摘要
目的探讨EphrinA2在鸡卡那霉素中毒后耳蜗毛细胞神经连接再生及重塑过程中的作用。方法66只新生罗曼鸡为实验对象。试验组48只,于生后3d开始连续肌注卡那霉素200mg·kg-1.d-1,共用10d,设施药完毕前2d、完毕后1、3、7、15、21、30、60d8组。对照组18只,设3、13、43d龄3组,不施与任何药物。所有动物按预定时间点处死,取听神经行Western印迹分析,处死前均作ABR测试。结果对照组动物各时间点Eph-rinA2蛋白表达量基本一致。施药完毕前2d及施药完毕后1d时,试验组动物听神经组织中EphrinA2蛋白表达较对照组明显降低,施药完毕15d后,EphrinA2蛋白表达明显升高,施药完毕30d时,EphrinA2蛋白表达已与对照组基本相同。同时,实验组用药10天后ABR阈值达116.3±4.3dBSPL,停药后3、7、10天时分别为112.0±5.2、101.5±4.3、94.3±4.8dBSPL,10天后无变化。结论鸡卡那霉素耳中毒后听神经组织中EphrinA2蛋白的表达与其耳蜗毛细胞神经连接的再生及重塑基本同步,提示EphrinA2在鸡卡那霉素耳中毒后耳蜗毛细胞神经连接的再生及重塑中可能有重要作用。
Objective To investigate the role of Ephrin A2 in the regeneration and reinnervation of hair cells in the chick cochlea following kanamycin ototoxicity. Methods 66 newly hatched Roman chickens （3 days old） were randomly divided into experimental group and control groups. Experimental chickens （n = 48） received intramuscu- lar kanamycin （200 mg/kg.. Sigma, St Louis, MO） for 10 consecutive days and were subsequently sacrificed 2 days before the last injection, and 1, 3, 7, 10, 15, 21, 30, and 60 days after the last injection （n=6 per subgroup）. Control chickens （n=18） were untreated and sacrificed 3, 13 and 43 days after hatching （n=6 per subgroup）. Ephrin A2 protein expression in acoustic ganglia was determined by western blot analysis in all chickens after sacrifice. Results Ephrin A2 protein expression was found and the protein level was almost same in acoustical ganglia of all normal chickens. After kanamycin exposure, the Ephrin A2 protein expression level in the cochlea of the experiment chickens from 2 to 7 days after last kanamycin injection was lower than that in control chickens, respectively. Ephrin A2 expression increased obviously at 15 days after kanamycin last injection. By 30 days after the cessation of kanamyein treatment, the level of Ephrin A2 protein approximated to that in normal control group. Conclusion The expression of Ephrin A2 protein in the acoustical ganglia basically synchronizes with the regeneration and the reinnervation of the hair cells in the chicken cochlea following kanamycin damage, indicating that Ephrin A2 may play an important role in this process.
出处
《听力学及言语疾病杂志》
CAS
CSCD
北大核心
2009年第6期570-572,共3页
Journal of Audiology and Speech Pathology
基金
上海市自然科学基金(08ZR1414900)
上海交通大学医学院基金(2007XJ031)
上海市卫生局基金(20070154)
上海市科委重点基金(06JC14056)资助
