title: Application of oxygen free radical scavengers to diminish the occurrence of myringosclerosis.
abstract: The present study was designed to establish whether or not an increased production of oxygen-derived free radicals is involved in the causation of myringosclerosis. Sclerotic lesions in the tympanic membrane were experimentally elicited by keeping rats with perforated tympanic membranes in an atmosphere containing roughly 40% oxygen. The animals were treated daily with a solution containing either copper zinc-superoxide dismutase plus catalase, deferoxamine, or copper sulfate plus iron chloride, applied to the traumatized area. After 1 week the extension of myringosclerotic plaques was determined otomicroscopically. The pars tensa and pars flaccida were then dissected free and prepared for light microscopic studies. The results showed that treatment with copper zinc-superoxide dismutase plus catalase and deferoxamine inhibited or reduced the development of myringosclerosis, whereas the ears treated with copper sulfate plus iron chloride appeared unaffected. Consequently, the findings support the hypothesis that the formation of oxygen free radicals contributes significantly to the development of myringosclerosis.
authors.affiliation: Department of Otorhinolaryngology, University Hospital of Umeå, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Mattsson
authors.forename: S L
authors.initials: SL
authors.lastname: Marklund
authors.forename: S
authors.initials: S
authors.lastname: Hellström
mesh_terms: D000818:Animals; D002114:Calcinosis / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D003676:Deferoxamine / Q000494:pharmacology*; D004848:Epithelium / Q000473:pathology; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005609:Free Radicals / Q000009:adverse effects; D018496:Hyperoxia / Q000150:complications*; D008297:Male; D010040:Otosclerosis / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism; D014432:Tympanic Membrane / Q000187:drug effects* / Q000473:pathology
chemical_list: D016166:Free Radical Scavengers; D005609:Free Radicals; D013481:Superoxides; D013482:Superoxide Dismutase; D003676:Deferoxamine