Effects of nicotine bitartrate on mucociliary activity.

The in vivo effect of nicotine bitartrate on mucociliary (mc) activity in the rabbit maxillary sinus was investigated. An animal model was used, which permitted administration of drugs directly into the artery feeding the sinus and simultaneous recording of changes in the mc activity. When nicotine was given ia (0.5-10.0 micrograms/kg) it resulted in a brief (1 min at most) acceleration of the mc wave frequency. The response was dose-dependent and a maximum increase of 34.9% was recorded at a dose of 10.0 micrograms/kg. The response was inhibited by a preceding injection of the ganglionic blocker hexamethonium (0.2 mg/kg) or the cholinergic antagonist atropine (0.2 mg/kg). The alpha and beta-adrenoceptor antagonists phentolamine (0.2 mg/kg) and propranolol (0.2 mg/kg) did not influence the response to nicotine injection. It is concluded that the acceleration of mc wave frequency after nicotine administration is probably mediated via stimulation of nicotinic receptors on postganglionic parasympathetic nerve cells.