Protection of cyclosporin A-induced biochemical changes by vitamin E pretreatment in hyperoxaluric rat kidney

The study was aimed to determine whether cyclosporin a administration increases oxalate retention in renal cells under hyperoxaluria and, if so, whether pretreatment with vitamin E abolishes this effect. Feeding cyclosporin A along with normal rat chow for 3 days resulted in increased oxalate retention in kidneys when compared with control. Pretreatment of vitamin E to cyclosporin A-administered rats prevented this increased oxalate retention, but it was only partial when cyclosporin A was coadministered with ammonium oxalate. Calcium accumulated by 260% of the control in both oxalate A- and ammonium oxalate-administered group. However, the enhanced lipid peroxidation, as well as oxalate-synthesizing enzymes due to cyclosporin A administration with or without hyperoxaluria, had been abolished completely, upon vitamin E pretreatment. Only when cyclosporin A and ammonium oxalate were coadministered, a highly significant decrease in the cytosolic enzyme aspartate transaminase was observed whereas alanine transaminase activity decreased considerably with cyclosporin or ammonium oxalate when given either together or separately. The concentrations of antioxidants and thiol components were significantly reduced in cyclosporin A-treated rats with or without ammonium oxalate coadministration. All these changes were restored to normal on pretreatment with vitamin E. In conclusion, the impact on oxalate and calcium retention, the susceptibility to lipid peroxidation and the related biochemical changes were absent upon vitamin E pretreatment and, thereby, favors protection from cyclosporin in A induced cell injury under hyperoxaluric condition. (C) Elsevier Science Inc. 1997.