过氧化氢对豚鼠心室肌细胞持续性钠电流的影响。

Effect of hydrogen peroxide on persistent sodium current in guinea pig ventricular myocytes.

作者信息

Ma Ji-Hua, Luo An-Tao, Zhang Pei-Hua

机构信息

Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and Technology, Wuhan 430080, China.

出版信息

Acta Pharmacol Sin. 2005 Jul;26(7):828-34. doi: 10.1111/j.1745-7254.2005.00154.x.

DOI:10.1111/j.1745-7254.2005.00154.x

PMID:15960889

Abstract

AIM

To study the effect of hydrogen peroxide (H2O2) on persistent sodium current (I(Na.P)) in guinea pig ventricular myocytes.

METHODS

The whole-cell, cell-attached, and inside-out patch-clamp techniques were applied on isolated ventricular myocytes from guinea pig.

RESULTS

H2O2 (0.1 mmol/L, 0.5 mmol/L and 1.0 mmol/L) increased the amplitude of whole-cell I(Na.P) in a concentration-dependent manner, and glutathione (GSH 1 mmol/L) reversed the increased I(Na.P). H2O2 (1 mmol/L) increased persistent sodium channel activity in cell-attached and inside-out patches. The mean open probability was increased from control values of 0.015+/-0.004 and 0.012+/-0.003 to 0.106+/-0.011 and 0.136+/-0.010, respectively (P< 0.01 vs control). They were then decreased to 0.039+/-0.024 and 0.027+/-0.006, respectively, after the addition of 1 mmol/L GSH (P<0.01 vs H2O2). The time when open probability began to increase and reached a maximum was shorter in inside-out patches than that in cell-attached patches (4.8+/-1.0 min vs 11.5+/-3.9 min, P<0.01; 9.6+/-1.6 min vs 18.7+/-4.7 min, P<0.01).

CONCLUSION

H2O2 increased the I(Na.P) of guinea pig ventricular myocytes in a concentration-dependent manner, possibly by directly oxidating the cell membrane.

摘要

目的

研究过氧化氢（H2O2）对豚鼠心室肌细胞持续性钠电流（I(Na.P)）的影响。

方法

采用全细胞膜片钳、细胞吸附膜片钳和内面向外膜片钳技术，对豚鼠分离的心室肌细胞进行研究。

结果

H2O2（0.1 mmol/L、0.5 mmol/L和1.0 mmol/L）以浓度依赖性方式增加全细胞I(Na.P)的幅度，谷胱甘肽（GSH 1 mmol/L）可逆转I(Na.P)的增加。H2O2（1 mmol/L）增加细胞吸附膜片和内面向外膜片中持续性钠通道的活性。平均开放概率分别从对照值0.015±0.004和0.012±0.003增加到0.106±0.011和0.136±0.010（与对照相比，P<0.01）。加入1 mmol/L GSH后，它们分别降至0.039±0.024和0.027±0.006（与H2O2相比，P<0.01）。内面向外膜片中开放概率开始增加并达到最大值的时间比细胞吸附膜片中短（4.8±1.0分钟对11.5±3.9分钟，P<0.01；9.6±1.6分钟对18.7±4.7分钟，P<0.01）。