论文部分内容阅读
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。
Objective To investigate the physiological and pharmacological properties of human tricyclic acid-sensing ion channels (hASIC3). Methods The physiological and pharmacological properties of hASIC3 channels transfected on COS-7 cells were examined using whole-cell voltage-clamp technique. Results The hASIC3 channel was activated by rapidly lowering the extracellular pH and rapidly desensitized in acidic environments. The time required to desensitize the hASIC3 channel to 50% standby was (618 ± 21) ms. The extracellular pH value at (6.40 ± 0.05) activated 50% of hASIC3 channels. Utilization of hASIC3 channels decreased at pH values below 8, reducing channel utilization by approximately 50% at physiological pH values. Amiloride specifically blocked the rapid inactivation of hASIC3 channel by rapid activation and the median inhibitory concentration (12.5 ± 3.0) μmol / L. The current-voltage (I-V) curve of hASIC3 channel has a linear relationship (-80 ~ + 80 mV) over a broad voltage range with a turn-on potential of (+43 ± 5) mV. Conclusion The hASIC3 channel, as an acid sensor, may play an important role in the changes of human pH.