title: Changes in cardiac structure and function in a modified rat model of myocardial hypertrophy.
abstract: OBJECTIVE
  In this study we designed a modified method of abdominal aortic constriction (AAC) in order to establish a stable animal model of left ventricular hypertrophy (LVH). We also evaluated cardiac structure and function in rats with myocardial hypertrophy using echocardiography, and provide a theory and experimental basis for the application of drug interventions using the LVH animal model. We hope this model will provide insight into novel clinical therapies for LVH.
  
  
  METHODS
  The abdominal aorta of male Wistar rats (80-100 g) was constricted between the branches of the coeliac and anterior mesenteric arteries, to a diameter of 0.55 mm. Echocardiography, using a linear phase array probe, combined with histology and plasma BNP concentration, was performed at three, four and six weeks post AAC.
  
  
  RESULTS
  The acute (24-hour) mortality rate was lower (8%) than in previous reports (15%) using this modified rat model. Compared with shams, animals who underwent AAC demonstrated significantly increased interventricular septal (IVS), LV posterior wall (LVPWd), LV mass index (LVMI), crosssectional area (CSA) of myocytes, and perivascular fibrosis; while the ejection fraction (EF), fractional shortening (FS) and cardiac output (CO) were consistently lower at each time interval. Notably, differences in these parameters between the AAC and sham groups were significant by three weeks and reached a peak at four weeks. Following AAC, plasma B-type natriuretic peptide (BNP) level was gradually elevated, compared with the sham group, between three and six weeks.
  
  
  CONCLUSIONS
  This modified AAC model induced LVH both stably and safely by week four post surgery. Echocardiography was accurately able to assess changes in chamber dimensions and systolic properties in the rats with LVH.
authors.affiliation: Department of Cardiology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China; Guangzhou Institute of Cardiovascular Disease, Guangzhou, China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Dai
authors.affiliation: Department of Physiology, Guangzhou Medical University, Guangzhou, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Dong
authors.affiliation: Guangzhou Institute of Cardiovascular Disease, Guangzhou, China. Email: gzminsheng@vip.163.com.
authors.forename: Minsheng
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Medical Experimental Centre, Guangzhou Medical University, Guangzhou, China.
authors.forename: Luning
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Ailan
authors.initials: A
authors.lastname: Chen
authors.affiliation: Department of Cardiology, The First Municipal People's Hospital of Guangzhou affiliated to Guangzhou Medical College, Guangzhou, China.
authors.forename: Zhenci
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Cardiology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China; Guangzhou Institute of Cardiovascular Disease, Guangzhou, China.
authors.forename: Shiming
authors.initials: S
authors.lastname: Liu
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D003250:Constriction; D004195:Disease Models, Animal; D018619:Echocardiography, Doppler, Pulsed; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D008297:Male; D009206:Myocardium / Q000473:pathology*; D020097:Natriuretic Peptide, Brain / Q000097:blood; D017208:Rats, Wistar; D013318:Stroke Volume; D013599:Systole; D013997:Time Factors; D015854:Up-Regulation; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain