Role of the Steady-State Na+ Channel Current in Pacemaker Depolarizations in Young Embryonic Chick Ventricular Myocytes

The Japanese Journal of Pharmacology

Nicholas Sperelakis²  Takashi Ban¹  Takeshi Fujita³  Hideaki Sada¹  Yoshio Ebina³ 

[1] Department of Pharmacology, School of Medicine, Fuculty of Engineering, Yamaguchi University;Department of Molecular and Cellular Physiology, School of Medicine, University Cincinnati;Department of Electric Engineering, Fuculty of Engineering, Yamaguchi University

关键词: Heart;    Voltage-clamp;    Development;    Automaticity;    Simulation;   

DOI  :  10.1254/jjp.69.159

学科分类：药理学

来源: Nihon Yakuri Gakkai Henshuubu / Japanese Pharmacological Society

【 摘 要 】

References(13)Cited-By(1)To assess the age-related changes in kinetic properties of the cardiac Na+ channel, whole-cell voltage-clamp (v-c) experiments were conducted using 3-, 10- and 17-day-old embryonic chick ventricular heart cells. In line with the first-order kinetic model, kinetic parameters for the activation and inactivation of the channel were determined from the v-c results. Simulation studies using kinetic parameters so determined have reproduced the current-voltage relations and the steady-state inactivation characteristics observed in cells in the three age groups. The rate of depolarization of the simulated action potentials was also comparable to that experimentally recorded. In conclusion, the steady-state Na+ conductance can play a significant role in the automatic depolarizations observed in young embryonic ventricular cells.

【 授权许可】

Unknown