New insights concerning the role of carnitine in the regulation of fuel metabolism in skeletal muscle
In skeletal muscle, carnitine plays an essential role in the translocation of long-chain fatty-acids into the mitochondrial matrix for subsequent β-oxidation, and in the regulation of the mitochondrial acetyl-CoA/CoASH ratio. Interest in these vital metabolic roles of carnitine in skeletal muscle a...
Saved in:
Published in | The Journal of physiology Vol. 581; no. 2; pp. 431 - 444 |
---|---|
Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
The Physiological Society
01.06.2007
Blackwell Publishing Ltd Blackwell Science Inc |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | In skeletal muscle, carnitine plays an essential role in the translocation of long-chain fatty-acids into the mitochondrial
matrix for subsequent β-oxidation, and in the regulation of the mitochondrial acetyl-CoA/CoASH ratio. Interest in these vital
metabolic roles of carnitine in skeletal muscle appears to have waned over the past 25 years. However, recent research has
shed new light on the importance of carnitine as a regulator of muscle fuel selection. It has been established that muscle
free carnitine availability may be limiting to fat oxidation during high intensity submaximal exercise. Furthermore, increasing
muscle total carnitine content in resting healthy humans (via insulin-mediated stimulation of muscle carnitine transport)
reduces muscle glycolysis, increases glycogen storage and is accompanied by an apparent increase in fat oxidation. By increasing
muscle pyruvate dehydrogenase complex (PDC) activity and acetylcarnitine content at rest, it has also been established that
PDC flux and acetyl group availability limits aerobic ATP re-synthesis at the onset of exercise (the acetyl group deficit).
Thus, carnitine plays a vital role in the regulation of muscle fuel metabolism. The demonstration that its availability can
be readily manipulated in humans, and impacts on physiological function, will result in renewed business and scientific interest
in this compound. |
---|---|
Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-3 content type line 23 ObjectType-Review-1 |
ISSN: | 0022-3751 1469-7793 |
DOI: | 10.1113/jphysiol.2006.125799 |