title: Myringosclerosis caused by increased oxygen concentration in traumatized tympanic membranes. Experimental study.
abstract: The purpose of this study was to elucidate possible relationships between the oxygen concentration of the middle ear cavity and the development of myringosclerosis. Three groups of rats with myringotomized tympanic membranes were exposed to different oxygen concentrations of 10%, 15%, and 40%, respectively, for 1 week. A fourth group was kept in ambient air. Two other groups of rats with myringotomized and intubated tympanic membranes were exposed to oxygen concentrations of 10% and 40%, respectively, for the same period of time. Otomicroscopically, all hyperoxic animals had more numerous myringosclerotic lesions compared with the ambient air group, and also displayed a pronounced hyperplasia of the keratinizing epithelium around the perforation border. By contrast, the hypoxic animals showed less pronounced myringosclerotic lesions or even completely lacked them. It is inferred that an increased oxygen concentration in the middle ear cavity will increase the likelihood of myringosclerotic deposits. The mechanism involved could be related to the formation of oxygen radicals.
authors.affiliation: Department of Otorhinolaryngology, University of Umeå, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Mattsson
authors.forename: K
authors.initials: K
authors.lastname: Magnuson
authors.forename: S
authors.initials: S
authors.lastname: Hellström
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D018496:Hyperoxia / Q000150:complications; D006965:Hyperplasia; D008297:Male; D008876:Middle Ear Ventilation / Q000009:adverse effects*; D010100:Oxygen / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012598:Sclerosis; D014432:Tympanic Membrane / Q000473:pathology* / Q000601:surgery
chemical_list: D010100:Oxygen