Fibrinolysis system (also called the fibrinolytic system or plasminogen–plasmin system) (None established; "FLS" is not common—generally referred to in full as "fibrinolytic system" or "plasminogen–plasmin system.")

The fibrinolysis system (or fibrinolytic system, plasminogen–plasmin system) is a coordinated biological pathway responsible for the regulated breakdown of fibrin clots in blood vessels—a process essential for limiting clot propagation and restoring vessel patency after injury[1][3][4][5][6][7]. It consists of zymogens (plasminogen), proteolytic enzymes (plasmin, tPA, urokinase), cell surface receptors (uPAR), and several inhibitors (PAI-1, α2-antiplasmin, TAFI). The balance of fibrinolytic activity is critical: insufficient activity predisposes to thrombosis and vascular occlusion, while excessive activity leads to bleeding disorders. The system is therapeutically modulated in clinical settings to either dissolve unwanted clots (using thrombolytics in stroke, myocardial infarction, pulmonary embolism) or prevent excessive fibrinolysis (using antifibrinolytics in trauma, surgery, or bleeding disorders)[1][3][4][6][7]. The system also participates in tissue remodeling, angiogenesis, and pathologies including cancer and inflammatory conditions[4].

Other names

Fibrinolytic systemplasminogen–plasmin systemfibrinolysis

Thrombolytics catalyze the conversion of plasminogen to plasmin to promote clot breakdown; antifibrinolytics inhibit plasminogen activation or plasmin activity to preserve clots and reduce bleeding