摘要
目的观察自由基清除剂α—硫辛酸对噪声性听力损伤的保护作用。方法 20只体重为250～350g的雄性杂色豚鼠,随机分为实验组(n=10)和对照组(n=10)。两组动物暴露倍频程噪声(4kHz中心频率)115dBSPL5h。实验组动物暴露前2d、暴露当天至暴露后7d连续给予α—硫辛酸10mg/kg,(i.p.1/d)。对照组动物相应时间腹腔注射等量的生理盐水。暴露后不同时间测试两组动物听神经复合动作电位(CAP)的阈移,组织学检查毛细胞缺失和损伤程度。结果暴露后1d,对照组平均阈移在50～60dB范围(2～10kHz),而实验组为10～16dB(P<0.001;t—test)。暴露后3w,实验组多数动物听阈恢复至暴露前水平,对照组平均残留永久性阈移(PIS)33～45dB。组织学检查,实验组动物无明显内外毛细胞缺失,毛细胞内形态结构正常。对照组动物耳蜗底回平均外毛细胞缺失率为13.2%,外毛细胞显示水肿、空泡变性和消亡等病变。结论α—硫辛酸对噪声性听力损伤有一定的保护作用。
Purpose To observe the protective effect of free radical scavenger, α-lipoic acid on hearing in acoustic trauma. Methods 20 pigmented guinea pigs were exposed to 115 dB SPL octave band noise with a center frequency of 4 kHz for 5h. Experiment animals(n = 10) received α-lipoic acid at 10 mg/kg/day (i. p.)dosage for 10 days (2 days before 0 day and 7 days after noise-exposure); control animals (n = 10) received the same dosage of physiological saline at the same time. Compound action potential (CAP) threshold shifts were recorded in all animals at different time after noise-exposure. Hair cell loss and damage were examined with histological means. Results 1 day after exposure, the control animals showed an average threshold shift of 50 - 60 dB( 2 - 10 kHz), while the experiment animals, only 10 - 16 dB( P < 0.001; t-test). 3 weeks after exposure, the threshold of most of experiment animals recovered to the level of threshold measured before exposure, the control animals had an average permanent threshold shift( PIS) of 33 - 45 dB. Histological examination showed that there were no significant loss of hair cells in experimental group and the intracellular structures of hair cells were normal. In control animals, 13.2% of the outer hair cells at the basal turn were missing. The outre hair cells appeared swollen or degenerated. Conclusion α-lipoic acid has a protective effect on noise-induced hearing loss.
出处
《中国眼耳鼻喉科杂志》
2002年第5期274-276,I002,共4页
Chinese Journal of Ophthalmology and Otorhinolaryngology
基金
国家自然科学基金(39970634)
