水杨酸钠对噪声性听力损失影响的实验观察

The effects of salicylate on noise induced hearing loss in the guinea pig

目的 观察水杨酸钠能否减轻噪声引起的听力损失。方法 将 3 6只健康且耳廓反射正常的花色豚鼠随机分为水杨酸钠实验组、生理盐水对照组、水杨酸钠对照组和噪声暴露组。噪声暴露采用 10 5dBSPL的 4kHz窄带噪声下暴露 2h ,连续 5d。水杨酸钠给药为每天 0 5g/kg体重连续10d。由短声诱发听性脑干反应 (auditorybrainstemresponse ,ABR) ,连续测试其阈值 ;而后取动物双侧耳蜗荧光染色后光镜下行毛细胞计数和形态学观察。结果 ABR阈值测试显示 ,实验组动物在噪声暴露结束后 2 4h的听力略好于对照组 ;形态学观察表明 ,实验组细胞核异常数据低于对照组。

Objective To investigate the effects of salicylate on noise induced hearing loss (NIHL) in guinea pigs Methods The animals were allocated into four groups (salicylate+noise, saline+noise, noise only and salicylate only) and were exposed to a 4 kHz octave band noise at 105 dB SPL for 2 hours for 5 consecutive days Dynamic changes of ABR thresholds evoked by clicks were monitored After physiological examination, the cochleae were processed for the morphological examination by light microscopy Results Mean thresholds of ABRs in the experimental group obtained on 5 th day of the noise exposure was positively lower than the control groups ( P <0 05) The similar trends of ABR changes were found during other exposure days and after exposure, but the differences were not statistically significant In the experimental group, there were 37 00±8 89 hair cell loses as assessed by nucleus staining, and 3 20±1 07 hair cells with nuclear deformation The noise group had 74 11±10 28 hair cell loses and 10 43±9 71 hair cells with nuclear deformation, whereas the saline group had 63 60±7 97 hair cell loses and 20 80±15 48 hair cells with nuclear deformation The difference between two groups was significant ( P <0 05) Conclusion The results suggest that administration of salicylate facilitates the recovery of cochlear hearing and reduces damage to hair cells after noise exposure