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听力学及言语疾病杂志JOURNAL OF AUDIOLOGY AND SPEECH PATHOLOGY
2002 Vol.10 No.1 P.31-34,49
乙酰胆碱对豚鼠外毛细胞的电压依赖性外向整流钾电流的影响
Effects of ACh on Voltage- dependent Outwardly Rectifying Potassium Currents in Isolated Outer Hair Cells in Cochlea of Guinea Pig
杨军
汪吉宝
摘 要：目的观察乙酰胆碱(ACh)对不同长度豚鼠耳蜗外毛细胞(OHC)电压依赖性外向整流钾电流的影响,分析ACh对钾电流激活动力学的影响.方法全细胞膜片钳技术.结果100μmol/L的ACh对短OHC电压依赖性外向整流钾电流的影响较大,刺激电压为50 mV时,最大外向电流的幅度增加了34.8%.ACh对峰电流的影响大于稳态电流,改变了外向整流钾电流的动力学特征.ACh将OHC的零电流电位向超极化方向移位约5 mV.100 mol/L的ACh使OHC电压依赖性外向整流钾电流的激活动力学发生改变,V1/2=(-52.38±3.98)mV,较作用前明显超极化,激活的电压敏感性也提高,S=(40±4.14)mV(n=5).结论 ACgh增加了OHC电压依赖性外向整流钾通道的电导,使通道的激活电压向超极化方向移位.ACh的作用是使OHC超极化.
关键词：外毛细胞 乙酰胆碱 外向整流钾电流 超极化 激活动力学
文章编号：1006-7299(2002)01-0031-04
作者简介：杨军(1967-),男,湖北人,医学博士,主要从事耳鼻咽喉临床和耳科基础研究工作.
作者单位：杨军（上海第二医科大学附属仁济医院耳鼻咽喉-头颈外科,上海,200001）
汪吉宝（华中科技大学同济医学院附属协和医院耳鼻咽喉科）
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