Suxiao Jiuxin Pills Prevent Ventricular Fibrillation from Inhibiting L-type Calcium Currents CaV1.2 in vivo and in vitro

Authors：Qi Jian-Yong; Kang Dong-yuan; Yu Juan; Zhang Min-zhou^*

Source：Chinese Journal of Integrative Medicine, 2023, 29(2): 108-118.

DOI：10.1007/s11655-022-3623-7

• Suxiao Jiuxin Pills
• ventricular fibrillation
• patch clamp
• simulation
• CaV1
• 2

Objective To investigate whether Suxiao Jiuxin Pills (SJP), a Chinese herbal remedy, is an anti-ventricular fibrillation (VF) agent. Methods VF was induced by isoproterenolol (ISO) intraperitoneal injection followed by electrical pacing in mice and rabbits. The effects of SJP on the L-type calcium channel current (CaV1.2), voltage-dependent sodium channel current (I-Na), rapid and slow delayed rectifier potassium channel current (I-Kr and I-Ks, respectively) were studied by whole-cell patch-clamp method. Computer simulation was implemented to incorporate the experimental data of SJP effects on the CaV1.2 current into the action potential (AP) and pseudo-electrocardiography (pseudo-ECG) models. Results SJP prevented VF induction and reduced VF durations significantly in mice and rabbits. Patch-clamp experiments revealed that SJP decreased the peak amplitude of the CaV1.2 current with a half maximal concentration (IC50) value of 16.9 mg/L (SJP-30 mg/L, -32.8 +/- 6.1 pA; Verapamil, -16.2 +/- 1.8 pA; vs. control, -234.5 +/- 16.7 pA, P<0.01, respectively). The steady-state activation curve, inactivation curve, and the recovery from inactivation of the CaV1.2 current were not shifted significantly. Specifically, SJP did not altered I-Na, I-Kr, and I-Ks currents significantly (SJP vs. control, P>0.05). Computer simulation showed that SJP-reduced CaV1.2 current shortened the AP duration, transiting VF into sinus rhythm in pseudo-ECG. Conclusion SJP reduced VF via inhibiting the CaV1.2 current with in vivo, in vitro, and in silico studies, which provide experimental basis for SJP anti-VF clinical application.

• Institution
  广州中医药大学; 广东省人民医院