ABSTRACT
The fibrinolytic system is a complex system
that is regulated by a balance between
activators and inhibitors (Figure 5.1).
Plasminogen activator inhibitor-1 (PAI-1) is
the main inhibitor of fibrinolysis. PAI-1 binds
to and inactivates tissue plasminogen activator
(t-pa) and urokinase-like plasminogen
activator (u-pa), the main activators of
plasminogen. As PAI-1 levels increase,
plasminogen activation is reduced and
consequently fibrin accumulates. In this
situation the balance is therefore in favour of
thrombosis. PAI-1 has also been shown to
have a local effect on the endothelium via
activation of proteases and growth factors.
