Effects of Aldosterone on Mitochondrial Enzyme(s) and Cytochromes of Rat Tissues

Abstract

The activities of the kidney mitochondrial enzymes citrate synthase, NAD–isocitrate dehydrogenase, and α-ketoglutarate dehydrogenase, and the levels of cytochromes a + a3 and b were decreased following adrenalectomy. These decreases in enzyme activity and cytochrome levels could be restored by the administration of 5 μg of aldosterone per 100 g body weight. The effects of adrenalectomy and aldosterone administration were not observed in mitochondria from rat heart or liver. It was also found that giving 250 μg of corticosterone per 100 g body weight to adrenalectomized animals did not restore kidney citrate synthase activity. Neither actinomycin D nor puromycin, when given to adrenalectomized rats prior to aldosterone administration, inhibited the stimulation of citrate synthase activity or the levels of cytochromes a + a3 and b. It is concluded that the effect of aldosterone on the oxidative enzyme system is not the result of its stimulation of transcription or translation mechanisms.