Interrelationship in the regulation of pyruvate dehydrogenase and adenine-nucleotide translocase by palmitoyl-CoA in isolated mitochondria.
Full activation of rat liver pyruvate dehydrogenase in vitro by ADP was prevented by palmitoyl-CoA at a concentration sufficiently low to preclude substrate effects secondary to its oxidation by mitochondria. Activation of pyruvate dehydrogenase by ADP in livers of fat-fed rats was less than in the control animal. The results are consistent with the experiments demonstrating an inhibition of adenine nucleotide translocase and on increased intramitochondrial ATP/ADP ratio by palmitoyl-CoA which could account for the effect on pyruvate dehydrogenase. Inactivation of brain pyruvate dehydrogenase by ATP was also diminished by palmitoyl-CoA indicating that the effect was at the level of the adenine nucleotides rather than at either the pyruvate dehydrogenase kinase or phosphatase enzymes.
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000201:enzymology; D002118:Calcium / Q000494:pharmacology; D003065:Coenzyme A / Q000494:pharmacology*; D004041:Dietary Fats; D004789:Enzyme Activation / Q000187:drug effects; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism*; D010169:Palmitic Acids / Q000494:pharmacology*; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*; D051381:Rats
D004041:Dietary Fats; D010169:Palmitic Acids; D011768:Pyruvate Dehydrogenase Complex; D000244:Adenosine Diphosphate; D000226:Mitochondrial ADP, ATP Translocases; D009713:Nucleotidyltransferases; D008274:Magnesium; D003065:Coenzyme A; D002118:Calcium