重极化K+流 ITO1和IKs在右心室中心肌中比左心室更大
P G Volders1, K R Sipido, E Carmeliet
1Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University, The Netherlands. p.volders@cardio.azm.nl
Circulation
|January 20, 1999
概括
右心室 (RV) 和左心室 (LV) K+电流的差异解释了动力潜力的变化. 与LV相比,RV中较大的短暂外向K+ (ITO1) 和延迟K+ (IKs) 电流有助于其独特的电气性能.
科学领域:
- 心血管生理学心血管生理学
- 电子生理学 电子生理学
- 心脏离子通道是什么
背景情况:
- 心室动作潜力在持续时间和配置方面呈现区域差异.
- 重极化K+电流解释了左心室自由壁的异质性.
- 右心室和左心室之间的电不均的离子基础尚不清楚.
研究的目的:
- 为了研究右心室 (RV) 和左心室 (LV) 中心肌细胞之间的电差异的离子基础.
- 为了比较RV和LVM细胞中的作用电位特征和关键电流 (ITO1,IKs,IKr,IK1).
主要方法:
- 微电极记录和全细胞电压技术用于从成犬心脏中取出的单个RV和LVM细胞.
- 测量了动作潜力的特性,包括持续时间和对节奏率变化的响应.
- 具体的K+电流 (ITO1,IKs,IKr,IK1) 被量化并在RV和LV之间进行比较.
主要成果:
- 与LV相比,RV动作潜力表现出更深的隙,更短的持续时间 (APD50,APD95) 和较少的速度依赖延长.
- 暂时向外的K+电流 (ITO1) 密度在RV中明显大于LV.
- 与LV相比,延迟K+ (IKs) 电流在RV中大得多,而IKr和IK1在心室之间没有显著差异.
结论:
- 特定电流的差异,特别是ITO1和IKs,可能解释了观察到的动力潜能特征的室间异质性.
- 这些发现增强了在生理条件下对心室动作潜力的表型的理解.
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