Yoshida M, Koeda T
Nihon Heikatsukin Gakkai Zasshi. 1986 Oct;22(5):437-46. doi: 10.1540/jsmr1965.22.437.
Authors observed the mechanical response of the tracheal muscle to electrical stimulation using only one transverse strip preparation of isolated guinea-pig trachea, 4-5 mm in width, which included only one tracheal muscle strip. The effects of various pharmacological agents on these responses were also investigated. A biphasic response which is a contractile response followed by a relaxing response usually appeared when the preparation was stimulated with rectangular pulses (50 volt, 0.5 msec) at 40 Hz for a period of 5 sec. A monophasic contractile response also appeared, only rarely but this response was shifted to the biphasic response as the resting tonus level of the preparation gradually increased in the course of the experiment. When the preparation was stimulated electrically at intervals of 15 min, the resting tonus level of the preparation gradually decreased and it subsequently reached a stable state. Then the amplitude of contractile response and depth of relaxing response in the biphasic response evoked by electrical stimulation of constant condition were, respectively, almost constant, whenever the preparation was stimulated at intervals of 15 min. The amplitude of monophasic contractile response which appeared only rarely was relatively constant to every trial of electrical stimulation throughout the experiment. The amplitude of contractile response and depth of relaxing response in the biphasic response were 283 +/- 65 mg (mean +/- SD, n = 10) and 293 +/- 93 mg (mean +/- SD, n = 10), respectively. The monophasic contractile response was abolished by atropine (5 X 10(-7) g/ml) or tetrodotoxin (2 X 10(-7) g/ml). The contractile response in the biphasic response was abolished by atropine (5 X 10(-7) g/ml). In the presence of atropine (5 X 10(-7) g/ml), therefore, only the relaxing response appeared. This relaxing response was respectively reduced by guanethidine (1 X 10(-5) g/ml-1 X 10(-6) g/ml) and propranolol (1 X 10(-5) g/ml-1 X 10(-6) g/ml), but complete inhibition was never seen. These findings suggest that the excitatory innervation is cholinergic and the inhibitory innervation is both adrenergic and non-adrenergic. In addition, from the results of this work it is clear that the preparation used by the authors are good enough to observe the electrical stimulation-induced response of the preparation.
作者仅使用一条宽度为4 - 5毫米的豚鼠离体气管横向条带制剂（其中仅包含一条气管肌条带）观察了气管肌对电刺激的机械反应。还研究了各种药理试剂对这些反应的影响。当用矩形脉冲（50伏，0.5毫秒）以40赫兹刺激该制剂5秒时，通常会出现双相反应，即先收缩后舒张的反应。也会出现单相收缩反应，只是很少见，但随着实验过程中制剂静息张力水平逐渐升高，这种反应会转变为双相反应。当每隔15分钟对制剂进行一次电刺激时，制剂的静息张力水平会逐渐下降，随后达到稳定状态。然后，在恒定条件下电刺激诱发的双相反应中，收缩反应的幅度和舒张反应的深度，每当每隔15分钟刺激制剂时，分别几乎保持恒定。整个实验过程中，仅偶尔出现的单相收缩反应的幅度在每次电刺激试验中相对恒定。双相反应中收缩反应的幅度和舒张反应的深度分别为283±65毫克（平均值±标准差，n = 10）和293±93毫克（平均值±标准差，n = 10）。单相收缩反应可被阿托品（5×10⁻⁷克/毫升）或河豚毒素（2×10⁻⁷克/毫升）消除。双相反应中的收缩反应可被阿托品（5×10⁻⁷克/毫升）消除。因此，在存在阿托品（5×10⁻⁷克/毫升）的情况下，仅出现舒张反应。这种舒张反应分别被胍乙啶（1×10⁻⁵克/毫升 - 1×10⁻⁶克/毫升）和普萘洛尔（1×10⁻⁵克/毫升 - 1×10⁻⁶克/毫升）降低，但从未完全抑制。这些发现表明，兴奋性神经支配是胆碱能的，而抑制性神经支配既是肾上腺素能的又是非肾上腺素能的。此外，从这项工作的结果可以清楚地看出，作者使用的制剂足以观察到电刺激诱发的制剂反应。
