Inhibition of palmitoylcarnitine oxidation by pyruvate in rat heart mitochondria. 1985

J T Brosnan, and K Reid

The oxidation of 1-14C-palmitoylcarnitine by rat heart mitochondria has been measured by assessing both the disappearance of substrate and the appearance of labelled products. Pyruvate inhibited palmitoylcarnitine oxidation by about 40%. Fifty percent inhibition occurred at about 20 mumol/L pyruvate. The inhibitory effect of pyruvate required entry of pyruvate into mitochondria since it did not occur in the presence of alpha-cyano-4-hydroxycinnamic acid, an inhibitor of the mitochondrial pyruvate transporter. The inhibitory effect of pyruvate also required an active pyruvate dehydrogenase. These studies indicate a mechanism that may be important in the replacement of fatty acids by carbohydrate as fuels of respiration of the heart during the transition from the starved to the fed state.

UI MeSH Term Description Entries
D008929 Mitochondria, Heart The mitochondria of the myocardium. Heart Mitochondria,Myocardial Mitochondria,Mitochondrion, Heart,Heart Mitochondrion,Mitochondria, Myocardial
D010084 Oxidation-Reduction A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471). Redox,Oxidation Reduction
D010172 Palmitoylcarnitine A long-chain fatty acid ester of carnitine which facilitates the transfer of long-chain fatty acids from cytoplasm into mitochondria during the oxidation of fatty acids. Palmitylcarnitine,Hexadecanoylcarnitine
D011768 Pyruvate Dehydrogenase Complex A multienzyme complex responsible for the formation of ACETYL COENZYME A from pyruvate. The enzyme components are PYRUVATE DEHYDROGENASE (LIPOAMIDE); dihydrolipoamide acetyltransferase; and LIPOAMIDE DEHYDROGENASE. Pyruvate dehydrogenase complex is subject to three types of control: inhibited by acetyl-CoA and NADH; influenced by the energy state of the cell; and inhibited when a specific serine residue in the pyruvate decarboxylase is phosphorylated by ATP. PYRUVATE DEHYDROGENASE (LIPOAMIDE)-PHOSPHATASE catalyzes reactivation of the complex. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed) Complex, Pyruvate Dehydrogenase,Dehydrogenase Complex, Pyruvate
D011773 Pyruvates Derivatives of PYRUVIC ACID, including its salts and esters.
D002331 Carnitine A constituent of STRIATED MUSCLE and LIVER. It is an amino acid derivative and an essential cofactor for fatty acid metabolism. Bicarnesine,L-Carnitine,Levocarnitine,Vitamin BT,L Carnitine
D003373 Coumaric Acids Hydroxycinnamic acid and its derivatives. Act as activators of the indoleacetic acid oxidizing system, thereby producing a decrease in the endogenous level of bound indoleacetic acid in plants. Coumaric Acid,Hydroxycinnamic Acid,Hydroxycinnamic Acids,Acid, Coumaric,Acid, Hydroxycinnamic,Acids, Coumaric,Acids, Hydroxycinnamic
D003921 Diabetes Mellitus, Experimental Diabetes mellitus induced experimentally by administration of various diabetogenic agents or by PANCREATECTOMY. Alloxan Diabetes,Streptozocin Diabetes,Streptozotocin Diabetes,Experimental Diabetes Mellitus,Diabete, Streptozocin,Diabetes, Alloxan,Diabetes, Streptozocin,Diabetes, Streptozotocin,Streptozocin Diabete
D003999 Dichloroacetic Acid A derivative of ACETIC ACID that contains two CHLORINE atoms attached to its methyl group. Sodium Dichloroacetate,Bichloroacetic Acid,Potassium Dichloroacetate,Acid, Bichloroacetic,Acid, Dichloroacetic,Dichloroacetate, Potassium,Dichloroacetate, Sodium
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

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