Brito A R, Jurkiewicz A
Department of Pharmacology, Escola Paulista de Medicina, São Paulo, Brazil.
J Pharm Pharmacol. 1988 Nov;40(11):781-6. doi: 10.1111/j.2042-7158.1988.tb05172.x.
Vas deferens preparations were perfused in-vitro through the lumen and externally with a modified Tyrode solution alone or containing drugs. Contractions of the circular (internal) smooth muscle layer were recorded as changes in the pressure of internal perfusion. Contractions of the longitudinal (external) layer were simultaneously recorded through a tension transducer. When the organ was perfused through the lumen, the circular layer contracted after addition of methacholine (pD2 = 4.13), and noradrenaline (pD2 = 5.00), and relaxed after addition of isoprenaline (pD2 = 5.22). These effects were also observed when the drugs were perfused externally, although with lower values of pD2 for noradrenaline and methacholine. The circular fibres were less sensitive when compared with the longitudinal fibres perfused externally with the above agonists. Methacholine-induced contractions of the circular layer were competitively antagonized by atropine (pA2 = 8.53), indicating the presence of muscarinic receptors. The effects induced by noradrenaline and isoprenaline were antagonized by indoramin (pA2 = 7.78), and timolol (pA2 = 8.68), respectively, indicating the presence of alpha- and beta-adrenoceptors. The effect of noradrenaline was potentiated by cocaine and denervation, indicating the presence of neuronal uptake, and by corticosterone, indicating the presence of extraneuronal uptake in the circular layer.
对输精管标本进行体外灌注，通过管腔以及外部单独使用改良的台氏液或含有药物的台氏液。环形（内层）平滑肌层的收缩通过内部灌注压力的变化来记录。纵向（外层）平滑肌层的收缩通过张力换能器同时记录。当通过管腔对器官进行灌注时，加入乙酰甲胆碱（pD2 = 4.13）和去甲肾上腺素（pD2 = 5.00）后环形层收缩，加入异丙肾上腺素（pD2 = 5.22）后环形层舒张。当药物从外部灌注时也观察到了这些效应，尽管去甲肾上腺素和乙酰甲胆碱的pD2值较低。与用上述激动剂从外部灌注的纵向纤维相比，环形纤维的敏感性较低。阿托品（pA2 = 8.53）竞争性拮抗乙酰甲胆碱诱导的环形层收缩，表明存在毒蕈碱受体。吲哚拉明（pA2 = 7.78）和噻吗洛尔（pA2 = 8.68）分别拮抗去甲肾上腺素和异丙肾上腺素诱导的效应，表明存在α和β肾上腺素能受体。可卡因和去神经支配增强了去甲肾上腺素的作用，表明存在神经元摄取，皮质酮也增强了去甲肾上腺素的作用，表明环形层存在非神经元摄取。
