腺恢复休眠犬肺静脉导电的机制
Tomás Datino1, Laurent Macle, Xiao-Yan Qi
15000 Belanger St East, Montreal, Quebec H1T 1C8, Canada.
Circulation
|February 18, 2010
概括
氨酸通过增加向内调整器电流 (I(KAdo)) 来选择性地超极化肺静脉 (PVs). 这种机制在无线电频率剥离后恢复休眠PV的导电,有助于识别重新连接风险.
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
- 节律失常的机制 节律失常机制
背景情况:
- 氨酸可以在射频剥离后急性地重新连接肺静脉 (PVs),揭示休眠导电.
- 氨酸对光伏和休眠导电的影响的确切机制尚不清楚.
研究的目的:
- 为了研究电生理学机制,通过它,腺恢复导电在犬肺静脉在射频剥离后的导电.
- 为了确定腺的作用是否对PV有选择性,以及它们是否可以逆转休眠导电.
主要方法:
- 记录了狗肺静脉 (PV) 和左心房 (LA) 的动作电位和离子电流,使用微电极和全细胞补丁.
- 使用隔离的,冠状动脉透的LA-PV制剂,经过射频电流的应用.
- 服用腺和监测静止电位,作用电位持续时间和导电性质的变化.
主要成果:
- 氨酸显著地超极化了静止潜力,并增加了最大脱极化速率 (dV/dt(max)) 特别是在PV中,而不是在LA中.
- 氨酸在PVs中比LA更显著地增加了进向整流器电流 (I(KAdo)) .
- 在休眠的PV中,腺通过过极化静止电位,抵消射频诱导的脱极化和消除电压依赖的通道 (I(Na)) 失活,恢复了兴奋性.
结论:
- 腺素选择性地超极化狗的PVs,主要是通过增加I(KAdo).
- 在PV中休眠传导的特点是,与非休眠静脉相比,无线电频率诱导的脱极化较少.
- 腺素诱导的超极化通过减轻I(Na) 失活,恢复了休眠PV的兴奋性,这解释了急性重新连接现象.
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