Arteriolar lesions in human renal biopsy material with special regard to the ultrastructural changes in the basal lamina network of the vascular wall.

The arteriolar changes in renal biopsy samples were studied by light and electron microscopy and immunohistologic observations. Arteriolar hyaline thickening was found to occur in virtually all renal diseases, regardless of whether these were accompanied by hypertension or not. Only amyloidosis and dense deposit glomerulonephritis were accompanied by specific ultrastructural arteriolar changes. The nonspecific "hyalin" was shown ultrastructurally to contain various components: accumulated basement membrane material, fine granular deposit (with filamentous or lipid details), and granulovesicular and threadlike membrane structures. Presumably the material constituting these structures originates partly from the blood and partly from elements of the vascular wall itself.