Faulkner D, Fryer A D, Maclagan J
Br J Pharmacol. 1986 May;88(1):181-7. doi: 10.1111/j.1476-5381.1986.tb09485.x.
The location of neuronal inhibitory muscarinic receptors in pulmonary parasympathetic nerves was investigated in vivo and in vitro. The effects of an agonist for neuronal muscarinic receptors (pilocarpine) and an antagonist (gallamine) were tested on contractions of airway smooth muscle induced by pre- and postganglionic cholinergic nerve stimulation. In anaesthetized guinea-pigs, gallamine potentiated constriction of the tracheal tube and smaller airways induced by preganglionic stimulation. Gallamine also potentiated postganglionic stimulation induced by transmural stimulation of the tracheal tube and by 1-1-dimethyl-4-phenylpiperazinium iodide in the rest of the lung. Bronchoconstriction and contraction of the tracheal tube induced by intravenous acetylcholine were not potentiated by gallamine, indicating that postjunctional muscarinic receptors in airway smooth muscle were not involved in the potentiation. The muscarinic agonist, pilocarpine, had the opposite effect to gallamine and inhibited contractions of the tracheal tube induced by both types of nerve stimulation. In vitro, the inhibitory effect of pilocarpine was demonstrated in the tracheal tube preparation stimulated both pre- and postganglionically. The effect of pilocarpine was antagonized by gallamine. Because gallamine and pilocarpine affected the responses to postganglionic stimulation, the inhibitory muscarinic receptors must be located on the postganglionic neurones of the parasympathetic nerves innervating the trachea and the smaller airways. However, these experiments cannot exclude the possibility that muscarinic receptors may also be located on the soma of the ganglion cells.
在体内和体外研究了肺副交感神经中神经元抑制性毒蕈碱受体的位置。测试了神经元毒蕈碱受体激动剂（毛果芸香碱）和拮抗剂（加拉明）对节前和节后胆碱能神经刺激诱导的气道平滑肌收缩的影响。在麻醉的豚鼠中，加拉明增强了节前刺激诱导的气管和较小气道的收缩。加拉明还增强了气管壁透壁刺激和肺其余部分注射碘化1-1-二甲基-4-苯基哌嗪诱导的节后刺激。加拉明未增强静脉注射乙酰胆碱诱导的气管收缩和支气管收缩，表明气道平滑肌中的节后毒蕈碱受体不参与这种增强作用。毒蕈碱激动剂毛果芸香碱具有与加拉明相反的作用，并抑制两种神经刺激诱导的气管收缩。在体外，毛果芸香碱的抑制作用在节前和节后刺激的气管制备中得到证实。毛果芸香碱的作用被加拉明拮抗。由于加拉明和毛果芸香碱影响对节后刺激的反应，抑制性毒蕈碱受体必定位于支配气管和较小气道的副交感神经的节后神经元上。然而，这些实验不能排除毒蕈碱受体也可能位于神经节细胞胞体上的可能性。
