Ultrastructural Analysis of Functional Properties of the Glomerular Filtration Barrier

(1)肾小球超微结构：采用冷脱水技术对大鼠肾脏进行TEM处理，可见肾小球包括系膜的超微结构。系膜细胞具有许多突起，含有丰富的肌动蛋白丝。这些突起经常与肾小球基底膜（glomerular basal membrane， GBM）发生明显的接触以固定肾小球基底膜。锚定被认为可以产生血管壁张力来平衡毛细血管血压。(2) GBM的超微结构：采用冷脱水后的透射电镜或高分辨率扫描电镜观察GBM的超微结构。我们观察到：(1)GBM是由颗粒状物质结合的纤维网络组成的；(2)原纤维的排列是为了支持机械应力；(3)不同类型的肾基底膜中原纤维的性质和排列是不同的。(3)肾小球结构变化：采用光镜和透射电镜对实验处理后大鼠肾脏的结构变化进行形态学分析。我们发现肾小球结构的改变并不像一些生理学研究所认为的Kf变化那样剧烈。

(1) Ultrastructure of the glomerulus : The rat kidneys were processed for TEM with a cold dehydration technique to visualize the ultrastructure of the glomerulus including the mesangium. The mesangial cells possessed many processes containing abundant actin filaments. The processes make frequent contact with the glomerular basement membrane (GBM) obviously to anchor it. The anchoring is thought to develop wall tention to counterbalance the capillary blood pressure.(2) Ultrastructure of GBM : The ultrastructure of GBM is visualized either with TEM after cold-dehydration technique or with high resolution SEM. It was observed (1) that the GBM is composed of fibrillar network associated by granular materials, (2) that the fibrils are arranged to support mechanical stresses, and (3) that the nature and arrangement of the fibrils are various among different types of basement membranes in the kidney.(3) Structural change of the glomerulus : The structural change of the rat kidney after experimental procedures was analyzed morphob\metrically by means of light and transmission electron microscopy. It was found that the glomerular structure alters not so dramatically as expected from Kf change which was suggested by several physiological studies.