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小檗碱激活人结肠癌细胞容积敏感的氯通道

刘善文, 李媛, 李华荣, 马文波, 潘廷才, 朱林燕, 叶文才, 王立伟^*, 陈丽新^*

暨南大学 医学院生理学系；医学院药理学系；药学院，广州 510632

摘要

本文旨在研究小檗碱对人结肠癌细胞(SW480)氯通道的作用。采用膜片钳技术记录小檗碱激活的SW480全细胞氯电流，并用高渗和低渗灌流液、以及氯通道阻断剂研究该电流的生理学和药理学特性。结果显示，当细胞处在等渗液中，可在SW480细胞膜上记录到微弱且稳定的背景电流；小檗碱(10 nmol/L)可诱发SW480细胞迅速产生氯电流，该电流的潜伏期为(115.6 ± 21.7) s，具有微弱的外向优势，在+80 mV电压钳制下其平均电流密度为(85.8 ± 4.6) pA/pF，在−80 mV电压钳制下其平均电流密度为(−71.9 ± 3.5) pA/pF。小檗碱激活的氯电流没有明显的时间依赖性失活和电压依赖性失活，其翻转电位为(−5.5 ± 1.2) mV，接近氯离子的平衡电位(−0.9 mV)。细胞外灌流高渗液可几乎完全抑制小檗碱激活的氯电流，而低渗液细胞外灌流可激活一个氯电流，其特性与小檗碱激活的氯电流相似。氯通道的阻断剂NPPB、tamoxifen 能显著地抑制小檗碱激活的氯电流。以上实验结果提示，小檗碱可以激活人结肠癌细胞氯通道，且该通道对氯通道阻断剂NPPB、tamoxifen和细胞容积变化敏感。

关键词： 小檗碱; 人结肠癌细胞; 氯通道; 膜片钳技术

分类号：R735.35

[Berberine activates volume-sensitive chloride channel in human colorectal carcinoma cells.] [Article in Chinese]

LIU Shan-Wen, LI Yuan, LI Hua-Rong, MA Wen-Bo, PAN Ting-Cai, ZHU Lin-Yan, YE Wen-Cai, WANG Li-Wei^*, CHEN Li-Xin^*

Department of Physiology of Medical College； Department of Pharmacology of Medical College； College of Pharmacy, Jinan University, Guangzhou 510632, China

Abstract

The present study aimed to clarify the effect of berberine on the chloride channels in human colorectal carcinoma cells (SW480). The whole-cell patch clamp technique was used to detect the Cl− current activated by berberine. The physiological and pharmacological characteristics of the current were clarified by changing the osmotic pressure of extracellular perfusate and applying chloride channel blockers. The results showed that, under isotonic conditions, the background current of SW480 cells was weak and stable. A large current was induced by perfusing the cells with the isotonic solution containing berberine (10 nmol/L), current density being (85.8 ± 4.6) pA/pF at +80 mV, (−71.9 ± 3.5) pA/pF at −80 mV, with a latency of (115.6 ± 21.7) s. The chloride current showed weak outward rectification and negligible time- and voltage-dependent inactivation. The reversal potential (−5.5 mV ± 1.2 mV) of the current was close to the calculated equilibrium potential for Cl− (ECl = –0.9 mV). Experiments under different osmotic pressures showed that the properties of hypotonicity-activated current recorded in SW480 cells were similar to those of the current induced by berberine, and hypertonic solutions suppressed the berberine-induced current by (98.6 ± 2.3)%. On the other hand, berberine-induced Cl− current was significantly inhibited by the chloride channel blockers NPPB (100 µmol/L) and tamoxifen (20 μmol/L), with the inhibition ratios of (83.1 ± 3.6)% and (95.6 ± 1.2)% respectively. These results suggest that berberine can activate the chloride channels that are sensitive to NPPB and tamoxifen, as well as the changes of cell volume in human colorectal carcinoma cells.

Key words: berberine; human colorectal carcinoma cells; chloride channels; patch-clamp techniques

收稿日期：2011-04-21　　录用日期：2011-07-18

通讯作者：王立伟,陈丽新　　E-mail: chenlixinw@sohu.com,wangliweic@sohu.com

引用本文：

刘善文, 李媛, 李华荣, 马文波, 潘廷才, 朱林燕, 叶文才, 王立伟, 陈丽新. 小檗碱激活人结肠癌细胞容积敏感的氯通道[J]. 生理学报 2011; 63 (6): 517-524.

LIU Shan-Wen, LI Yuan, LI Hua-Rong, MA Wen-Bo, PAN Ting-Cai, ZHU Lin-Yan, YE Wen-Cai, WANG Li-Wei, CHEN Li-Xin. [Berberine activates volume-sensitive chloride channel in human colorectal carcinoma cells.] [Article in Chinese]. Acta Physiol Sin 2011; 63 (6): 517-524 (in Chinese with English abstract).