Morphological alterations of glomerulus induced by infusion of cationized ferritin

Morphological alterations of the glomerulus were induced by infusion of cationized ferritin. After a direct injection of highly cationized ferritin (CF) into the left kidney of rats, endothelial injuries were followed by activation of platelets and the coagulation system after 1-2 h, which occluded capillary loops. In most glomeruli, resolving processes occurred from 2 h onward, leaving a mild thickening of the mesangial region at 7 days. On the other hand, in severely involved glomeruli, capillary loops were still obstructed even at 24 h by hypertrophic and proliferated endothelial cells as well as mesangial cells, instead of platelets and fibrin strands. After this period, exfoliation of podocytes and endothelial cells occurred over a wide area, which resulted in glomerular obsolescence at 7 days. These progressive glomerular injuries were assumed to be closely related to the persistence of CF in glomeruli, which might be caused by disturbances of glomerular clearing systems. Mild proteinuria was only noticed in severely involved cases. It is concluded that an assault on glomerular endothelial cells by cationic macro-molecules can cause thrombotic complications leading to glomerular obsolescence.