Racké K, Hey C, Wessler I
Department Pharmacology, University of Frankfurt, Germany.
Br J Pharmacol. 1992 Sep;107(1):3-4. doi: 10.1111/j.1476-5381.1992.tb14454.x.
Overflow of endogenous noradrenaline (NA) from guinea-pig isolated tracheae was evoked by electrical field stimulation (3 Hz, 540 pulses). The muscarinic receptor agonist oxotremorine inhibited the evoked overflow of NA in a concentration-dependent manner (EC50 84 nM). Methoctramine, pirenzepine and p-fluoro-hexahydrosiladiphenidol (each 1 microM) shifted the concentration-response curves of oxotremorine to the right with apparent pA2 values of 7.60, 6.74 and 6.18, respectively. It is concluded that sympathetic nerve terminals in the guinea-pig trachea are endowed with inhibitory muscarinic M2 receptors.
电场刺激(3赫兹,540个脉冲)可诱发豚鼠离体气管释放内源性去甲肾上腺素(NA)。毒蕈碱受体激动剂氧化震颤素以浓度依赖性方式抑制诱发的NA释放(半数有效浓度84纳摩尔)。甲溴东莨菪碱、哌仑西平及对氟六氢硅二苯乙醇胺(各1微摩尔)使氧化震颤素的浓度-反应曲线右移,其表观拮抗常数分别为7.60、6.74和6.18。结论是豚鼠气管中的交感神经末梢具有抑制性毒蕈碱M2受体。