The effects of a new immunosuppressive agent, FK506, on the glomerular injury in rats with accelerated nephrotoxic serum glomerulonephritis.

The aim of the present work was to study the effects of a new immunosuppressive drug, FK506, in accelerated nephrotoxic serum glomerulonephritis. Glomerulonephritis was induced in female Wistar rats by the preimmunization with normal rabbit IgG (Day-4) and the subsequent intravenous injection of rabbit anti-GBM serum (Day 0). Without treatment with FK506, rats developed proteinuria at Day 6 and onward. Rat anti-rabbit IgG was strongly detected at Day 6 and the titer was maintained through Day 20. Moderate hypercellularity and focal crescent formation were observed at Day 20. Rats injected intramuscularly with 0.3 or 1 mg/kg of FK506 did not develop proteinuria and the anti-rabbit IgG titer was much less or was undetectable throughout the experiments. These data suggest that FK506 is effective in the present model of glomerulonephritis.