title: Development of a novel rabbit model of abdominal aortic aneurysm via a combination of periaortic calcium chloride and elastase incubation.
abstract: BACKGROUND
  The purpose of this study was to introduce a novel, simple and effective technique for creating a reliable rabbit model of abdominal aortic aneurysm (AAA) via a combination of periaortic calcium chloride (CaCl2) and elastase incubation.
  
  
  METHODS
  Forty-eight New Zealand white rabbits were divided into four groups. The AAA model was developed via a 20-minute periaortic incubation of CaCl2 (0.5 mol/L) and elastase (1 Unit/µL) in a 1.5-cm aortic segment (Group CE). A single incubation of CaCl2 (Group C) or elastase (Group E) and a sham operation group (Sham Group) were used for the controls. Diameter was measured by serial digital subtraction angiography imaging on days 5, 15 and 30. Animals were sacrificed on day 5 and day 30 for histopathological and immunohistochemical studies.
  
  
  RESULTS
  All animals in Group CE developed aneurysm, with an average dilation ratio of 65.3% ± 8.9% on day 5, 86.5% ± 28.7% on day 15 and 203.6% ± 39.1% on day 30. No aneurysm was found in Group C, and only one aneurysm was seen on day 5 in Group E. Group CE exhibited less intima-media thickness, endothelial recovery, elastin and smooth muscle cell (SMC) content, but stronger expression of matrix metalloproteinase-2, matrix metalloproteinase-9 and RAM11 compared to the controls.
  
  
  CONCLUSIONS
  The novel rabbit model of AAA created by using a combination of periaortic CaCl2 and elastase incubation is simple and effective to perform and is valuable for elucidating AAA mechanisms and therapeutic interventions in experimental studies.
authors.affiliation: Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang, China.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Bi
authors.forename: Hongshan
authors.initials: H
authors.lastname: Zhong
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xun
authors.initials: X
authors.lastname: Qi
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Xia
authors.forename: Ling
authors.initials: L
authors.lastname: Ren
mesh_terms: D015901:Angiography, Digital Subtraction; D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D017544:Aortic Aneurysm, Abdominal / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000378:metabolism*; D002122:Calcium Chloride; D059168:Carotid Intima-Media Thickness; D004195:Disease Models, Animal; D004549:Elastin / Q000378:metabolism; D006801:Humans; D007440:Intubation; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D010196:Pancreatic Elastase; D011817:Rabbits
chemical_list: D004549:Elastin; D010196:Pancreatic Elastase; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D002122:Calcium Chloride