Effect of chronic ethanol consumption on energy-linked processes associated with oxidative phosphorylation: Proton translocation and ATP-Pi exchange

Male rats were administered an ethanol-containing diet for 31 days during which time they demonstrated fatty liver. Mitochondria and submitochondrial particles were prepared from their livers (ethanol mitochondria, ethanol submitochondrial particles) and from their pair-fed partners (control mitochondria, control submitochondrial particles). The H⁺/coupling site ratio was not significantly different in ethanol and control mitochondria with succinate as electron donor. A 13% decrease in the H⁺/coupling site ratio was observed in ethanol mitochondria, however, when β-hydroxybutyrate was used as substrate. The rate of ATP-P_i exchange was decreased significantly in both ethanol mitochondria and submitochondrial particles as compared to control preparations. These observations demonstrate ethanol-elicited decreases in energy conservation in the site I region of the electron transport chain and in the activity of the ATP synthetase complex.