plasmiiniaktivatsiooni

Plasmiiniaktivatsiooni refers to the process by which plasmin, a key enzyme in the fibrinolytic system, is activated. Fibrinolysis is the body's natural mechanism for breaking down blood clots. Plasmin is the primary enzyme responsible for degrading fibrin, the protein that forms the meshwork of a blood clot. However, plasmin exists in the blood in an inactive precursor form called plasminogen.

The activation of plasminogen to plasmin is a tightly regulated process. The most important physiological activator is tissue plasminogen activator (t-PA). t-PA binds to fibrin within a blood clot and cleaves plasminogen, converting it into active plasmin. Other activators exist, such as urokinase plasminogen activator (u-PA), which plays a role in various physiological processes beyond clot dissolution, including tissue remodeling and cell migration.

Inhibitors also play a crucial role in regulating fibrinolysis. The primary inhibitor of plasmin activity is alpha-2-antiplasmin, which rapidly neutralizes free plasmin. Additionally, plasminogen activator inhibitors (PAIs), particularly PAI-1, are important for controlling the activity of t-PA and u-PA. Dysregulation of plasminogen activation can lead to either excessive bleeding due to insufficient clot breakdown or thrombotic disorders due to excessive clot formation. Therapies that enhance plasminogen activation, such as thrombolytics, are used to dissolve dangerous blood clots in conditions like heart attacks and strokes.