Document Detail

Isoform-specific and exercise intensity-dependent activation of 5'-AMP-activated protein kinase in human skeletal muscle.
MedLine Citation:
PMID:  11018120     Owner:  NLM     Status:  MEDLINE    
1. 5'-AMP-activated protein kinase (AMPK) has been suggested to play a key role in the regulation of metabolism in skeletal muscle. AMPK is activated in treadmill-exercised and electrically stimulated rodent muscles. Whether AMPK is activated during exercise in humans is unknown. 2. We investigated the degree of activation and deactivation of alpha-isoforms of AMPK during and after exercise. Healthy human subjects performed bicycle exercise on two separate occasions at either a low ( approximately 50% maximum rate of O2 uptake (VO2,max) for 90 min) or a high ( approximately 75% VO2,max for 60 min) intensity. Biopsies from the vastus lateralis muscle were obtained before and immediately after exercise, and after 3 h of recovery. 3. We observed a 3- to 4-fold activation of the alpha2-AMPK isoform immediately after high intensity exercise, whereas no activation was observed after low intensity exercise. The activation of alpha2-AMPK was totally reversed 3 h after exercise. In contrast, alpha1-AMPK was not activated during either of the two exercise trials. 4. The in vitro AMP dependency of alpha2-AMPK was significantly greater than that of alpha1-AMPK ( approximately 3- vs. approximately 2-fold). 5. We conclude that in humans activation of alpha2-AMPK during exercise is dependent upon exercise intensity. The stable activation of alpha2-AMPK, presumably due to the activation of an upstream AMPK kinase, is compatible with a role for this kinase complex in the regulation of skeletal muscle metabolism during exercise, whereas the lack of stable alpha1-AMPK activation makes this kinase complex a less likely candidate.
J F Wojtaszewski; P Nielsen; B F Hansen; E A Richter; B Kiens
Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of physiology     Volume:  528 Pt 1     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  2000 Oct 
Date Detail:
Created Date:  2000-11-14     Completed Date:  2000-11-30     Revised Date:  2013-06-11    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  221-6     Citation Subset:  IM    
Copenhagen Muscle Research Centre, Department of Human Physiology, University of Copenhagen, Denmark.
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MeSH Terms
AMP-Activated Protein Kinases
Enzyme Activation / physiology
Exercise Test
Glycogen / metabolism
Isoenzymes / metabolism
Multienzyme Complexes / metabolism*
Muscle, Skeletal / enzymology*
Physical Exertion / physiology*
Protein-Serine-Threonine Kinases / metabolism*
Reg. No./Substance:
0/Isoenzymes; 0/Multienzyme Complexes; 9005-79-2/Glycogen; EC Protein Kinases; EC protein, human; EC protein, human; EC Kinases
Comment In:
J Physiol. 2000 Oct 1;528 Pt 1:3   [PMID:  11018100 ]

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