| Objective: To establish an acute myocardial infarction model by ligation of the left coronary artery in rats,and to investigate the effects of Ghrelin on behavior and cardiac function,heart and brain histology in rats with acute myocardial infarction,It provides a theoretical basis for the adjuvant treatment of heart failure after acute myocardial infarction with Ghrelin.Methods: Thirty male Sprague-Dawley rats were randomly divided into 3 groups: sham operation group(SHAM group,n=6),Chronic heart failure group(CHF group,n=12),and Chronic heart failure+Ghrelin group(CHF+Gh group,n=12).In the sham operation group,only the left coronary artery was threaded but not ligated;in the acute myocardial infarction group,the left coronary artery was ligated to make an acute myocardial infarction model.CHF+Gh group was given 100 ug/kg Ghrelin and Bid subcutaneously for 4 weeks after modeling for 12 hours.After 4 weeks,the first sugar water ingestion experiment,the elevated plus-maze test(EPM),the open field experiment,then to record the electrocardiogram,and sympathetic nerve discharge.Finally,the experimental rats were sacrificed under anesthesia,and the brain water content(BWC)of the rats was determined.Finally,the experimental rats were sacrificed under anesthesia,and the brain water of brain content(BWC)was determined.Remove brain and heart tissue for HE staining and Masson staining.HE staining was used to observe cell size and morphology,inflammatory infiltration and cardiac tissue hyperplasia and edema in the hippocampus of the myocardium and brain;Masson staining was used to compare myocardial interstitial fibrosis,and myocardial tissue remodeling was further explored by measuring collagen volume fraction(CVF)and wall thickness of vessel(WTV).Results: After 4 weeks,there were 8 rats in the CHF group and 6 in the CHF+Gh group,all the rats in the Sham group survived.1.In the elevated plus maze experiment,the number of times(OE)and time(OT)of the open enter in the CHF group were reduced compared with the Sham group(P<0.05).The CHF+Gh group significantly increased the number of times the rats entered the open arm(OE)and time(OT),and the total number of arms(OE+CE)was also increased.The difference was statistically significant(P<0.05);2.In the open field experiment,the total movement distance and average walking speed of rats in CHF group were significantly lower than those in Sham group.The total movement distance of rats in CHF+Gh group was slightly improved compared with that in CHF group,but the difference was not statistically significant(P>0.05),Average walking speed improved(P<0.05),compared with the CHF group,the movement distance and walking speed of the CHF+Gh group in the central area were improved(P<0.05);3.In the sucrose intake test,compared with the Sham group,the sucrose intake and total fluid intake were significantly decreased in the CHF group(P<0.05),and the CHF+Gh group was improved(P<0.05);4.In the synchronous detection of cervical sympathetic nerve discharge and electrocardiogram in rats,the sympathetic nerve discharge amplitude was higher in CHF group,and ventricular arrhythmia occurred more frequently(P<0.01),The CHF+Gh group significantly reduced the amplitude of sympathetic nerve discharge(P<0.01),and less arrhythmia occurred;5.Compared with the Sham group,the brain water content(BWC)of the CHF group was significantly increased,and the CHF+Gh group was decreased(P<0.01);6.HE staining in the hippocampus of rats in CHF group,nucleated cells were significantly reduced,and inflammatory mediators in hippocampus were increased.In HE staining of cardiomyocytes,the diameter of cardiomyocytes was increased,cytoplasm was lightly stained,and interstitial edema was observed,the volume of myocardial cells in CHF+Gh group was slightly improved(P<0.05),and interstitial edema was reduced;In myocardial Masson staining,the collagen volume fraction(CVF)and vessel wall thickness(WTV)of CHF+Gh group were significantly lower than those of CHF group(P<0.05).Conclusion: Ghrelin can improve the dysfunction of sympathetic nerves and improve the anxiety and depression of rats with heart failure after myocardial infarction,enhance the learning and memory function of rats,and improve the exercise tolerance of heart failure rats after myocardial infarction;improve myocardial cell remodeling and improve heart function. |
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