Role of Thromboxane A2 in Coronary Vascular Disorders
Thromboxane A2 (TxA2) is a potent eicosanoid having a biological profile consistent with its being a mediator of circulatory disease states. Thus, TxA2 is a very potent vasoconstrictor. Indeed, TxA2 constricts all vascular beds in which it has been studied, and is generally regarded as the most potent endogenous vasoconstrictor known at this time (1, 2). Thromboxane A2 also is a powerful inducer of platelet aggregation and thus considered to be a very important thrombogenic substance (3). In addition to these obvious mediator actions, TxA2 also is a membrane lytic substance promoting leakiness of lysosomal and endothelial cell membranes (1, 4). These actions all complement each other in the mediation of ischemic disorders. Thus, vasoconstriction in the region around a thrombus will further obstruct flow in an artery, and endothelial cell membrane leakiness will further contribute to hypovolemia and restrict oxygen delivery to an already ischemic area.
KeywordsMyocardial Ischemia Sudden Death Platelet Activate Factor Ischemic Damage Acute Myocardial Ischemia
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