Document Detail


Physical activity changes the regulation of mitochondrial respiration in human skeletal muscle.
MedLine Citation:
PMID:  12181291     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study explores the importance of creatine kinase (CK) in the regulation of muscle mitochondrial respiration in human subjects depending on their level of physical activity. Volunteers were classified as sedentary, active or athletic according to the total activity index as determined by the Baecke questionnaire in combination with maximal oxygen uptake values (peak V(O2), expressed in ml min(-1) kg(-1)). All volunteers underwent a cyclo-ergometric incremental exercise test to estimate their peak V(O2) and V(O2) at the ventilatory threshold (VT). Muscle biopsy samples were taken from the vastus lateralis and mitochondrial respiration was evaluated in an oxygraph cell on saponin permeabilised muscle fibres in the absence (V(0)) or in the presence (V(max)) of saturating [ADP]. While V(0) was similar, V(max) differed among groups (sedentary, 3.7 +/- 0.3, active, 5.9 +/- 0.9 and athletic, 7.9 +/- 0.5 micromol O2 min(-1) (g dry weight)(-1)). V(max) was correlated with peak V(O2) (P < 0.01, r = 0.63) and with V(T) (P < 0.01, r = 0.57). There was a significantly greater degree of coupling between oxidation and phosphorylation (V(max)/V(0)) in the athletic individuals. The mitochondrial K(m) for ADP was significantly higher in athletic subjects (P < 0.01). Mitochondrial CK (mi-CK) activation by addition of creatine induced a marked decrease in K(m) in athletic individuals only, indicative of an efficient coupling of mi-CK to ADP rephosphorylation in the athletic subjects only. It is suggested that increasing aerobic performance requires an enhancement of both muscle oxidative capacity and mechanisms of respiratory control, attesting to the importance of temporal co-ordination of energy fluxes by CK for higher efficacy.
Authors:
J Zoll; H Sanchez; B N'Guessan; F Ribera; E Lampert; X Bigard; B Serrurier; D Fortin; B Geny; V Veksler; R Ventura-Clapier; B Mettauer
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of physiology     Volume:  543     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  2002 Aug 
Date Detail:
Created Date:  2002-08-15     Completed Date:  2003-02-03     Revised Date:  2013-06-09    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  191-200     Citation Subset:  IM    
Affiliation:
Département de Physiologie, Equipe d'Accueil 3072, Faculté de Médecine, Université Louis Pasteur, Strasbourg, France. Joffrey.Zoll@chru-strasbourg.fr
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MeSH Terms
Descriptor/Qualifier:
Adult
Cell Respiration / physiology
Creatine Kinase / metabolism
Cytosol / enzymology
Energy Metabolism / physiology
Exercise / physiology
Female
Humans
Male
Middle Aged
Mitochondria / metabolism*
Muscle, Skeletal / metabolism*
Myosin Heavy Chains / metabolism
Oxygen Consumption / physiology
Physical Exertion / physiology*
Chemical
Reg. No./Substance:
0/Myosin Heavy Chains; EC 2.7.3.2/Creatine Kinase
Comments/Corrections

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