Chromium(V) is produced upon reduction of chromate by mitochondrial electron transport chain complexes

摘要: Incubation of chromate with isolated rat liver submitochondrial particles under anaerobic conditions in vitro results reduction chromium(VI) and formation chromium(V). In the presence NADH, (SMPs) were active reducing as shown by UV-vis spectroscopic studies, forming a chromium(V) species which was detectable electron paramagnetic resonance spectroscopy. succinate, SMPs less effective relative to their NADH-dependent activity. However, showed higher rate oxygen depletion NADH compared succinate substrate, suggesting that differences versus succinate-dependent chromate-reductase activity is probably due efficiency donation NADH. The use specific transport chain inhibitors allowed sites be determined. Rotenone, antimycin cyanide all produced approximately 40% inhibition Thus, complex I (NADH:ubiquinone oxidoreductase) appears responsible for inhibitor-insensitive, IV (ferrocytochrome c:oxygen inhibitor-sensitive formation. Cyanide 50% SMPs, while no observed rotenone. These confirm IV, suggest II (succinate:ubiquinone inhibitor-insensitive SMPs. Since effectively metabolized complexes mitochondrial inner membrane vitro, formed an intermediate process, mitochondria may play role carcinogenesis.