The role of the ADP/ATP-antiporter in the inhibition of nonspecific permeability of the inner mitochondrial membrane by cyclosporin A

The effect of the conformational state of the ADP/ATP-antiporter on the efficiency of inhibition by cyclosporine A of the Ca(2+)-induced increase of nonspecific permeability of the inner mitochondrial membrane was under study. It was found that the ADP/ATP-antiporter inhibitor carboxyatractyloside is able to reverse the cyclosporine A-induced inhibition of this nonspecific permeability. The effect of carbocyatractyloside is manifested only in mitochondria depleted of adenine nucleotides. The bifunctional SH-reagent phenylarsine oxide is also able to reverse the cyclosporine A effect. The data obtained testify to the fact that inhibition by cyclosporine A of nonspecific permeability is due to its effect on the conformational state of the ADP/ATP-antiporter.