Document Detail


Chemoreflex and metaboreflex control during static hypoxic exercise.
MedLine Citation:
PMID:  15604123     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
To investigate the effects of muscle metaboreceptor activation during hypoxic static exercise, we recorded muscle sympathetic nerve activity (MSNA), heart rate, blood pressure, ventilation, and blood lactate in 13 healthy subjects (22 +/- 2 yr) during 3 min of three randomized interventions: isocapnic hypoxia (10% O(2)) (chemoreflex activation), isometric handgrip exercise in normoxia (metaboreflex activation), and isometric handgrip exercise during isocapnic hypoxia (concomitant metaboreflex and chemoreflex activation). Each intervention was followed by a forearm circulatory arrest to allow persistent metaboreflex activation in the absence of exercise and chemoreflex activation. Handgrip increased blood pressure, MSNA, heart rate, ventilation, and lactate (all P < 0.001). Hypoxia without handgrip increased MSNA, heart rate, and ventilation (all P < 0.001), but it did not change blood pressure and lactate. Handgrip enhanced blood pressure, heart rate, MSNA, and ventilation responses to hypoxia (all P < 0.05). During circulatory arrest after handgrip in hypoxia, heart rate returned promptly to baseline values, whereas ventilation decreased but remained elevated (P < 0.05). In contrast, MSNA, blood pressure, and lactate returned to baseline values during circulatory arrest after hypoxia without exercise but remained markedly increased after handgrip in hypoxia (P < 0.05). We conclude that metaboreceptors and chemoreceptors exert differential effects on the cardiorespiratory and sympathetic responses during exercise in hypoxia.
Authors:
Anne Houssiere; Boutaina Najem; Agniezka Ciarka; Sonia Velez-Roa; Robert Naeije; Philippe van de Borne
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2004-12-16
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  288     ISSN:  0363-6135     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2005 Apr 
Date Detail:
Created Date:  2005-03-17     Completed Date:  2005-04-20     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H1724-9     Citation Subset:  IM    
Affiliation:
Dept. of Physiology, Faculty of Medicine, Erasme University Hospital, 808 Lennik Rd., B-1070 Brussels, Belgium.
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MeSH Terms
Descriptor/Qualifier:
Adult
Anoxia / metabolism*,  physiopathology*
Blood Pressure / physiology
Carbon Dioxide / blood
Chemoreceptor Cells / physiology*
Energy Metabolism / physiology
Exercise / physiology*
Female
Hand Strength / physiology
Humans
Male
Muscle, Skeletal / innervation,  metabolism*
Sympathetic Nervous System / physiology
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide

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


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