CAJ | 학술논문

目的评价一种药理学中分析电压依赖性瞬时外向钾电流(Ito)的积分方法.方法 Ito的失活相可被2指数或3指数方程拟合.原始电流曲线下面积(AUC)可通过指数方程积分获得.以细胞膜电容标准化后的曲线下面积表示除极化时程中钾离子的净通量,作为比较指标.钙调磷酸酶过表达转基因鼠心肌细胞表现Ito下调,此数据用于验证Ito的积分分析方法的可靠性.结果 AUC可通过3指数或2指数方程的积分公式获得:AUC=A1τ1+A2τ2+A3τ3+A0t-A1τ1e-t/τ1-A2τ2e-t/τ2-A3τ3e-t/τ3或AUC=A1τ1+A2τ2+A0t-A1τ1e-t/τ1-A2τ2e-t/τ2.小鼠心室肌50%和90%动作电位时程分别约为10 ms和30 ms.将Ito 0～10 ms (AUC50)和0～30 ms(AUC90)的曲线下面积以细胞膜电容进行标准化.野生型鼠心肌细胞的AUC50和AUC90明显高于钙调磷酸酶过表达转基因鼠,此结果与转基因鼠心室肌细胞动作电位时程延长相一致,与前期发表结果一致(钙调磷酸酶过表达转基因鼠心肌细胞Ito各成分下调).结论积分法是药理学中一种简便准确的分析Ito的方法.
목적평개일충약이학중분석전압의뢰성순시외향갑전류(Ito)적적분방법.방법 Ito적실활상가피2지수혹3지수방정의합.원시전류곡선하면적(AUC)가통과지수방정적분획득.이세포막전용표준화후적곡선하면적표시제겁화시정중갑리자적정통량,작위비교지표.개조린산매과표체전기인서심기세포표현Ito하조,차수거용우험증Ito적적분분석방법적가고성.결과 AUC가통과3지수혹2지수방정적적분공식획득:AUC=A1τ1+A2τ2+A3τ3+A0t-A1τ1e-t/τ1-A2τ2e-t/τ2-A3τ3e-t/τ3혹AUC=A1τ1+A2τ2+A0t-A1τ1e-t/τ1-A2τ2e-t/τ2.소서심실기50%화90%동작전위시정분별약위10 ms화30 ms.장Ito 0～10 ms (AUC50)화0～30 ms(AUC90)적곡선하면적이세포막전용진행표준화.야생형서심기세포적AUC50화AUC90명현고우개조린산매과표체전기인서,차결과여전기인서심실기세포동작전위시정연장상일치,여전기발표결과일치(개조린산매과표체전기인서심기세포Ito각성분하조).결론적분법시약이학중일충간편준학적분석Ito적방법.
AIM To evaluate the integration method for analysis of voltage-dependent Ca2+-independent transient outward K+ currents (Ito) in pharmacology. METHODSThe inactivation phases of Ito were best fitted by the sum of two or three exponentials equations. The area under the raw current curves (AUC) was obtained by the integration of exponential equations. The AUC normalized to the cell capacitance represented the net K+ charge flow during any depolarized duration and was as the index for comparison. Calcineurin overexpression transgenic (TG) mice showed downregulation of Ito. These data were tested by the integration method. RESULTS AUC obtained from three or two exponentials fittings was calculated as: AUC=A1τ1+A2τ2+A3τ3+A0t-A1τ1e-t/τ1-A2τ2e-t/τ2-A3τ3e-t/τ3 or AUC=A1τ1+A2τ2+A0t-A1τ1e-t/τ1-A2τ2e-t/τ2. The 50% and 90% action potential duration (APD50, APD90) in ventricular myocytes of mice are about 10 ms and 30 ms, respectively. AUC at 10 ms (AUC50, AUC of 50% APD) and 30 ms (AUC90, AUC of 90% APD) in left ventricle cardiomyocytes of wild type (WT) and TG mice were normalized to the cell capacitance. The normalized AUC50 and AUC90 of WT group were significantly more than those of TG group, which was consistent to the prolongation of APD in TG mice and the previous published results(downregulation of components of Ito in TG mice). CONCLUSION The integration method was an ideal way for analysis of transient outward K+ currents in pharmacology.