AIMS Detect the antiarrhythmic effect of crotonoside (Cro). MAIN METHODS We used whole-cell patch-clamp techniques to detect the effects of Cro on action potentials (APs) and transmembrane ion currents in isolated rabbit left ventricular myocytes. We also verified the effect of Cro on ventricular arrhythmias caused by aconitine in vivo. KEY FINDINGS Cro reduced the maximum depolarization velocity (Vmax) of APs and shortened the action potential duration (APD) in a concentration-dependent manner, but it had no significant effect on the resting membrane potential (RMP) or action potential amplitude (APA). It also inhibited the peak sodium current (INa) and L-type calcium current (ICaL) in a concentration-dependent manner with half-maximal inhibitory concentrations (IC50) of 192 μmol/L and 159 μmol/L, respectively. However, Cro had no significant effects on the inward rectifier potassium current (IK1) or rapidly activating delayed rectifier potassium current (IKr). Sea anemone toxin II (ATX II) increased the late sodium current (INaL), but Cro abolished this effect. Moreover, Cro significantly abolished ATX II-induced early afterdepolarizations (EADs) and high extracellular Ca2+ concentration (3.6 mmol/L)-induced delayed afterdepolarizations (DADs). We also verified that Cro effectively delayed the onset time and reduced the incidence of ventricular arrhythmias caused by aconitine in vivo. SIGNIFICANCE These results revealed that Cro effectively inhibits INa, INaL, and ICaL in ventricular myocytes. Cro has antiarrhythmic potential and thus deserves further study.

中文翻译：

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通过调节兔心室肌细胞的钠和钙通道，巴豆苷的抗心律失常作用。

目的检测巴豆苷（Cro）的抗心律失常作用。主要方法我们使用全细胞膜片钳技术检测Cro对离体兔左心室心肌细胞中动作电位（APs）和跨膜离子电流的影响。我们还证实了Cro对体内乌头碱引起的室性心律失常的作用。主要发现Cro以浓度依赖的方式降低了AP的最大去极化速度（Vmax），并缩短了动作电位持续时间（APD），但对静息膜电位（RMP）或动作电位振幅（APA）没有显着影响。 。它还以浓度依赖性方式抑制了峰值钠电流（INa）和L型钙电流（ICaL），其最大抑制浓度（IC50）分别为192μmol/ L和159μmol/ L。然而，Cro对内向整流钾电流（IK1）或快速激活延迟整流钾电流（IKr）均无明显影响。海葵毒素II（ATX II）增加了后期钠电流（INaL），但Cro取消了这种作用。此外，Cro显着取消了ATX II诱导的早期去极化（EAD）和高细胞外Ca2 +浓度（3.6 mmol / L）诱导的延迟去极化（DAD）。我们还证实，Cro有效地延迟了乌头碱在体内引起的发作时间并减少了室性心律失常的发生。意义这些结果表明，Cro有效抑制心室肌细胞中的INa，INaL和ICaL。Cro具有抗心律失常的潜力，因此值得进一步研究。