Prostacyclin and thromboxane have opposing effects on hemost

Prostacyclin and thromboxane have opposing effects on hemostasis, and both are produced through the action of cyclooxygenase.

1 Briefly describe the opposing effects of these two compounds.

2 Explain why treatment with aspirin, a cyclooxygenase inhibitor, acts as an anticoagulant.

Solution

1: Prostacyclin and thromboxane have opposite effects on homeostasis. They have opposing effect on arterial tonus and platlet adherence to the endothelial cells of blood vessels. Thromboxane have stimulating effect on platlet activation and aggregation and stimulates vasoconstriction. On the other hand, prostacyclin inhibits the aggregation and activation of platlets and serves as vasodialator. Therefore, a shift between synthesis of these two compounds regulates platlet activation during blood clotting as well as tone of vessel wall.