内耳拟老化大鼠模型对噪声损伤易感性研究  

The study of the high sensitivity to noise trauma in the inner ear mimetic aging model

作　　者：许黎[1,2] 胡钰娟[1] 孔维佳[1] 师洪[1] 彭炜[1] 胡媛[1] 

机构地区：[1]华中科技大学同济医学院附属协和医院耳鼻咽喉科,武汉430022 [2]湖北省新华医院耳鼻咽喉科,武汉430015

出　　处：《临床耳鼻咽喉头颈外科杂志》2010年第19期895-898,900,共5页Journal of Clinical Otorhinolaryngology Head And Neck Surgery

基　　金：国家杰出青年基金项目(No:39925035);国家自然科学基金项目(No:2004BA720A18-02);国家自然科学基金重点项目(No:30730094)

摘　　要：目的:应用本研究小组建立的内耳拟老化模型,研究其对噪声损伤的敏感性,并探讨线粒体DNA缺失(mtDNA)在大鼠对噪声损伤易感的可能作用。方法:2月龄Wistar大鼠32只随机分为4组,A组每日皮下注射D-半乳糖150mg/kg体重,持续8周;继而暴露于声强为110dBSPL的噪声环境中,每日连续刺激4h,持续2d。B组每日皮下注射0.9%生理盐水150mg/kg体重,持续8周,然后给予噪声暴露,噪声条件同A组。C组用药方法同A组,D组用药方法同B组,C组和D组均不予噪声暴露。造模后2周测试ABR反应阈改变,并测试各组大鼠膜迷路总超氧化物歧化酶活力(T-SOD)、丙二醛(MDA)水平,同时应用巢式PCR(nestPCR)方法检测大鼠膜迷路mtDNA4834缺失突变,并对PCR产物进行测序。结果:A组大鼠ABR反应阈改变[(66.250±6.409)dBSPL]较B组[(35.625±4.955)dBSPL]明显提高,差异有统计学意义(P<0.01)。A组T-SOD显著下降,MDA水平明显提高,与B组差异有统计学意义(P<0.01)。大鼠内耳组织mtDNA4834缺失突变率分别为:A组87.5%(7/8),B组12.5%(1/8),C组75.0%(6/8),D组0(0/8)。结论:内耳拟老化模型大鼠对噪声性聋易感,大鼠内耳组织mtDNA缺失突变可增加模型大鼠对噪声性听力损伤的易感性。Objective：Use the inner ear mimetic aging model which has been established by our research institute,investigate its sensitivity to niose trauma and the possible role of mitochondrial DNA deletions.Method：Thirty-two Wistar rats of 2months old were randomly divided into four groups.In group A,D-galactose was subcutaneously injected at dose of 150mg/kg weigh per day for 8weeks,after that these rats were exposed to 110dB SPL noise 4hours each day,for 2days.Group B were given nomal saline（NS）injected at dose of 150mg/kg weigh per day for 8weeks,also given noise exposure as that of group A.Group C were give D-galactose without noise exposure.Group D were given nomal saline（NS）without noise exposure.The thresholds of auditory brainstem response（ABR）were measured 2weeks after stopping of noise exposure.And T-SOD and MDA of the inner membranous labyrinthine tissue were measured.Nest polymerase chain reaction（Nest PCR）were used to identify the mtDNA common deletion（CD）,and PCR products were sequenced in the meantime.Result：The elevation of the mean ABR thresholds in group A was higher than that in group B,and the difference had statistic significance（P 0.01）.The reduction of T-SOD in group A was obvious,while the level of MDA was greatly increased.The difference in the levels of T-SOD and MDA between group A and group B had statistic significance（P0.01）.The detection rate of mtDNA 4834deletion were as follows：group A 87.5%（7/8）;group B 12.5%（1/8）;group C 75.0%（1/8）;group D 0（0/8）.Conclusion：The rat in the inner ear mimetic aging model are hypersensitive to noise exposure,and mtDNA4834deletions in the inner ear may play an important role in it.

关 键 词：D-半乳糖 噪声暴露 动物模型 线粒体DNA突变 

分 类 号：R764[医药卫生—耳鼻咽喉科]