阿米卡星对豚鼠耳蜗毛细胞的损伤作用

阿米卡星对豚鼠耳蜗毛细胞的损伤作用       【摘要】  目的 研究阿米卡星(amikacin，AMK)在不同给药时间内对豚鼠耳蜗毛细胞的损伤作用，探讨AMK的耳毒性。 豚鼠随机分为对照组、AMK 3 d组、AMK 7 d组和AMK 11 d组。采用异硫氰酸四甲基罗丹明标记的鬼笔环肽荧光染色方法，并结合听脑干反应(auditory brainstem response，ABR)测试，观察用药前后耳蜗毛细胞形态及听功能的改变。结果 AMK首先损伤耳蜗底回的外毛细胞,并且随着给药时间延长，损伤逐渐向顶回发展，外毛细胞缺失明显增多，而AMK对内毛细胞的损伤要轻于外毛细胞。听功能改变与形态学变化基本一致。结论 AMK可损伤豚鼠耳蜗毛细胞，导致听功能下降。       【关键词】  阿米卡星;豚鼠;耳蜗;听脑干反应         Impairment Effect of Amikacin on Cochlear Hair Cells in Guinea PigLIU Shuangyue, WANG Aimei, XU Tao, MU Hua(Department of Physiology, Liaoning Medical University, Jinzhou 121001 China)Abstract:Objective To investigate the impairment effect of amikacin (AMK) on cochlear hair cells in guinea pig at different injection time, and to explore ototoxicity of AMK. Methods Guinea pigs were randomly assigned to four groups: control group, AMK 3-day group, 7-day group and 11-day group. Tetramethylrhodamine isothiocyanate-labeled phalloidine staining and auditory brainstem response (ABR) measurement were used to evaluate the changes of hair cells morphology and auditory function before and after the drug treatment. Results Outer hair cells (OHCs) in the basal turns were first impaired by AMK, and the impairment of OHCs developed to the apical turns with time prolonging, and the loss of OHCs was increased significantly. The injury of inner hair cells (IHCs) induced by AMK was lighter than OHCs. Change of auditory function was basically consistent with that of morphology. Conclusions AMK can damage the cochlear hair cells, leading to decline in auditory function. 　　Key words:amikacin; guinea pig; cochlea; auditory brainstem response 　　氨基糖苷类抗生素(aminoglycoside antibiotics，AmAn)具有强大的抗革兰氏阴性杆菌的作用, 加之价格低廉, 是临床控制感染的常用抗生素[1]。但是AmAn具有严重的耳毒性，可导致耳蜗毛细胞、前庭毛细胞及螺旋神经节细胞的损伤[2-3]。阿米卡星(amikacin, AMK)为半合成的AmAn，亦可对耳蜗毛细胞造成不可逆性的损伤[4]，然而AMK在不同给药时间内对豚鼠耳蜗毛细胞的损伤特点及其与听功能变化的关系，目前尚不清楚。据此，本研究应用异硫氰酸四甲基罗丹明(Tetramethylrhodamine isothiocyanate，TRITC)标记的鬼笔环肽荧光染色方法，并结合听脑干反应(auditory brainstem response，ABR)测试，观察用药前后豚鼠耳蜗毛细胞形态及听功能的改变，以探讨AMK的耳毒性。 　　1 材料与方法 　　1.1 实验动物 　　健康白毛红目豚鼠47 只，体重250～300 g，雌雄不限，耳廓反射灵敏，无中耳炎，由辽宁医学院实验动物中心提供。实验期间所有豚鼠均在安静状态下饲养并给予常规饮食。 　　1.2 主要试剂和仪器 　　阿米卡星注射液(0.1 g/mL，批号090327)由苏州第六制药厂生产，TRITC-鬼笔环肽购自美国Sigma公司，Smart EP & OAE听觉诱发电位-耳声发射记录系统由美国智听公司生产，ZEISS A1荧光显微镜由德国Zeiss公司生产。 　　1.3 动物分组与耳毒模型建立