Yang X P, Chiba S
Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
Jpn J Pharmacol. 2000 Jan;82(1):67-70. doi: 10.1254/jjp.82.67.
The periarterial electrical nerve stimulation readily induced a double-peaked vasoconstriction in the isolated, perfused canine splenic artery. P2X-Purinoceptors have previously been shown to be involved mainly in the 1st-phase response and alpha 1-adrenoceptors, mostly in the 2nd-one. The dose used of neuropeptide Y (NPY) (0.01-0.1 microM) given into the preparation caused a slight but insignificant vasoconstriction. The treatment with NPY at concentrations of 0.01-0.1 microM produced a parallel inhibition on the 1st- and 2nd-phase responses following nerve stimulation at the frequencies used (1-10 Hz) in a dose-dependent manner. The vasoconstrictor responses to administered ATP (0.01-1 mumol) or noradrenaline (0.03-3 nmol) were slightly but not significantly potentiated by 0.1 microM NPY. The results indicate that NPY predominantly exerts a prejunctionally inhibitory modulation on the purinergic and adrenergic transmission in peripheral sympathetic nerves innervating the canine splenic artery.
动脉周围电神经刺激很容易在离体灌注的犬脾动脉中诱发双峰血管收缩。先前已表明，P2X嘌呤受体主要参与第一阶段反应，而α1肾上腺素受体主要参与第二阶段反应。向制剂中注入的神经肽Y（NPY）剂量（0.01 - 0.1微摩尔）引起轻微但不显著的血管收缩。在0.01 - 0.1微摩尔浓度下用NPY处理，以剂量依赖方式对所用频率（1 - 10赫兹）的神经刺激后的第一阶段和第二阶段反应产生平行抑制。0.1微摩尔NPY对给予的ATP（0.01 - 1微摩尔）或去甲肾上腺素（0.03 - 3纳摩尔）引起的血管收缩反应有轻微但不显著的增强作用。结果表明，NPY主要对支配犬脾动脉的外周交感神经中的嘌呤能和肾上腺素能传递发挥节前抑制性调节作用。
