Thromboxane A2

Definition

Thromboxane A2 (TXA2) is a potent vasoconstrictor and promoter of platelet aggregation. It plays a crucial role in the clotting process by facilitating blood vessel constriction and platelet plug formation.

5 Must Know Facts For Your Next Test

1. Thromboxane A2 is produced by platelets from arachidonic acid via the cyclooxygenase (COX) pathway.
2. TXA2 promotes platelet aggregation, which is vital for the formation of blood clots.
3. Nonsteroidal anti-inflammatory drugs (NSAIDs), like aspirin, inhibit COX enzymes, thereby reducing TXA2 production and preventing clot formation.
4. TXA2 has a short half-life and is rapidly converted to inactive Thromboxane B2.
5. Dysregulation of TXA2 can lead to thrombotic disorders, increasing the risk of conditions such as myocardial infarction and stroke.

Review Questions

• What enzyme pathway leads to the production of Thromboxane A2?
• How does aspirin affect Thromboxane A2 levels?
• Why is Thromboxane A2 important in the clotting process?

Related terms

Cyclooxygenase (COX): An enzyme responsible for converting arachidonic acid into prostaglandins and thromboxanes.

Platelet Aggregation:

The clumping together of platelets in the blood, part of the sequence leading to the formation of a thrombus or clot.

Prostaglandin: Lipid compounds that perform hormone-like actions, involved in various physiological processes including inflammation and hemostasis.