title: Immunoradiometric assay to measure the binding of a specific inhibitor to tissue-type plasminogen activator.
abstract: A functional, immunoradiometric assay for a specific plasminogen activator inhibitor (PAI) was developed. This assay was based on the ability of the PAI to bind rapidly and strongly to immobilized tissue-type plasminogen activator (tPA). The extent of binding was quantified by incubating the PAI-tPA complex first with rabbit antiserum to the PAI and then with 125I-labeled goat anti-rabbit IgG. The interaction between tPA and the PAI was rapid, time- and concentration-dependent, sensitive over a broad range of PAI concentrations (1 to 100 ng/ml), and competed by urokinase but not streptokinase. The widespread application of this new technique was indicated by its ability to detect an immunologically related PAI not only in a number of other cell types, but also in platelets from which it can be released by thrombin, and in blood. This assay thus provides a quantitative approach for assessing the role of this PAI in a variety of fibrinolytic processes.
mesh_terms: D000230:Adenocarcinoma; D000818:Animals; D001011:Aorta / Q000378:metabolism*; D002417:Cattle; D002460:Cell Line; D002478:Cells, Cultured; D004727:Endothelium / Q000378:metabolism; D006023:Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007680:Kidney Neoplasms; D007700:Kinetics; D008168:Lung; D008545:Melanoma; D008970:Molecular Weight; D009928:Organ Specificity; D015849:Plasminogen Inactivators; D011863:Radioimmunoassay; D010959:Tissue Plasminogen Activator / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D015849:Plasminogen Inactivators; D010959:Tissue Plasminogen Activator