[Animal modeling] - Establishment of a mouse model of abdominal aortic aneurysm and analysis of its histological characteristics

  Objective To establish an abdominal aortic aneurysm model in C57BL/6J mice by perfusion of porcine trypsin and evaluate its pathological changes.

  Methods 30 male mice were divided into two groups, 20 mice as model group and 10 mice as solvent control group. After the abdominal cavity of all animals was opened, the lower abdominal aorta of the kidney was free to the iliac artery segment, and the PPE solution with a dose of 1.5 U/mL was perfused for 5 minutes. After the operation, the abdomen was closed and sutured; PBS was perfused into blood vessels in solvent control group. The diameter of the abdominal aorta was measured before and 14 days after the operation, and the perfused arteries were taken 14 days after the operation. The histological characteristics of the aneurysms were analyzed and rated by histological and immunohistochemical methods.

  Results Compared with the abdominal aorta straight [(0.53 ± 0.03) mm, (0.78 ± 0.06) mm] before operation and PBS solvent control group, the abdominal aorta diameter [(1.20 ± 0.12) mm] of mice in PPE perfusion group 14 days after operation was significantly increased (all P<0.01); Histological analysis showed that the typical AAA pathological features such as elastic fiber breakage, smooth muscle cell depletion and increased inflammatory reaction appeared in the diseased artery segment, suggesting that the AAA model was successfully constructed. According to the pathological characteristics, the model aneurysms were classified histologically, and a set of feasible methods for evaluating the aneurysm pathological model were established.

  Conclusion The analytical method system of AAA and histopathology in mice induced by PPE was successfully established.