低分化鼻咽癌细胞的自发氯电流特性

摘要

目的：研究自发的低分化鼻咽癌细胞（ CNE-2Z）氯电流特征。方法采用全细胞膜片钳记录自发的CNE-2Z细胞氯电流，通过去除电极内液中的ATP、细胞外灌流氯离子通道阻断剂或高渗液等方法观察并分析电流的特性。结果细胞处于等渗环境中可自发激活一个具有明显外向优势的电流，该电流没有明显的时间依赖性失活，电流的翻转电位为（-7．6±0．9） mV，接近氯离子平衡电位（-0．9 mV）。该电流的激活依赖于细胞内ATP。氯通道阻断剂ATP可抑制该电流，且其对外向电流的抑制作用大于内向电流。细胞外灌流高渗液对该电流有明显抑制作用。结论 CNE-2Z细胞处于等渗环境中可自发激活一个电流特征与容积敏感性氯通道相似的氯通道。%Objective To explore the spontaneous chloride currents in poorly differentiated nasopharyngeal carcinoma ( CNE-2Z ) cells.Methods The whole-cell patch-clamp technique was used to detect the Cl -currents.The characteris-tics of the currents were clarified by ATP depletion in the pipette solution , extracellular applications of chloride channel blockers and hypertonic challenges .Results A chloride current was activated spontaneously and occasionally in the iso-tonic solution in CNE-2Z cells, showing significant outward rectification but no time-dependent inactivation .The reversal potential of the current was (-7.6 ±0.9) mV, which was close to the calculated equilibrium potential for Cl -.The in-duction of the chloride channel was dependent on the intracellular ATP .The spontaneous chloride currents were inhibited by extracelluar applications of the chloride channel blocker ATP and 47% hypertonic solution .Conclusion A chloride channel can be activated spontaneously and occasionally under the isotonic condition in CNE -2Z cells, showing the similar characteristics to the volume-sensitive chloride channel .