title: Tissue-type plasminogen activator and streptokinase induce platelet hyperaggregability in the rabbit.
abstract: The ex vivo aggregability of rabbit platelets was assessed after rabbits were treated in vivo with thrombolytic doses of tissue plasminogen activator (t-PA) or streptokinase (SK). t-PA was evaluated at 2 doses; an effective thrombolytic dose of 10 micrograms/kg/min, i.v. and a higher dose of 30 micrograms/kg/min, i.v.. At both concentrations, ex vivo platelet hyperaggregability was observed when collagen, arachidonic acid or ADP were employed as the aggregating agonists. Significant falls in circulating platelet counts were observed after t-PA infusion. Infusion of SK also resulted in ex vivo platelet hyperaggregation. These data reveal that thrombolytic therapy may result in hyperaggregable platelets which may play a role in reocclusion of successfully recanalized blood vessels.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001792:Blood Platelets / Q000166:cytology; D003094:Collagen / Q000494:pharmacology; D004617:Embolism / Q000209:etiology; D005069:Evaluation Studies as Topic; D007262:Infusions, Intravenous; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010976:Platelet Count; D011817:Rabbits; D013300:Streptokinase / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D001095:Arachidonic Acids; D016718:Arachidonic Acid; D000244:Adenosine Diphosphate; D003094:Collagen; D013300:Streptokinase; D010959:Tissue Plasminogen Activator