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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(10nmol/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+80mV电压钳制下其平均电流密度为(85.8±4.6)pA/pF,在80mV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(0.9mV)。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。
This article aims to study the effect of berberine on human colon cancer cell (SW480) chloride channel. Patch clamp technique was used to record berberine-activated SW480 whole-cell chloride current and the physiological and pharmacological properties of this current were studied using hypertonic and hypotonic perfusate and chloride channel blockers. The results showed that when the cells were in isotonic solution, a weak and stable background current could be recorded on SW480 cell membrane; berberine (10nmol / L) could induce the rapid generation of chloride current in SW480 cells with the incubation period of (115.6 ± 21.7) s, with a slight extrinsic advantage. The average current density was (85.8 ± 4.6) pA / pF at + 80mV and the average current density was (71.9 ± 3.5) pA / pF at 80mV voltage clamping. Berberine-activated chloride current had no significant time-dependent inactivation and voltage-dependent inactivation, and its turnover potential was (5.5 ± 1.2) mV, which was close to the equilibrium potential of chloride (0.9mV). Extracellular perfused hypertonic fluid can almost completely inhibit the chloride current activated by berberine, whereas extracellular fluid extracellular perfusion can activate a chloride current, which is similar to the chloride current activated by berberine. Chloride channel blockers NPPB, tamoxifen can significantly inhibit berberine-activated chloride current. The above results suggest that berberine can activate human colon cancer cell chloride channel, and the channel is sensitive to chloride channel blockers NPPB, tamoxifen and cell volume changes.