Document Detail

Enzyme mechanisms for pyruvate-to-lactate flux attenuation: a study of Sherpas, Quechuas, and hummingbirds.
MedLine Citation:
PMID:  1483747     Owner:  NLM     Status:  MEDLINE    
During incremental exercise to fatigue under hypobaric hypoxia, Andean Quechua natives form and accumulate less plasma lactate than do lowlanders under similar conditions. This phenomenon of low lactate accumulation despite hypobaric hypoxia, first discovered some half century ago, is known in Quechuas to be largely unaffected by acute exposure to hypoxia or by acclimatization to sea level conditions. Earlier Nuclear Magnetic Resonance (NMR) spectroscopy and metabolic biochemistry studies suggest that closer coupling of energy demand and energy supply in Quechuas allows given changes in work rate with relatively modest changes in muscle adenylate and phosphagen concentrations, thus tempering the activation of glycolytic flux to pyruvate--a coarse control mechanism operating at the level of overall pathway flux. Later studies of enzyme activities in skeletal muscles of Quechuas and of Sherpas have identified a finely-tuned control mechanism which by adaptive modifications of a few key enzymes apparently serves to specifically attenuate pyruvate flux to lactate.
P W Hochachka; C Stanley; D C McKenzie; A Villena; C Monge
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  International journal of sports medicine     Volume:  13 Suppl 1     ISSN:  0172-4622     ISO Abbreviation:  Int J Sports Med     Publication Date:  1992 Oct 
Date Detail:
Created Date:  1993-02-18     Completed Date:  1993-02-18     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8008349     Medline TA:  Int J Sports Med     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  S119-22     Citation Subset:  IM; S    
Dept. of Zoology, University of British Columbia, Vancouver, Canada.
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MeSH Terms
Adaptation, Physiological / physiology
Anoxia / blood
Birds / physiology*
China / ethnology
Energy Metabolism / physiology
Exercise / physiology
Glycolysis / physiology
Indians, South American
Lactates / biosynthesis,  blood*
Lactic Acid
Muscles / enzymology*
Nepal / ethnology
Pyruvates / blood*
Reg. No./Substance:
0/Lactates; 0/Pyruvates; 50-21-5/Lactic Acid

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

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