Document Detail


Alpha-adrenergic vasoconstriction in arterial and arteriolar sections of the canine coronary circulation.
MedLine Citation:
PMID:  6255937     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Using a method which allowed the in-situ measurement of segmental coronary vascular resistances, the reaction of arterial and arteriolar sections of the coronary vascular system to alpha-receptor stimulation was studied i anaesthetized dogs. The left coronary artery was cannulated, and the perfusion pressure was kept constant. Allowance was made for extravascular and metabolic influences of alpha-stimulation on coronary vascular resistances. On an average, submaximal alpha-stimulation with xylometazoline increased the arterial resistance by about 60% and the arteriolar resistance by about 90%. The cannulation of the left coronary artery increased the sympathetic reactivity of the arterioles. Moreover, xylometazoline increased the extravascular component of the coronary vascular resistance by about 4%. Thus it can be assumed that under normal in-vivo conditions alpha-receptor vasoconstriction might be less different in coronary arteries and arterioles. Since the arterial resistance ranges from 20% to 50% of total coronary resistance, a sympathetic vasoconstriction of this vascular section might lead even to a critical limitation of coronary blood flow. On the other hand, a predominant constriction in arterioles leads to an increase in peripheral coronary pressure, i.e. to a "reverse coronary steal phenomenon".
Authors:
G Ertl; M Fuchs
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Basic research in cardiology     Volume:  75     ISSN:  0300-8428     ISO Abbreviation:  Basic Res. Cardiol.     Publication Date:    1980 Sep-Oct
Date Detail:
Created Date:  1981-02-26     Completed Date:  1981-02-26     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0360342     Medline TA:  Basic Res Cardiol     Country:  GERMANY, WEST    
Other Details:
Languages:  eng     Pagination:  600-14     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Arteries / physiology
Arterioles / physiology
Coronary Circulation / drug effects
Coronary Vessels / physiology*
Dogs
Imidazoles / pharmacology
Receptors, Adrenergic / pharmacology*
Receptors, Adrenergic, alpha / pharmacology*
Vascular Resistance / drug effects
Vasoconstriction / drug effects*
Chemical
Reg. No./Substance:
0/Imidazoles; 0/Receptors, Adrenergic; 0/Receptors, Adrenergic, alpha; 526-36-3/xylometazoline

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


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