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Updated: Jun 17, 2026

Isolation and Functional Characterization of Human Ventricular Cardiomyocytes from Fresh Surgical Samples
Published on: April 21, 2014
[Electrophysiologic characteristics of Ito in myocytes from cardiac Koch triangle]
Fu-Xian Ren1, Xiao-Lin Niu, Zhen-Hua Han
1Department of Cardiology, Second Affiliated Hospital, Xi'an Jiaotong University, College of Medicine, Xi'an 710004, China.
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) alpha,beta, 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 TCalpha, TCbeta and PL cells (P > 0.05). (2) The half activation potential (V(mIto1/2), mV) of steady state activation among PC, TCalpha, TCbeta, AC and PL were significantly different (P < 0.05); The paired comparison between TCalpha and TCbeta, AC and PL, and TCbeta and PC showed significant difference (P < 0.05); but the differences between TCa and PC, TCbeta and AC, and TCbeta and PL were not significant (P > 0.05). (3) The half inactivation potential (V5(hIto1/2), mV) of steady state inactivation between TCalpha and PC, TCa and PL, TCbeta and PC, and TCbeta and PL demonstrated significant differences(P < 0.05). The differences of K(hIto) between TCalpha and TCbeta, PC and PL, TCbeta 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.
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