【摘要】 目的 研究阿米卡星(amikacin，AMK)在不同給藥時間內對豚鼠耳蝸毛細胞的損傷作用，探討AMK的耳毒性。方法 豚鼠隨機分爲對照組、AMK 3 d組、AMK 7 d組和AMK 11 d組。採用異硫氰酸四甲基羅丹明標記的鬼筆環肽熒光染色方法，並結合聽腦幹反應(auditory brainstem response，ABR)測試，觀察用藥前後耳蝸毛細胞形態及聽功能的改變。結果 AMK首先損傷耳蝸底回的外毛細胞,並且隨着給藥時間延長，損傷逐漸向頂回發展，外毛細胞缺失明顯增多，而AMK對內毛細胞的損傷要輕於外毛細胞。聽功能改變與形態學變化基本一致。結論 AMK可損傷豚鼠耳蝸毛細胞，導致聽功能下降。
【關鍵詞】 阿米卡星;豚鼠;耳蝸;聽腦幹反應
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
氨基糖苷類抗生素(aminoglycoside antibiotics，AmAn)具有強大的抗革蘭氏陰性桿菌的作用, 加之價格低廉, 是臨牀控制感染的常用抗生素[1]。但是AmAn具有嚴重的耳毒性，可導致耳蝸毛細胞、前庭毛細胞及螺旋神經節細胞的損傷[2-3]。阿米卡星(amikacin, AMK)爲半合成的AmAn，亦可對耳蝸毛細胞造成不可逆性的損傷[4]，然而AMK在不同給藥時間內對豚鼠耳蝸毛細胞的損傷特點及其與聽功能變化的關係，目前尚不清楚。據此，本研究應用異硫氰酸四甲基羅丹明(Tetramethylrhodamine isothiocyanate，TRITC)標記的鬼筆環肽熒光染色方法，並結合聽腦幹反應(auditory brainstem response，ABR)測試，觀察用藥前後豚鼠耳蝸毛細胞形態及聽功能的改變，以探討AMK的耳毒性。
1 材料與方法
1.1 實驗動物
健康白毛紅目豚鼠47 只，體重250～300 g，雌雄不限，耳廓反射靈敏，無中耳炎，由遼寧醫學院實驗動物中心提供。實驗期間所有豚鼠均在安靜狀態下飼養並給予常規飲食。
1.2 主要試劑和儀器
阿米卡星注射液(0.1 g/mL，批號090327)由蘇州第六製藥廠生產，TRITC-鬼筆環肽購自美國Sigma公司，Smart EP & OAE聽覺誘發電位-耳聲發射記錄系統由美國智聽公司生產，ZEISS A1熒光顯微鏡由德國Zeiss公司生產。
1.3 動物分組與耳毒模型建立