Effect of Salicylate on DPOAEs and ABRs in Guinea Pigs

Lee, O Young; Park, Yong Ho; Lee, Suk Ho; Nam, Boo Hyun; Park, Chan Il

Abstract

BACKGROUND AND OBJECTIVES: Salicylates are well-known for producing reversible hearing loss and tinnitus. However, the site and mechanism of salicylate ototoxicity remain unresolved. Recent experiments suggest that reversible biochemical and/or metabolic changes in the cochlea seem to play an important role in salicylate ototoxicity. The purpose of this study was to investigate the site of lesion in salicylate ototoxicity by audiometric study. MATERIALS AND METHOD: ABRs and DPOAEs were observed after intraperitoneal injection of 500 mg/kg of sodium salicylate on 24 ears of guinea pigs.
RESULTS
Salicylate produced a significant increase in the ABR threshold. Maximum changes were obtained in 4 hours, and recovered to the baseline in 24 hours after salicylate administration. The pattern of hearing loss shown by latency-intensity function was compatible with the cochlear type of hearing loss. The echo amplitude on DPOAEs at f2=2002, 4004 Hz was significantly decreased at 2, 4, 6, 8 hours, and returned to the baseline in 24 hours after salicylate administration. The time course of the change of DPOAEs was parallel with that of ABRs.
CONCLUSION
These results reflect that the cochlear outer hair cells may be the main site of lesion in salicylate ototoxicity.