Rats develop more robust and persistent peritoneal adhesion phenotypes than mice: a multimodal comparative study

Area of Science:

• Biomedical research
• Surgical pathology
• Translational science

Background:

• Peritoneal adhesions (PAs) are a significant postsurgical complication.
• Animal models are crucial for understanding PA pathogenesis and developing treatments.
• Existing models may not fully recapitulate human PA characteristics.

Purpose of the Study:

• To compare the development and characteristics of peritoneal adhesions in rat and mouse models.
• To evaluate the suitability of rat and mouse models for clinical phenotype studies and translational research.

Main Methods:

• Established postoperative PA models using cecum-abdominal wall ischemic injury suture in Sprague-Dawley rats and BALB/c mice.
• Systematically evaluated adhesion progression using micro-computed tomography (CT), macroscopic scoring (DASI), histopathology, immunohistochemistry, and scanning electron microscopy (SEM).
• Compared peritoneal morphology between humans and rodents via SEM.

Main Results:

• Rats exhibited significantly more severe and persistent adhesions than mice, with denser CT shadows and higher DASI scores.
• Histological analysis revealed greater collagen deposition and higher TGF-β1 and fibronectin expression in rats.
• SEM showed the rat peritoneum possesses more abundant microvilli and a regular texture, resembling the human peritoneum more closely than the mouse peritoneum.

Conclusions:

• The rat model demonstrates more robust and persistent peritoneal adhesion features compared to the mouse model.
• The rat model is a more suitable platform for clinical phenotype studies and translational evaluation of peritoneal adhesions.
• Morphological similarities between the rat peritoneum and human peritoneum provide a valuable reference for interspecies differences in PA development.