摘要/Abstract
摘要： 目的 ·用电生理学方法证明 RIN-14B细胞是一种可用的肠嗜铬细胞（ enterochromaffin cells, EC）模型；明确 Nav1.3通道在其兴奋性调控中的作用。方法 ·在传代培养的 RIN-14B细胞中，用电流钳记录静息电位，观察给予河豚毒素（ tetrodotoxin，TTX）和 Nav1.3阻断剂 ICA-121431后电位变化；用电压钳记录 Na+电流，观察给予 TTX和 ICA-121431后电流变化。结果 · RIN-14B细胞静息膜电位约为 -60 mV，在去极化刺激下发放动作电位。 TTX可以完全阻断动作电位，而 ICA-121431可以浓度依赖性地抑制动作电位。钠通道的激活电流和失活电流被 TTX完全阻断，激活电流被 ICA-121431浓度依赖性抑制。结论 · RIN-14B细胞是一种可兴奋细胞，TTX敏感型的钠通道介导其动作电位的发放， Nav1.3参与调控其兴奋性，与 EC特征相似；说明 RIN-14B细胞是一种良好的 EC模型。
关键词: RIN-14B细胞, 钠通道亚型 Nav1.3, 肠嗜铬细胞, 河豚毒素, ICA-121431
Abstract:
Objective · To provide electrophysiological evidence for RIN-14B cells as an useful model of enterochromaffin cells (EC) and to study the role of Nav1.3 channel in the control of its excitability. Methods · Resting membrane potential was recorded and the effects of TTX and ICA-121431 were examinedcurrent-clamp in cultured RIN-14B cells. The effects of TTX and ICA-121431 on Na+ current of RIN-14B cells were examinedvoltage-clamp. Results · RIN-14B cells had a resting potential around -60 mV and fired action potentials when stimulated with depolarizing current pulses. The action potential was completely blockedTTX and inhibitedICA-121431 in a dose-dependent manner. TTX blocked activation and inactivation of sodium current. In addition ICA-121431 dose-dependently inhibited activation of Na+ current. Conclusion · The action potential of RIN-14B cells is inducedTTX-sensitive sodium channel and the excitability is controlledNav1.3. These results suggest RIN-14B cells are similar to EC and it may be a good model of EC.
Key words: RIN-14B cell, Nav1.3, enterochromaffin cell, tetrodotoxin, ICA-121431
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