title: Determination of tissue plasminogen activator and its "fast" inhibitor in plasma.
abstract: We describe efficient, accurate methods for specific determination of tissue plasminogen activator (t-PA, EC 3.4.21.31) and its "fast" inhibitor in plasma. In this coupled assay, a sample containing t-PA is incubated with plasminogen, a plasmin (EC 3.4.21.7) substrate of low Km and high Kcat, and fibrin as a stimulator. The inhibitor of t-PA is determined by incubating the sample with a known amount of t-PA in excess, then determining the residual t-PA. Both t-PA and t-PA inhibitor can be determined in many samples simultaneously within a few hours. These assays are modifications of procedures described by us (Clin Chim Acta 1983;127:279-88 and Thromb Res 1983;31:427-36). Their accuracy as assessed by analytical recovery of pure t-PA added to blood samples (91 +/- 4%) or of partly purified inhibitor added to plasma samples (102 +/- 10%) is satisfactory, as is their precision. For the t-PA assay the CV was 1.6% (within run) or 4.1% (between run). The corresponding values for the inhibitor assay were 4.5% (within run) or 8.4% (between run) if the inhibitor concentration exceeded 3 arb. units/mL.
authors.forename: J
authors.initials: J
authors.lastname: Chmielewska
authors.forename: B
authors.initials: B
authors.lastname: Wiman
mesh_terms: D000328:Adult; D002863:Chromogenic Compounds; D005069:Evaluation Studies as Topic; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D015849:Plasminogen Inactivators; D013379:Substrate Specificity; D010959:Tissue Plasminogen Activator / Q000037:antagonists & inhibitors / Q000097:blood*
chemical_list: D002863:Chromogenic Compounds; D006023:Glycoproteins; D015849:Plasminogen Inactivators; D010959:Tissue Plasminogen Activator