Document Detail

Cardiovascular and plasma catecholamine response to static exercise in normotensive blacks and whites.
MedLine Citation:
PMID:  9395595     Owner:  NLM     Status:  MEDLINE    
OBJECTIVES: The objectives of the present study were (1) to evaluate the pressor response to an isometric handgrip exercise in normotensive black and white males; (2) to measure plasma catecholamine levels pre- and post-exercise, as an index of sympathetic nervous system activity; and (3) to quantify the pressor response to bolus intravenous injections of phenylephrine (an alpha-specific agonist). METHODS: Cardiovascular and catecholamine responses to an isometric handgrip exercise (3 minutes at 30% MVC) were measured in 15 normotensive blacks and whites. In another phase of the study, pressor responses to bolus injections of phenylephrine were assessed to evaluate alpha-adrenergic sensitivity. RESULTS: The blood pressure in the blacks increased from 119/69 to 160/120 mm HG during isometric exercise, while in the whites it increased from 118/67 to 153/110 mm HG. The blacks exhibited a greater diastolic blood pressure reactivity, as evidenced by a significant race x time interaction (p < 0.05). The heart rate responses were not significantly different between the two groups. The plasma levels of norepinephrine were similar at rest, but were 25% lower in the blacks than in the whites following isometric exercise (p < 0.01). Black subjects also demonstrated an increased pressor response to intravenous injections of phenylephrine at rest (p < 0.05). CONCLUSIONS: The enhanced vascular sensitivity to norepinephrine may have contributed to the greater exercise pressor response in the blacks.
W J Duey; D R Bassett; A J Walker; D J Torok; E T Howley; D Ely; M O Pease
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Ethnicity & health     Volume:  2     ISSN:  1355-7858     ISO Abbreviation:  Ethn Health     Publication Date:    1997 Mar-Jun
Date Detail:
Created Date:  1997-12-31     Completed Date:  1997-12-31     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9608374     Medline TA:  Ethn Health     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  127-36     Citation Subset:  IM    
Exercise Science Unit, University of Tennessee-Knoxville, USA.
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MeSH Terms
Adrenergic alpha-Agonists / pharmacology
African Continental Ancestry Group*
Blood Pressure / physiology*
Epinephrine / blood*
European Continental Ancestry Group*
Exercise / physiology*
Hand Strength
Heart Rate / physiology*
Injections, Intravenous
Norepinephrine / blood*
Phenylephrine / pharmacology
Reference Values
Sympathetic Nervous System / physiology
Vasoconstrictor Agents / blood*
Reg. No./Substance:
0/Adrenergic alpha-Agonists; 0/Vasoconstrictor Agents; 51-41-2/Norepinephrine; 51-43-4/Epinephrine; 59-42-7/Phenylephrine

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

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