【摘要】 目的研究人类三型酸敏感离子通道(hASIC3)的生理学和药理学特性。方法应用全细胞电压钳技术检测转染在COS-7细胞上的hASIC3通道的生理学和药理学特性。结果hASIC3通道能通过迅速降低胞外pH值而被激活,并在酸性环境中迅速脱敏。脱敏后的hASIC3通道恢复到50%备用状态时所需的时间为(618±21)ms。胞外pH值在(6.40±0.05)时可使50%的hASIC3通道激活。pH值低于8时hASIC3通道的利用率降低,在生理状态pH值条件下,通道利用率降低了大约50%。阿米洛利能特异性阻断快速激活快速失活hASIC3通道且半数抑制浓度为(12.5±3.0)μmol/L。hASIC3通道的电流电压(I-V)关系曲线在很宽广的电压范围内呈线性关系(-80~+80 mV),翻转电位为(+43±5)mV。结论hASIC3通道作为一种酸感受器,可能对感受人体pH值的变化起很重要的作用。更多还原

【Abstract】 Objective To investigate the physiological and pharmacological characterizations of human ASIC3（hASIC3） expressed in COS-7 cells.Methods By using cell culture,gene transfection and whole cell patch clamp technique,the characterizations of human ASIC3（hASIC3） expressed in COS7 cells were studied.Results hASIC3 currents were activated by changing the pH of the bathing solution and exhibited rapid desensitization upon exposure to acidic solutions;Time of 50% hASIC3 channel recovering from desensitization was（618±21） ms.Fast activated and fast inactivated hASIC3 currents were inhibited by amiloride with IC₅₀ values of（12.5±3.0） μmol/L.In COS-7 cells the ASIC3 I-V relationship was linear over a wide voltage range（-80—+80 mV） and the current reversal potential was（+43±5） mV.Conclusion hASIC3 is an acid sensor and might play an important role in the detection of pH change in human.更多还原