title: Protraction of whole blood and plasma clot lysis in patients with high levels of an inhibitor of tissue-type plasminogen activator.
abstract: The influence of the newly discovered, fast-acting inhibitor of tissue-type plasminogen activator (t-PA) on the lysis time of plasma clots was studied by visual observation of lysis of clotted citrated plasma after addition of purified t-PA. To a series of plasma samples with various concentrations of naturally occurring PA-inhibitor purified t-PA was added to a final concentration, which in pooled normal plasma is sufficient to induce clot lysis within a few hours. In those plasma samples with a high free inhibitor level, determined by measuring the recovery of the activity of added purified t-PA, clot lysis was retarded. Whole blood clots were made by clotting freshly collected non-anticoagulated blood with thrombin after admixture of a trace amount of radiolabeled fibrinogen and a fixed amount of t-PA. Lysis rate, read from the appearance of radioactivity in the serum after centrifugation, was significantly lower in clots obtained from subjects with a high free inhibitor level than in those with a low inhibitor level. It is concluded that the PA-inhibitor protracts clot lysis and may be relevant for physiological fibrinolysis.
mesh_terms: D001777:Blood Coagulation; D005342:Fibrinolysis; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D008107:Liver Diseases / Q000097:blood; D010960:Plasminogen Activators / Q000037:antagonists & inhibitors*; D015849:Plasminogen Inactivators; D013923:Thromboembolism / Q000097:blood; D013997:Time Factors; D000979:alpha-2-Antiplasmin / Q000502:physiology
chemical_list: D006023:Glycoproteins; D015849:Plasminogen Inactivators; D000979:alpha-2-Antiplasmin; D010960:Plasminogen Activators