【Animal Modeling】-A retrospective study on the effect of different body weights on the progression of abdominal aortic aneurysm in mice under normal diet

  Objective To analyze the effect of preoperative body weight on the progression of porcine pancreatic elastase (PPE)-induced abdominal aortic aneurysm in mice under normal diet.

  Methods A retrospective analysis was carried out in 44 cases of PPE-induced mouse abdominal aortic aneurysm models in our laboratory in the last six months, and the effects of different body weights before surgery on the later abdominal aortic diameter and the progression of abdominal aortic aneurysm were analyzed, and the correlation between the two was analyzed. Body weight, fat distribution, abdominal aorta diameter, abdominal aorta were measured for 8 selected mice with preoperative weight less than 25 g (model group 1) and 8 selected mice with preoperative weight greater than 30 g (model group 2). Comparison of diameter changes, abdominal aortic aneurysm lesions histology and immunohistochemistry. Normal negative control mice were not given any treatment.

  Results The correlation coefficient between the vascular diameter of abdominal aortic aneurysm and the preoperative body weight in 44 mice was 0.005. No significant effect of body weight on the progression of abdominal aortic aneurysm was found. Further analysis found that there was no significant difference in the vascular diameter (1.35 mm vs 1.27 mm) and the changes in vessel diameter (0.85 mm vs 0.72 mm) between the model 1 group and the model 2 group at 14 days after surgery. Compared with normal blood vessels, the diameter of the infrarenal perfusion segment of the abdominal aorta was significantly increased in the model group 1 and model group 2 mice at 14 days after surgery, and all aneurysms were formed. Histology showed typical abdominal aortic aneurysm lesions such as elastic fiber rupture, smooth muscle cell depletion, increased inflammation, and abnormal angiogenesis.

  Conclusion In normal diet mice, body weight did not affect the progression of abdominal aortic aneurysm.