Ionic Basis of the Pacemaker Activity of SA Node Revealed by the Lead Potential Analysis
Ionic Basis of the Pacemaker Activity of SA Node Revealed by the Lead Potential Analysis
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DOI：
10.1007/978-3-642-17575-6_2
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发表时间：
2011-01-01
期刊：
影响因子：
--
通讯作者：
Noma, Akinori
中科院分区：
文献类型：
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作者：
Himeno, Yukiko;Cha, Chae Young;Noma, Akinori
窦房结起搏细胞自发动作电位的离子机制已被讨论了几十年。尽管许多理论研究提出了不同的数学模型，但由于用于开发模型的实验结果的复杂性和变化，尚未达成科学共识。在这里，我们介绍了一种理论方法，在模拟研究中，铅电位分析，使我们能够隔离的修改通道活动的二次效应的个人电流的贡献。我们比较了三种模型，表明不同的离子机制（Himeno等人的模型、Kurata等人的模型以及Maltsev和Lakatta模型），并估计了Ca 2+通过激活INaCa的贡献。最后，在β1-肾上腺素能信号级联反应的SA结细胞模型上讨论了儿茶酚胺刺激的效应，并分析了正性变时性的机制。
Ionic mechanisms of spontaneous action potential in sinoatrial (SA) node pacemaker cells have been discussed for decades. Although a number of theoretical studies have proposed different mathematical models, no scientific consensus has been achieved yet, because of the complexity and variations in experimental findings used for developing models. Here, we introduce a theoretical method in simulation study, the lead potential analysis, which enabled us to isolate the contribution of individual currents from the secondary effect of modified channel activities. We compared three models, suggesting different ionic mechanisms (Himeno et al. model, Kurata et al. model, and Maltsev and Lakatta model), and contributions of Ca2+through activation ofINaCais estimated. Finally, the effect of catecholamine stimulation is discussed based on a SA node cell model with β1-adrenergic signaling cascade and mechanisms of the positive chronotropy are analyzed.