Role of Lipid Peroxidation and Poly(ADP-ribose) Polymerase Activation in Oxidant-Induced Membrane Transport Dysfunction in Opossum Kidney Cells

Abstract

This study was undertaken to examine the role of lipid peroxidation and poly(ADP-ribose) polymerase (PARP) activation in H2O2-induced inhibition of Na+-dependent phosphate (Na+–Pi) uptake in opossum kidney (OK) cells. H2O2 inhibited Na+–Pi uptake in a dose-dependent manner. H2O2-induced inhibition of Na+–Pi uptake was prevented by dithiothreitol and glutathione. A potent antioxidant, DPPD, had no effect on H2O2 inhibition of Na+–Pi uptake, despite completely inhibiting lipid peroxidation induced by H2O2. However, in primary cultured rabbit proximal tubular cells, the effect of H2O2 on Na+–Pi uptake was significantly prevented by DPPD, suggesting a species difference in the role of lipid peroxidation in the inhibition of Na+–Pi uptake occurring with H2O2. t-Butylhydroperoxide (tBHP) caused the inhibition of Na+–Pi uptake that was prevented by DPPD in OK cells and rabbit proximal tubular cells. The PARP inhibitor 3-aminobenzamide completely protected the inhibition of Na+–Pi uptake induced by H2O2 but not by tBHP. H2O2-induced ATP depletion was prevented by 3-aminobenzamide but not by DPPD. tBHP-induced ATP depletion was prevented by DPPD, whereas it was not altered by 3-aminobenzamide. Effects of H2O2 and tBHP on Na+–Pi uptake and ATP depletion were prevented by an iron chelator, deferoxamine, suggesting that the oxidants inhibit Na+–Pi uptake through an iron-dependent mechanism. The extent of DNA damage by tBHP was similar to that by H2O2. These results indicate that the effect of H2O2 on membrane transport function in OK cells is associated with PARP activation but not lipid peroxidation, whereas the effect of tBHP is associated with lipid peroxidation.