豚鼠心肌细胞中Kir2.1对内向整流钾电流组成的贡献

The contribution of Kir2.1 to the inward rectifier K+ currents in the cardiomyocytes of guinea pig

目的研究心肌细胞中Kir2.1对心肌细胞静息电位中内向整流电流组成的贡献。方法采用二型胶原酶急性分离豚鼠心室肌细胞,利用膜片钳技术,研究500 mmol/L Ba2+阻断豚鼠心肌细胞内向整流钾电流Kir2.1,从而确定Kir2.1在所有内向整流电流所占比例。结果 Ba2+对豚鼠心肌细胞内向整流钾电流Kir2.1有较强的抑制作用,Kir2.1对豚鼠心肌细胞内向整流钾电流组成的贡献为(81±7)%。结论 正常豚鼠心肌细胞中的Kir2.1在心肌细胞内向整流钾电流中大约占80%,对维持心肌细胞正常功能有重要作用。

Objective To investigate the contribution of Kir2.1 to the inward rectifier potassium channels in the cardiomyocytes of guinea pig during resting potential.Methods The cardiomyocytes of guinea pig were isolated by collagenase II.The patch clamp technique was used to detect the inhibition of 500 mM Ba2＋ on Kir2.1 in ventricular cardiomyocytes of guinea pig,and to determine the proportion of Kir2.1 in all the inward rectifier potassium channels.Results The Ba2＋ had a strongly inhibitory effect on Kir2.1,and Kir2.1 accounted for（81±7）% of the inward rectifier potassium channels in cardiomyocytes of guinea pig.Conclusion The Kir2.1 accountes for about 80% of the inward rectifier potassium channels in cardiomyocytes of normal guinea pig,which plays an important role in maintaining the normal function of cardiomyocytes.