Effect of angiotensin receptor neprilysin inhibitor on ventricular remodeling after myocardial infarction in rats

Objective:To investigate the effect of Angiotensin Receptor Neprilysin Inhibitor(ARNI)on ventricular remodeling after AMI in rats.Methods:Sixty male SD rats were randomly divided into Control group,AMI group,AMI-valsartan group,AMI-ARNI group,15 rats in each group,ligating the left coronary anterior descending artery to establish the rat model of AMI.Valsartan group and ARNI group were treated with valsartan(34mg/kg/day)and ARNi(68mg/kg/day)for 6 weeks,the Control group and AMI group were given the same amount of normal saline.LVIDd,LVIDs,EF were measured by color doppler echocardiography before and 6 weeks after treatment.After 6 weeks,the rats were sacrificed,the hearts were weighed,then myocardial tissue Masson staining was performed to calculate the collagen volume fraction(CVF).Results:compared with the control group,LVIDs increased significantly with the reduction of EF in the AMI group,valsartan group and ARNI group(P<0.05).After 6 weeks of treatment,compared with the AMI group,LVIDd and LVIDs both reduced significantly with the increase of EF in the ARNI group(P<0.05).Compared with the control group,the left ventricular weight,right ventricular weight and atrial weight all increased significantly in the AMI group,valsartan group,and ARNI group(P<0.05);compared with the AMI group,the left ventricular weight,right ventricular weight,atrial weight and CVF reduced significantly in the valsartan group and ARNI group(P<0.05);compared with the valsartan group,the left ventricular weight and CVF further reduced in the ARNI group.(P<0.05).Conclusions:ARNI has the effect of reversing ventricular remodeling after AMI in rats,which can reduce left ventricular volume,increase myocardial contractility,and inhibit myocardial cell hypertrophy and fibrosis.