[Mechanisms for improving the energy metabolism and function of the hypoxic myocardium with amino acids].

The relationship between metabolism of the main myocardial amino acids, glutamate, aspartate and alanine, and energy state of hypoxic myocardium, was studied. Depression of cardiac contractile function during asphyxia in rats was accompanied by a decrease in glutamate mitochondrial and tissue contents and an increase in the tissue alanine and mitochondrial aspartate. The reduction of mitochondrial glutamate in asphyxia was related to losses of intramitochondrial ATP and state 3 respiration with glutamate and malate. Using NMR technique, exogenous glutamate and oxaloacetate were shown to increase succinate formation coupled with ATP and CTP production in the rat heart mitochondria in absence of aeration. These data suggest that glutamate and products of its transamination decrease the contraction of hypoxic myocardium stimulating anaerobic energy formation in the tricarboxylic acid cycle.