A group of compounds, included in the eicosanoids, formally based on thromboxane, but with the terminal COOH group present; biochemically related to the prostaglandins and formed from them through a series of steps involving the formation of an endoperoxide (an O–O bridge between carbons 9 and 11 in the prostaglandins) by a cyclooxygenase, followed by a rearrangement (catalyzed by thromboxane synthase) that inserts one of the two oxygen atoms between carbons 11 and 12, leaving the other still bridging carbons 9 and 11. T. are so named from their influence on platelet aggregation and the formation of the oxygen-containing six-membered ring (pyran or oxane). Like the prostaglandins, individual t. (abbreviated TX) are designated by letters (A, B, C, etc.) and subscripts indicating structural features.
Medical dictionary. 2011.