摘要
目的探讨钩吻总碱对肝癌(HepG_2)细胞氯通道的激活作用及对细胞容积的影响。方法活细胞图像法观察记录钩吻总碱作用后HepG_2细胞容积的变化;全细胞膜片钳技术记录钩吻总碱对HepG_2细胞膜电流的作用,通过细胞外灌流高渗液,氯通道阻断剂tamoxifen和5-硝基-2-(3-苯丙胺)苯甲酸(NPPB)研究电流的生理学及药理学特性。结果细胞外灌流钩吻总碱50min,细胞体积减小(12.48±2.2)%(P<0.01),该现象可被氯通道阻断剂tamoxifen抑制。膜片钳结果显示,细胞外灌流钩吻总碱(2μmol·L^(-1))可激活HepG_2细胞膜氯电流,该电流有明显外向优势,无电压及时间依赖性失活,其翻转电位为(-3.21±0.67)mV,接近氯离子平衡电位(-0.9mV),可被氯通道阻断剂tamoxifen和NPPB抑制,细胞外灌流47%高渗溶液亦可明显抑制该电流。结论钩吻总碱可引起肝癌HepG_2细胞体积缩小,诱导凋亡性容积缩小(AVD)发生,该作用可被氯通道阻断剂明显抑制,提示氯通道可能为钩吻总碱抗癌作用的靶点之一。
Aim To investigate the effect of gelsemium alkaloids on chloride channels and cell volume in he-patic carcinoma cells. Methods The time-lapse live cell imaging and whole-cell patch clamp techniques were used respectively to detect the volume changes and currents induced by gelsemium alkaloids in HepG2 cells. Results It was found that the cell volume was decreased by (12. 48 ± 2. 2) % (P<0. 01) when ex-posed to gelsemium alkaloids for 50 min and this phe-nomenon could be inhibited by the chloride channel blocker tamoxifen. It was shown by whole-cell patch clamping that a chloride current could be evoked by extracellular application of gelsemium alkaloids ( 2μmol·L-1 ) . The current was outward-rectified with-out obvious voltage- and time-dependent inactivation. The reversal potential of the current was ( -3. 21 ± 0. 67) mV ,which was close to the equilibrium poten-tial of chloride. The extracellular application of the chloride blockers, tamoxifen and 5-notro-2-(3-phenyl-propylamino)benzoic acid (NPPB), and 47% hyper-tonic solution inhibited the current significantly ( P <0. 01 ) . Conclusion Gelsemium alkaloids could acti-vate chloride channels and induce a volume decrease ( named apoptotic volume decrease, AVD) , and these effect could be inhibited by chloride channel blockers. The results suggest that the chloride channel can be one of the targets of gelsemium alkaloids in their anti-cancer action.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2015年第11期1529-1535,共7页
Chinese Pharmacological Bulletin
基金
国家自然科学基金资助项目(No 81273539
81173064)
教育部基金资助项目(No 20124401110009)
广州市科技计划基金资助项目(No 2013J450015)
东莞科技计划基金资助项目(No 2011108102006)
关键词
钩吻总碱
肝癌细胞
凋亡性容积缩小
膜片钳技术
氯通道
氯通道阻断剂
gelsemium alkaloids
hepatic carcinoma cells
apoptotic volume decrease
patch clamp techniques
chloride channels
chloride channel blockers
