长期注射水杨酸钠大鼠下丘EphA4的表达  

The Expression of EphA4 in Inferior Colliculus Involves in the Pathology of Salicylate Induced Tinnitus in Rat

作　　者：王文静[1] 杨琨[1] 廖华[1] 杨希林[1] 刘行[1] 

机构地区：[1]武汉大学人民医院耳鼻咽喉头颈外科,武汉430060

出　　处：《听力学及言语疾病杂志》2017年第1期40-43,共4页Journal of Audiology and Speech Pathology

基　　金：国家自然科学基金青年基金(81100712);湖北省自然科学基金面上项目(220100653)资助

摘　　要：目的通过观察长期水杨酸钠作用后大鼠ABR及下丘EphA4mRNA表达变化,探讨下丘EphA4表达在水杨酸钠耳毒性中的作用。方法将30只健康成年雄性SD大鼠随机分为5组,每组6只:正常对照组(不予任何处理),肌注7天组(肌肉注射水杨酸钠175mg/kg,每天2次,间隔8小时,连续7天),肌注14天组(水杨酸钠用法同前,持续14天),恢复14天组(肌注水杨酸钠14天后,停药恢复14天),恢复28天组(肌注水杨酸钠14天后,停药恢复28天)。对各组大鼠分别于相应时间点进行ABR检测后处死并迅速分离下丘,采用实时荧光定量PCR(real-time PCR)的方法检测各组大鼠下丘中EphA4mRNA表达。结果 1肌注7、14天组大鼠的ABR反应阈分别为38.33±3.73、44.16±1.86dB SPL,较对照组(30.83±1.86dB SPL)明显升高(P<0.05);恢复28天组大鼠的ABR反应阈(32.50±2.50dB SPL)与对照组(30.83±1.86dB SPL)相比,差异无明显统计学意义(P>0.05);2肌注7天组和恢复14天组大鼠下丘EphA4mRNA表达(分别为:0.69±0.11、0.67±0.09)均低于对照组大鼠(0.99±0.01)(均为P<0.05);恢复28天组大鼠下丘EphA4mRNA表达(0.88±0.04)与对照组大鼠比较差异无统计学意义(P>0.05)。结论长期注射水杨酸钠后大鼠下丘的EphA4表达呈可逆性下降,且与水杨酸钠注射后大鼠听功能损伤的变化一致,推测下丘神经元轴突中EphA4参与了水杨酸钠耳毒性的机制。Objective To investigate the influences of sodium salicylate on the auditory brainstem response（ABR）and expression of EphA4 mRNA in rat inferior colliculus and its effects on salicylate ototoxicity.Methods A total of 30 healthy SPF rats were randomly divided into five groups：the control group（without any treatment）,S7（i.m.injection of sodium salicylate,175mg/kg,twice daily for 7days）,S14（the same method as S7,twice daily for14days）,S14＋R14（the same method as S14,twice daily for 14 days and recovered for 14days）,and S14＋R28（the same method as S14,twice daily for 14 days and recovered for 28days）.After the ABR assessment,rats were sacrificed after deep anesthesia and the inferior colliculus tissues were dissected.Real-time PCR was used to detect the expression of EphA4 mRNA.Results Compared with the control group,ABR thresholds in the S7 group and S14 group were increased significantly（P〈0.05）,while there was no significant difference between the control group and the S14＋R28group（P〉0.05）.The inferior colliculus EphA4 mRNA expression level of S7 group was significantly decreased than the control group（P〈0.05）.The EphA4 mRNA expression level of S7 group was significantly decreased than the control group（P〈0.05）,while there was no significantly difference between the control group and the S14＋R28group（P〉0.05）.Conclusion Long term injection of sodium salicylate can cause changes in the inferior colliculus of EphA4 mRNA which are related closely with synaptic plasticity.It may lead the alteration of the inferior colliculus synaptic plasticity,which is associated with the changes of the hearing failure and the tinnitus behavior.This indicates that EphA4 which is considered as a related protein in the inferior colliculus may play an important role in the pathology of tinnitus.

关 键 词：水杨酸钠 耳毒性 下丘 EphA4 

分 类 号：R764.5[医药卫生—耳鼻咽喉科]