模拟中长期微重力和噪声环境对大鼠听功能及内耳毛细胞凋亡的影响  

The Effects of Mid-long Term Simulated Microgravity and Noises on the Auditory Functions and the Cell Apoptosis in Inner Ear of Rats

作　　者：陈娜[1] 吴玮[1,2] 韩浩伦[2] 王刚[2] 周丽斌[2] 王鸿南[2] 李保卫[2] 丁瑞英[2] 刘钢[3] 

机构地区：[1]北京大学解放军306医院教学医院,北京100101 [2]解放军306医院耳鼻咽喉头颈外科 [3]中国航天员科研训练中心

出　　处：《听力学及言语疾病杂志》2016年第1期39-44,共6页Journal of Audiology and Speech Pathology

基　　金：全军十二五重大课题子课题(AWS11J003)资助

摘　　要：目的研究模拟中长期微重力和噪声环境对大鼠听功能及内耳细胞凋亡的影响。方法 36只SD大鼠随机分为两组:空白组(6只)和实验组(30只)。实验组给予持续尾部悬吊模拟微重力及飞船舱内噪声(稳态噪声+脉冲噪声)暴露,分别于悬吊及暴露前、悬吊及暴露3天、1周、2周、4周和8周后检测双耳ABR反应阈,并于悬吊及暴露3天、1周、2周、4周和8周取实验动物耳蜗行免疫组化染色观察半胱氨酸天冬氨酸蛋白酶3(caspase-3)在内耳的表达。空白组不做任何处理,常规饲养,于实验前及实验3天、1周、2周、4周和8周分别检测双耳ABR反应阈,并于饲养8周后取耳蜗行免疫组化染色观察。结果实验前两组大鼠ABR反应阈差异无统计学意义(P>0.05)。实验组大鼠悬吊及噪声暴露后各时间点ABR反应阈较空白组均明显增高(P<0.01),悬吊及暴露4周实验组大鼠ABR反应阈为90.00±4.26dB SPL,明显高于3天、1周、2周及8周时(P<0.05);悬吊及暴露8周大鼠ABR反应阈(80.00±5.22dB SPL)有所下降,与暴露2周(85.00±4.77dB SPL)、4周大鼠比较差异有统计学意义(P<0.01)。悬吊及噪声暴露后大鼠内耳细胞caspase-3的表达较空白组明显增强,且在一定时间内随暴露时间的延长其表达有逐渐增强的趋势,尤以悬吊及暴露4周时最明显,暴露8周时其表达强度较4周时明显下降。结论模拟中长期微重力和噪声环境对大鼠的听功能有明显损伤,且与内耳细胞凋亡呈相同的趋势;微重力和噪声因素造成的听功能损伤可能与内耳细胞的凋亡有关。Objective To investigate the effects of mid-long term simulated microgravity and noises on the auditory functions and the cell apoptosis in inner ear of rats.Methods Thirty-six rats were randomly divided into control group（n=6）and experimental group（n=30）.The experimental group was exposed to 30°head down tilt as simulated microgravity and noises including steady-state noise which was 72±2dB SPL and impulse noise up to160 dB SPL of spaceship environment.The control group was kept in normal conditions without exposure to microgravity and noise.Bilateral auditory brainstem response（ABR）thresholds were tested before and after 3-days,1-week,2-weeks,4-weeks and 8-weeks exposure,respectively,and examine expression of caspase-3（an apoptotic marker）in the inner ear hair cells by immunohistochemical staining.Results The ABR thresholds of all rats had no differents before experiment（P〉0.05）.The experimental group was significantly higher than those of in control group（P〈0.01）.The rats exposed to microgravity and noises for 4weeks showed the highest ABR thresholdshifts（86.25±4.83dB）in the experimental group（P〈0.05）.After 8-weeks exposure,the rat ABR threshold shifts（74.10±5.45dB）were lower and significantly lower than 2-weeks and 4-weeks（P〈0.01）.The damage has the same tendency with the cell apoptosis condition.The caspase-3expression in the experimental group was positive in the inner ear cells.The expression had a growing tendency with the exposure time,especially after 4weeks exposure.The expression of caspase-3after 8-weeks exposure was significantly lower than 4-weeks.The auditory damage of 8-weeks exposure was significantly lower than 4-weeks and sound conditioning or certain recovery might have been involved.Conclusion The environment of mid-long term simulated microgravity and inboard noises of spaceship leads to obvious damages to the auditory functions of the rats and it may caused by the cell apoptosis in the inner ear.

关 键 词：微重力 噪声 听性脑干反应 细胞凋亡 半胱氨酸天冬氨酸蛋白酶-3 

分 类 号：R764.433[医药卫生—耳鼻咽喉科]