Document Detail


Hypothalamic influences on cardiovascular response of beagles to dynamic exercise.
MedLine Citation:
PMID:  2801983     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We studied nine young adult beagles at rest and during four levels of dynamic exercise before and after electrolytic lesions were made in the hypothalamus in the region of the fields of Forel. The beagles were habituated to run freely on a motor-driven treadmill and were instrumented chronically to allow repeated measurement of cardiovascular variables. Variables measured or calculated included O2 consumption, cardiac output, arteriovenous O2 difference, systemic arterial pressure, systemic vascular resistance, heart rate, and mixed venous blood lactate concentration. In addition, regional blood flow was measured with radioactive microspheres in two beagles at rest and during peak exercise (6.4 km/h, 20% grade). After prelesion treadmill studies, the beagles were anesthetized and the tips of stainless steel electrodes were placed bilaterally in the hypothalamus in locations that when stimulated (100-300 microA) evoked increases in cardiovascular and muscle motor function. Lesioning (5 mA; 15 s) abolished the responses evoked by stimulation. By contrast, the cardiovascular variables measured in the beagles at rest and during dynamic exercise were similar pre- and postlesion. Therefore, loss of hypothalamic sites that produce increases in cardiovascular and muscle motor function when stimulated electrically does not appear to comprise the cardiovascular response of awake beagles to dynamic exercise.
Authors:
G A Ordway; T G Waldrop; G A Iwamoto; B J Gentile
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  257     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1989 Oct 
Date Detail:
Created Date:  1989-11-17     Completed Date:  1989-11-17     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H1247-53     Citation Subset:  IM; S    
Affiliation:
Department of Physiology, University of Texas Southwestern Medical Center, Dallas 75235.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure
Body Temperature
Cardiac Output
Dogs
Female
Heart Rate
Hemodynamics*
Hypothalamus / physiology*
Male
Oxygen / blood
Oxygen Consumption
Physical Exertion*
Reference Values
Stroke Volume
Vascular Resistance
Grant Support
ID/Acronym/Agency:
HL-01856/HL/NHLBI NIH HHS; HL-34362/HL/NHLBI NIH HHS; HL-38433/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

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


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