Thrombolytic Mechanisms

3. Fibrinolysis also known as thrombolysis.

During fibrin formation two plasminogen activators are produced by endothelial and other cells which convert plasminogen, a circulating precursor which binds to fibrin, into plasmin, a proteolytic enzyme.

Plasmin breaks down both fibrinogen and fibrin to form fibrin degradation products (fragments X, Y, D and E). Fibrin breakdown is confined to the clot and any circulating plasmin is rapidly inhibited by alpha2-antiplasmin also produced by the liver.

Glossary

Plasminogen Activators - These are termed t-PA (tissue plasminogen activator) and u-PA (urokinase-type plasminogen activator).