Carlson E C, Kenney M C
Ren Physiol. 1980;3(1-6):280-7. doi: 10.1159/000172772.
Our recent morphological studies showed that basement membranes isolated from renal tubules tended to collapse and form folded sheets while glomerular basement membranes were more resilient. In an effort to study the shapes of various isolated basement membranes in undissociated tissues, a method was developed to remove all cellular elements and leave the extracellular matrix and associated basement membranes intact. Accordingly, transplant quality human kidneys were harvested, perfused with Collin's medium and transported to the laboratory on ice. The renal cortex was then peeled away by blunt dissection, further minced to 2 mm3 and placed in 1 mM EDTA (with gentle intermittent stirring) for 72 h at 4 degrees C. Solubilization of cellular materials was carried out by successive washings with 3% Triton X-100, 0.025% DNAse and 1-4% sodium deoxycholate (all with gentle stirring or shaking at 22 degrees C). Each solution contained 0.1% sodium azide. At the level of fine structure, glomerular, tubular, Bowman's capsular and peritubular capillary basement membranes all maintained their respective shapes and did not collapse. Glomerular basement membrane was particularly striking in this regard and exhibited an open, lobulated form that closely resembled its in vivo histoarchitecture. Moreover, when the acellular tissue blocks were prepared for scanning electron microscopic observation, the glomerular basement membranes exposed at the surface of the block showed a remarkable structural rigidity. These basement membranes were free-standing, convoluted electron-dense sheets, continuous with highly folded central mesangial regions. It seems significant that glomerular basement membranes maintain their in vivo conformation irrespective of the presence of other extracellular matrix components while removal of these materials by organ subfractionation results in folding and general shapelessness of tubular basement membrane. It is possible that in addition to its unique role in filtration, glomerular basement membrane may also serve to preserve glomerular shape, regardless of changing cell populations or alterations in hydrostatic pressures.
我们最近的形态学研究表明，从肾小管分离出的基底膜往往会塌陷并形成折叠片，而肾小球基底膜则更具弹性。为了研究未解离组织中各种分离的基底膜的形状，我们开发了一种方法来去除所有细胞成分，同时使细胞外基质和相关基底膜保持完整。因此，获取移植质量的人类肾脏，用柯林氏培养基灌注，并在冰上运至实验室。然后通过钝性解剖剥离肾皮质，进一步切碎至2立方毫米，并置于1毫摩尔/升乙二胺四乙酸（轻轻间歇性搅拌）中，在4摄氏度下放置72小时。通过用3% Triton X - 100、0.025%脱氧核糖核酸酶和1 - 4%脱氧胆酸钠连续洗涤（均在22摄氏度下轻轻搅拌或振荡）来溶解细胞物质。每种溶液都含有0.1%叠氮化钠。在精细结构水平上，肾小球、肾小管、鲍曼囊和肾小管周围毛细血管基底膜均保持各自的形状，未发生塌陷。在这方面，肾小球基底膜尤为显著，呈现出开放的、分叶状的形态，与体内组织结构非常相似。此外，当为扫描电子显微镜观察制备无细胞组织块时，组织块表面暴露的肾小球基底膜显示出显著的结构刚性。这些基底膜是独立的、卷曲的电子致密片，与高度折叠的中央系膜区域相连。肾小球基底膜无论其他细胞外基质成分是否存在都能保持其体内构象，而通过器官分级分离去除这些物质会导致肾小管基底膜折叠且总体形状不规则，这似乎具有重要意义。有可能除了在滤过方面的独特作用外，肾小球基底膜还可能有助于维持肾小球的形状，而不受细胞群体变化或静水压力改变的影响。
