The stimulation of respiration by long-chain fatty adds and FCCP was studied with oligomycin-inhibited mitochondria from rat liver, heart and kidney tissue. By addition of equal amounts of palmitate and oleate, mitochondrial respiration was increased in the order RLM < RKM < RHM. Using the classical protonophore FCCP, this difference could not be observed. Inhibition of oleate-stimulated respiration by carboxyatractyloside decreased in the order RHM > RKM > RLM. As CAT sensitivity of oleate-stimulated respiration and the mitochondrial ANT content were found to be correlated, it is suggested that the weak CAT sensitivity of oleate-stimulated respiration of RLM [(1989) Biochim. Biophys. Acta 977, 266-272] is due to the low content of ANT.
