Changes in lipid peroxidation and activities of xanthine oxidase, superoxide dismutase and catalase in kidneys of cephaloridine-administered rats.

To elucidate the toxic and protective mechanisms responsible for cephaloridine (CER)-induced nephrotoxicity, changes in renal formation of malondialdehyde and renal activities of xanthine oxidase, superoxide dismutase and catalase were mainly investigated for 15 days in rats that received single intravenous injections of CER in doses of 100 and 1,000 mg/kg body weight. In the 100 mg/kg group, the above items determined remained within the control levels. In the 1,000 mg/kg group, renal formation of malondialdehyde was observed to be accelerated with the following two stages: highly in the early stage (the 3rd hour to the 2nd day, especially at the 3rd hour) and more highly in the late stage (the 2nd to the 7th day). Concerning the other items determined, significantly different changes were hardly observed in the 1,000 mg/kg group within the 12th hour of the early stage, while the rises in renal activities of xanthine oxidase and falls in renal activities of superoxide dismutase and catalase were observed in the late stage. These results suggested that the increment in malondialdehyde formation in the late stage might be explained enzymatically by both the rises in the activities of xanthine oxidase and the declines in the activities of superoxide dismutase and catalase and that those in the early stage did not relate directly to the above renal enzymatic systems.