Nephritogenic glycoprotein. 3. Immunochemical studies on nephritogenic activity of homologous water-soluble glycoproteins extracted from various rat organs.

Rats given a single injection in the hind footpads of homologous, water-soluble, organ glycoprotein and Freund's incomplete adjuvant developed proliferative glomerulonephritis. Among the glycoproteins obtained from various rat organs, the nephritogenic activity (on a dry weight basis) of the active glycoprotein prepared from lung was a little lower than that from renal cortex, and was followed by those from aorta, heart, liver, spleen and muscle in that order. This nephritogenic glycoprotein is present also in renal medulla, and also in renal pyramids (inner medulla) which contain neither glomeruli nor proximal convoluted tubules. The activity of nephritogenic glycoproteins prepared from various rat organs is nearly parallel with both the hexose content and the yield of the cathodal part of the hexose peak in zone electrophoresis. Nephritogenic glycoproteins obtained from various rat organs share a structural component isolated from GBM. However, the immunofluorescence pattern in the glomerulonephritis induced by a single injection of each of these glycoproteins was mesangial' rather than linear'.