花生四烯酸对兔心室肌细胞电压门控钠通道的影响

Effects of arachidonic acid on the voltage-gated sodium channel of rabbit cardiac ventricular myocytes

目的研究花生四烯酸(AA)对兔心室肌细胞电压门控钠通道(VGSC)的影响。方法酶解法分离兔心室肌细胞,采用标准全细胞膜片钳技术记录电压门控钠通道电流(INa)。结果AA可浓度依赖性抑制INa,使INa的I-U曲线上移,但其激活电位、电位峰值和反转电位保持不变;AA使INa稳态失活曲线左移,恢复曲线右移;但对INa的抑制作用不具有明显的频率依赖性。结论AA对INa具有浓度依赖性抑制作用,主要是通过抑制失活和失活后恢复过程而发挥作用。因此AA对INa的抑制作用可能是AA抗心律失常,保护心肌的作用机制之一。

Aim To study the effect of arachidonic acid on the vohage-gated sodium channel of rabbit cardiac ventricular myocytes. Methods Single ventricular myocytes of rabbits were obtained by enzymatic dissociation method. And the whole-cell patch-clamp recording technique was used to record the change of voltagegated sodium channel current （lNa）. Results Arachidonic acid decreased INa in a dose-dependent manner. AA shifted the INa I-U curves but didn＇t change their active, peak and reverse potentials; The inactivation curve was moved to more negative potential and the recovery curve was delayed. But AA can not affect INa in a frequency-dependent manner and the activation curve had no significant change. Conclusion AA can block INa in a concentration-dependent manner, and it mainly affects the inactivated state and recovery curve of INa, which may be one of the mechanisms of its antiarrhythmic effect and myocardial preservation.