Free oxygen radicals contribute to platelet aggregation and cyclic flow variations in stenosed and endothelium-injured canine coronary arteries. 1994

H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
Third Department of Internal Medicine, Kurume University School of Medicine, Japan.

OBJECTIVE 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.

UI MeSH Term Description Entries
D010974 Platelet Aggregation The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS. Aggregation, Platelet
D001783 Blood Flow Velocity A value equal to the total volume flow divided by the cross-sectional area of the vascular bed. Blood Flow Velocities,Flow Velocities, Blood,Flow Velocity, Blood,Velocities, Blood Flow,Velocity, Blood Flow
D002374 Catalase An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA. Catalase A,Catalase T,Manganese Catalase,Mn Catalase
D003328 Coronary Thrombosis Coagulation of blood in any of the CORONARY VESSELS. The presence of a blood clot (THROMBUS) often leads to MYOCARDIAL INFARCTION. Thrombosis, Coronary,Coronary Thromboses,Thromboses, Coronary
D003331 Coronary Vessels The veins and arteries of the HEART. Coronary Arteries,Sinus Node Artery,Coronary Veins,Arteries, Coronary,Arteries, Sinus Node,Artery, Coronary,Artery, Sinus Node,Coronary Artery,Coronary Vein,Coronary Vessel,Sinus Node Arteries,Vein, Coronary,Veins, Coronary,Vessel, Coronary,Vessels, Coronary
D004285 Dogs The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065) Canis familiaris,Dog
D004730 Endothelium, Vascular Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components. Capillary Endothelium,Vascular Endothelium,Capillary Endotheliums,Endothelium, Capillary,Endotheliums, Capillary,Endotheliums, Vascular,Vascular Endotheliums
D005609 Free Radicals Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated. Free Radical
D006861 Hydrogen Peroxide A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials. Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

Related Publications

H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
November 1993, Circulation research,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
January 1992, Circulation research,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
October 1992, Circulation,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
April 1994, Circulation,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
January 1988, Transactions of the Association of American Physicians,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
November 2001, Thrombosis and haemostasis,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
December 1995, Methods and findings in experimental and clinical pharmacology,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
February 1982, Circulation,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
March 1997, Circulation,
H Ikeda, and Y Koga, and T Oda, and K Kuwano, and H Nakayama, and T Ueno, and H Toshima, and L H Michael, and M L Entman
March 1986, Circulation,
Copied contents to your clipboard!