Open AccessSuppression of Pyruvate Oxidation in Liver Mitochondria in the Presence of Long‐Chain Fatty Acid
Author(s) -
Jagow G.,
Westermann B.,
Wieland O.
Publication year - 1968
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1967.tb19561.x
Subject(s) - pyruvate decarboxylation , pyruvate dehydrogenase complex , pyruvate carboxylase , dihydrolipoyl transacetylase , pyruvate dehydrogenase kinase , beta oxidation , biochemistry , chemistry , carnitine , pyruvic acid , pyruvate dehydrogenase phosphatase , decarboxylation , gluconeogenesis , acetylcarnitine , metabolism , catalysis , enzyme
An incubation system for rat liver mitochondria is described in which pyruvate is almost exclusively metabolised by oxidative decarboxylation. The oxidation of [1‐ 14 C]pyruvate was determined by measurement of 14 CO 2 ‐formation and pyruvate disappearance. At the same time O 2 consumption and ketone body formation were followed. Carnitine stimulated pyruvate oxidation. Oxidation of pyruvate was inhibited by physiological concentrations of palmitate. The inhibition was not relieved by increasing concentrations of DL ‐carnitine. Palmitoyl‐carnitine inhibited pyruvate oxidation in the same manner as palmitate. The inhibition was not influenced by increasing the concentration of carnitine in the medium. The possible mechanisms for this effect of palmitate and palmitoyl‐carnitine on pyruvate oxidation are discussed. Under conditions of lack of carbohydrate the inhibition of mitochondrial pyruvate oxidation by fatty acid seems of major importance for directing pyruvate carbon into the direction of glucose synthesis.