The time-course of the effects of ethanol on the redox and phosphorylation states of rat liver

Abstract

1. The time-course of the effects of ethanol administration on the metabolite concentrations, redox states and phosphorylation state was studied in the freeze-clamped liver of starved rats. The response was found to vary with the time after ethanol administration. 2. Administration of ethanol caused an immediate decrease in the [NAD⁺]/[NADH] ratio of both cytoplasm and mitochondria, which persisted over the 30min studied. 3. The free cytoplasmic [NADP⁺]/[NADPH] ratio in liver decreases immediately after ethanol administration but returns nearly to control values after 15min. 4. The cytoplasmic [ATP]/[ADP][HPO₄^2-] ratio is elevated 15min after ethanol administration in the starved rat. 5. The rapid and large changes in most metabolite concentrations measured appeared to result from the maintenance of near-equilibrium in a wide interlinked network. 6. Differences between fed and starved rats 15min after ethanol administration were slight.