Effects of Kir2.1 channels with inward rectification on hypokalemia-in-duced abnormal pacemaker activities of cardiomyocytes
10.3969/j.issn.1000-4718.2025.06.018
- VernacularTitle:Kir2.1钾通道的内向整流特性在低血钾诱发心肌细胞异常起搏活动中的作用
- Author:
Jinxian XIANG
1
;
Jinhua LÜ
;
Yangxin JIANG
;
Jin ZENG
;
Li LIU
;
Yingying ZHANG
;
Zheng LIU
;
Xiaobin WANG
;
Dongchuan ZUO
Author Information
1. 西南医科大学附属医院麻醉科,四川 泸州 646000
- Publication Type:Journal Article
- Keywords:
Kir2.1 channels;
hypokalemia;
cardiomyocytes;
abnormal pacemaker activities
- From:
Chinese Journal of Pathophysiology
2025;41(6):1207-1211
- CountryChina
- Language:Chinese
-
Abstract:
AIM:To investigate the impact of Kir2.1 channels on abnormal spontaneous pacemaker activities induced by hypokalemia and to elucidate the underlying mechanisms.METHODS:Human induced pluripotent stem cell-derived cardiomyocytes(hiPSC-CMs)were transfected with lentiviral particles containing sequences for human Kir2.1,the Kir2.1-E224G mutant,or Kir4.1.Patch clamp techniques were employed to examine the effects of low extracellular potassium concentration([K+]e)of 1 mmol/L on the resting membrane potentials and whole-cell currents of the cells in each group,assessed via both current and voltage clamp modes.RESULTS:Under conditions of 1 mmol/L[K+]e,cur-rent clamp data revealed that hiPSC-CMs overexpressing Kir2.1 channels exhibited both hyperpolarized and depolarized resting membrane potentials,with the depolarized state triggering abnormal pacemaker activities.In contrast,cells overex-pressing the Kir2.1-E224G mutant or Kir4.1 channels displayed only hyperpolarized resting membrane potentials.Voltage clamp analysis indicated that hiPSC-CMs overexpressing Kir2.1 channels produced"N"-shaped whole-cell currents,whereas cells expressing the Kir2.1-E224G mutant or Kir4.1 exhibited typical K+currents.CONCLUSION:Kir2.1 channels play a crucial role in mediating hypokalemia-induced abnormal spontaneous pacemaker activities in human car-diomyocytes through their inward rectification properties.
