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

Abstract

Aim: We aimed to study the effect of allocryptopine (All) on the late sodium current (I_Na,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,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,Late current in SHR myocytes was found. After treatment with 30 µM All, the current densities were markedly decreased; the ratio of I_Na,Late/I_Na,peak of SHR was reduced by 30 µM All. All reduced I_Na,Late by alleviating inactivation of the channel and increasing the window current of the sodium channel. Furthermore, I_Na,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 I_Na,Late in SHR atrial myocytes was inhibited by All derived from Chinese herbal medicine.

Keywords: allocryptopine; atrial myocytes; late sodium current; spontaneously hypertensive rats.