Histologic changes in the auditory tube mucosa of rats after long-term exposure to cigarette smoke

PurposeThe aim of the study was to investigate the effect of cigarette smoke on the auditory tube and middle ear mucosa after long-term exposure (4 and 6 months).Materials and methodsFifteen rats were divided into 3 groups. The experimental groups were exposed to cigarette in a smoking chamber for 4 and 6 months (n = 5 each). A control group (n = 5) was placed in the same chamber without exposure to cigarette smoke. Histologic changes of the auditory tube mucosa were observed through light and electron microscopes. Histologic changes of the middle ear mucosa were also observed through light microscopes.ResultsThe histologic changes consisted of a proliferation of goblet cells and an increase of mucus secretion in auditory tube. Squamous metaplasia was paradoxically decreased according to the duration of exposure in auditory tube. The number of goblet cell was gradually increased according to the duration of exposure in the auditory tube and middle ear.ConclusionsLong-term passive smoke directly affects the auditory tube and middle ear mucosa. Histologic changes of auditory tube mucosa consisted of goblet cell proliferation and excessive mucus secretion.