McCaig D J
Br J Pharmacol. 1987 Jun;91(2):385-94. doi: 10.1111/j.1476-5381.1987.tb10293.x.
Mechanical and electrical responses to stimulation of the vagus nerve were studied in the isolated, innervated trachea of the guinea-pig. In approximately half the preparations tested, the amplitudes of mechanical constrictor responses to stimulation of the vagus were reduced substantially during a period of sympathetic stimulation. Vagal responses were unaltered in the remainder. In single trachealis cells, stimulation of the vagus nerve or sympathetic stellate ganglion elicited depolarization and hyperpolarization, respectively. Vagally-mediated depolarization was decreased, unchanged or increased in amplitude after a period of sympathetic stimulation. Isoprenaline almost abolished mechanical responses induced by stimulation of the vagus, and this effect was blocked by propranolol. Noradrenaline attenuated markedly vagal mechanical responses also, and this effect was blocked by a combination of propranolol and phentolamine. Both noradrenaline and isoprenaline hyperpolarized single trachealis cells and greatly reduced the amplitude of vagally-mediated depolarization. Neither sympathetic stimulation nor applied catecholamines altered mechanical responses to applied acetylcholine, strongly suggesting that their effects on vagal responses are predominantly presynaptic.
在豚鼠离体且有神经支配的气管中，研究了对迷走神经刺激的机械和电反应。在大约一半的受试标本中，在交感神经刺激期间，对迷走神经刺激的机械收缩反应幅度大幅降低。其余标本中迷走神经反应未改变。在单个气管平滑肌细胞中，刺激迷走神经或交感星状神经节分别引起去极化和超极化。在交感神经刺激一段时间后，迷走神经介导的去极化幅度降低、不变或增加。异丙肾上腺素几乎消除了由迷走神经刺激诱导的机械反应，且这种效应被普萘洛尔阻断。去甲肾上腺素也显著减弱迷走神经的机械反应，且这种效应被普萘洛尔和酚妥拉明的联合用药阻断。去甲肾上腺素和异丙肾上腺素均使单个气管平滑肌细胞超极化，并大大降低迷走神经介导的去极化幅度。交感神经刺激或应用儿茶酚胺均未改变对应用乙酰胆碱的机械反应，这强烈表明它们对迷走神经反应的影响主要是突触前的。
