Takami H, Naramoto A, Shigematsu H, Ohno S
Department of Pathology, Shinshu University School of Medicine, Matsumoto, Japan.
Kidney Int. 1991 Apr;39(4):659-64. doi: 10.1038/ki.1991.79.
The glomerular basement membrane of rat kidneys were three-dimensionally observed by quick-freeze and deep-etch replica methods at high resolution. The middle layer (lamina densa) was composed of 6 to 10 nm fibrils which formed a meshwork structure. The space between the fibrils had polygonal shape. The average long dimension of the space between fibrils was 17 nm and the short one was 13 nm. At the outer layer (lamina rara externa), fibrils connected podocytes perpendicularly with the meshwork of the middle layer. At the inner layer (lamina rara interna), similar perpendicular fibrils also connected endothelial cells with the meshwork of the middle layer. This is the first report to visualize the three-dimensional meshwork structure of the middle layer (the lamina densa) in situ. The function of anchoring podocytes to the lamina densa was suggested in the perpendicularly arranged fibrils of the outer layer. The quick-freeze and deep-etch method is useful in analyzing filamentous ultrastructure in glomeruli, and will be applied to clarifying pathological ultrastructure in kidney diseases.
采用快速冷冻和深蚀刻复型方法在高分辨率下对大鼠肾脏的肾小球基底膜进行了三维观察。中间层（致密层）由6至10纳米的原纤维组成，形成网状结构。原纤维之间的空间呈多边形。原纤维之间空间的平均长径为17纳米，短径为13纳米。在外层（外疏松层），原纤维与中间层的网状结构垂直连接足细胞。在内层（内疏松层），类似的垂直原纤维也将内皮细胞与中间层的网状结构连接起来。这是首次原位观察到中间层（致密层）三维网状结构的报道。外层垂直排列的原纤维提示了足细胞与致密层的锚定功能。快速冷冻和深蚀刻方法有助于分析肾小球中的丝状超微结构，并将应用于阐明肾脏疾病的病理超微结构。
