Regulation of transcervical permeability by two distinct P2 purinergic receptor mechanisms.
Regulation of transcervical permeability by two distinct P2 purinergic receptor mechanisms.
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通过两种不同的 P2 嘌呤受体机制调节经宫颈通透性。
DOI：
10.1152/ajpcell.2002.282.1.c75
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Gorodeski,GeorgeI
中科院分区：
文献类型：
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作者：
Gorodeski,GeorgeI
微摩尔浓度的 ATP 会刺激 CaSki 培养物中跨上皮电导的双相变化，先是急剧增加（I 相反应），然后缓慢下降（II 相反应）。I 相和 II 相反应涉及两种不同的钙依赖性途径：钙动员和钙流入。为了检验 I 相和 II 相反应由不同 P2 嘌呤能受体介导的假设，分别通过用 1,2-双（2-氨基苯氧基）乙烷-N,N,N',N'-四乙酸 (BAPTA) 阻断钙动员或降低细胞外钙来解耦通透性变化。在这些条件下，对于 I 期反应，ATP EC50 为 25 μM，对于 II 期反应，ATP EC50 为 2 μM。各自的激动剂谱为 ATP > UTP > 腺苷 5'-O-(3-硫代三磷酸) (ATP-γS) =N6-([6-氨基己基]氨基甲酰甲基)腺苷 5'-三磷酸 (A8889) > GTP 和 UTP > ATP > GTP = A8889 > ATP-γS。苏拉明阻断相反应和 ATP 诱导的钙动员，而磷酸吡哆醛-6-偶氮苯基-2',4-二磺酸 (PPADS) 阻断相 II 反应和 ATP 增强的钙流入。 II 期反应和增强的钙流入的 ATP 时程和药理学特征相似，时间常数为 2 分钟，具有可饱和的浓度依赖性效应（EC50 为 2-3 μM）。 RT-PCR 实验揭示了 P2Y2 和 P2X4 受体的 mRNA 表达。这些结果表明 ATP 诱导的 I 相和 II 相反应是由不同的 P2 嘌呤受体机制介导的。
Micromolar concentrations of ATP stimulate biphasic change in transepithelial conductance across CaSki cultures, an acute increase (phase I response) followed by a slower decrease (phase IIresponse).Phase Iandphase IIresponses involve two distinct calcium-dependent pathways, calcium mobilization and calcium influx. To test the hypothesis thatphase Iandphase IIresponses are mediated by distinct P2 purinergic receptors, changes in permeability were uncoupled by blocking calcium mobilization with 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA) or by lowering extracellular calcium, respectively. Under these conditions ATP EC50was 25 μM forphase Iresponse and 2 μM forphase IIresponse. The respective agonist profiles were ATP > UTP > adenosine 5′-O-(3-thiotriphosphate) (ATP-γS) =N6-([6-aminohexyl]carbamoylmethyl)adenosine 5′-triphosphate (A8889) > GTP and UTP > ATP > GTP = A8889 > ATP-γS. Suramin blockedphase Iresponse and ATP-induced calcium mobilization, whereas pyridoxal phosphate-6-azophenyl-2′,4-disulfonic acid (PPADS) blockedphase IIresponse and ATP-augmented calcium influx. ATP time course and pharmacological profiles forphase IIresponse and augmented calcium influx were similar, with a time constant of 2 min and a saturable concentration-dependent effect (EC50of 2–3 μM). RT-PCR experiments revealed expression of mRNA for both the P2Y2and P2X4receptors. These results suggest that the ATP-inducedphase Iandphase IIresponses are mediated by distinct P2 purinergic receptor mechanisms.