Lipophilic and respiratory properties of NADH and succinate dehydrogenase sites in mitochondria from various tissues of the rat.

Mitochondria were isolated from heart, liver, kidney, spleen, and brain of the rat. With overall regard to both resting and activated respiratory velocities with either glutamate or succinate, as well as the respective degrees of respiratory control, kidney mitochondria were most efficient and spleen mitochondria least so. A probe of mitochondrial inner membrane lipophilicity with tetrabutylammonium bromide showed that NADH dehydrogenases from liver and heart were similar, as were also those from kidney and spleen. With the exception of brain, only small differences were observed in lipophilic properties of succinate dehydrogenases from the various other tissues. Variation in lipophilic characteristics of the two sites on the mitochondrial inner membranes could not be correlated with embryological origin of the tissue.