ABSTRACT
BACKGROUND AND OBJECTIVES: To elucidate the mechanism of salicylate ototoxicity of free oxygen radicals (FORs), we made an animal model with Na-salicylate cochlear toxicity and evaluated the protective effect of free oxygen radical inhibitors. MATERIALS AND METHODS: Na-salicylate soaked in gelfoam was placed on the round window niche of guinea pigs for 2 hours. After removal of gelfoam, electrocochleography and evoked otoacoustic emission test were performed at regular time intervals. These tests were repeated to see the protective effect of FORs inhibitors after the injection of allopurinol or superoxide dismutase (SOD). RESULTS: Hearing loss was noted after removal of gelfoam which was soaked with Na-salicylate. After 6 hours, these ototoxicity effects disappeared. The OAE test showed similar response. FORs inhibitors showed protective effects and SOD was more effective than allopurinol. CONCLUSION: These results support the idea that FORs activity contributes to ototoxicity of Na-salicylate. This damage can be diminished by treatment with drugs that scavenge and inhibit the formation of FORs.