Stretton C D, Belvisi M G, Barnes P J
Department of Thoracic Medicine, National Heart and Lung Institute, London, UK.
Neuropeptides. 1990 Dec;17(4):163-70. doi: 10.1016/0143-4179(90)90031-s.
Non-adrenergic, non-cholinergic (NANC) neural mechanisms regulate airway tone in guinea-pigs, and it is possible that they may be regulated by other nerves. We have investigated effects of neuropeptide Y (NPY), a co-transmitter of adrenergic nerves, on the excitatory (bronchoconstrictor) NANC (e-NANC) response elicited both in vivo (via bilateral vagal nerve stimulation) and in vitro (via electrical field stimulation [EFS]), and on inhibitory (bronchodilator) NANC (i-NANC) responses in upper trachea elicited by EFS. NPY inhibited the e-NANC to vagal stimulation in vivo in a dose-dependent manner (90.0 +/- 3.4% inhibition at 500 micrograms/kg), but failed to alter the bronchoconstrictor response to exogenous substance P (SP). NPY also inhibited the e-NANC response to EFS in main and hilar bronchi (57.2 +/- 8.6% in main and 46.34 +/- 7.5% in hilar bronchi at 10(-6) M), whilst having no effect on the contractile response to SP. In contrast NPY had no effect on the i-NANC response in vitro. Thus, NPY exerts a powerful inhibitory action on tachykinin release from peripheral endings of capsaicin-sensitive airway sensory nerves, but has no effect on the i-NANC neural mechanisms. This suggests that adrenergic nerves may modulate e-NANC responses in the airways.
非肾上腺素能、非胆碱能（NANC）神经机制调节豚鼠气道张力，并且它们可能受其他神经调控。我们研究了肾上腺素能神经的共同递质神经肽Y（NPY）对体内（通过双侧迷走神经刺激）和体外（通过电场刺激[EFS]）诱发的兴奋性（支气管收缩）NANC（e-NANC）反应，以及对EFS诱发的上呼吸道抑制性（支气管舒张）NANC（i-NANC）反应的影响。NPY在体内以剂量依赖方式抑制对迷走神经刺激的e-NANC反应（500微克/千克时抑制率为90.0±3.4%），但未能改变对外源性P物质（SP）的支气管收缩反应。NPY还抑制主支气管和肺门支气管对EFS的e-NANC反应（10⁻⁶M时主支气管为57.2±8.6%，肺门支气管为46.34±7.5%），而对SP的收缩反应无影响。相比之下，NPY在体外对i-NANC反应无作用。因此，NPY对辣椒素敏感的气道感觉神经外周末梢的速激肽释放有强大的抑制作用，但对i-NANC神经机制无影响。这表明肾上腺素能神经可能调节气道中的e-NANC反应。
