The secretory cells in the eustachian tube of an experimental model of otitis media with effusion

Abstract

To overcome the difficulty to observe the eustachian tube of the patient with otitis media with effusion, an animal model of otitis media with effusion was induced by the inoculation of soluble immune complex into guinea pig's bulla and its eustachian tube was studied by an immunohistochemical technique. Most of the secretory cells of the additional glands of the eustachian tube were stained with alcian blue and PAS reaction, whereas in the mucous membrane of the eustachian tube such stained cells were approximately one out of ten epithelial cells. On the other hand, dolichos bifrolus agglutinin (DBA) or ulex europaeus agglutinin (UEA-I) positive cells were mainly located in the mucous membrane of the eustachian tube. The inoculation of an immune complex resulted in an aseptic serous effusion and brought about the quantitative as well as qualitative changes in the secretory activity of the eustachian tube. Alcianophilic or UEA-I positive cells increased in number especially in the cartilagenous portion and the pharyngeal orfice of the eustachian tube, however, the increase of such cells was not evident in the bony potion and tympanic orfice of the eustachian tube. In contrast, the DBA positive cells decreased in number since 7th day after injection. These findings indicate that the several kinds of secretory cells with different secretory components showed different distribution in the eustachian tube, which increase or decrease in number in response to inflammation in the middle ear.