Effect Of ShenSongYangXin Capsule On The Electrophysiology And Mechanism In A Rat Model Of Post-myocardial Infarction Depression

Objective Post-myocardial infarction depression is known to be associated with increased hospital admissions, particularly cardiac admissions, and with a significantly elevated the risk of mortality. Shensong Yangxin Capsule is shown to effectively decrease the risk of mortality coronary heart disease (CHD) prognosis. We observed the effect of Shensong Yangxin Capsule on behavior and electrophysiology in vivo and in vitro in a rat model of post-MI depression to investigate the potential mechanism of post-myocardial infarction depression.Methods and results Sixty Sprague-Dawley rats (220g) were randomly assigned to five groups:sham-operation riats (control group), myocardial infarction rats (MI group), depression rats (depression group), post-MI depression rats (model group), post-MI depression rats treated with intragastric administration of Shensong Yangxin Capsule (Shensong group). The myocardial infarction was produced by ligation the left inferior artery of coronary artery and depression was developed by 4-week chronic mild stress. Model rats were treated with intragastric administration of 400mg/kg ShenSongYangXin Capsule. Electrophysiology study in vivo and molecular biological detection was carried on after 28-days intragastric administration of ShenSongYangXin Capsule. Behavior measurements including open field test and sucrose preference test were done before and after experiment. The levels of plasma epinephrine and norepinephrine was tested using high performance liquid chromatography; then the ventricular electrophysiology study was performed in vitro, and evaluate the effect of isopropyl epinephrine (ISO) on the susceptibility of ventricular fibrillation; The above experiments were compared with the control group. The expressions of NR1 in rats were analyzed by Western-blot. We also test the fibrosis in rats heart tissue use masson dye. After 4-week CMS, depression-like behaviors, such as lower sucrose preference and reduced locomotor activities were observed in MI, depression and model groups, and chronic Shensong administration could significantly improve (p<0.05). Compare with post-MI depression group,the Shensong group rats showed smaller ERP and higher susceptibility of ventricular fibrillation(Burst:85.7% vs 71.4%, P<0.01, and ISO: 85.7% vs 57.1%, P<0.01). In masson dye MI rats show fibrosis in heart tissue(40.27%±8.44%), which increased in post-MI depression group(45.13± 10.54%), Shensong could decreased the fibrosis in heart tissue (37.41±9.12%).Compare with the CTL group, the depression group,the MI group,the post-MI depression group expression of NR1 was increased by (28.15%±5.2%?39.9%±4.9%?46.9%±4.2%), which could be decreased by ShenSongYangXin Capsule (27.3%±3.4%).Conclusion 1. ShenSongYangXin Capsule can decrease expression of NR1 and decrease ventricular arrhythmias in myocardial infarction rats.2. Depression rats showed sympathetic nervous system hyperactivities, and increased susceptibility of ventricular fibrillation; this may be an important mechanism link depression to cardiovascular events.