[Participation of the ADP/ATP-antiporter in the uncoupling action of fatty acids in liver mitochondria].

The controversial data on the involvement of the ATP/ADP-antiporter in the uncoupling effect of fatty acids in liver mitochondria as well as on the sensitivity of the uncoupling process to the ATP/ADP-antiporter inhibitor, carboxyatractylate, have been analyzed. It has been shown that in liver mitochondria uncoupled by palmitic acid, pyridoxal-5-phosphate, diethyl pyrocarbonate and glutamate produce an additional recoupling action against the background of carboxyatractylate. No such effect is observed during mitochondrial uncoupling by FCCP. Micromolar concentrations of ADP added prior to palmitic acid produce a far more potent coupling action; the subsequent recoupling effect of carboxyatractylate diminishes thereby. This finding suggests that the reduction of endogenous ADP is responsible for the increased sensitivity of the uncoupling action of fatty acids to carboxyatractylate. It is concluded that the ATP/ADP-antiporter and other membrane carriers play a role in the uncoupling action of fatty acids on liver mitochondria.