Document Detail


Chemoreflex and metaboreflex responses to static hypoxic exercise in aging humans.
MedLine Citation:
PMID:  16531899     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: We tested the hypothesis that aging decreases the contribution of metaboreceptors to sympathetic responses during exercise in hypoxia. METHODS: We recorded sympathetic nerve traffic to muscle circulation (MSNA), heart rate (HR), blood pressure (BP), minute ventilation (VE), and blood lactate (BL) in 12 older (55 +/- 10 yr) and 12 younger (22 +/- 2 yr) normal subjects during three randomized interventions: isocapnic hypoxia (chemoreflex activation), isometric handgrip exercise (HG) in normoxia (metaboreflex activation), and HG during isocapnic hypoxia (concomitant metaboreflex and chemoreflex activation). All interventions were followed by a forearm circulatory arrest period to allow metaboreflex activation in the absence of exercise and chemoreflex activation. RESULTS: Older subjects had higher resting MSNA (38 +/- 12 vs 23 +/- 9 bursts per minute; P < 0.01) and BP (P < 0.001). Heart rate, minute ventilation, and blood lactate did not differ (all P > 0.5). MSNA responses to HG in normoxia (P < 0.05) and in hypoxia (P < 0.05) were smaller in the older subjects, but were similar during hypoxia alone. The increase in HR was smaller in the older subjects for all interventions (all P < 0.05). In contrast, the increase in systolic and diastolic BP, VE, and BL were similar in both groups (P > 0.05). During the local circulatory arrest, MSNA and BP remained elevated in both groups after HG in normoxia (P < 0.01) and in hypoxia (P < 0.01), but MSNA changes were smaller in the older subjects (P < 0.05). CONCLUSION: Aging reduces sympathetic reactivity to isometric handgrip, but does not prevent the metaboreceptors to remain the main determinant of sympathetic activation during exercise in hypoxia.
Authors:
Anne Houssiere; Boutaina Najem; Atul Pathak; Olivier Xhaët; Robert Naeije; Philippe Van De Borne
Related Documents :
10766969 - Spontaneous contractions in elasmobranch vessels in vitro.
7369979 - Retinal studies at 446 torr in a hypobaric chamber.
8002119 - The effect of acute hypoxia at low altitude and acute normoxia at high altitude on perf...
22817979 - Creatine supplementation with specific view to exercise/sports performance: an update.
468699 - Cross-adaptive effects of cold, hypoxia, or physical training on decompression sickness...
7696059 - Interaction of the effects of domperidone and sub-anaesthetic concentrations of isoflur...
11542919 - How can plants tell which way is up?
3655599 - Atrioventricular wenckebach periodicity in athletes: influence of increased vagal tone ...
9451129 - The role of exercise in diabetes management.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  38     ISSN:  0195-9131     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  2006 Feb 
Date Detail:
Created Date:  2006-03-13     Completed Date:  2006-06-23     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  305-12     Citation Subset:  IM; S    
Affiliation:
Department of Physiology, Erasme Hospital, Brussels, Belgium.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Aging / physiology*
Analysis of Variance
Anoxia / physiopathology*
Blood Pressure / physiology
Chemoreceptor Cells / physiology
Exercise / physiology*
Female
Hand Strength / physiology
Heart Rate / physiology
Humans
Lactates / blood
Male
Middle Aged
Muscle, Skeletal / blood supply
Sympathetic Nervous System / physiology*
Chemical
Reg. No./Substance:
0/Lactates

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


Previous Document:  Immunological changes in response to exercise: influence of age, puberty, and gender.
Next Document:  Heart rate variability during night sleep and after awakening in overtrained athletes.