Effect of amrinone on myocardial mitochondria function

The effect of amrinone on cardiac mitochondria of guinea pig was studied. It was found that amrinone does not change the respiratory function of cardiac mitochondria in the presence of α-ketoglutarate, whereas it inhibits glutamate oxidation. It was also found that amrinone strongly inhibits the activity of glutamic dehydrogenase of both crude extract from sonicated heart mitochondria and of purified preparation from bovine liver. This inhibition may explain the effect of amrinone on the oxidation of glutamate in mitochondria. These results are discussed in view of the contradictory effects of amrinone on cardiac and other tissues.