Increased intracellular calcium concentration causes electrical turbulence in guinea pig ventricular myocytes
Increased intracellular calcium concentration causes electrical turbulence in guinea pig ventricular myocytes作者机构:Cardio-Electrophysiological Research Laboratory Medical College of Wuha~ University of Science and Technology Wuhan 430081 China Department of Biology Gilead Sciences Inc. Palo Alto California 94304 USA Department of Cardiology Renmin Hospital of Wuhan University Wuhan 430060 China
出 版 物:《Science China(Life Sciences)》 (中国科学(生命科学英文版))
年 卷 期:2011年第54卷第3期
页 面:240-247页
核心收录:
学科分类:0710[理学-生物学] 0830[工学-环境科学与工程(可授工学、理学、农学学位)] 07[理学] 071009[理学-细胞生物学] 071003[理学-生理学]
基 金:supported by the National Natural Science Foundation of China(Grant No. 30870912) Department of Biology,Gilead Sciences,Inc.,USA.
主 题:细胞内钙 钙离子浓度 心室肌 全细胞膜片钳技术 豚鼠 电动 动作电位 心律失常
摘 要:Dysregulation of intracellular Ca2+ homeostasis is associated with various pathological conditions and arrhythmogenesis of the heart.The objective of this study was to investigate the effects of an acute increase in intracellular Ca2+ concentration ([Ca2+] i) on the electrophysiology of ventricular myocytes by mimicking intracellular Ca 2+ overload.The [Ca2+] i was clamped to either a controlled (65-100 nmol L-1) or increased (1 μmol L-1) level.The transmembrane action potentials and ionic currents were recorded using whole-cell patch clamp techniques.We found that the acute increase in [Ca2+] i shortened the action potential duration,reduced the action potential amplitude,maximum depolarization velocity and resting membrane potential,caused delayed after-depolarizations (DADs),and triggered activity--compared with these parameters in the control.The increased [Ca2+] i augmented late I Na in a time-dependent manner,reduced ICaL and IK1,and increased IKr but not IKs.The results of this study can be used to explain calcium overload-induced ventricular arrhythmias.