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During thrombolytic therapy, patients are treated with a plasminogen activator in order to stimulate the fibrinolytic system by converting the precursor plasminogen into the active enzyme plasmin. The fibrinolytic process can be divided into two phases. In the first phase, plasminogen binds to intact fibrin and initial fibrinolysis takes place. As a result,(More)
Circadian fluctuation in blood fibrinolytic activity was studied in 10 volunteers in the day-time period at 09.00, 12.00 and 15.00 h. Activity of tissue-type plasminogen activator (t-PA) was found to increase from 09.00 to 15.00 h in accordance with known results with global assays of blood activity. Also, activity and antigen of plasminogen activator(More)
Endothelial cells from human umbilical cord were cultured to study plasminogen activator synthesis and secretion. Since simultaneous production of plasminogen activator inhibitor(s) prevented detection of plasminogen activators by use of fibrinolytic assays, an enzyme immunoassay for tissue-type plasminogen activator (t-PA) was developed. In this assay,(More)
Although this chapter does not represent a historical review, it will be clear how the biochemistry of t-PA, u-PA, PAI-1 and PAI-2 has evolved and where we stand in 1994. While the functional activities of the proteins were recognized at least three to four decades ago, highly purified preparations became available around 1980. In the mid-eighties the cDNAs(More)
Pharmacokinetics and systemic effects of recombinant tissue-type plasminogen activator (rt-PA) were studied in 18 healthy male volunteers after 30-minute intravenous infusions of placebo, 0.25 mg/kg rt-PA, and 0.5 mg/kg rt-PA. Highly comparable pharmacokinetic parameters were obtained after analysis of rt-PA as both an antigen and an activity. Mean(More)
The plasma activity level of the recently discovered fast-acting inhibitor of tissue-type plasminogen activator (t-PA) was found to be temporarily increased after surgery, myocardial infarction and severe trauma. Detailed analysis of the postoperative period revealed simultaneously increased t-PA antigen and inhibition and decreased t-PA activity only on(More)
Several proteins are known to bind to a fibrin network and to change clot properties or function. In this study we aimed to get an overview of fibrin clot-bound plasma proteins. A plasma clot was formed by adding thrombin, CaCl(2) and aprotinin to citrated platelet-poor plasma and unbound proteins were washed away with Tris-buffered saline. Non-covalently(More)
The kinetics of the activation of Glu-plasminogen and Lys-plasminogen (P) by a two-chain form of human tissue plasminogen activator (A) were studied in purified systems, and in the presence of fibrinogen (f) and of fibrin films (F) of increasing size and surface density. The activation in the purified systems followed Michaelis-Menten kinetics with a(More)
Culture fluid of a monkey kidney cell culture was harvested every two days, for a two week period, in order to obtain urokinase in the zymogen form. Pro-urokinase was isolated by immunoadsorption chromatography and gel filtered on Sephadex G-150, which resulted in three peaks with pro-urokinase activity. SDS-polyacrylamide gel electrophoresis showed that(More)
The ultimate step in the blood coagulation cascade is the formation of fibrin. Several proteins are known to bind to fibrin and may thereby change clot properties or clot function. Our previous studies identified carboxypeptidase N (CPN) as a novel plasma clot component. CPN cleaves C-terminal lysine and arginine residues from several proteins. The activity(More)