Establishment Of An Animal Model Of Ventricular Remodeling And Related Basic Research

Background:Ventricular Remodeling(VR): refers to the pathophysiological changes in the size,shape,thickness and tissue structure of the ventricle caused by damage or increased load in the ventricle.It is a self-change,by Baumbach(et al.)First proposed in 1989.Ventricular remodeling is mainly characterized by an increase in cardiac morphology,an increase in ventricular volume,hypertrophy of the myocardium,and an increase in extracellular matrix.Generally can be divided into compensation period and decompensation period,which will eventually lead to heart failure and death.In recent years,medical research has confirmed that ventricular remodeling is the most basic pathological basis for the occurrence and development of heart failure,and is an important factor affecting the incidence and mortality of heart disease.Therefore,the experiment is further strengthened by establishing an animal model of ventricular remodeling.Basic research on ventricular remodeling has become a research topic of concern in the cardiovascular field.Objective:To establish an animal model of ventricular remodeling that is close to the actual pathological symptoms of human ventricular remodeling,and lay the foundation for relevant basic research.Methods:Surgical bundle of sheep pulmonary artery trunk(Banding surgery),forming a high load on the right ventricle,triggering a right ventricular mechanical response to establish a ventricular remodeling animal model,using echocardiography,HE staining pathological observation techniques,ventricular weight The basic research of the structure and summarize the practicality and scientificity of the animal model.1.Prepare 13 clean animal sheep,weighing about 25-30 kg,and divide the animal experiments into 2 groups by random number table method,which are divided into 5groups in normal control group(group A)and 8 in operation group(group B).And select 5to enter the later research project).According to the structure and function of the left and right ventricles,the quality of the right ventricle is relatively small in the heart,which is more sensitive to the mechanical stimulation of increased afterload.It takes less time to successfully establish an animal model of ventricular remodeling.In this study,the right ventricular remodeling animal model was made by surgical pulmonary artery ligation in the surgical group.The normal control group only underwent puncture of the pulmonary artery.The normal two groups were given normal feeding.2.Thoracic CT scan was performed 3 months after operation in the operation group,and the changes of cardiac ventricle were observed in comparison with preoperative color Doppler ultrasound.3.In the normal group and the operation group,cardiac Doppler ultrasonography was performed before and after surgery at 3 time nodes(preoperative,3 months,and 6 months after surgery).Then,the changes of pulmonary artery pressure(the apical four-chamber view)were compared between the two groups.The maximum blood flow velocity(the echocardiographic short-axis view)of the proximal ventricle was compared between the operation group and the right ventricular systole.Group animal models were subjected to high loads,mechanical stimuli,and hemodynamic changes in the right ventricle.Left ventricular EF values and right ventricular EF values were measured,and changes in ventricular function were measured for statistical analysis.4.Measurement of right ventricular wall thickness,left ventricular wall thickness(two-dimensional measurement of the parasternal long axis),right ventricular end diastolic diameter,right ventricular end diastolic diameter,left ventricular end systolic diameter,left ventricular end systolic diameter(Two-dimensional measurement of apical four-chamber view),right ventricular end-diastolic volume,right ventricular end-systolic volume,left ventricular end-diastolic volume,left ventricular end-systolic volume(three-dimensional measurement of apical four-chamber view),contrast ventricular thickness,size,morphological change5.Six months later,the animal model of the operation group and the normal control group were sacrificed by excessive anesthesia.The cardiac specimens of the experimental animal model were taken out,and the myocardial sections of the horizontal plane and the coronal plane were prepared.The pathological morphology of right ventricular tissue was stained by HE staining.,basic research on ventricular remodeling.Results:1.In the surgery group included animals in eight sheep(to select five research into the late),total Sheep pulmonary artery cerclage 8,when the row cerclage pulmonary hemorrhage death due to an excessive,cerclage line model of postoperative gastrointestinal bleeding due to the death of one,a total of six survived,survived for 6 months to achieve the desired requirements,modeling success rate of 75%.2.Thoracic CT examination was performed in the operation group 3 months after operation,and the right ventricular compensatory thickening was observed in comparison with preoperative color Doppler ultrasound.3.In the operation group,the systolic pressure of the pulmonary artery was significantly increased before surgery(P < 0.01),which reflected the high load of the right ventricle.The maximum blood flow velocity increased when the proximal end of the pulmonary artery was contracted.The right ventricular EF value showed a decreasing trend at 6 months after operation(P < 0.01),and there was no statistical difference in left ventricular EF values.It indicates that the right ventricle has high load and mechanical stimulation,which is consistent with the pathological characteristics of induced ventricular remodeling.The established animal model meets the requirements for ventricular remodeling research.4.Results of ventricular remodeling in the surgical group.In the operation group,the anterior wall of the right ventricle was significantly thickened(P < 0.01),there was no significant change in the posterior wall of the left ventricle,and ventricular wall thickening occurred in the right ventricle.5.The right ventricular end-diastolic diameter and right ventricular end-diastolic volume of the operation group were all larger(P < 0.01).Left ventricular end-diastolic diameter and left ventricular end-diastolic volume were all decreased(P < 0.01).The overall heart of the surgical group became larger.6.In the observation of the operation group,control group were stained pathological Comparative obtain ventricular cardiomyocytes increase volume operation group,myocardial cells arranged in disturbance,cytoplasmic swelling may occur,as a dual-core state some nuclei,nuclei appear large abnormal,increased interstitial cardiomyocytes,myocardial fibrosis,hyperplasia,but can also have found that infiltration of inflammatory cells,a small amount of apoptosis,scar tissue.Conclusions:1.Through the Banding operation,the right ventricular high load is caused by ventricular remodeling.It is feasible to monitor the ventricular enlargement,increase the ventricular volume,increase the ventricular thickness and the pathophysiological changes of myocardial fibrosis and establish the ventricular remodeling model.,scientific.2.Ventricular remodeling showed changes in myocardial cell volume,inflammatory cell infiltration,a small amount of apoptosis,scar tissue formation,myocardial interstitial increase and so on.