丹参酮ⅡA对低分化鼻咽癌细胞氯通道的激活作用

Activation of chloride channels by tanshinone ⅡA in nasopharyngeal carcinoma cells

目的研究丹参酮ⅡA对低分化鼻咽癌细胞(CNE-2Z)氯通道的激活作用并分析该通道的生理学和药理学特性。方法采用膜片钳全细胞记录技术记录丹参酮ⅡA激活的CNE-2Z细胞氯电流,细胞外高张刺激或灌流氯离子通道阻断剂,观察并分析电流的特性。结果细胞外灌流1nmol.L-1的丹参酮ⅡA激活CNE-2Z细胞产生一个具有明显外向优势的电流,该电流没有明显的电压依赖性和时间依赖性的失活,电流的翻转电位为(-5.9±0.2)mV,接近氯离子平衡电位。渗透性容积缩小可以完全抑制该电流,氯通道阻断剂NPPB可以部分抑制该电流。结论丹参酮ⅡA激活鼻咽癌细胞膜上的氯通道,诱导氯电流,该电流具有容积敏感性。

Aim To study the activation and the prop- erties of chloride channels activated by tanshinone 11 A （Tan 11 A ） in nasopharyngeal carcinoma （CNE-2Z） cells. Methods The whole-cell patch clamp technique was used to record chloride currents. The chloride cur- rents were characterized by extracellular applications of hypertonic challenges and the chloride channel block- ers. Results A chloride current was activated by ex- tracellular applications of tanshinone II A （ 1 nmol · L-1）. The current showed significant outward rectifica- tion and was reversed at a potential （ -5.9 ：l： 0. 2 mV） close to the calculated equilibrium potential for C1-. There was no significant time- or voltage-dependent in-activation. Hypertonicity-induced cell shrinkages or extracellular applications of the chloride channel bloc- ker 5-nitro-2-（ 3-henylpropylamino ） benzoic acid （NPPB） inhibited significantly tanshinone 1/A-activa- ted chloride currents. Conclusions Tanshinone 11 A can induce a C1- current by activation of the chloride channels on the plasmic membrane of CNE-2Z cells. The tanshinone II A-induced current is volume-sensi- tive.