Carboxyatractyloside increases the effect of oleate on mitochondrial permeability transition

Addition of a low concentration of carboxyatractyloside (0.075 mu M) render s mitochondria susceptible to the opening of the non-specific pore by 5 mu M oleate, in a cyclosporin A-sensitive fashion. Matrix Ca2+ efflux as well as collapse of the transmembrane potential reveal permeability transition. The effect of oleate is reached after the titration, by carboxyatractylosid e, of 38 pmol of adenine nucleotide translocase per mg mitochondrial protei n. We propose that permeability transition may result from an additive acti on of carboxyatractyloside plus oleate on the ADP/ATP carrier. (C) 1999 Fed eration of European Biochemical Societies.