Long-term observation of passive Heymann nephritis.

Chronic renal lesion with membranous changes and massive proteinuria similar to human membranous nephropathy was induced in rats through repeated intravenous injections of gamma-globulin fraction of rabbit anti-rat F X 1A antisera (GRAFA) 0.37-1.5 mg/100 g body weight. The injections were administered every 2 or 3 days over a 68-day period for a total of 26 times. It is suggested that a sufficient amount of GRAFA was given to the rats to induce renal lesion, judging from the result that no remarkable differences were observed between the severity of the histopathological and clinical changes in each rat given the various doses of GRAFA. Furthermore, this renal lesion is considered to correspond to human membranous nephropathy morphologically and clinically, judging from the fact that the protein excretion was kept at a plateau, and the capillary lumen was kept almost intact with advanced membranous changes.