흰쥐 내이에서 CoCl2 전 처치에 의한 소음성 난청의 예방 효과

Abstract

Background and Objectives：1α (HIF-1α) acording to time after being exposed to noise trauma and find out the efect of HIF-1 α in the prevention of noise-induced hearing los by pre-treatment with cobalt chloride (CoCl2). Subjects and Method：BALB/c hybrid mice with 25 dB HL or les ABR were used in this study. In the study group, subjects were exposed to 120 dB SPL broad white band noise for 3 hours per day for 3 days. The changes in their hearing were documented before and after 1, 2, 3, 4, and 9 days of the first noise exposure. CoCl2 α on noise-induced hearing los. For the control, injection with distilled water was performed and hearing thresholds were measured in the same manner. Cochlea from each group was obtained in order to observe the morphological changes in the iner ear and the expression of the HIF-1α using imunohistochemial staining and imuno-fluorescein staining along with quantification of the hair cell los. Results：Mice exposed to the noise for 3 days, showed permanent threshold shift and the expression of HIF-1α was increased. When HIF-1α was induced by pre-treatment of CoCl2was observed to some degree. And hair cel survival rate was also higher when treated with CoCl2 compared to the distilled water treated group. Conclusion：When pre-treated with CoCl2, inducing HIF-1α before the noise trauma, it allowed for a less stereocilia los in the hair cells in the organ of Corti. HIF-1α may play an important role in the prevention of noise-induced hearing loss. (Korean J Otorhinolaryngol-Head Neck Surg 2007 ;50 :743-9)