Amino acid incorporation into mitochondria from hypertrophying hearts of rats with aortic constriction

Abstract Conditions are described which favour incorporation of leucine and valine into the protein of isolated rat heart mitochondria. Such incorporation can be preserved at liquid nitrogen temperature, provided that dimethylsulphoxide is present during freezing. Left ventricular hypertrophy induced by aortic constriction is associated with a pronounced increase in the rate of incorporation of [ 14 C]leucine into the mitochondria isolated from this part of the heart. The rate returns to preconstriction values during the second half of the first week as the process of cardiac hypertrophy nears completion. Lesser increases in [ 14 C]leucine incorporation were observed 1 day after the start of the experiments in heart mitochondria of sham-operated rats and in liver mitochondria of operated and shamoperated animals.