Morphological change of foot processes of podocytes in glomerulus is correlated with the change of α-actinin 4. Electron microscopic appearance of glomerular capillary (A, B) and immuno-electron microscopic localization of α-actinin 4 in glomerular capillaries (C, D). (A, B) Comparison of electron micrographs of the capillary wall of the glomerulus from nondiabetic (A) and diabetic (B) kidneys revealed fused foot processes of podocytes and a thickened basement membrane in the sections from the diabetic rat. En, endothelial cell; GBM, glomerular basement membrane; P, foot process of podocyte. Scale bar, 200 nm. (C, D) Sections of nondiabetic and diabetic kidneys were immunolabeled for α-actinin 4 (12-nm gold particles). Whereas the gold particles were localized mainly in the periphery of the foot processes in the nondiabetic kidney, they were found not only in the periphery but also in the inner aspect of foot processes in the diabetic kidney. (E) Density (number/μm2) of colloidal gold particles representing α-actinin 4 in the foot processes of podocytes from nondiabetic (open bar) and diabetic (closed bar) kidneys. Data are the means ± SEM from 3 different rats. *P < 0.01 vs. control (Wistar rat).