Role of lipid peroxidation and poly(ADP-ribose) polymerase activation in oxidant-induced membrane transport: Dysfunction in opossum kidney cells

This study was undertaken to examine the role of lipid peroxidation and pol y(ADP-ribose) polymerase (PARP) activation in H2O2-induced inhibition of Na +-dependent phosphate (Na+-Pi) uptake in opossum kidney (OK) cells. H2O2 in hibited Na+-Pi uptake in a dose-dependent manner. H2O2-induced inhibition o f Na+-Pi uptake was prevented by dithiothreitol and glutathione. A potent a ntioxidant, DPPD, had no effect on H2O2 inhibition of Na+-Pi uptake, despit e completely inhibiting lipid peroxidation induced by H2O2. However, in pri mary cultured rabbit proximal tubular cells, the effect of H2O2 on Na+-Pi u ptake was significantly prevented by DPPD, suggesting a species difference in the role of lipid peroxidation in the inhibition of Na+-Pi uptake occurr ing with H2O2. t-Butylhydroperoxide (tBHP) caused the inhibition of Na+-Pi uptake that was prevented by DPPD in OK cells and rabbit proximal tubular c ells. The PARP inhibitor 3-aminobenzamide completely protected the inhibiti on of Na+-Pi uptake induced by H2O2 but not by tBHP. H2O2-induced ATP deple tion was prevented by 3-aminobenzamide but not by DPPD. tBHP-induced ATP de pletion was prevented by DPPD, whereas it was not altered by 3-aminobenzami de. Effects of H2O2 and tBHP on Na+-Pi uptake and ATP depletion were preven ted by an iron chelator, deferoxamine, suggesting that the oxidants inhibit Na+-Pi uptake through an iron-dependent mechanism. The extent of DNA damag e by tBHP was similar to that by H2O2. These results indicate that the effe ct of H2O2 on membrane transport function in OK cells is associated with PA RP activation but not lipid peroxidation, whereas the effect of tBHP is ass ociated with lipid peroxidation. (C) 2000 Academic Press.