Exploration of the Effect of Maishen Tongtiao Method on Sympathetic Paroxysmal Atrial Fibrillation in Rats Based on the β1-AR Pathway of Myocardial Cells
Objective To observe the effect of Dingchan formula on the electrophysiology and adrenergic β1 receptor(β1-AR)signaling pathway in rats with sympathetic paroxysmal atrial fibrillation(AF),and to explore the underlying mechanism of Maishen Tongtiao treatment method.Methods 48 SD rats were randomly divided into control group,model group,Dingchan formula group(10.67 g/kg)and amiodarone group(52.89 mg/kg),with 12 rats in each group.Rats in each group were continuously administered by gavage for 14 days.From the 12th day of the experiment,except for the control group,all rats in the other groups were daily injected with isoprenaline(ISO)1.5 mg/kg intraperitoneally for 3 days.On the 14th day,except for the control group,all rats in other groups were subjected to transesophageal atrial burst stimulation to induce AF,and electrophysiological indexes such as effective refractory period,AF induction rate and duration were observed.The serum levels of norepinephrine(NE)were measured by ELISA,and the expression of β1-AR,PKA and Cav1.2 protein and mRNA in the atrial tissues of rats in each group were detected by Western blot and RT-qPCR.Results Compared with the control group,the NE levels,β1-AR protein and mRNA levels,and PKA mRNA levels were significantly higher(P<0.01),while Cav1.2 protein and mRNA expression levels were significantly lower(P<0.05)in the model group.Compared with the model group,the frequency of AF induction was significantly less(P<0.01),the duration of AF was significantly shorter(P<0.05),the expression of β1-AR protein and mRNA and PKA mRNA were significantly decreased(P<0.05),while the expression of Cav1.2 protein and mRNA were significantly increased(P<0.01)in Dingchan formula group and amiodarone group.The serum NE levels of rats were significantly reduced(P<0.05)in the Dingchan formula group.Conclusion Dingchan formula can effectively inhibit the occurrence and maintenance of AF,and its mechanism is related to the regulation of NE,β1-AR and calcium channels,which may play the role of Maishen Tongtiao method in the treatment of AF by inhibiting sympathetic activity and promoting calcium homeostasis.