Document Detail


Free oxygen radicals contribute to platelet aggregation and cyclic flow variations in stenosed and endothelium-injured canine coronary arteries.
MedLine Citation:
PMID:  7963124     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: The purpose of this study was to test the hypothesis that free oxygen radicals contribute to platelet aggregation and cyclic flow variations in stenosed and endothelium-injured coronary arteries. BACKGROUND: Although free oxygen radicals, such as superoxide anion and hydrogen peroxide, have been shown to alter platelet function in vitro, the potential role of free oxygen radicals has not been fully described in an in vivo model of coronary artery thrombosis. METHODS: Cyclic flow variations were produced in dogs by an external constrictor placed at the site of the left anterior descending coronary artery with injured endothelium. Blood flow in this artery was monitored by a pulsed Doppler flow probe. If cyclic flow variations were observed during postoperative days, dogs intravenously received superoxide dismutase plus catalase. In anesthetized dogs that did not develop an episode of cyclic flow variations, the effect of intracoronary infusion of xanthine plus xanthine oxidase or hydrogen peroxide on arterial blood flow velocity was studied. In platelet studies, the effect of free oxygen radicals and radical scavengers on platelet aggregation was examined. RESULTS: In conscious dogs with cyclic flow variations, superoxide dismutase plus catalase significantly reduced cyclic flow variations (n = 7), whereas saline infusion had no effect (n = 7). The infusion of xanthine plus xanthine oxidase or hydrogen peroxide significantly induced cyclic flow variations in four of six dogs or in five of seven dogs, respectively. In vitro platelet studies showed that xanthine plus xanthine oxidase or hydrogen peroxide significantly enhanced platelet aggregation, and superoxide dismutase or catalase significantly inhibited such aggregation. CONCLUSIONS: Reduction of free radical formation decreases platelet aggregation and may eliminate cyclic flow variations, whereas promotion of free radical generation enhances platelet aggregation and may induce cyclic flow variations. Thus, free oxygen radicals are an important mediator in this model.
Authors:
H Ikeda; Y Koga; T Oda; K Kuwano; H Nakayama; T Ueno; H Toshima; L H Michael; M L Entman
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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:  Journal of the American College of Cardiology     Volume:  24     ISSN:  0735-1097     ISO Abbreviation:  J. Am. Coll. Cardiol.     Publication Date:  1994 Dec 
Date Detail:
Created Date:  1994-12-16     Completed Date:  1994-12-16     Revised Date:  2010-03-24    
Medline Journal Info:
Nlm Unique ID:  8301365     Medline TA:  J Am Coll Cardiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1749-56     Citation Subset:  AIM; IM    
Affiliation:
Third Department of Internal Medicine, Kurume University School of Medicine, Japan.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Flow Velocity
Catalase / physiology
Coronary Thrombosis / blood,  physiopathology*
Coronary Vessels / metabolism,  physiopathology*
Dogs
Endothelium, Vascular / metabolism,  physiopathology
Free Radicals / metabolism
Hydrogen Peroxide / pharmacology
Platelet Aggregation / physiology*
Superoxide Dismutase / physiology
Xanthine
Xanthine Oxidase / pharmacology
Xanthines / pharmacology
Grant Support
ID/Acronym/Agency:
HL-22512/HL/NHLBI NIH HHS; HL-23161/HL/NHLBI NIH HHS; HL-42550/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Free Radicals; 0/Xanthines; 69-89-6/Xanthine; 7722-84-1/Hydrogen Peroxide; EC 1.11.1.6/Catalase; EC 1.15.1.1/Superoxide Dismutase; EC 1.17.3.2/Xanthine Oxidase

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


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