Adebanjo A O, Ambache N
Arch Int Pharmacodyn Ther. 1978 Jun;233(2):261-9.
Isolated vas deferens preparations from 9 dogs were subjected to electrical stimulation and chemical excitation under physiological conditions. The experimental smooth muscle cylinders were confined to the terminal 3 cm portions of either the distal 'urethral' segment or the proximal 'epididymal' segment. Intermittent field stimulation, at 60 sec intervals, was provided by a stimulator of low output impedance under constant parameters of frequency and voltage and an occasionally varied pulse width. Results from this examination completely confirmed the following: (i) a high degree of contractile sensitivity to minute doses of noradrenaline (0.03--0.03 micron; 10(-8)-10(-7) g/ml) and tyramine 0.58 micron (10(-7) g/ml; (ii) an apparent ease and rapidity of extinguishing the electrically-induced twitches by either small doses of phentolamine 0.25 micron (10(-7) g/ml) or phenoxybenzamine 5.8 micron (2 x 10(-6) g/ml); (iii) a complete absence of any inhibitory action by tyramine or noradrenaline on the electrically-induced twitches. The behavior of this motor transmission of the longitudinal muscle of the vas deferens to classical alpha-adrenoceptor blocking agents and the intense susceptibility to the motor actions of the putative neurotransmitter clearly fit in with a picture of an adrenergic implication in this mode of transmission.
对9只犬的离体输精管标本在生理条件下进行电刺激和化学刺激。实验用的平滑肌条取自远端“尿道”段或近端“附睾”段的末端3厘米部分。在频率、电压参数恒定且脉宽偶尔变化的情况下，由低输出阻抗的刺激器以60秒的间隔进行间歇性场刺激。本次检查结果完全证实了以下几点：（i）对微量去甲肾上腺素（0.03--0.03微米；10⁻⁸ - 10⁻⁷克/毫升）和酪胺0.58微米（10⁻⁷克/毫升）具有高度的收缩敏感性；（ii）小剂量酚妥拉明0.25微米（10⁻⁷克/毫升）或酚苄明5.8微米（2×10⁻⁶克/毫升）能明显轻松且快速地消除电诱导的抽搐；（iii）酪胺或去甲肾上腺素对电诱导的抽搐完全没有任何抑制作用。输精管纵肌的这种运动传递对经典α-肾上腺素能受体阻断剂的反应以及对假定神经递质的运动作用的高度敏感性，显然符合这种传递方式中存在肾上腺素能参与的情况。
