What inhibits fibrinolysis?

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Multiple Choice

What inhibits fibrinolysis?

Fibrinolysis is regulated by inhibitors that dampen plasmin generation and its activity. A key brake in this system is Thrombin Activatable Fibrinolysis Inhibitor. When thrombin activates it, TAFI trims away the C-terminal lysine residues on fibrin. Those lysines are the critical docking sites for plasminogen and tissue plasminogen activator; without them, plasmin generation on the clot is reduced and fibrinolysis slows down. So TAFI acts upstream to blunt the fibrinolytic cascade, making it a principal inhibitor of fibrinolysis. Plasmin is the enzyme that dissolves fibrin, and tissue plasminogen activator promotes fibrinolysis, so they are not inhibitors. Alpha-2 antiplasmin does inhibit fibrinolysis by directly inhibiting plasmin, but its action comes after plasmin is formed, whereas TAFI modulates the process at the substrate level to prevent plasmin from being generated efficiently in the first place.

Fibrinolysis is regulated by inhibitors that dampen plasmin generation and its activity. A key brake in this system is Thrombin Activatable Fibrinolysis Inhibitor. When thrombin activates it, TAFI trims away the C-terminal lysine residues on fibrin. Those lysines are the critical docking sites for plasminogen and tissue plasminogen activator; without them, plasmin generation on the clot is reduced and fibrinolysis slows down. So TAFI acts upstream to blunt the fibrinolytic cascade, making it a principal inhibitor of fibrinolysis.

Plasmin is the enzyme that dissolves fibrin, and tissue plasminogen activator promotes fibrinolysis, so they are not inhibitors. Alpha-2 antiplasmin does inhibit fibrinolysis by directly inhibiting plasmin, but its action comes after plasmin is formed, whereas TAFI modulates the process at the substrate level to prevent plasmin from being generated efficiently in the first place.

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