Which thrombolytic agent activates tissue plasminogen to dissolve clots?

• A. Streptokinase
• B. Alteplase
• C. Urokinase
• D. Warfarin

Answer: (B)

Alteplase is a recombinant tissue plasminogen activator (tPA) that plays a crucial role in the process of thrombolysis, specifically by activating plasminogen to plasmin, which then leads to the dissolution of blood clots. When administered, alteplase selectively converts bound plasminogen, which is present within the clot, into plasmin, thereby facilitating the breakdown of the fibrin mesh that stabilizes the clot. This targeted action makes it particularly effective in treating conditions such as acute myocardial infarction, pulmonary embolism, and ischemic stroke.

The other options listed do not operate in the same manner as alteplase. Streptokinase, for example, is derived from streptococci and also activates plasminogen but is less specific and has a higher chance of triggering an immune response. Urokinase is another thrombolytic agent that has a similar mechanism to alteplase but is not as commonly used in clinical settings. Warfarin, on the other hand, is an anticoagulant that works by inhibiting vitamin K-dependent clotting factors, thus preventing new clots from forming rather than breaking down existing clots.