【Animal Modeling】-Establishment of a mouse model of abdominal aortic aneurysm and analysis of histological characteristics

  Objective To establish a model of abdominal aortic aneurysm in C57BL/6J mice by porcine pancreatic elastase perfusion method and to evaluate its lesions histologically.

  Methods Thirty male mice were divided into two groups, 20 mice were the model group and 10 mice were the solvent control group. After the abdominal cavity of all animals was opened, the infrarenal abdominal aorta to the iliac artery was dissociated, and the PPE solution at a dose of 1.5 U/mL was perfused for 5 min, and the abdomen was closed and sutured after the operation. The diameter of the abdominal aorta was measured before and 14 days after the operation, and the perfused artery was collected on the 14th day after the operation. The histological characteristics of the aneurysm were analyzed and graded by histology and immunohistochemistry.

  Results Compared with the abdominal aorta of the mice in the preoperative and PBS solvent control group [(0.53±0.03) mm, (0.78±0.06) mm], the abdominal aorta diameter of the mice in the PPE perfusion group at 14 days after operation [(1.20 ±0.12) mm] significantly increased (all P<0.01); histological analysis found that typical AAA lesions such as elastic fiber rupture, smooth muscle cell depletion and increased inflammatory response appeared in the lesioned artery segment, indicating that the AAA model was successfully constructed. According to the characteristics of the lesion, the model aneurysm was histologically graded, and a set of feasible methods for evaluating the aneurysm lesion model was established.

  Conclusion The PPE-induced mouse AAA and histopathological analysis method system were successfully established.