Document Detail


Regulation of native collateral vessel dilation after coronary occlusion in the dog.
MedLine Citation:
PMID:  8141378     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The purpose of this study was to examine mechanisms involved in the response of native collaterals to coronary occlusion. In anesthetized dogs native collaterals were identified as vessels coursing between the left anterior descending and left circumflex arteries using fluorescence angiography. After a left anterior descending occlusion in 12 dogs, collaterals < 100 microns in diameter progressively dilated by 21 +/- 4% (n = 12) 1 min after occlusion and by 39 +/- 6% 15 min after occlusion. Collaterals > 100 microns in diameter did not dilate after coronary occlusion. NG-nitro-L-arginine (1 mg/min intracoronary) caused constriction under basal conditions in collaterals < 100 microns but did not prevent the dilation of collaterals after occlusion. In contrast, glibenclamide (10(-5) M), an inhibitor of ATP-sensitive potassium channels, had no effect on baseline diameter of collaterals < 100 microns diameter but completely prevented dilation of collaterals after occlusion. We conclude that collaterals are not maximally dilated immediately after a coronary occlusion but rather progressively dilate for at least 15 min after an occlusion. This dilation of native collaterals after an occlusion is not mediated by release of an endothelium-derived relaxing factor derived from L-arginine but is mediated by activation of ATP-sensitive K+ channels.
Authors:
K G Lamping; E N Bloom; D G Harrison
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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:  266     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1994 Feb 
Date Detail:
Created Date:  1994-04-26     Completed Date:  1994-04-26     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H769-78     Citation Subset:  IM    
Affiliation:
Department of Internal Medicine, College of Medicine, University of Iowa, Iowa City 52242.
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MeSH Terms
Descriptor/Qualifier:
Acetylcholine / pharmacology
Animals
Arginine / analogs & derivatives,  pharmacology
Blood Pressure / drug effects
Coronary Vessels / physiology*
Diastole
Dogs
Female
Fluorescein Angiography / methods
Heart Rate / drug effects
Male
Microcirculation / anatomy & histology,  drug effects,  physiology
Muscle, Smooth, Vascular / drug effects,  physiology
Nitroarginine
Nitroprusside / pharmacology
Potassium Channels / drug effects,  physiology
Systole
Time Factors
Vasodilation / drug effects,  physiology*
Grant Support
ID/Acronym/Agency:
HL-32295/HL/NHLBI NIH HHS; HL-39050/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Potassium Channels; 15078-28-1/Nitroprusside; 2149-70-4/Nitroarginine; 51-84-3/Acetylcholine; 74-79-3/Arginine

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


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