title: Dramatic decrease of aortic longitudinal elastic strength in a rat model of aortic dissection.
abstract: BACKGROUND
  This study aimed to evaluate thoracic aortic longitudinal elastic strength in a rat model of aortic dissection (AD).
  
  
  METHODS
  Young Sprague Dawley rats were fed 0.25% β-aminopropionitrile (BAPN). Biomechanical and biochemistry properties of the aorta were analyzed. Elasticity modulus, maximum stretching length, draw ratio, maximum load, maximum strength, and maximum extensibility were measured.
  
  
  RESULTS
  More than one-half of BAPN-treated rats (52.9%) died of aortic rupture secondary to AD during the experiment. The diameter of the aneurysms was 6.33 ± 1.17 mm and the length was 9.33 ± 4.95 mm. The maximum diameter was significantly increased in BAPN-treated rats with AD (group B2) compared with rats without AD (group B1) and control group (group A) (P = 0.001 and P < 0.001, respectively), but was not different between group B1 and group A (P = 0.108). Thickness of media and initial area in aorta of BAPN-treated rats were significantly increased compared with control group (P = 0.001 and P < 0.001, respectively), but no difference in initial area was observed between group B1 and group B2 (P = 0.54). Maximum stretching length, draw ratio, maximum load, maximum strength, maximum extensibility, and elasticity modulus were dramatically decreased in group B2 compared with group B1 and group A (group B2 vs. group B1: P < 0.001; group B1 vs. group A: P < 0.001).
  
  
  CONCLUSIONS
  We successfully established a rat model of AD with a high incidence of rupture and mortality. Examinations of strain and stress parameters as well as elasticity modulus of the dissected and the nondissected aorta help understand pathogenesis of AD.
authors: Department of Vascular Surgery, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China.
authors: Lei
authors: L
authors: Zhang
authors: Yi-fei
authors: YF
authors: Pei
authors: Liang
authors: L
authors: Wang
authors: Ming-fang
authors: MF
authors: Liao
authors: Qing-sheng
authors: QS
authors: Lu
authors: Yu-feng
authors: YF
authors: Zhuang
authors: Su-ming
authors: SM
authors: Zhang
authors: Zai-ping
authors: ZP
authors: Jing
mesh_terms: D000629:Aminopropionitrile; D000784:Aortic Dissection / Q000139:chemically induced / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D000818:Animals; D001013:Aorta, Thoracic / Q000473:pathology* / Q000503:physiopathology; D017545:Aortic Aneurysm, Thoracic / Q000139:chemically induced / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D001019:Aortic Rupture / Q000209:etiology / Q000473:pathology; D001696:Biomechanical Phenomena; D004195:Disease Models, Animal; D018450:Disease Progression; D055119:Elastic Modulus; D005260:Female; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling / Q000379:methods; D013314:Stress, Mechanical; D013997:Time Factors; D059289:Vascular Stiffness
chemical_list: D000629:Aminopropionitrile