Document Detail

Exercise-induced pyruvate dehydrogenase activation is not affected by 7 days of bed rest.
MedLine Citation:
PMID:  21680880     Owner:  NLM     Status:  MEDLINE    
To test the hypothesis that physical inactivity impairs the exercise-induced modulation of pyruvate dehydrogenase (PDH), six healthy normally physically active male subjects completed 7 days of bed rest. Before and immediately after the bed rest, the subjects completed an oral glucose tolerance test (OGTT) and a one-legged knee extensor exercise bout [45 min at 60% maximal load (W(max))] with muscle biopsies obtained from vastus lateralis before, immediately after exercise, and at 3 h of recovery. Blood samples were taken from the femoral vein and artery before and after 40 min of exercise. Glucose intake elicited a larger (P ≤ 0.05) insulin response after bed rest than before, indicating glucose intolerance. There were no differences in lactate release/uptake across the exercising muscle before and after bed rest, but glucose uptake after 40 min of exercise was larger (P ≤ 0.05) before bed rest than after. Muscle glycogen content tended to be higher (0.05< P ≤ 0.10) after bed rest than before, but muscle glycogen breakdown in response to exercise was similar before and after bed rest. PDH-E1α protein content did not change in response to bed rest or in response to the exercise intervention. Exercise increased (P ≤ 0.05) the activity of PDH in the active form (PDHa) and induced (P ≤ 0.05) dephosphorylation of PDH-E1α on Ser²⁹³, Ser²⁹⁵ and Ser³⁰⁰, with no difference before and after bed rest. In conclusion, although 7 days of bed rest induced whole body glucose intolerance, exercise-induced PDH regulation in skeletal muscle was not changed. This suggests that exercise-induced PDH regulation in skeletal muscle is maintained in glucose-intolerant (e.g., insulin resistant) individuals.
Kristian Kiilerich; Stine Ringholm; Rasmus S Biensø; James P Fisher; Ninna Iversen; Gerrit van Hall; Jørgen F P Wojtaszewski; Bengt Saltin; Carsten Lundby; Jose A L Calbet; Henriette Pilegaard
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2011-06-16
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  111     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2011 Sep 
Date Detail:
Created Date:  2011-09-09     Completed Date:  2012-01-11     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  751-7     Citation Subset:  IM    
August Krogh Bldg., Dept. of Biology, Universitetsparken 13, 2100 Copenhagen, Denmark.
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MeSH Terms
Bed Rest*
Blood Glucose / metabolism
Enzyme Activation
Exercise Test
Gene Expression Regulation, Enzymologic
Glucose Intolerance / blood,  metabolism
Glucose Tolerance Test
Glycogen / metabolism
Insulin / metabolism
Insulin Resistance
Lactic Acid / blood
Muscle Contraction*
Oxygen Consumption
Protein Processing, Post-Translational
Protein-Serine-Threonine Kinases / genetics,  metabolism
Pyruvate Dehydrogenase (Lipoamide) / metabolism*
Pyruvate Dehydrogenase (Lipoamide)-Phosphatase / genetics,  metabolism
Quadriceps Muscle / enzymology*
RNA, Messenger / metabolism
Time Factors
Young Adult
Reg. No./Substance:
0/Blood Glucose; 0/Insulin; 0/RNA, Messenger; 50-21-5/Lactic Acid; 56-45-1/Serine; 9005-79-2/Glycogen; EC Dehydrogenase (Lipoamide); EC dehydrogenase E1alpha subunit; EC Kinases; EC dehydrogenase (acetyl-transferring) kinase; EC Dehydrogenase (Lipoamide)-Phosphatase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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