Immunohistochemical Localization of Alpha 1-antitrypsin in the Rat Eustachian Tube and Tympanic Membrane / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: The major antielastase involved in preventing breakdown of elastic fiber in the airway is alpha 1-antitrypsin. In this regard, the eustachian tube may have the protease (elastase)-antiprotease (alpha 1-antitrypsin) system. MATERIALS AND METHODS: Sprague-Dawley rats were perfused with 4% paraformaldehyde. After fixation, the eustachian tube containing a part of middle ear was transfered to a 0.1 M EDTA solution, followed by embedding in paraffin wax. The avidin-biotin-peroxidase procedure was used to identify alpha 1-antitrypsin. RESULTS: The immunoreactivity for alpha 1-antrypsin in the eustachian tube appeared strongly in the cilia of pseudostratified columnar epithelium and serous cells of the submucous glands. In the tympanic membrane, it was distributed selectively in the inner mucosal epithelium. The strong immunostaining was also noticed in the glands of external auditory canal. CONCLUSION: We found that elastic fibers and alpha 1-antitrypsin in the eustachian tube and tympanic membrane may be interrelated to the maintenance of the normal function of the middle ear.