Influence of malonyl-CoA and palmitate concentration on rate of palmitate oxidation in rat muscle

G. F. Merrill, E. J. Kurth, B. B. Rasmussen, W. W. Winder

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) is taken up by perfused skeletal muscle and phosphorylated to form 5-aminoimidazole-4- carboxamide-1-β-D-ribofuraosyl-5'-monophosphate (analog of 5'-AMP) with consequent activation of AMP-activated protein kinase, phosphorylation of acetyl-CoA carboxylase, decrease in malonyl-CoA, and increase in fatty acid oxidation. This study was designed to determine the effect of increasing levels of palmitate on the rate of fatty acid oxidation. Malonyl-CoA concentration was manipulated with AICAR at different palmitate concentrations. Rat hindlimbs were perfused with Krebs-Henseleit bicarbonate containing 4% bovine serum albumin, washed bovine red cells, 200 μU/ml insulin, 10 mM glucose, and different concentrations of palmitate (0.1-1.0 mM) without or with AICAR (2.0 mM). Perfusion with medium containing AICAR was found to activate AMP-activated protein kinase in skeletal muscle, inactivate acetyl-CoA carboxylase, and decrease malonyl-CoA at all concentrations of palmitate. The rate of palmitate oxidation increased as a function of palmitate concentration in both the presence and absence of AICAR but was always higher in the presence of AICAR. These results provide additional evidence that malonyl-CoA is an important regulator of the rate of fatty acid oxidation at palmitate concentrations in the physiological range.

Original languageEnglish (US)
Pages (from-to)1909-1914
Number of pages6
JournalJournal of Applied Physiology
Issue number5
StatePublished - Nov 1998
Externally publishedYes


  • 5-aminoimidazole-4-carboxamide 1-β-D- ribofuranoside
  • Acetyl-CoA carboxylase
  • Adenosine 5'-monophosphate-activated protein kinase
  • Fatty acid oxidation

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)


Dive into the research topics of 'Influence of malonyl-CoA and palmitate concentration on rate of palmitate oxidation in rat muscle'. Together they form a unique fingerprint.

Cite this