title: Tissue-type plasminogen activator inhibits aggregation of platelets in vitro.
abstract: The effects of tissue-type plasminogen activator (t-PA) on the platelet aggregation were studied using citrated whole blood and platelet-rich plasma (PRP) obtained from human donors. t-PA suppressed adenosine 5'-diphosphate (ADP)- or collagen-induced platelet aggregation in a dose-dependent manner. The 50% inhibitory concentration (IC50) for t-PA was lower by one order of magnitude than that for urokinase (UK) in whole blood and PRP. The suppression of platelet aggregation was not completely inhibited by alpha-2-antiplasmin. t-PA did not cause the degradation of fibrinogen or fibrin in PRP, whereas UK caused the reduction of fibrinogen and fibrin, and the increase of fibrinogen- and fibrin-degradation products (FDP). These results suggest that the mode of action of t-PA in inhibiting platelet aggregation may be different from that of UK.
mesh_terms: D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate / Q000097:blood; D001792:Blood Platelets / Q000502:physiology; D002460:Cell Line; D003094:Collagen; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D007700:Kinetics; D008297:Male; D010958:Plasminogen / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects; D012016:Reference Values; D010959:Tissue Plasminogen Activator / Q000502:physiology*; D014568:Urokinase-Type Plasminogen Activator / Q000494:pharmacology
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D010958:Plasminogen; D003094:Collagen; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator