Sodium current in human intestinal interstitial cells of Cajal
Sodium current in human intestinal interstitial cells of Cajal
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DOI：
10.1152/ajpgi.00152.2003
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发表时间：
2003-12-01
影响因子：
4.5
通讯作者：
Farrugia, G
中科院分区：
文献类型：
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作者：
Strege, PR;Ou, YJ;Farrugia, G
Cajal间质细胞（ICC）产生正常胃肠运动所需的电慢波。在人肠ICC中表达的离子电导是未知的。本研究的目的是确定人肠ICC中Na（+）电流的表达，并确定Na（+）电流对慢波的影响。通过使用单细胞RT-PCR，通过c-kit mRNA的存在来验证视觉识别的、新鲜解离的单个ICC。从在脉冲方案之间保持在-100 mV的膜片钳ICC记录标准全细胞电流。在人小肠ICC中发现了Na（+）电流。电流在-55 mV激活，在-30 mV达到峰值。细胞外N-甲基-D-葡糖胺消除和QX-314（500 μ M）阻断Na（+）电流，但硝苯地平和Ni（2+）没有。Na（+）电流被切应力激活。单细胞RT-PCR检测单个人小肠ICC中Na（+）α亚基SCN 5A的mRNA。利多卡因（200 μ M）和QX-314（500 μ M）降低慢波频率，而牵张增加慢波频率。机械敏感性Na（+）通道电流存在于人小肠ICC中，并且似乎在控制肠运动功能中起作用。
Interstitial cells of Cajal (ICC) generate the electrical slow wave required for normal gastrointestinal motility. The ionic conductances expressed in human intestinal ICC are unknown. The aim of this study was to determine expression of a Na(+) current in human intestinal ICC and to determine the effects of the Na(+) current on the slow wave. Visually identified, freshly dissociated, single ICC were verified by the presence of c-kit mRNA by using single-cell RT-PCR. Standard whole cell currents were recorded from patch-clamped ICC held at -100 mV between pulse protocols. A Na(+) current was identified in human intestinal ICC. The current activated at -55 mV and peaked at -30 mV. Extracellular N-methyl-D-glucamine abolished and QX-314 (500 muM) blocked the Na(+) current, but nifedipine and Ni(2+) did not. The Na(+) current was activated by shear stress. Single-cell RT-PCR detected mRNA for the Na(+) alpha-subunit SCN5A in single human intestinal ICC. Lidocaine (200 mum) and QX-314 (500 muM) decreased slow wave frequency, and stretch increased slow wave frequency. A mechanosensitive Na(+) channel current is present in human intestinal ICC and appears to play a role in the control of intestinal motor function.