Capsular basement membrane alterations after tubulus atrophy and glomerulosclerosis in the dog kidney: contribution to the pathology of basement membrane genesis.
After K2HPO4 had been given to beagle dogs orally at a dose of 0.8 g/kg body weight for 14-38 weeks disseminated atrophy of the proximal tubule was apparent. As a result of this process glomerular alterations occur which develop via various stages of inflammation into glomerulosclerosis. Electron microscope findings of particular interest were obtained in the parietal epithelial cells and their basement membrane (BM). Ergastoplasma-rich epithelial cells often have organelle-free intracytoplasmic zones which contain solely microfilamentous and finely flocculent BM-like material. Such regions often appear lacuna-like and are sharply demarcated from the remaining cytoplasma. These areas are in close topographical contact with the parietal BM. The parietal epithelial cells make contact with the BM through dense bundles of filaments. These contacts resemble hemidesmosomes. We also found comparable relationships between epithelial cells and the BM in the proximal tubules. We are convinced that the conditions which we have described in the intracellular production of a material which is similar to the BM and the attachment of these areas onto the BM by filament bundles and hemidesmosomes represent sequestrations and extrusion of BM material. We believe that these could be pathological secretory processes of dedifferentiated epithelial cells.
D000818:Animals; D001284:Atrophy; D001485:Basement Membrane / Q000648:ultrastructure*; D003593:Cytoplasm / Q000648:ultrastructure; D003599:Cytoskeleton / Q000648:ultrastructure; D003896:Desmosomes / Q000648:ultrastructure; D004285:Dogs; D004848:Epithelium / Q000648:ultrastructure; D005921:Glomerulonephritis / Q000473:pathology*; D005923:Glomerulosclerosis, Focal Segmental / Q000139:chemically induced / Q000473:pathology*; D007678:Kidney Glomerulus / Q000098:blood supply / Q000648:ultrastructure*; D007684:Kidney Tubules / Q000187:drug effects / Q000648:ultrastructure*; D010710:Phosphates
D010710:Phosphates