Open AccessEffects of Methysergide on the Cough Reflex
Author(s) -
Junzo Kamei,
Tomokazu Hosokawa,
Saiζo Yanaura,
Takehiko Hukuhara
Publication year - 1986
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.42.450
Subject(s) - methysergide , dextromethorphan , cough reflex , reflex , anesthesia , medicine , serotonergic , respiratory system , pharmacology , serotonin , receptor
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.