论文部分内容阅读
目的探讨低频声预处理对强噪声及中频强噪声引起听力损伤的保护作用。方法两组声预处理组豚鼠在中心频率 0 .5kHz 85dB倍频带噪声作用下 ,连续暴露 4d(6h/d)后 ,在无噪声情况下恢复 3d。随后分别在中心频率 0 .5kHz和 1kHz 1 1 0dB的倍频带噪声下 ,暴露 1h。两组对照组豚鼠不经声预处理 ,分别直接暴露在中心频率 0 .5KHz和 1KHz 1 1 0dB的信频带噪声下 ,暴露 1h。然后观察各组在强噪声暴露后 ,听力恢复情况、红细胞膜丙二醛 (MDA)含量以及耳蜗外毛细胞铺片检查。结果强噪声暴露后 ,经过声预处理的两组动物 ,听阈偏移程度、红细胞膜MDA含量、耳蜗外毛细胞受损情况明显好于对照组 (P <0 .0 5)。结论声预处理不仅可以减轻随后同一频率段的强噪声 (0 .5kHz、1 1 0dB)引起的听力损伤 ,还可减轻随后稍高频率段的强噪声 (1kHz、1 1 0dB)引起的听力损伤 ,声预处理的保护作用可能是通过激活细胞抗氧化酶系统 ,抑制或减少毒性自由基产生 ,从而减轻毒性自由基对细胞膜的损伤。
Objective To investigate the protective effect of low frequency acoustic pretreatment on hearing loss caused by strong noise and strong intermediate frequency noise. Methods The guinea pigs in the two pretreatment groups were resumed for 3d after noise exposure for 4h (6h / d) at the center frequency of 0 .5kHz and 85dB octave band noise. Followed by exposure to 1h at octave band noise centered at 0,5 kHz and 1 kHz, respectively. The guinea pigs in the two groups were exposed without sound pretreatment for 1h, which were directly exposed to the frequency band noise of 110 KHz and 1 KHz at 110dB respectively. And then observed in each group after strong noise exposure, hearing recovery, erythrocyte membrane malondialdehyde (MDA) content and cochlear outer hair cell patch check. Results After the strong noise exposure, the sound pretreatment of the two groups of animals, hearing threshold deviation, erythrocyte membrane MDA content, cochlear outer hair cell damage was significantly better than the control group (P <0.05). Conclusion Acoustic preconditioning can not only reduce the hearing impairment caused by the subsequent strong noise (0. 5kHz, 110dB) in the same frequency band, but also reduce the hearing loss caused by the subsequent strong noise (1kHz, 110dB) in the higher frequency band The protective effect of acoustic pretreatment may be through the activation of cellular antioxidant enzyme system, inhibit or reduce the generation of toxic free radicals, thereby reducing the toxic free radicals damage to the cell membrane.