Regulation of excitability of smooth muscle by endothelium in cerebral arterioles -Intercellular humoral and electrical signal transduction-

脑小动脉内皮细胞对平滑肌兴奋性的调节-细胞间体液和电信号转导-

• 批准号: 13670108
• 负责人: YAMAZAKI Jun
• 金额: $ 2.18万
• 依托单位: Fukuoka Dental College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13670108/
• 关键词: smooth muscle; endothelium; nitric oxide; gap junction; chloride current; arteriole; patch-clamp; electrophysiology; コンダクタンス; 対称性; コネキシン; エンドセリン; Cl^-電流

In the present research project, I attended to investigate regulation of smooth muscle cells (SMCs) by endothelium (EC) via cell-to-dell humoral and electrical communication, using arterioles dissected from the rat cerebral pial membrane. 1. By means of the perforated whole-cell patch-clamp technique, a hyperpolarizing voltage step applied to SMC in voltage-clamp mode elicited the inward current through the SMC membrane as well as the outward current through EC membrane (gap-junctional current), which was attenuated by α-glycyrrhetinic acid (α-GA). This result suggests the existence of electrical coupling between SMC and EC. 2. To investigate the role of humoral factors, I examined the effect of bradykinin on endothelin-1 (ET-1)-evoked oscillatory Ca2+-activated Cl- currents (I_<Cl(Ca)>) under the condition where junctional current was abolished by α-GA. As a result, bradykinin was shown to release nitric oxide to an extracellular space, and to inhibit an ET-1-evoked I_<Cl(Ca)> in smooth muscle cells. 3. Gap junction was demonstrated to exist between adjacent SMCs. The junctional current declined time-dependently. This phenomenon was voltage-dependent, and symmetrical for the positive and negative junctional voltages. On the other hand, the junctional current between SMC and EC exerted asymmetrical voltage-dependency. Gap-conductance could be estimated according to the macroscopic current measured, series resistance created by the electrodes, and assumption that gap-resistance among the surrounded cells should be connected in parallel. Single-channel conductance could also be calculated under the condition where a gap-junction inhibitor was performed at a modest concentration. All of these techniques are likely to enable to analyze various types of communication between cells of microvasculature with intact structure.

在本研究项目中，我参加了调查的平滑肌细胞（SMCs）的内皮细胞（EC）通过细胞到细胞的体液和电通信的调节，使用小动脉从大鼠脑软膜解剖。1.应用穿孔全细胞膜片钳技术，在电压钳模式下，对SMC施加一个超极化电压阶跃，可引起SMC膜的内向电流和EC膜的外向电流（缝隙连接电流），α-甘草次酸（α-GA）可减弱该电流。这一结果表明SMC和EC之间存在电耦合。2.为了探讨体液因素的作用，我们在α-GA阻断连接电流的条件下，观察了缓激肽对内皮素-1（ET-1）诱发的振荡性钙激活氯电流（I_<Cl（Ca）>）的影响。结果表明，缓激肽释放一氧化氮到细胞外空间，并抑制ET-1诱导的平滑肌细胞I_<Cl（Ca）>。3.平滑肌细胞之间存在缝隙连接。结电流随时间的延长而下降。这种现象是电压依赖性的，并且对于正结电压和负结电压是对称的。另一方面，SMC和EC之间的连接电流表现出不对称的电压依赖性。间隙电导可以根据所测量的宏观电流、由电极产生的串联电阻以及被包围的细胞之间的间隙电阻应该并联的假设来估计。单通道电导也可以计算的条件下，其中间隙连接抑制剂在适度的浓度进行。所有这些技术都有可能使分析具有完整结构的微血管系统的细胞之间的各种类型的通信成为可能。

项目成果

Yamazaki, Kitamura: "Cell-to-cell communication via nitric oxide modulation of oscillatory Cl-currents in rat intact cerebral arterioles"J.Physiol.(Lond.). 536.1. 67-78 (2001)

Yamazaki, Kitamura：“通过一氧化氮调节大鼠完整脑小动脉中振荡氯电流的细胞间通讯”J.Physiol.（伦敦）。

Yamazaki, Kitamura: "Cell-to-cell communicationvia nitric oxide modulation of oscillatory Clcurrents in rat intact cerebral arterioles"J.Physiol.(Lond.). 536.1. 67-78 (2001)

Yamazaki, Kitamura：“通过一氧化氮调节大鼠完整脑小动脉中振荡电流的细胞间通讯”J.Physiol.（伦敦）。

J. Yamazaki and K. Kitamura: "Cell-to-cell communication via nitric oxide modulation of oscillatory Cl- currents in rat intact cerebral arterioles"J. Physiol. (Lond.). 536.1. 67-78 (2001)

J. Yamazaki 和 K. Kitamura：“通过一氧化氮调节大鼠完整脑小动脉中振荡氯电流的细胞间通讯”

Kitamura, Yamazaki: "Chloride channels and their and their functional roles in smooth muscle tone in the vasculature"Jpn.J.Pharmacol.. 85. 351-357 (2001)

Kitamura, Yamazaki：“氯离子通道及其在脉管系统平滑肌张力中的功能作用”Jpn.J.Pharmacol.. 85. 351-357 (2001)

J.Yamazaki: "Cell-to-cell communication via nitric oxide modulation of oscillatory Cl-currents in rat intact cerebral arterioles"J Physiol. (Lond.). 536. 67-78 (2001)

J.Yamazaki：“通过一氧化氮调节大鼠完整脑小动脉中振荡氯电流的细胞间通讯”J Physiol。