目的:研究抗癌药顺铂对低分化鼻咽癌细胞(CNE-2Z)氯通道的激活作用以及该电流的特性。方法:采用膜片钳技术记录顺铂激活的CNE-2Z细胞全细胞电流;离子置换法等方法分析通道的特性。结果:细胞外灌流5μmol/L的顺铂诱发CNE-2Z细胞产生一个有明显外向优势的电流,电流的翻转电位为(-6.69±0.51)mV,接近氯离子平衡电位(-0.9mV)。该电流的激活依赖于细胞内ATP。顺铂激活的细胞膜氯通道对阴离子的通透性顺序为:I^-≥Br^-〉Cl^-〉gluconate。氯通道阻断剂tamoxifen完全抑制该电流。结论:抗癌药顺铂可以激活一个电流特征与容积激活性氯通道相似的氯通道。
AIM: To study the activation and the properties of chloride channels activated by the antineoplastic agent cisplatin (cDDP) in nasopharyngeal carcinoma (CNE -2Z) cells. METHODS: The whole -cell patch clamp tech- nique was used to record chloride currents. The characteristics of the channel were investigated using ion - exchange and pharmacological methods. RESULTS : A chloride current was activated by extracellular application of cDDP (5 μmol/L). The current showed significant outward rectification. The reversal potential of the current was close to the calculated equilibrium potential for Cl- (ECl = -0. 9 mV). The activation of the chloride channel was dependent on the existence of the intracelhdar ATP. The permeability sequence of the four anions was I^- ≥ Br^- 〉 Cl^ - 〉 gluconate. The current was almost completely inhibited by extracellular application of chloride channel blocker tamoxifen (30μmol/L). CONCLUSION: Antineoplastic agent cDDP can activate a chloride channel with characteristics similar to the volume - activated chloride channel in CNE -2Z cells.