Role of the renin-angiotensin system in myocardial injury in rats with vascular dementia
Objective To observe the role of the renin-angiotensin system in myocardial injury induced by experi-mental vascular dementia.Methods Eighteen adult male rats were categorized into a normal group,sham group,and modified 2-vessel occlusion group(model).To assess the myocardial injury caused by experimental vascular dementia,immunostaining was conducted to evaluate the interstitial collagen fraction and myocyte cross-sectional ar-ea.The concentrations of angiotensin Ⅱ(Ang Ⅱ)and angiotensin 1-7(Ang1-7)in the serum,as well as the ex-pression levels of angiotensin converting enzyme(ACE),angiotensin converting enzyme 2(ACE2),Ang Ⅱ,Ang1-7,angiotensin type 1(AT1)receptor,and Mas receptor in the myocardium,were assessed.Results Modified 2-vessel occlusion led to pronounced cognitive dysfunction(P<0.01)and myocardial injury(P<0.000 1)when compared to the sham and normal groups.Additionally,modified 2-vessel occlusion induced significant upregulation of the ACE/Ang Ⅱ/AT1 receptor axis(P<0.01)and downregulation of the ACE2/Ang1-7/Mas axis(P<0.05)of the renin-angiotensin system in the myocardium.Conclusion Myocardial injury in rats with experimental vascu-lar dementia may be related to dysregulation of the renin-angiotensin system.