tromboxano

Tromboxano is an eicosanoid in the prostanoid family, produced primarily by activated platelets from arachidonic acid. The principal active species is thromboxane A2 (TXA2), a short‑lived molecule that rapidly hydrolyzes to thromboxane B2 (TXB2), which is more stable and often measured as a proxy for TXA2 production.

Biosynthesis occurs when phospholipase A2 releases arachidonic acid from membrane phospholipids. Cyclooxygenase-1 (COX-1) converts it to prostaglandin G2/H2 (PGH2), and thromboxane synthase converts PGH2 to TXA2. TXA2 is released by platelets and acts locally, with a very brief circulatory half-life.

Mechanistically, TXA2 engages the thromboxane receptor (TP) on platelets and on vascular smooth muscle. In platelets, TP activation promotes activation and aggregation; in blood vessels, TXA2 induces vasoconstriction. Together these actions support hemostasis at sites of vascular injury but can contribute to pathologic thrombosis if TXA2 signaling is excessive.

Clinically, TXA2 production is a target of antiplatelet therapy. Aspirin inhibits COX-1 in platelets, reducing TXA2 synthesis and platelet aggregation. TP receptor antagonists and other modulators of TXA2 signaling have been explored for cardiovascular risk management. TXB2 is commonly measured in research and clinical contexts as a surrogate marker of TXA2 production.