A glomerulonephritis was induced in mice by injection of subnephrotoxic dose of nephrotoxic serum (NTS) after preimmunization with rabbit IgG. In order to characterize this glomerulonephritis, light, electron and immunofluorescence microscopic studies were carried out 15 days after NTS injection, the time when increases in urinary protein and serum cholesterol and a decrease in serum albumin were apparent.
Characteristic changes were widespread thickening of capillary walls and narrowing of the capillary lumen owing to widening of mesangial areas. In those capillary walls, the mesangial interposition into subendothelial areas was often noted ultrastructurally and double track was confirmed on sections stained with PAM. Linear deposition of mouse IgG was detected in capillary walls by immunofluorescence. In severely affected glomeruli, PAS-positive hyaline nodular lesion was observed light microscopically and massive mesangial deposits ultrastructurally.
Visceral epithelial cells demonstrated fusion of the foot processes, microvilli formation, occasional proliferation and enlargement. Parietal epithelial cells proliferated, forming cellular or fibrocellular crescent.
Based on these characteristics, it appears this nephritic model shares a common pathology with human membranoproliferative glomerulonephritis type 1 and crescentic glomerulonephritis and can be considered an appropriate model for producing severe nephritis for short periods.
