INTRODUCTION: In vivo, initial platelet activation is likely caused by platelet contacts with collagen in the subendothelium or from the small amounts of @entity556 formed by the tissue factor/factor VIIa complex. Our aim was to study the coagulative role of @entity857 released by the platelets after activation with strong stimuli such as collagen and/or @entity556 , and the relative importance of the platelet @entity857 receptors @entity15094 and @entity3075 . MATERIALS AND METHODS: We used 10 Hz free oscillation rheometry to measure clotting time, clot elasticity and fibrinolysis resistance of non-anticoagulated whole blood. The platelets were activated with a collagen-related peptide (CRP), with the @entity8781 @entity556 receptor activating peptide TRAP-6 or by @entity556 , the latter generated by small amounts of thromboplastin. To inhibit the platelet @entity857 receptors, we used the @entity15094 antagonist @entity24001 and the @entity3075 antagonist @entity37502 . RESULTS: Both antagonists significantly retarded the clotting induced by CRP. The effects were most pronounced with @entity37502 . For TRAP-6, the same trend was seen, but the retardation was only significant with @entity37502 . Clotting induced by small amounts of thromboplastin was not affected by any @entity857 -receptor antagonist. Addition of both antagonists did not change the results as compared to samples with @entity37502 alone. Nor did the antagonists, one at a time or in concert, effect fibrinolysis or the elastic properties of the clot. CONCLUSION: We conclude that @entity857 -receptor inhibition prolongs the clotting time for whole blood activated by CRP, but that it does not affect the properties of the subsequently formed coagulum.

Effects of inhibition of @entity15094 and XXXX on whole blood clotting, coagulum elasticity and fibrinolysis resistance studied with free oscillation rheometry.

@entity24001 :: ('MESH:C111914', 'Chemical') :: ['MRS2179'] @entity556 :: ('2147', 'Gene') :: ['thrombin'] @entity37502 :: ('MESH:C117446', 'Chemical') :: ['AR-C69931MX'] @entity857 :: ('MESH:D000244', 'Chemical') :: ['ADP'] @entity3075 :: ('64805', 'Gene') :: ['P2Y(12)'] @entity15094 :: ('5028', 'Gene') :: ['P2Y(1)'] @entity8781 :: ('2149', 'Gene') :: ['PAR1']
@entity3075 :: (64805,Gene) :: ['P2Y(12)']
