三磷酸肌醇诱导大鼠背根神经节神经元超极化

Inositol trisphosphate-induced hyperpolarization in rat dorsal root ganglion neurons.

作者信息

Wang Z, Ypey D L, Van Duijn B

机构信息

Department of Physiology, University of Leiden, The Netherlands.

出版信息

FEBS Lett. 1992 Jun 15;304(2-3):124-8. doi: 10.1016/0014-5793(92)80602-d.

DOI:10.1016/0014-5793(92)80602-d

PMID:1618310

Abstract

Inositol 1,4,5-trisphosphate (1,4,5-InsP3) was perfused into rat dorsal root ganglion (DRG) neurons by whole-cell patch-clamp electrodes, while measuring the membrane potential. This operation evoked a transient (2-3 min) membrane hyperpolarization of about -15 mV (from -42 mV) followed by a depolarization. The membrane hyperpolarization was abolished when 30 mM EGTA was perfused together with 1,4,5-InsP3 or when 0.2 mM quinine was added to the bath solution. The hyperpolarizing response was enhanced when a low-Ca2+ EGTA-free intracellular solution was used. Two InsP2 isomers induced a different response. Our results suggest that the hyperpolarization is due to 1,4,5-InsP3-induced Ca2+ release which may trigger Ca-sensitive K+ channels to open. Present results show that cultured DRG neurons are able to respond to 1,4,5-InsP3 perfusion in the whole-cell configuration.

摘要

通过全细胞膜片钳电极将肌醇 1,4,5 -三磷酸（1,4,5 - InsP3）灌流到大鼠背根神经节（DRG）神经元中，同时测量膜电位。此操作诱发了约 -15 mV（从 -42 mV 开始）的短暂（2 - 3 分钟）膜超极化，随后是去极化。当 30 mM 乙二醇双乙醚二胺四乙酸（EGTA）与 1,4,5 - InsP3 一起灌流时，或者当向浴槽溶液中添加 0.2 mM 奎宁时，膜超极化被消除。当使用低钙无 EGTA 的细胞内溶液时，超极化反应增强。两种 InsP2 异构体诱导出不同的反应。我们的结果表明，超极化是由于 1,4,5 - InsP3 诱导的 Ca²⁺释放，这可能触发钙敏感钾通道开放。目前的结果表明，培养的 DRG 神经元能够在全细胞模式下对 1,4,5 - InsP3 灌流做出反应。