低渗条件下小肠上皮细胞调节性细胞容积减小的离子通道机制  

ION CHANNEL MECHANISM OF REGULATORY VOLUME DECREASE IN HUMAN EPITHELIAL CELLS

作　　者：史路平[1] 臧益民[2] 侯晓莉[1] 王军[1] 

机构地区：[1]首都医科大学基础医学院生理学教研室,北京100069 [2]第四军医大学生理学教研室,陕西西安710032

出　　处：《中国应用生理学杂志》2008年第3期356-360,共5页Chinese Journal of Applied Physiology

基　　金：国家自然科学基金资助项目(30670765);北京市自然科学基金资助项目(7072010)

摘　　要：目的:观察人小肠上皮细胞调节性细胞容积减小(RVD)的过程,探讨参与RVD过程的离子通道机制。方法:将培养的人小肠上皮细胞暴露于低渗溶液,利用电子细胞体积测量系统测定细胞平均容积变化过程和离子通道的参与过程;采用RT-PCR方法检测人小肠上皮细胞上离子通道的表达。结果:人小肠上皮细胞具有良好的RVD功能;其RVD过程可被氯通道阻断剂NPPB和钾通道阻断剂四乙铵所阻断;进一步的研究发现,中等电导钙激活性钾通道(IK)的特异性阻断剂Clotrimazole(CLT)(1μmol/L)可以明显抑制细胞的RVD过程,而大电导钙激活性钾通道(BK)和小电导钙激活性钾通道(SK)的特异阻断剂iberiotoxin(100nmol/L)和apamin(100nmol/L)对RVD过程无任何抑制作用。RT-PCR的结果也显示,人小肠上皮细胞只有IK表达,而无SK和BK的表达。结论:人小肠上皮细胞具有RVD功能,RVD过程的完成有赖于氯通道和钾通道的平行激活,而其中参与容积调节的钾通道是中等电导钙激活型钾通道IK。Aim： To observe the regulatory volume decrease（RVD） process of human intestine cells and investigate its ion channel mechanism. Methods： Cultured human intestine cells were exposed to hypotonic solution and the cell volume was measured using Coulter Counter System. RT-PCR was explored to detect the mRNA expression of Ca^2＋ -activated K^＋ channel. Results： Human intestine cells showed a RVD process and this process could be blocked by CI channel blocker NPPB and K＋ channel blocker TEA. Further results demonstrated the subtype of K^＋ channel involved in RVD was an intermediate-conductance, Ca^2 ＋ -activated K^＋ channel（IK） because of its high sensitivity to clotrimazole. RT-PCR results also showed the expression of IK in this cell line. Conclusion： The RVD process of intestine cell was dependent on the parallel activation of CI- channel and K^＋ channel. The subtype of K^＋ channel involved in the RVD process was IK channel.

关 键 词：调节性细胞容积减小 容积敏感性钾通道 容积敏感性氯通道 钙激活性钾通道 

分 类 号：R331[医药卫生—人体生理学]