1.Laboratory Animal Center, Xi’an Jiaotong University School of Medicine, Xi’an 710061, China. 2. Department of Vascular Surgery, the Second Hospital of Tianjin Medical University, Tianjin 300211
Objective This study aimed to analyze the effect of preoperative body weight on the progression of porcine pancreatic elastase (PPE)-induced abdominal aortic aneurysm (AAA) in mice fed a normal diet. Methods We retrospectively analyzed the association of preoperative body weight and postoperative abdominal aortic diameter in 44 PPE- induced abdominal aortic aneurysm mouse models in our laboratory. Sixteen mice, divided into group 1 (n= 8, preoperative weight less than 25 g) and group 2 (n= 8, preoperative weight of more than 30 g) were chosen for the following analysis. The body weight, fat distribution, abdominal aorta diameter and diameter changes of all mice were analyzed. Comparative analysis of histology and immunohistochemistry of AAA lesions was conducted among group 1, group 2 and normal control animals. The normal control mice were free of surgery. Results The correlation coefficient between the aortic diameter and preoperative body weight was 0. 005 (using the 44 included mice). No significant influence of body weight was found on the progression of AAA in mice fed a normal diet in this study. Further analysis found that there were no significant differences in the abdominal aortic diameter (1. 35 mm vs 1. 27 mm) and diameter changes (0. 85 mm vs 0. 72 mm) between the model groups 1 and 2 at day 14 after the surgery. Compared with normal control mice, PPE-treated mice in model groups 1 and 2 had a significant increase in the diameter of the infrarenal aorta at postoperative day 14, and all formed aneurysms. Histological observations showed typical AAA lesion features, such as elastic fiber breakage, smooth muscle exhaustion, increased inflammation and abnormal angiogenesis. Conclusions Body weight was not associated with the progression of PPE-induced AAA in mice fed a normal diet.