HEK293细胞内源性电压门控钾离子通道电生理学特性研究

目的探讨人胚胎肾细胞(HEK293细胞)内源性电压门控钾通道的电生理特性,避免HEK293细胞上内源性离子通道对外源性离子通道表达时的干扰。方法利用全细胞膜片钳技术分析了HEK293细胞内源性电压门控钾通道的电生理特性。结果在HEK293细胞上去极化电压从-80 mV开始可触发1个外向电流。在+100 mV时电流为(422.78±68.87)pA,电流密度为(21.91±3.20)pA/pF。钾通道阻断剂四乙胺(tetraethylammonium,TEA)、4-氨基吡啶(4-aminopyri-dine,4-AP),在将细胞外液钾浓度由4 mmol/L提高到40 mmol/L时,对外向电流有影响。结论正常培养的HEK293细胞本身有内源性的钾通道。该外向电流可能包括了IK、IK1、IKur和Ito。

Study on Electrophysiological Properties of Endogenous Voltage-Gated Potassium Channels in Human Embryonic Kidney (HEK293) Cells

Objective To study electrophysiological properties of endogenous voltage-gated outward currents of potassium channels in HEK293 cells.Methods Whole-cell voltage patch clamp experiment was performed on this expression system.Results In HEK293 cells, depolarizing voltage steps from-80 mVtriggered an outward current.This current had an amplitude (422.78±68.87) pAat +100 mVand a current density of (21.91±3.20) pA/pF.TEA, 4-APas potassium channel blockers and a rise in extracellular K⁺ concentration from 4 to 40 mmol/Lcould block the outward currents.Conclusion Functional endogenous K⁺ channels exist in HEK293 cells under normal culture conditions.Their outward current may consist of I_K, I_K1, I_Kur and I_to.