title: Changes in the subcellular distribution of metabolites due to ethanol oxidation in the perfused rat liver.
abstract: The subcellular distribution of metabolites involved in the transfer of reducing equivalents across the mitochondrial membrane was studied in perfused livers from fed rats. A tenfold increase in the flux rate of the malate-aspartate shuttle and the inhibition of the citrate cycle due to ethanol oxidation, were reflected by characteristic changes in the cytosolic and mitochondrial concentrations of malate, 2-oxoglutarate, aspartate, glutamate and citrate. The data suggest that the malate-aspartate shuttle is triggered by a decrease in the cytosolic oxaloacetate concentration which, due to the cytosolic aspartate aminotransferase equilibrium, leads to an increased efflux of 2-oxoglutarate and aspartate from the mitochondria in exchange for malate and glutamate, respectively. The first site at which the citrate cycle is inhibited appears to be the level of 2-oxoglutarate oxidation.
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure; D008293:Malates / Q000378:metabolism; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism; D010071:Oxaloacetates / Q000378:metabolism; D010084:Oxidation-Reduction; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism*
chemical_list: D008293:Malates; D010071:Oxaloacetates; D001224:Aspartic Acid; D000431:Ethanol