Frequency dependent alpha(2)-adrenoceptor mediated modulation of excitatory junction potentials in guinea-pig mesenteric artery.
Frequency dependent alpha(2)-adrenoceptor mediated modulation of excitatory junction potentials in guinea-pig mesenteric artery.
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DOI：
10.1016/s0014-2999(00)00905-5
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发表时间：
2001-01
影响因子：
5
通讯作者：
V. Mutafova-Yambolieva;K. Keef
中科院分区：
文献类型：
--
作者：
V. Mutafova-Yambolieva;K. Keef
短暂（10秒）电场刺激豚鼠肠系膜动脉引起的兴奋性连接电位（EJP）几乎被磷酸吡哆醛-6-偶氮苯基-2',4'-二磺酸（PPADS，30 μM）消除，但在利血平化后仍然存在。苏拉明 (100 μM) 增强了 0.2–0.5 Hz 响应的 EJP，并降低了 2–32 Hz 响应的 EJP。酚妥拉明 (1 μM) 和育亨宾 (0.1 μM) 在 0.2–8 Hz 下增强 EJP，但在 16–32 Hz 下则不增强。羟甲唑啉 (0.3 μM) 会在 0.2–0.5 Hz 时降低 EJP，但在 1–32 Hz 时不会降低 EJP。利血平化后，EJP 在 0.2-2 Hz 处增强，但在 4-32 Hz 处没有增强。可乐定 (0.1 μM) 对对照动脉的所有频率都没有影响，但在利血平治疗的动脉中减少了 0.2–2 Hz 的 EJP。总之，连接前 α2-肾上腺素受体在低频、短暂交感神经刺激期间调节 ATP 释放。
Excitatory junctional potentials (EJPs) elicited with brief duration (10 s) electrical field stimulation of guinea-pig mesenteric arteries were nearly abolished at all frequencies by pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS, 30 μM) but persisted following reserpinization. Suramin (100 μM) enhanced EJPs at 0.2–0.5 Hz responses and reduced them at 2–32 Hz. Phentolamine (1 μM) and yohimbine (0.1 μM) enhanced EJPs at 0.2–8 Hz but not at 16–32 Hz. Oxymetazoline (0.3 μM) reduced EJPs at 0.2–0.5 Hz but not at 1–32 Hz. Following reserpinization, EJPs were enhanced at 0.2–2 Hz but not at 4–32 Hz. Clonidine (0.1 μM) was without effect at all frequencies in control arteries but reduced EJPs at 0.2–2 Hz in reserpine-treated arteries. In conclusion, pre-junctional α2-adrenoceptors modulate ATP release during low frequency, brief duration sympathetic nerve stimulation.