查看文章

Platelet activation results in shape change, aggregation, generation of thromboxane A₂, and release of granule contents. We have recently demonstrated that secreted ADP is essential for thromboxane A₂-induced platelet aggregation (J. Biol. Chem. 274: 29108-29114, 1999). The aim of this study was to investigate the role of secreted ADP interacting at P2 receptor subtypes in platelet secretion. Platelet secretion induced by the thromboxane A₂ mimetic U46619 was unaffected by adenosine-3’phosphate-5’-phosphate, a P2Y1 receptor selective antagonist. However, AR-C66096, a selective antagonist of the P2T _AC receptor, inhibited U46619-induced platelet secretion, indicating an important role for G_i signaling in platelet secretion. Selective activation of either the P2T _AC receptor or the α_2A adrenergic receptor did not cause platelet secretion, but potentiated U46619-induced platelet secretion. SC57101, a …