MODIFICATION OF CISPLATIN-INDUCED RENAL P-AMINOHIPPURATE UPTAKE ALTERATION AND LIPID-PEROXIDATION BY THIOLS, GINKGO-BILOBA EXTRACT, DEFEROXAMINE AND TORBAFYLLINE

To determine whether inhibition of lipid peroxidation modifies cisplatin-induced changes of renal p-aminohippurate (PAH) uptake, we examined the effects of various radical scavengers and torbafylline on cisplatin-induced lipid peroxidation and PAH accumulation changes in rat renal cortical slices. Renal cortical slices were incubated with different cisplatin concentrations (0.3, 0.6, 1.0 mg/ml) in the presence of either glutathione, N-acetylcysteine, the iron chelator deferoxamine, Ginkgo biloba extract or the xanthine derivate torbafylline. Lipid peroxidation monitored as the production of malondialdehyde (MDA) was stimulated by increasing cisplatin concentrations in a dose-related manner. At a cisplatin concentration of 1.0 mg/ml, MDA production was twofold compared to controls (0.69 +/- 0.06 vs. 1.36 +/- 0.07 nmol/mg; p < 0.05). In turn, cisplatin decreased PAH uptake of kidney slices dose-dependently from 13.3 +/- 1.3 to 2.6 +/- 0.2 (p < 0.01). All agents tested inhibited cisplatin-induced lipid peroxidation; however, at a cisplatin concentration of 1.0 mg/ml, none of them prevented the decline of cisplatin-induced PAH uptake. Of the agents tested, deferoxamine proved to be the most effective antioxidant, completely inhibiting cisplatin-induced lipid peroxidation but in contrast preventing the decrease in PAH uptake only at a cisplatin concentration of 0.3 mg/ml. No strict association between lipid peroxidation and decline of PAH uptake was found, suggesting that lipid peroxidation may only in part participate in cisplatin-induced alterations of PAH uptake.