Which fibrinolytic agent selectively activate fibrin bound plasminogen rather than circulating plasminogen
**Core Concept**
The question is testing the understanding of fibrinolytic agents, specifically their mechanism of action on plasminogen activation. Fibrinolytic agents work by activating plasminogen, a zymogen, to form plasmin, which then breaks down fibrin clots.
**Why the Correct Answer is Right**
Streptokinase and urokinase are non-selective fibrinolytic agents that activate both fibrin-bound and circulating plasminogen. In contrast, **tissue plasminogen activator (tPA)** selectively activates fibrin-bound plasminogen. tPA binds to fibrin clots and converts fibrin-bound plasminogen to plasmin, which then breaks down the clot. This selective activation reduces the risk of bleeding complications associated with systemic plasminogen activation.
**Why Each Wrong Option is Incorrect**
* **Option A:** Streptokinase is a non-selective fibrinolytic agent that activates both fibrin-bound and circulating plasminogen.
* **Option B:** Urokinase is also a non-selective fibrinolytic agent that activates both fibrin-bound and circulating plasminogen.
* **Option C:** No information is provided about this option, but it is likely incorrect because the question specifically asks for a selective agent.
**Clinical Pearl / High-Yield Fact**
tPA is a fibrin-selective agent that reduces the risk of bleeding complications by minimizing systemic plasminogen activation. This makes it a preferred choice for treating acute ischemic stroke and other conditions where rapid clot lysis is necessary.
**Correct Answer:** .