Vigne P, Pacaud P, Loirand G, Breittmayer J P, Frelin C
Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UPR 411, Valbonne, France.
Biochem Biophys Res Commun. 1998 Mar 17;244(2):332-5. doi: 10.1006/bbrc.1998.8262.
P2Y1 receptor-like responses were analyzed in rat ileal myocytes and in rat brain capillary endothelial cells. In endothelial cells, pyridoxal phosphate-6-azophenyl-2',4'disulfonic acid (PPADS) inhibits ADP induced intracellular Ca2+ transients with a half maximum effect at 3 microM. PPADS shifts ADP dose response curves to larger concentrations. Yet PPADS is inactive when added at the same time as ADP. A preequilibration of the cells with PPADS is necessary to observe its inhibitory action. Similarly in ileal myocytes, PPADS has no action on ADP responses when it is applied at the same time as ADP. Actions of PPADS require a preequilibration with the cells and are fully reversible. These results suggest that PPADS is not a competitive antagonist of P2Y1 receptors and caution about its usefulness to distinguish subtypes of P2Y1 receptors.
在大鼠回肠肌细胞和大鼠脑毛细血管内皮细胞中分析了P2Y1受体样反应。在内皮细胞中，磷酸吡哆醛 - 6 - 偶氮苯基 - 2',4' - 二磺酸（PPADS）抑制ADP诱导的细胞内Ca2+瞬变，在3 microM时具有半数最大效应。PPADS将ADP剂量反应曲线向更高浓度偏移。然而，当与ADP同时添加时，PPADS无活性。细胞与PPADS预平衡对于观察其抑制作用是必要的。同样在回肠肌细胞中，当PPADS与ADP同时应用时，对ADP反应无作用。PPADS的作用需要与细胞预平衡且完全可逆。这些结果表明PPADS不是P2Y1受体的竞争性拮抗剂，并对其用于区分P2Y1受体亚型的有效性提出了警示。
