Effect of superoxide dismutase on glomerular nephritis

The antiinflammatory effect of superoxide dismutase was studied in rats with kidney intoxication induced by the injection of nephrotoxic serum. The urinary excretion of protein was increased significantly by the administration of an intravenous injection of nephrotoxic serum. The daily injection of superoxide dismutase significantly suppressed the increase in urinary excretion of protein. The injection of nephrotoxic serum increased the renal malondialdehyde level by 3-fold compared to the level in the control rats. The daily injection of superoxide dismutase also significantly suppressed the renal malondialdehyde concentration. The change of serum Cu,Zn-superoxide dismutase level and tissue distribution after the intramuscular injection of this enzyme was investigated by immunoassay. Human Cu,Zn-superoxide dismutase localized in kidney exclusively and reached maximum concentration at about 3 hr after the injection. From these results, we propose that superoxide dismutase, which is a scavenger of superoxide anion radicals, inhibits lipid hydroperoxidation in the kidney induced by activated oxygen, and thus protects the renal cells from the damage induced by the injection of nephrotoxic serum.