EFFECT OF CYCLOSPORINE-A ON TISSUE LIPID-PEROXIDATION AND MEMBRANE-BOUND PHOSPHATASES IN HYPEROXALURIC RAT AND THE PROTECTION BY VITAMIN-E PRETREATMENT

The effect of cyclosporin A, a highly effective immunosuppressant, was investigated on hyperoxaluric rats with and without vitamin E pretrea tment. Hyperoxaluria was induced by oral feeding of 3% ammonium oxalat e in water for 3 days. Cyclosprin A (50 mg/kg body wt.) was administer ed for 3 days. Pretreatment with vitamin E (50 mg/100 g body wt., once a week for 3 weeks) was carried out before the administration of cycl osproin A and ammonium oxalate. Nonenzymatic ascorbate-induced lipid p eroxidation was increased to 1.55-fold in either cyclosporin A-adminis tered or hyperoxaluric rat kidney and liver when compared to control. The lipid peroxidation was further elevated to 1.9-fold when both cycl osporin A and ammonium oxalate were coadministered. The activities of renal and hepatic ATPase, glucose-6-phosphatase as well as the concent rations of thiols were decreased significantly (p<0.001) when cyclospo rin A was administered under hyperoxaluric condition. On pretreatment with vitamin E the cyclosporin A-induced biochemical changes observed in the presence of hyperoxaluria were abolished.