Change in late sodium current of atrial myocytes in spontaneously hypertensive rats with allocryptopine treatment

AIM: We aimed to study the effect of allocryptopine (All) on the late sodium current (INa,Late) of atrial myocytes in spontaneously hypertensive rats (SHR). METHODS: The enzyme digestion method was used to separate single atrial myocytes from SHR and Wistar-Kyoto (WKY) rats. INa,Late was recorded using the patch-clamp technique, and the effect of All was evaluated on the current. RESULTS: Compared with WKY rat cells, an increase in the INa,Late current in SHR myocytes was found. After treatment with 30 µM All, the current densities were markedly decreased; the ratio of INa,Late/INa,peak of SHR was reduced by 30 µM All. All reduced INa,Late by alleviating inactivation of the channel and increasing the window current of the sodium channel. Furthermore, INa,Late densities of three SCN5A mutations declined substantially with 30 µM All in a concentration-dependent manner. CONCLUSIONS: The results clearly show that an increase in INa,Late in SHR atrial myocytes was inhibited by All derived from Chinese herbal medicine.