Document Detail


Effect of hindlimb suspension on cardiovascular responses to sympathomimetics and lower body negative pressure.
MedLine Citation:
PMID:  2312478     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
To determine whether hindlimb suspension is associated with the development of cardiovascular deconditioning, male rats were studied before and after undergoing one of three treatment conditions for 9 days: 1) cage control (n = 15, CON), 2) horizontal suspension (n = 15, HOZ), and 3) head-down suspension (n = 18, HDS). Testing included lower body negative pressure administered during chloralose-urethan anesthesia and graded doses of sympathomimetic agents (norepinephrine, phenylephrine, and tyramine) administered to conscious unrestrained animals. Both HDS and HOZ were associated with a small decrease in the hypotensive response to lower body negative pressure. The HOZ group, but not the HDS group, exhibited augmented reflex tachycardia. Furthermore, both HDS and HOZ groups manifested reduced pressor responses to phenylephrine after treatment. These reductions were associated with significantly attenuated increases in mesenteric vascular resistance. However, baroreflex control of heart rate was not altered by the treatment conditions. Collectively, these results indicate that 9 days of HDS in rats does not elicit hemodynamic response patterns generally associated with cardiovascular deconditioning induced by hypogravic conditions.
Authors:
J M Overton; C M Tipton
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  68     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1990 Jan 
Date Detail:
Created Date:  1990-04-17     Completed Date:  1990-04-17     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  355-62     Citation Subset:  IM; S    
Affiliation:
Department of Exercise and Sport Sciences, University of Arizona, Tucson 85721.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Circulation / drug effects*
Blood Flow Velocity / drug effects
Blood Pressure / drug effects*
Decompression*
Heart Rate / drug effects
Hindlimb / blood supply,  physiology
Lower Body Negative Pressure*
Male
Norepinephrine / pharmacology
Phenylephrine / pharmacology
Rats
Sympathomimetics / pharmacology*
Tyramine / pharmacology
Weightlessness*
Grant Support
ID/Acronym/Agency:
HL-33782-02/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Sympathomimetics; 51-41-2/Norepinephrine; 51-67-2/Tyramine; 59-42-7/Phenylephrine

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


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