title: Transient effect of aspirin on collagen-induced platelet accumulation.
abstract: A piece of collagen fiber (catgut) was placed into polyethylene tubing and perfused with heparinized blood. The perfusion pressure was monitored, and the pressure rise indicated platelet accumulation around collagen leading to occlusion of the tubing. Continuous slow infusion of prostacyclin into the blood or monoclonal antibody against von Willebrand factor completely prevented thrombus formation. Aspirinization of blood (0.1-2 mM) resulted in a concentration-dependent delay of the onset of thrombus growth, but even at the highest aspirin concentration, the thrombus did finally grow and at the same rate as that of the nonaspirinated control platelets. These findings question the clinical anti-thrombotic benefit of aspirin as platelet release inhibitor.
mesh_terms: D000293:Adolescent; D000328:Adult; D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D003094:Collagen / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D011464:Epoprostenol / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D013927:Thrombosis / Q000139:chemically induced; D014841:von Willebrand Factor / Q000037:antagonists & inhibitors
chemical_list: D014841:von Willebrand Factor; D003094:Collagen; D011464:Epoprostenol; D001241:Aspirin