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用细胞内微电极法研究普罗帕酮消旋体及两对映体对豚鼠右心室乳头肌快反应动作电位（ＦＡＰ）和慢反应动作电位（ＳＡＰ）的作用．普罗帕酮消旋体及两对映体均浓度依赖性地降低ＦＡＰ和ＳＡＰ的０相最大除极速率（Ｖｍａｘ）和动作电位幅值（ＡＰＡ），３药≤３μｍｏｌ·Ｌ－１时均延长动作电位时程（ＡＰＤ）．１０μｍｏｌ·Ｌ－１时，ＡＰＤ５０和ＡＰＤ９０反缩短至给药前水平，（Ｒ）－普罗帕酮延长ＦＡＰ的ＡＰＤ２０而（Ｓ）－普罗帕酮则无影响，两组间有显著性差异（Ｐ＜０．０５）．３药对ＦＡＰ和ＳＡＰ静息电位，Ｖｍａｘ，ＡＰＡ，ＡＰＤ５０及ＡＰＤ９０影响均无显著性差异．结果表明，普罗帕酮两对映体的钠通道阻滞作用及钙拮抗作用无差异，对心肌动作电位平台期内向钠和／或钙离子流的作用可能表现立体选择性．
The effect of propafenone racemate and enantiomers on fast response action potential (FAP) and slow response action potential (SAP) of right ventricular papillary muscle in guinea pigs were studied by intracellular microelectrode method. Propafenone racemate and enantiomers both decreased the maximal depolarization rate (Vmax) and action potential amplitude (APA) of phase 0 in FAP and SAP in a concentration-dependent manner, both prolonged when the concentration of 3-drug was less than 3μmol·L-1 Action potential duration (APD). (R) -propafenone prolonged the APD20 of FAP but did not affect (S) -propafenone at 10μmol·L-1, PD50 and APD90 contracted to the level before pretreatment, there was a significant difference between the two groups (P <0.05). 3 drugs on FAP and SAP resting potential, Vmax, APA, APD50 and APD90 no significant difference. The results showed that there was no difference in sodium channel block and calcium antagonism between propafenone enantiomers and stereoselectivity on the action of sodium and / or calcium ions during plateau of myocardial action potential.