Intramuscular fatty acid metabolism in contracting and non-contracting human skeletal muscle.
Published
Journal Article
The present study was undertaken to investigate the fate of blood-borne non-esterified fatty acids (NEFA) entering contracting and non-contracting knee extensor muscles of healthy young individuals. [U-(13)C]-palmitate was infused into a forearm vein during 5 h of one-legged knee extensor exercise at 40 % of maximal work capacity and the NEFA kinetics, oxidation and rate of incorporation into intramuscular triacylglycerol (mTAG) were determined for the exercising and the non-exercising legs. During 4 h of one-legged knee extensor exercise, mTAG content decreased by 30 % (P < 0.05) in the contracting muscle, whereas it was unchanged in the non-contracting muscle. The uptake of plasma NEFA, as well as the proportion directed towards oxidation, was higher in the exercising compared to the non-exercising leg, whereas the rate of palmitate incorporation into mTAG was fourfold lower (0.70 +/- 0.14 vs. 0.17 +/- 0.04 micromol (g dry wt)(-1) h(-1); P < 0.05), resulting in fractional synthesis rates of 1.0 +/- 0.2 and 3.8 +/- 0.9 % h(-1) (P < 0.01) for the contracting and non-contracting muscle, respectively. These findings demonstrate that mTAG in human skeletal muscle is continuously synthesised and degraded and that the metabolic fate of plasma NEFA entering the muscle is influenced by muscle contraction, so that a higher proportion is directed towards oxidation at the expense of storage in mTAG.
Full Text
Duke Authors
Cited Authors
- Sacchetti, M; Saltin, B; Osada, T; van Hall, G
Published Date
- April 1, 2002
Published In
Volume / Issue
- 540 / Pt 1
Start / End Page
- 387 - 395
PubMed ID
- 11927695
Pubmed Central ID
- 11927695
International Standard Serial Number (ISSN)
- 0022-3751
Digital Object Identifier (DOI)
- 10.1113/jphysiol.2001.013912
Language
- eng
Conference Location
- England