Document Detail

Exercise-induced changes in plasma potassium and the ventilatory threshold in man.
MedLine Citation:
PMID:  7990030     Owner:  NLM     Status:  MEDLINE    
1. It has been reported that, during incremental exercise testing, the patterns of change in ventilation (VE) and arterial K+ (Ka+) are similar, suggesting that changing Ka+ may lead to the phenomenon of the ventilatory threshold through its action on the peripheral chemoreceptors. 2. Expiratory ventilation, oxygen consumption, CO2 production (VE, VO2, VCO2), arterialized venous PCO2 (Pav, CO2; see Methods), pH (pHav), K+ (Kav+) and lactate were measured during incremental exercise tests undertaken by six normal male subjects under control conditions and during lactic acidosis following severe exercise (experimental trial). 3. A ventilatory threshold, associated with a period of isocapnic buffering, was observed under both control and experimental conditions. During the control trial, plots of Kav+ against VO2 showed an inflexion close to the ventilatory threshold. Throughout the experimental trial Kav+ rose linearly relative to VO2. In both control and experimental trials Kav+ concentrations were similar at the ventilatory threshold. 4. These results suggest that the pattern of change of Ka+ cannot account for the phenomenon of the ventilatory threshold. The possibility that the peripheral chemoreceptor response is non-linear above a critical value of Ka+ requires further investigation.
P McLoughlin; P Popham; R A Linton; R C Bruce; D M Band
Publication Detail:
Type:  Clinical Trial; Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of physiology     Volume:  479 ( Pt 1)     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  1994 Aug 
Date Detail:
Created Date:  1995-01-11     Completed Date:  1995-01-11     Revised Date:  2010-08-25    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  139-47     Citation Subset:  IM; S    
Laboratory of Applied Physiology, United Medical and Dental School, St Thomas's Hospital, London.
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MeSH Terms
Blood Gas Analysis
Carbon Dioxide / blood
Chemoreceptor Cells / physiology
Exercise / physiology*
Hydrogen-Ion Concentration
Lactates / blood
Oxygen Consumption / physiology
Potassium / blood*
Respiration / physiology*
Respiratory Function Tests
Grant Support
//Wellcome Trust
Reg. No./Substance:
0/Lactates; 124-38-9/Carbon Dioxide; 7440-09-7/Potassium

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