Shirato I, Tomino Y, Koide H, Sakai T
Department of Medicine, Juntendo University, School of Medicine, Tokyo, Japan.
Cell Tissue Res. 1991 Oct;266(1):1-10. doi: 10.1007/BF00678705.
The fine structure of the glomerular basement membrane (GBM) of the rat kidney was studied by means of high resolution scanning electron microscopy. Specimens were taken from kidneys perfused with paraformaldehyde, freeze-fractured and then processed with conductive staining. The fractured surface of glomerular tufts exhibited the inner and outer surface of the GBM uncovered by endothelial and epithelial cells. The lamina densa was composed of densely packed granular material together with scattered fibrils. The laminae rarae interna and externa were composed of a meshwork that showed some structural heterogeneities. The meshwork composing the lamina rara interna contained 5- to 9-nm-thick fibrils, had pores 11-30 nm wide, and was associated with granular material except in those places that corresponded with endothelial fenestrae. The meshwork of the lamina rara externa was made up of 6- to 11-nm-thick fibrils, and had smaller pores under the foot processes (10-24 nm wide) than those near the filtration slits (16-32 nm wide). In addition to the meshwork, the lamina rara interna contained microfibrils that were arranged differently depending on the topography of the capillary wall: scattered fibrils had no predominant orientation at the convex side, circumferential bundles lay at the concave side of the peripheral capillary wall, and had a circumferential arrangement in the paramesangial wall.
采用高分辨率扫描电子显微镜研究了大鼠肾脏肾小球基底膜（GBM）的精细结构。标本取自用多聚甲醛灌注的肾脏，进行冷冻断裂，然后进行导电染色处理。肾小球丛的断裂表面显示出GBM的内表面和外表面，未被内皮细胞和上皮细胞覆盖。致密层由紧密堆积的颗粒物质和散在的纤维组成。内疏松层和外疏松层由显示出一些结构异质性的网络组成。构成内疏松层的网络包含5至9纳米厚的纤维，有11至30纳米宽的孔隙，并且除了与内皮窗孔相对应的部位外，都与颗粒物质相关联。外疏松层的网络由6至11纳米厚的纤维组成，在足突下方的孔隙较小（10至24纳米宽），而在滤过裂隙附近的孔隙较大（16至32纳米宽）。除了网络结构外，内疏松层还含有微纤维，其排列根据毛细血管壁的地形不同而有所差异：在凸面，散在的纤维没有主要方向；在周边毛细血管壁的凹面，有周向束状排列；在系膜旁壁则呈周向排列。
