Kamei J, Hosokawa T, Yanaura S, Hukuhara T
Jpn J Pharmacol. 1986 Nov;42(3):450-2. doi: 10.1254/jjp.42.450.
The present study had two basic purposes: to observe the effect of methysergide on the cough reflex and to investigate the effect of methysergide on the antitussive effect of dextromethorphan. Male and female cats were anesthetized with pentobarbital-Na. Respiration and cough reflex were measured using a pneumotachograph via a cannula inserted into the trachea. The cough reflex was elicited by electrical stimuli to the superior laryngeal nerve. Methysergide (3 mg) injected into the vertebral artery increased the number of coughs and respiratory frequency. Dextromethorphan in a dose of 3 mg inhibited the cough reflex. Methysergide (1 and 3 mg) reduced the antitussive effect of dextromethorphan in a dose-dependent manner, but did not inhibit the excitatory effect on respiratory frequency. These findings might indicate that the central serotonergic system has an inhibitory role on the cough reflex and may be related to the antitussive mechanisms of dextromethorphan.
观察美西麦角对咳嗽反射的影响，并研究美西麦角对右美沙芬镇咳作用的影响。用戊巴比妥钠麻醉雄性和雌性猫。通过插入气管的插管，使用呼吸速度描记器测量呼吸和咳嗽反射。通过电刺激喉上神经引发咳嗽反射。注入椎动脉的美西麦角（3毫克）增加了咳嗽次数和呼吸频率。3毫克剂量的右美沙芬抑制了咳嗽反射。美西麦角（1毫克和3毫克）以剂量依赖的方式降低了右美沙芬的镇咳作用，但没有抑制其对呼吸频率的兴奋作用。这些发现可能表明，中枢5-羟色胺能系统对咳嗽反射有抑制作用，并且可能与右美沙芬的镇咳机制有关。
