[Quantification of a specific inhibitor (PAI-1) of tissue-type plasminogen activator (t-PA) in the plasma].
In human plasma, the activation of plasminogen by tissue plasminogen activator (t-PA) is a fibrin localized process which allows the specific dissolution of thrombi. Most of the t-PA circulates as a complex with its inhibitor, PAI-1, which thereby regulates its activity. In the present work the authors have studied the kinetics of inhibition of t-PA by PAI-1 and have developed an assay for its specific detection. The assay is performed in microtitration plates containing a solid-phase fibrin network, as follows: the source of inhibitor is mixed with solutions containing increasing amounts of t-PA, then the residual t-PA is separated by means of a solid-phase fibrin support and detected with a coupled reaction using a plasmin selective chromogenic substrate. The change in absorbance is measured in a microtiter plate reader and converted to t-PA activity by reference to a standard curve. The residual t-PA activity is inversely proportional to the concentration of PAI-1. The quantitation of PAI-1 is based on the variation of the dissociation constant of the fibrin/t-PA interaction obtained in the presence of the inhibitor. Since other serine-protease inhibitors do not interfere with the assay, the method is specific for PAI-1 and can be safely used in other biological fluids.
Masson
C
C
INSERM U 143, Institut de Pathologie Cellulaire, Hôpital de Bicêtre.
Angles-Cano
E
E
D000328:Adult; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008433:Mathematics; D008875:Middle Aged; D015849:Plasminogen Inactivators; D013053:Spectrophotometry / Q000379:methods; D010959:Tissue Plasminogen Activator / Q000037:antagonists & inhibitors* / Q000097:blood / Q000493:pharmacokinetics
D006023:Glycoproteins; D015849:Plasminogen Inactivators; D010959:Tissue Plasminogen Activator
Quantification de l'inhibiteur spécifique (PAI-1) de l'activateur tissulaire du plasminogène (t-PA) dans le plasma.