Yamasaki Y, Makino H, Ota Z
Third Department of Internal Medicine, Okayama University Medical School, Japan.
Nephron. 1994;66(2):189-99. doi: 10.1159/000187800.
We examined the ultrastructure of the bovine glomerular basement membrane (GBM) and tubular basement membrane (TBM) using ultra-high-resolution scanning electron microscopy after conductive staining without metal coating. Purified basement membranes (BMs) were obtained by sonication and acellular BMs by detergent treatments. Purified GBMs (PGBMs) and acellular GBMs (AGBMs) showed similar meshwork structures composed of regular round or oval pores and branching strands. Pore diameters were 10.2 +/- 2.4 nm (mean +/- SD) in PGBMs and 9.8 +/- 3.1 nm in AGBMs. Purified TBMs (PTBMs) and acellular TBMs (ATBMs) exhibited heterogeneous meshwork structures in which compact meshes in the cristae were combined with coarse meshes in the invaginations on the epithelial surfaces. Pore diameters were 12.6 +/- 5.2 nm in PTBMs and 11.4 +/- 4.0 nm in ATBMs which were significantly larger than those in GBMs. The width of the strands ranged from 3 to 15 nm in all BMs. A 4 M guanidine hydrochloride extraction of the acellular BMs revealed large polygonal networks in the invaginations of the TBM and twisted strands which were considered to be type IV collagen fibrils. Ultra-high-resolution scanning electron microscopy and conductive staining were useful for the study of three-dimensional architectures of BMs and revealed heterogeneous meshwork structures in the GBM and TBM which were probably caused by a different ratio of the major components.
我们使用超高分辨率扫描电子显微镜，在无金属镀膜的导电染色后，检查了牛肾小球基底膜（GBM）和肾小管基底膜（TBM）的超微结构。通过超声处理获得纯化的基底膜（BM），通过去污剂处理获得无细胞BM。纯化的GBM（PGBM）和无细胞GBM（AGBM）显示出相似的网状结构，由规则的圆形或椭圆形孔和分支链组成。PGBM中的孔径为10.2±2.4nm（平均值±标准差），AGBM中的孔径为9.8±3.1nm。纯化的TBM（PTBM）和无细胞TBM（ATBM）表现出异质的网状结构，其中嵴中的紧密网孔与上皮表面内陷中的粗网孔相结合。PTBM中的孔径为12.6±5.2nm，ATBM中的孔径为11.4±4.0nm，明显大于GBM中的孔径。所有BM中链的宽度范围为3至15nm。对无细胞BM进行4M盐酸胍提取后，在TBM的内陷处发现了大的多边形网络和扭曲的链，这些链被认为是IV型胶原纤维。超高分辨率扫描电子显微镜和导电染色有助于研究BM的三维结构，并揭示了GBM和TBM中的异质网状结构，这可能是由主要成分的不同比例引起的。
