Role of thromboxane A2 as a mediator of platelet-activating-factor-induced aggregation of human platelets. 1989

R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
Department of Medicine, University of Western Australia, Royal Perth Hospital.

1. At present it is unclear whether platelet-activating-factor (PAF)-induced aggregation is mediated by thromboxane. To obtain further information about this event we have compared the affects of aspirin on platelet aggregation and secretion induced by PAF and collagen. 2. Collagen and PAF induced aggregation and secretion in human platelets in a dose-related manner. 3. Aspirin inhibited the magnitude of both platelet aggregation and secretion induced by PAF and collagen, but the degree of inhibition was much greater for collagen. 4. Aspirin strongly inhibited the aggregation rate of collagen-induced platelet aggregation, but had no measurable effect on the rate of PAF-induced aggregation. 5. Inconsistencies reported in previous studies of the effect of aspirin on PAF-induced platelet aggregation may be explained, in part, by the doses of PAF used and the method of inactivating cyclo-oxygenase (in vitro compared with in vivo). 6. Our results suggest that the initial events of PAF-induced aggregation are independent of thromboxane A2 formation and that thromboxane A2 plays only a minor role in the later phase of PAF-induced aggregation.

UI MeSH Term Description Entries
D008297 Male Males
D010972 Platelet Activating Factor A phospholipid derivative formed by PLATELETS; BASOPHILS; NEUTROPHILS; MONOCYTES; and MACROPHAGES. It is a potent platelet aggregating agent and inducer of systemic anaphylactic symptoms, including HYPOTENSION; THROMBOCYTOPENIA; NEUTROPENIA; and BRONCHOCONSTRICTION. AGEPC,Acetyl Glyceryl Ether Phosphorylcholine,PAF-Acether,Phosphorylcholine, Acetyl Glyceryl Ether,1-Alkyl-2-acetyl-sn-glycerophosphocholine,Platelet Aggregating Factor,Platelet Aggregation Enhancing Factor,Platelet-Activating Substance,Thrombocyte Aggregating Activity,1 Alkyl 2 acetyl sn glycerophosphocholine,Aggregating Factor, Platelet,Factor, Platelet Activating,PAF Acether,Platelet Activating Substance
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
D003094 Collagen A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH). Avicon,Avitene,Collagen Felt,Collagen Fleece,Collagenfleece,Collastat,Dermodress,Microfibril Collagen Hemostat,Pangen,Zyderm,alpha-Collagen,Collagen Hemostat, Microfibril,alpha Collagen
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328 Adult A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available. Adults
D001241 Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. (From Martindale, The Extra Pharmacopoeia, 30th ed, p5) Acetylsalicylic Acid,2-(Acetyloxy)benzoic Acid,Acetysal,Acylpyrin,Aloxiprimum,Colfarit,Dispril,Easprin,Ecotrin,Endosprin,Magnecyl,Micristin,Polopirin,Polopiryna,Solprin,Solupsan,Zorprin,Acid, Acetylsalicylic
D012701 Serotonin A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator. 5-HT,5-Hydroxytryptamine,3-(2-Aminoethyl)-1H-indol-5-ol,Enteramine,Hippophaine,Hydroxytryptamine,5 Hydroxytryptamine
D013928 Thromboxane A2 An unstable intermediate between the prostaglandin endoperoxides and thromboxane B2. The compound has a bicyclic oxaneoxetane structure. It is a potent inducer of platelet aggregation and causes vasoconstriction. It is the principal component of rabbit aorta contracting substance (RCS). Rabbit Aorta Contracting Substance,A2, Thromboxane
D013929 Thromboxane B2 A stable, physiologically active compound formed in vivo from the prostaglandin endoperoxides. It is important in the platelet-release reaction (release of ADP and serotonin). B2, Thromboxane

Related Publications

R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
March 1996, Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis,
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
February 1975, Lancet (London, England),
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
November 1991, Journal of applied physiology (Bethesda, Md. : 1985),
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
December 1984, Science (New York, N.Y.),
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
January 1990, Prostaglandins,
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
August 1982, Prostaglandins,
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
January 1980, Minerva nefrologica,
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
April 1998, Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis,
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
April 1992, American journal of kidney diseases : the official journal of the National Kidney Foundation,
R K McCulloch, and J Summers, and R Vandongen, and I L Rouse
January 1979, Rinsho byori. The Japanese journal of clinical pathology,
Copied contents to your clipboard!