Aconitine has potential cardio-and neurotoxicity and can produce various arrhythmias, so its application in the clinic is seriously limited.However, the mechanisms for its arrhythmogenic effects are still under exploration.To elucidate the possible roles of Na/K pump currents (IP) and TTX-sensitive sodium currents (INa-TTX) in the arrhythmogenic effects of ACO, we investigated the effects of ACO on action potential parameters in the presence or absence of inhibitors for Ip or INa-TTX using the perforated patch-clamp technique.