Platelet aggregation will occur with the end production of:

Platelet aggregation will occur with the end production of:

• A. Cyclooxygenase
• B. Arachidonic acid
• C. Prostacyclin
• D. Thromboxane A2

Answer: (D)

Platelet aggregation is driven by thromboxane A2, produced by activated platelets from arachidonic acid through the cyclooxygenase pathway and thromboxane synthase. When platelets are activated, arachidonic acid is liberated and COX-1 in platelets converts it to prostaglandin intermediates, which thromboxane synthase then converts to thromboxane A2. This thromboxane A2 acts on platelet receptors to promote aggregation and also causes local vasoconstriction, helping to stabilize a platelet plug. Prostacyclin from endothelial cells actually inhibits aggregation, so it does not promote the process. Arachidonic acid is the substrate, not the end product, and cyclooxygenase is the enzyme in the pathway, not the final product.

Platelet aggregation is driven by thromboxane A2, produced by activated platelets from arachidonic acid through the cyclooxygenase pathway and thromboxane synthase. When platelets are activated, arachidonic acid is liberated and COX-1 in platelets converts it to prostaglandin intermediates, which thromboxane synthase then converts to thromboxane A2. This thromboxane A2 acts on platelet receptors to promote aggregation and also causes local vasoconstriction, helping to stabilize a platelet plug. Prostacyclin from endothelial cells actually inhibits aggregation, so it does not promote the process. Arachidonic acid is the substrate, not the end product, and cyclooxygenase is the enzyme in the pathway, not the final product.