Control of the transport of reducing equivalents across the mitochondrial membrane in perfused rat heart

摘要: Abstract A comparison of the functional significance malate-aspartate and α-glycerophosphate hydrogen shuttles was made in isolated perfused rat heart. Amino-oxyacetate, a competitive inhibitor aspartate aminotransferase, inhibited lactate glucose oxidation normal Although oxidase activity increased sixfold by tri-iodothyronine, flux through shuttle limited low tissue concentrations oxidase. Significant only achieved when cytosolic NADH NAD ratio concentration rose to highly unphysiological levels. It is concluded that predominant mechanism for reoxidation Examination changes levels citric acid cycle intermediates heart under these experimental conditions also suggests introduction or withdrawal carbon moieties from pool can occur concerted action both alanine aminotransferases.