Thromb Haemost 1992; 67(01): 106-110
DOI: 10.1055/s-0038-1648389
Original Articles
Schattauer GmbH Stuttgart

Effect of Plasminogen Activator Inhibitor-1 on Tissue-Type Plasminogen Activator-Induced Fibrinolysis

Authors

  • Marcus E Carr Jr.

    1   The Medical Service, McGuire Veterans Administration Hospital, the Departments of Internal Medicine and Pathology, Medical College of Virginia, Richmond, VA, USA
  • C Krishnamurti

    2   The Division of Medicine, Hematology Branch, Walter Reed Army Institute of Research, Washington, D. C., USA
  • B M Alving

    2   The Division of Medicine, Hematology Branch, Walter Reed Army Institute of Research, Washington, D. C., USA
Further Information

Publication History

Received 28 November 1990

Accepted after revision 18 July 1991

Publication Date:
02 July 2018 (online)

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Summary

The effect of fibrin on the interaction of human recombinant single-chain tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) was studied in normal rabbit plasma and in plasma with high levels of native PAI-1. t-PA was added to diluted plasma containing calcium (10 mM) and 125I-fibrinogen at 37° C. Clotting was initiated with human thrombin, and lysis was monitored both turbidimetrically and by release of 125I-fibrin degradation products (fdp). The activity of t-PA (50 IU/ml) was rapidly reduced to 15% of the initial value in plasma containing PAI-1 (23 AU/ml). When thrombin and t-PA were added simultaneously to the plasma, more than 70% of the activity was retained through incorporation of t-PA into the fibrin clot. t-PA-induced fibrinolysis in PAI-1 enriched plasma was further delayed when the temperature was reduced from 37 to 25° C. Turbidimet-ric and 125I-fdp release data provided complementary information. The former technique traced fiber dissolution, while the latter reflected network integrity. These results indicate that t-PA-induced fibrinolysis in PAI-1 enriched plasma is modulated by the presence of fibrin and by temperature.