number of visceral epithelial cells, leading to a substantial reduction in the density of these cells within the capillary tuft. The severity of segmental glomerulosclerosis showed a significant correlation with the glomerular volume and the reciprocal of the visceral epithelial cell density. Ultrastructural observations indicate that epithelial defects with detachment of the cell processes from the underlying basement membrane are almost invariably seen in areas of segmental glomerulosclerosis with hyalinosis. These findings suggest that the process of progressive glomerulosclerosis is, to a great extent, contingent upon the development of epithelial cell defects, that result from direct injury or from a reduction in the cell density after inordinate compensatory glomerular hypertrophy.
通过将肾切除叠加于阿霉素诱导的大鼠肾病模型上，研究肾小球大小及脏层上皮细胞完整性对进行性肾小球硬化发展的影响。单独使用阿霉素可导致局灶性上皮细胞损伤和蛋白尿，但仅有轻微的节段性肾小球硬化。在正常大鼠中，肾切除伴有轻度进行性蛋白尿和肾小球硬化。然而，阿霉素肾病大鼠进行肾切除后，蛋白尿显著增加，节段性肾小球硬化的发生率异常高。阿霉素处理的大鼠肾切除后肾小球损伤加速，与肾小球显著肥大有关，肾小球体积几乎翻倍。形态计量学和放射自显影研究表明，代偿性肾小球肥大发生时，脏层上皮细胞数量没有相应增加，导致这些细胞在毛细血管襻内的密度大幅降低。节段性肾小球硬化的严重程度与肾小球体积及脏层上皮细胞密度的倒数显著相关。超微结构观察表明，在伴有玻璃样变的节段性肾小球硬化区域，几乎总是可见上皮细胞缺陷，表现为细胞突起与下方基底膜分离。这些发现提示，进行性肾小球硬化的过程在很大程度上取决于上皮细胞缺陷的发展，这些缺陷源于直接损伤或过度代偿性肾小球肥大后细胞密度降低。
