Amino acid degradation and effect of leucine on pyruvate oxidation in rat atrial muscle.

Marc E Tischler, A. L. Goldberg

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Both left and right atria from fasted rats produced significant amounts of 14CO2 during incubation with U-14C-labeled leucine, isoleucine, valine, alanine, glutamate, glutamine, aspartate, asparagine, proline, threonine, or lysine. This pattern of amino acid metabolism resembles that of skeletal muscle. Production of 14CO2 from [1-14C]leucine was 2.5-fold greater in atria from fasted than from fed rats and was due to greater alpha-ketoisocaproic dehydrogenase activity in the tissue from fasted animals. At normal plasma concentrations, leucine reduced the oxidation of glucose and lactate in atria from fasted but not from fed rats by inhibiting pyruvate oxidation and without altering the rate of glycolysis. Leucine also reduced glucose oxidation when added in the presence of ketone bodies or other amino acids and stimulated the release of lactate into the medium. Although the leucine skeleton can be completely oxidized to CO2 and thus can serve as an alternative fuel in fasting in place of glucose, oxidation of leucine (like glucose or lactate oxidation) accounts only for a very small fraction of the total oxygen consumption of the resting atria.

Original languageEnglish (US)
JournalThe American journal of physiology
Volume238
Issue number5
StatePublished - May 1980
Externally publishedYes

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Pyruvic Acid
Leucine
Amino Acids
Muscles
Glucose
Lactic Acid
Heart Atria
Ketone Bodies
Isoleucine
Asparagine
Valine
Glycolysis
Threonine
Glutamine
Proline
Skeleton
Aspartic Acid
Oxygen Consumption
Alanine
Lysine

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Amino acid degradation and effect of leucine on pyruvate oxidation in rat atrial muscle. / Tischler, Marc E; Goldberg, A. L.

In: The American journal of physiology, Vol. 238, No. 5, 05.1980.

Research output: Contribution to journalArticle

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