Thromboxane

Thromboxane: A substance made by platelets that causes blood clotting and constriction of blood vessels. There are two thromboxanes. Thromboxane A2 (TXA2) is active but is very unstable and has a half-life of only 30 seconds before it undergoes hydrolysis to form thromboxane B2 (TXB2) which is inactive. The thromboxanes are derived from arachidonic acid and are related to prostaglandin.