Human nephrectomy specimens with ischemic glomerular changes were studied by colloidal iron staining and immunofluorescence with respect to glomerular polyanion, immunoprotein deposition and proteinase inhibitor deposition. In the sclerotic area of ischemic glomerular changes, polyanion loss and deposition of IgM, C1q, C4 and C3 were observed. These findings were common in cases with and without chronic pyelonephritis showing a considerable similarity to the glomerular changes of experimental focal sclerosis in rats or focal sclerosing glomerulonephropathy in human. α1-Antitrypsin and α2-macroglobulin (proteinase inhibitors) were also found in the sclerotic area. In particular, α1-antitrypsin was always present in the sclerotic portions of every atrophic nephron and an important role of α1-antitrypsin in atrophy of nephrons was sugges