title: Inhibition of the thrombin-platelet reaction by hirudin.
abstract: The influence of hirudin on the thrombin-platelet reaction was studied by determination of thrombin-induced serotonin release from blood platelets. The dissociation constant for the thrombin-hirudin complex calculated from data obtained by measuring the platelet reaction (Ki 50 pmol/1) was in accordance with the value obtained by determination of fibrinogen clotting. Prevention of the effect of thrombin on platelets required the addition of hirudin in at least 10-fold molar excess. The release of serotonin could be immediately stopped by hirudin at any time when the special conditions for the reaction of thrombin with the tight-binding inhibitor and the receptors on the platelet surface were taken into account.
mesh_terms: D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D006629:Hirudins / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D012701:Serotonin / Q000378:metabolism; D013917:Thrombin / Q000037:antagonists & inhibitors / Q000502:physiology*
chemical_list: D006629:Hirudins; D012701:Serotonin; D013917:Thrombin