摘要
目的探讨鸡卡那霉素耳中毒后耳蜗听神经节EphrinA2蛋白的表达有无变化。方法 66只新生罗曼鸡分为实验组48只,于生后3d开始按200mg.kg-1.d-1连续肌肉注射卡那霉素10d,再将其设为施药完毕前2d、完毕后1、3、7、15、21、30、60d8个组。对照组18只,设3、13、43d龄3个组,不施与任何药物。所有动物按预定时间点处死,取听神经组织行免疫组化荧光染色。结果正常对照组听神经节ephrinA2阳性染色细胞数多,呈梯度分布现象,各时间点无明显差异。实验组用药完毕前2d、完毕后1、3、7d组听神经节ephrinA2阳性染色细胞数较正常对照组明显减少,药毕后15d时ephrinA2阳性染色细胞数较前明显增多,药毕后30d时ephri-nA2阳性染色细胞数已接近正常对照组。结论鸡卡那霉素耳中毒后听神经节ephrinA2蛋白的表达随着耳蜗毛细胞神经连接的再生及重塑而有先明显降低后逐渐恢复正常的现象。
Objective To investigate the expression of ephrin A2 in the acoustic ganglia of the chick cochlea following kanamycin ototoxicity. Methods A total of 66 newly hatched Roman chickens （ 3 days old） were randomly divided into experimental groups and control groups. Experimental chickens （n= 48） received intramuscular kanamycin （200 mg/kg,Sigma, St Louis, MO） for 10 consecutive days and were subsequently sacrificed 2 days before, and 1, 3, 7, 10, 15, 21, 30, or 60 days after the last injection （n=6 per subgroup）. Control chickens （n=18） were untreated and sacrificed 3, 13 or 43 days after hatching （n= 6 per subgroup）. Ephrin A2 protein expression and localization in acoustic ganglia were determined by fluorescence immunohistochemistry in all chickens after sacrifice. Results Nearly all ganglion cell bodies in all control ganglia were labeled positively for ephrin A2 protein and the nonhomogeneous level of immunolabeling was evident. After kanamycin exposure, few positive ganglion cell bodies labeled for ephrin A2 were observed in the cochlea of the experiment chickens from 2 to 7 days after kanamycin last injection. Ephrin A2 positive ganglion cell increased obviously at 15 days after kanamycin last injection. By the 30 days after the cessation of kanamycin treatment, the number of ephrin A2 positive ganglion cell bodies approximated to that in normal control group. Conclusion The expression of ephrin A2 protein in the ganglion cell bodies basically synchronizes with the regeneration and plasticity of the reinnervation of the regenerated hair cells in the chick cochlea following kanamycin ototoxicity.
出处
《听力学及言语疾病杂志》
CAS
CSCD
北大核心
2010年第3期257-259,共3页
Journal of Audiology and Speech Pathology
基金
上海市自然科学基金资助项目(08ZR1414900)
上海交通大学医学院基金资助项目(2007XJ031)
上海市卫生局基金资助项目(20070154)
上海市科委重点基金资助项目(06JC14056)
