通过构造性活跃的GIRK通道阻塞在老鼠中选择性抑制肺静脉刺激性
Ian Findlay1, Côme Pasqualin2, Angèle Yu2
1Laboratoire de Pharmacologie, Faculté de Pharmacie, Université de Tours, 37200 Tours, France.
International journal of molecular sciences
|September 9, 2023
概括
阻断肺静脉 (PV) 中的与G蛋白结合的内向整正 (GIRK) 通道,消除了动作潜力,为心房治疗提供了一个新的标. 这项研究发现,GIRK通道在PV中具有构成性活性,与左前庭不同.
科学领域:
- 电子生理学 电子生理学
- 心血管研究研究心血管研究
- 分子心脏病学分子心脏病学
背景情况:
- 肺静脉 (PV) 是导致心房动的子宫外心跳的主要来源.
- 与G蛋白结合的内向整合通道 (GIRK) 在心脏电活动中起作用.
研究的目的:
- 研究GIRK通道在老鼠肺静脉 (PV) 和左心房 (LA) 中的作用和分布.
- 确定光伏中的GIRK通道是否可以作为从LA中断电的分子目标.
主要方法:
- 从老鼠的LA和PV同时进行细胞内微电极记录.
- 来自孤立的PV和LA肌细胞的贴片记录.
- 使用GIRK通道阻断剂tertiapin-Q.Q的应用.
- 对于GIRK子单位表达的西方斑点分析.
- 使用ROMK1和KCa1.1通道阻断剂的实验,以排除非目标效应.
主要成果:
- 在LA中,tertiapin-Q诱导了动作潜能持续时间 (APD) 的延长,并消除了PV动作潜能的超越,这表明在两个组织中都有构成性活跃的GIRK通道.
- 补丁研究显示,tertiapin-Q抑制了PV细胞的基底内向整正电流,但对LA细胞的影响很小.
- 西方斑点分析显示,与LA心肌细胞相比,PV心肌细胞中的GIRK4亚单元表达显著更高.
结论:
- 在大鼠PV和LA中,GIRK通道具有构成性活性,GIRK4亚单元在PV心肌细胞中表达更大.
- 封锁GIRK频道选择性地取消了PV的行动潜力,但不是LA.
- GIRK通道代表了实现PV与LA的电断开的潜在分子标,为心房的治疗提供了一种新的方法.
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