ANTIOXIDANT ACTIVITY OF FUROSEMID UNDER CONDITIONS OF EXPERIMENTAL ISCHEMIA OF THE KIDNEYS

Abstract

THE AIM of the investigation was to study effects of furosemid on the indices of oxidant and antioxidant statuses of the kidney under conditions of acute experimental ischemia. MATERIAL AND METHODS. Ischemia of the kidney was caused in rats by ligation of the left renal artery for 4 hours. Furosemid (20 mg/kg) was injected intraperitoneally 1,3 and 10 hours before ischemia. Total oxidant activity and thiobarbiturate sensitive products of lipid peroxidation were determined. The antioxidant status was estimated by changes of the indices of total antioxidant activity (TAA) and by activity of antioxidant enzymes catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPO). RESULTS. Experiments in vivo have shown that after injection of furosemide the oxidant status indices did not practically differ from those in control animals against the background of four hour long ischemia. In contrast, the antioxidant activity indices were substantially changed under the influence of the diuretic. If in control experiments the dramatic growth of the radical level in ischemia activated the antioxidant system in the kidneys, the preliminary injection of furosemide prevented activation of TAA in ischemic kidneys. The maximal effect was noted after injection of the diuretic 10 hours before ischemia. The catalase activity correlated with the changes of TAA activity. Changes of activity of SOD and GPO were less pronounced. CONCLUSION. In direct experiments with experimental acute ischemia of the kidney it was shown that furosemid increased the resistance of the renal tissue to hypoxia thus preventing activation of the antioxidant system. It is fairly possible that the ability of the diuretic to suppress the intensity of processes of free radical oxidation is a good contribution to prevent an ischemic lesion of the kidney.