Document Detail


Exercise training in normobaric hypoxia in endurance runners. III. Muscular adjustments of selected gene transcripts.
MedLine Citation:
PMID:  16540710     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We hypothesized that specific muscular transcript level adaptations participate in the improvement of endurance performances following intermittent hypoxia training in endurance-trained subjects. Fifteen male high-level, long-distance runners integrated a modified living low-training high program comprising two weekly controlled training sessions performed at the second ventilatory threshold for 6 wk into their normal training schedule. The athletes were randomly assigned to either a normoxic (Nor) (inspired O2 fraction = 20.9%, n = 6) or a hypoxic group exercising under normobaric hypoxia (Hyp) (inspired O2 fraction = 14.5%, n = 9). Oxygen uptake and speed at second ventilatory threshold, maximal oxygen uptake (VO2 max), and time to exhaustion (Tlim) at constant load at VO2 max velocity in normoxia and muscular levels of selected mRNAs in biopsies were determined before and after training. VO2 max (+5%) and Tlim (+35%) increased specifically in the Hyp group. At the molecular level, mRNA concentrations of the hypoxia-inducible factor 1alpha (+104%), glucose transporter-4 (+32%), phosphofructokinase (+32%), peroxisome proliferator-activated receptor gamma coactivator 1alpha (+60%), citrate synthase (+28%), cytochrome oxidase 1 (+74%) and 4 (+36%), carbonic anhydrase-3 (+74%), and manganese superoxide dismutase (+44%) were significantly augmented in muscle after exercise training in Hyp only. Significant correlations were noted between muscular mRNA levels of monocarboxylate transporter-1, carbonic anhydrase-3, glucose transporter-4, and Tlim only in the group of athletes who trained in hypoxia (P < 0.05). Accordingly, the addition of short hypoxic stress to the regular endurance training protocol induces transcriptional adaptations in skeletal muscle of athletic subjects. Expressional adaptations involving redox regulation and glucose uptake are being recognized as a potential molecular pathway, resulting in improved endurance performance in hypoxia-trained subjects.
Authors:
Joffrey Zoll; Elodie Ponsot; Stéphane Dufour; Stéphane Doutreleau; Renée Ventura-Clapier; Michael Vogt; Hans Hoppeler; Ruddy Richard; Martin Flück
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  100     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2006 Apr 
Date Detail:
Created Date:  2006-03-16     Completed Date:  2007-01-04     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:  1258-66     Citation Subset:  IM    
Affiliation:
Department of Anatomy, University of Bern, Bühlstrasse 26, 3000 Bern 9, Switzerland.
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological
Adult
Anoxia / metabolism*,  physiopathology
Carbonic Anhydrase III / genetics,  metabolism
Exercise Tolerance / physiology*
Gene Expression Regulation*
Glucose Transporter Type 4 / genetics,  metabolism
Humans
Male
Monocarboxylic Acid Transporters / genetics,  metabolism
Muscle, Skeletal / metabolism*
Oxygen Consumption
Pulmonary Ventilation
RNA, Messenger / metabolism
Running*
Sports Medicine
Symporters / genetics,  metabolism
Chemical
Reg. No./Substance:
0/Glucose Transporter Type 4; 0/Monocarboxylic Acid Transporters; 0/RNA, Messenger; 0/Symporters; 0/monocarboxylate transport protein 1; EC 4.2.1.-/Carbonic Anhydrase III

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


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