title: Inhibition of PAF-induced platelet aggregation by WEB 2086 'in-vitro', an antagonist to the receptor for platelet-activating factor, in bovine.
abstract: The sensitivity of bovine platelet aggregation in response to PAF stimulation and the ability of WEB 2086 (a thieno-triazolodiazepine) to inhibit response to PAF-induced platelet aggregation were investigated in the blood from five healthy male Belgian Blue calves. The recorded response to PAF showed a plateau which was dependent on the PAF concentration. Platelet aggregation induced by PAF consists of two mechanisms: reversible and irreversible aggregations which are accompanied by the release of platelet granule contents. Reversible aggregation occurred above (2 . 10(-9) mol/l) PAF, and irreversible aggregation occurred above (2 . 10(-7) mol/l) PAF. Addition of WEB 2086 to bovine platelets in vitro induced a rightward shift in the dose-response curve to PAF. WEB 2086 inhibited PAF-induced aggregation in a competitive reversible manner (pA2 = 7.61). The results of our study show that PAF induces platelet aggregation in platelet-rich plasma (PRP) and that addition of WEB 2086 to bovine platelets in vitro inhibits PAF-induced Platelet Aggregation.
authors.affiliation: Laboratory for Functional Investigation, Faculty of Veterinary Medicine, University of Liège, Belgium.
authors.forename: M B
authors.initials: MB
authors.lastname: da Silva
authors.forename: F
authors.initials: F
authors.lastname: Herion
authors.forename: R
authors.initials: R
authors.lastname: Raskinet
authors.forename: J L
authors.initials: JL
authors.lastname: David
authors.forename: P
authors.initials: P
authors.lastname: Gustin
authors.forename: C
authors.initials: C
authors.lastname: Dessy
authors.forename: P
authors.initials: P
authors.lastname: Lekeux
mesh_terms: D000818:Animals; D001381:Azepines / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D002417:Cattle / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008297:Male; D008854:Microscopy, Electron; D010972:Platelet Activating Factor / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000502:physiology; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D014230:Triazoles / Q000494:pharmacology*
chemical_list: D001381:Azepines; D010972:Platelet Activating Factor; D010975:Platelet Aggregation Inhibitors; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D014230:Triazoles; C039351:platelet activating factor receptor; C052518:WEB 2086