• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>American Journal of Physiology >Transmembrane action potential heterogeneity in the canine isolated arterially perfused right atrium: effect of IKr and IKur/Ito block.
【24h】

Transmembrane action potential heterogeneity in the canine isolated arterially perfused right atrium: effect of IKr and IKur/Ito block.

机译：犬离体动脉灌注右心房的跨膜动作电位异质性：IKr和IKur / Ito阻滞的作用。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The role of electrical heterogeneity in development of cardiac arrhythmias is well recognized. The extent to which transmembrane action potential (TAP) heterogeneity contributes to the normal electrophysiology of well-oxygenated atria is not well defined. The principal objective of the present study was to define regional and transmural differences in characteristics of the TAP in isolated superfused and arterially perfused canine right atrial (RA) preparations under baseline, rapidly activating delayed rectifier K(+) current (I(Kr)) block, and combined block of ultrarapid delayed rectifier and transient outward K(+) current (I(Kur)/I(to) block). Superfused preparations that survived generally displayed a triangle-shaped TAP. Exceptions included cells from the crista terminalis, where TAPs with a normal plateau could be recorded. In contrast, most TAPs recorded from throughout the perfused RA displayed a spike-and-dome and/or plateau morphology. The perfused RA displayed a heterogeneous distribution ofrepolarization, V(max), and spike-and-dome morphology along the epicardial and endocardial surfaces as well as transmurally, in the region of the upper crista terminalis. I(Kr) block with E-4031 prolonged repolarization homogeneously in the perfused RA, whereas I(Kur)/I(to) block using low concentrations of 4-aminopyridine abbreviated action potential duration at 90% repolarization heterogeneously, leading to a reduction in dispersion of repolarization. Our data indicate that the electrical heterogeneities, previously described for the canine ventricle, also exist within the atria and that I(Kr) block does not accentuate and I(Kur)/I(to) block reduces RA dispersion of repolarization. Our study also points to major differences in the transmembrane activity recorded using superfused vs. arterially perfused atrial preparations.
机译：电异质性在心律不齐发展中的作用是众所周知的。跨膜动作电位（TAP）异质性对充氧心房的正常电生理的影响程度尚不清楚。本研究的主要目的是确定基线以下隔离的经灌注和经动脉灌注的犬右心房（RA）制剂中TAP的特征的区域和透壁差异，从而迅速激活延迟整流K（+）电流（I（Kr））块，以及超快延迟整流器和瞬态向外K（+）电流（I（Kur）/ I（to）块）的组合块。存活下来的超融合制剂通常显示出三角形的TAP。例外情况是来自crista terminalis的单元格，在那里可以记录具有正常平稳期的TAP。相比之下，从整个灌注RA记录的大多数TAP均显示出峰顶和/或平台形态。灌注的RA在上cr末端区域内沿心外膜和心内膜表面以及透壁显示复极，V（max）和峰顶穹顶形态的异质分布。用E-4031进行的I（Kr）阻断在灌注的RA中均一地延长了复极化，而使用低浓度的4-氨基吡啶的I（Kur）/ I（to）阻断了90％复极化的动作电位持续时间的异质性，从而降低了复极分散。我们的数据表明，先前针对犬心室描述的电异质性也存在于心房内，并且I（Kr）阻滞不加重，I（Kur）/ I（to）阻滞降低了RA复极化的分散性。我们的研究还指出了使用超融合与动脉灌注心房制剂记录的跨膜活性的主要差异。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号