Effects of antioxidants and Ca2+ in cisplatin-induced cell injury in rabbit renal cortical slices.

Effects of antioxidants, reactive oxygen species (ROS) scavengers, and Ca2+ on cisplatin-induced renal cell injury were studied in rabbit renal cortical slices in vitro. Cisplatin induced LDH release and lipid peroxidation, inhibition of PAH uptake, and GSH depletion. These changes were significantly prevented by thiols (DTT and GSH), antioxidants (DPPD and BHA), and an iron chelator (deferoxamine). Superoxide dismutase partially reduced the cisplatin-induced LDH release without affecting the lipid peroxidation and the GSH depletion. Catalase did not affect the LDH release and the lipid peroxidation induced by cisplatin. Hydroxyl radical scavengers prevented the lipid peroxidation, whereas they did not alter the LDH release, the inhibition of PAH uptake, and the GSH depletion induced by cisplatin. Removal of Ca2+ or addition of EGTA to the incubation medium did not alter cisplatin effects on LDH release and lipid peroxidation. Buffering intracellular Ca2+ with quin-2/AM or inhibition of intracellular Ca2+ release with TMB-8 significantly reduced the cisplatin effect on LDH release without any effect on the lipid peroxidation and the GSH depletion. Ruthenium red attenuated the LDH release, the lipid peroxidation, and the inhibition of PAH uptake mediated by cisplatin. La3+ prevented the cisplatin effect on the LDH release, whereas it did not affect the lipid peroxidation, the inhibition of PAH uptake, and the GSH depletion by cisplatin. These results suggest that cisplatin induces a lethal cell injury by lipid peroxidation-dependent and -independent mechanisms and that the cell injury and the lipid peroxidation by cisplatin are iron-dependent. In addition, the data indicate that the Ca2+ released from intracellular stores, but not the Ca2+ moved from extracellular space, plays a role in the cisplatin-induced cell injury independent of lipid peroxidation.