Document Detail

Catecholamine responses to environmental stressors in trained and untrained men after 3-day bed rest.
MedLine Citation:
PMID:  14503670     Owner:  NLM     Status:  MEDLINE    
INTRODUCTION: The effect of decreased physical activity with reduced gravitational stress on activity, sensitivity, and reactivity of the sympathetic nervous system (SNS) is not fully recognized. We hypothesized that the effect is most pronounced in physically active subjects. Thus, basal plasma norepinephrine [NE] and epinephrine [E], and catecholamine responses to physiological stimuli were determined after 3 d of horizontal bed rest (BR) in subjects differing in level and kind of habitual activity. METHODS: Before and after BR, 11 untrained students, 8 endurance athletes, and 10 power/strength athletes were submitted to oral glucose tolerance test (OGTT) and orthostatic stand test (OST). Another 32 men (12 untrained, 10 endurance athletes, and 10 power/strength athletes) underwent cold pressor test (CPT) and graded exercise test (GET) performed until volitional exhaustion. RESULTS: After BR, basal [NE] was decreased only in athletes (p < 0.01). Increases in both catecholamines during OGTT were diminished (p < 0.05), particularly in endurance athletes. Plasma [NE] response to standing was not affected by BR in individual groups, but it was diminished in the whole group (p < 0.05). Bed rest did not affect the increases in catecholamines induced by CPT and GET. Heart rate response to OST, and BP responses to OST, CPT, and glucose ingestion were enhanced. CONCLUSIONS: Basal sympathetic activity is diminished after 3 d of BR in physically active men. Although catecholamine responses to glucose load and standing were reduced, the general reactivity and sensitivity of SNS were not attenuated since catecholamine responses to the most (exercise) and least (CPT) powerful stimuli were unchanged.
H Kaciuba-Uscilko; J Smorawinski; K Nazar; J Adrian; J E Greenleaf
Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Aviation, space, and environmental medicine     Volume:  74     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  2003 Sep 
Date Detail:
Created Date:  2003-09-23     Completed Date:  2004-02-09     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  928-36     Citation Subset:  IM; S    
Department of Applied Physiology, Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
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MeSH Terms
Bed Rest*
Cold Temperature / diagnostic use
Epinephrine / blood*
Exercise Test
Glucose Tolerance Test
Heart Rate / physiology
Norepinephrine / blood*
Physical Education and Training
Physical Endurance / physiology*
Physical Fitness / physiology*
Reference Values
Sympathetic Nervous System / physiology
Reg. No./Substance:
51-41-2/Norepinephrine; 51-43-4/Epinephrine

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

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