Document Detail


Vascular control of brain cooling in reindeer.
MedLine Citation:
PMID:  2834969     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The cold venous effluent returning from the nose of the heat-stressed reindeer may be distributed through angular oculi veins for selective cooling of the brain and through facial veins for general body cooling. In vitro experiments indicate that adrenergic receptors of the angular oculi vein are exclusively of the alpha-adrenergic type, whereas facial veins contain mainly beta-adrenergic receptors. We suggest that the antagonistic adrenergic neuroeffector organization of these veins plays a major role in control of brain cooling. Thus simultaneous sympathetic stimulation results in constriction of angular oculi veins and release of a preexisting stretch-induced tone in facial veins. In this situation cold venous blood is directed via facial veins and used for general body cooling. Reduction of sympathetic activity, on the other hand, results in dilatation of angular oculi veins and constriction of facial veins, due to development of myogenic tone in the latter vessels. In this situation cold venous blood is distributed via angular oculi veins and used for selective cooling of the brain.
Authors:
H K Johnson; L P Folkow
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The American journal of physiology     Volume:  254     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1988 May 
Date Detail:
Created Date:  1988-06-09     Completed Date:  1988-06-09     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:  R730-9     Citation Subset:  IM    
Affiliation:
Department of Arctic Biology, University of Tromsø, Norway.
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MeSH Terms
Descriptor/Qualifier:
Animals
Body Temperature Regulation*
Cerebrovascular Circulation*
Electric Stimulation
Face / blood supply
Norepinephrine / pharmacology
Nose / blood supply
Receptors, Adrenergic, alpha / physiology
Reference Values
Reindeer / physiology*
Stress, Physiological / physiopathology
Sympathetic Nervous System / physiology
Vasoconstriction / drug effects
Vasodilation
Chemical
Reg. No./Substance:
0/Receptors, Adrenergic, alpha; 51-41-2/Norepinephrine

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


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