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 (I-Na,I-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. I-Na,I-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 I-Na,I-Late current in SHR myocytes was found. After treatment with 30 mu M All, the current densities were markedly decreased; the ratio of I-Na,I-Late/I-Na,I-peak of SHR was reduced by30 mu M All. All reduced I-Na,I-Late by alleviating inactivation of the channel and increasing the window current of the sodium channel. Furthermore, I-Na,I-Late densities of three SCN5A mutations declined substantially with 30 mu M All in a concentration-dependent manner. Conclusion: The results clearly show that an increase in I-Na,I-Late in SHR atrial myocytes was inhibited by All derived from Chinese herbal medicine.