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ATP激活鼻咽癌细胞氯电流并减小细胞容积

何庆丰, 陈丽新, 毛建文, 孙雪荣, 李攀, 钟平, 聂思槐, Jacob T, 王立伟

广东医学院细胞生物学研究室.广东,湛江 524023；广东医学院生理研究室.广东,湛江 524023；School of Biosciences,Cardiff University,Cardiff CF10 3US

摘要

采用全细胞膜片钳技术和细胞容积测量技术,在低分化鼻咽癌细胞株CNE--2Z上观察ATP诱导的Cl~(-)电流的特性及其对细胞容积的影响。细胞外微摩尔水平的ATP以剂量依赖性的方式激活一个具有弱外向整流特性、没有时间依赖性失活的电流。此电流反转电位[(--0.05±0.03)mV]接近Cl~(-)的平衡电位(--0.9mV)。用葡萄糖酸置换细胞外液Cl~(-)后,ATP激活的电流明显减小并且反转电位发生改变。氯通道抑制剂NPPB (200#mu#mol/L)可以抑制这一电流[(81.03±9.3)%]。此电流亦可被嘌呤受体(P2Y)拮抗剂反应蓝2抑制[(67.39±5.06)%]。50#mu#mol/L的ATP使在等渗状态下的细胞容积缩小,替代和耗竭细胞外、内的Cl~(-)后,ATP的此一作用消失。结果提示细胞外微摩尔水平的ATP可通过兴奋P2Y受体激活氯通道而产生与细胞容积调节相关的Cl~(-)电流。

关键词： 氯通道; 腺苷三磷酸; 受体,嘌呤的; 膜片钳技术; 细胞大小

Activation of chloride current and decrease of cell volume by ATP in nasopharyngeal carcinoma cells

He Qingfeng, Chen Lixin, Mao Jianwen, Sun Xuerong, Li Pan, Zhong Ping, Nie Sihuai, Jacob T, Wang Liwei

Laboratory of Cell Biology,Guangdong Medical College.Zhanjiang 524023,Guangdong；China；School of Biosciences,Cardiff University,Cardiff CF10 3US

Abstract

Whole-cell patch clamp and cell volume measurement techniques were used to investigate the ATP-activated chloride current and the ATP effect on cell volume in nasopharyngeal carcinoma cells. Extracellular application of ATP in micromolar concentrations activated a current with the properties of modest outward rectification and negligible time-dependent inactivation in a dose-dependent manner. The current reversed at a potential [(-0.05±0.03)mV] close to the Cl~(-) equilibrium potential (-0.9mv). Substitution of Cl~(-) with gluconate in the extracellular solution decreased the ATP-activated current and shifted the reversal potential positively. NPPB, one of the chloride channel blockers, inhibited the current by (81.03±9.36)%. The current was also depressed by the P2Y purinergic receptor antagonist reaction blue 2 by (67.39±5.06)%. ATP (50#mu#mol/L) decreased the cell volume under the isotonic condition. Depletion of extracellular and intracellular Cl~(-) abolished the ATP effect on cell volume. The results suggest that extracellular ATP of micromolar scales can induce a chloride current associated with cell volume regulation by activation of chloride channel through binding to purinergic receptor P2Y.

Key words: chloride channels;adenosine triphosphate;receptors,purinergic;patch clamp technique;cell size

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引用本文：

何庆丰, 陈丽新, 毛建文, 孙雪荣, 李攀, 钟平, 聂思槐, Jacob T, 王立伟. ATP激活鼻咽癌细胞氯电流并减小细胞容积[J]. 生理学报 2004; 56 (6): .

He Qingfeng, Chen Lixin, Mao Jianwen, Sun Xuerong, Li Pan, Zhong Ping, Nie Sihuai, Jacob T, Wang Liwei. Activation of chloride current and decrease of cell volume by ATP in nasopharyngeal carcinoma cells. Acta Physiol Sin 2004; 56 (6): (in Chinese with English abstract).