Question

The mechanism of action of tissue plasminogen activator is 

• A. Inhibit extrinsic pathway
• B. Inhibits platelet aggregation
• C. Enhance fibrin degradation
• D. Inhibit clot formation

Answer 1

The Correct Option is C

Tissue Plasminogen Activator (tPA) is a serine protease involved in the breakdown of blood clots. It plays a vital role in the thrombolytic or fibrinolytic process, helping to convert plasminogen to plasmin. Plasmin is an enzyme that breaks down fibrin, a protein involved in blood clotting. Therefore, tPA enhances fibrin degradation.

Here's how it works:

1. Activation of Plasminogen: tPA catalyzes the conversion of plasminogen to plasmin.
2. Formation of Plasmin: The generated plasmin is a powerful enzyme responsible for degrading fibrin fibers.
3. Fibrin Degradation: Plasmin breaks down the fibrin matrix within a clot, leading to the dissolution of the clot and restoration of normal blood flow.

This mechanism highlights the thrombolytic function of tPA, primarily used in clinical settings to treat acute ischemic strokes, myocardial infarctions, and pulmonary embolisms by dissolving the clots that block blood flow. Thus, the correct answer to the question regarding tPA's mechanism of action is:

Enhance fibrin degradation

Other options such as "Inhibit extrinsic pathway," "Inhibits platelet aggregation," and "Inhibit clot formation" do not accurately describe the primary mechanism of action of tPA.