CAJ | 학술논문

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,此电流的反转电位[(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 μmol/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 μmol/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的这一作用消失.这些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.
채용전세포막편겸기술화세포용적측량기술,재저분화비인암세포주CNE-2Z상관찰ATP유도적Cl-전류적특성급기대세포용적적영향.세포외미마이수평적ATP이제량의뢰성적방식격활일개구유약외향정류특성,몰유시간의뢰성실활적전류,차전류적반전전위[(0.05±0.03)mV]접근Cl-적평형전위(-0.9mV).용포도당산치환세포외액Cl-후,ATP격활적전류명현감소병차반전전위발생개변.록통도억제제NPPB(200 μmol/L)가이억제저일전류[(81.03±9.3)%].차전류역가피표령수체(P2Y)길항제반응람2억제[(67.39±5.06)%].50 μmol/L적ATP사재등삼상태하적세포용적축소,체대화모갈세포외、내적Cl-후,ATP적저일작용소실.저사결과제시세포외미마이수평적ATP가통과흥강P2Y수체격활록통도이산생여세포용적조절상관적Cl-전류.
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 (-0.9 mV). 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 purinoceptor antagonist, reactive blue 2, by (67.39±5.06)%.ATP (50 μmol/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 purinoceptor P2Y.