Koch三角心肌细胞瞬间外向钾电流电生理学特征研究  

Electrophysiologic Characteristics of Ito in Myocytes from Cardiac Koch Triangle

作　　者：任付先[1,2] 牛小麟[2] 韩振华[2] 欧研[2] 凌凤东[3] 周仕胜[4] 李雅杰[4] 

机构地区：[1]河南省濮阳市油田总医院心内科,濮阳457001 [2]西安交通大学医学院附属第二医院心内科 [3]西安交通大学医学院解剖学教研室 [4]大连大学医学研究中心

出　　处：《四川大学学报（医学版）》2009年第6期988-993,共6页Journal of Sichuan University(Medical Sciences)

基　　金：国家自然科学基金(批准号30070307);教育部全国高校博士点基金(No.20030698009)资助

摘　　要：目的探讨Koch三角区心肌细胞瞬时外向钾电流(Ito)电生理学特征。方法采用单细胞膜片钳技术研究家兔Koch三角区心肌细胞Ito电流-电压及电流密度-电压关系曲线、稳态激活以及稳态失活特征。结果①起搏细胞(PC)、过渡细胞α(TCα)、过渡细胞β(TCβ)、心房肌细胞(AC)和浦肯野样细胞(PL)+20 mV时的最大峰值电流(pA)幅值及峰值电流密度(pA/pF)任意两类细胞间差异均有统计学意义(P<0.05);除TCα、TCβ与PL相比外(P>0.05),各类细胞两两比较电流密度(pA/pF)差异均有统计学意义(P<0.05)。②五种细胞稳态激活曲线之半数激活电压(VmIto1/2,mV)在各组细胞间差异均有统计学意义(P<0.05)。但TCα与PC以及TCβ与AC和PL相比差异无统计学意义(P>0.05)。③五种细胞稳态失活曲线之半数失活电压(VhIto1/2,mV)TCα、TCβ与PC和PL分别相比以及PC、AC、PL间相比差异均有统计学意义(P<0.05);TCα与TCβ、TCβ与PC、AC和PL以及PC与PL之间相比差异均有统计学意义(P<0.05),但TCα与PC、AC相比差异无统计学意义(P>0.05)。结论家兔Koch三角区各种心肌细胞之Ito存在异质性;不同心肌细胞间又具有相对特殊性及Ito梯度。Objective To explore the electrophysiologic characteristics of Ito in myocytes from cardiac Koch triangle.Methods Patch clamp technique was employed to investigate the I-V and D-V relation,steady-state activation and inactivation kinetics of Ito from myocytes in Koch triangle of rabbit hearts.Results ① The maximum peak current（pA）and peak current density（pA/pF） at ＋20 mV in PC（pacing cell）,TC（transitonal cell）α,β,AC（atrial cell） and PL（purkinje-like cell） cells were different from each other（P〈0.05）;The cells also had different current density（P〈0.05） except between TCα,TCβ and PL cells（P〉0.05）.②The half activation potential（V mIto1/2,mV）of steady state activation among PC,TCα,TCβ,AC and PL were significantly different（P〈0.05）;The paired comparison between TCα and TCβ,AC and PL,and TCβ and PC showed significant difference（P〈0.05）;but the differences between TCα and PC,TCβ and AC,and TCβ and PL were not significant（P〉0.05）. ③The half inactivation potential（V hIto1/2,mV）of steady state inactivation between TCα and PC,TCα and PL,TCβ and PC,and TCβ and PL demonstrated significant differences（P〈0.05）.The differences of K hIto between TCα and TCβ,PC and PL,TCβ and PC,and AC and PL were significant（P〈0.05）.Conclusions Ito of cardiac cells from Koch triangle in rabbit hearts are heterogeneous,but relatively specified and distributed in different groups.

关 键 词：心律失常 ITO 膜片钳 离子通道 动力学 

分 类 号：R331.38[医药卫生—人体生理学]