To explore the significance of early intervention with rapamycin in a rabbit model of corrosive esophagitis stenosis.

Twelve clean-grade New Zealand white rabbits (labeled 1-12, male and female, aged 5 months, with a body weight of 2.5-3.0 kg) were andomly divided into 4 groups, with 3 animals in each group. The control group did not receive treatment after modeling; experimental group A was given rapamycin 1 hour after modeling; experimental group B was given rapamycin on the second day after modeling; experimental group C was given rapamycin on the 7th day after modeling. On the 7th day after treatment, esophageal angiography was performed and inflammatory indicators of esophageal stenosis (interleukin-2, tumor necrosis factor- γ and protein expression (collagenⅠ, collagen Ⅲ, α- smooth muscle actin) were detected,and compared between groups.

All 12 New Zealand white rabbits were successfully used to establish animal models of esophageal inflammatory stenosis. Esophagography in control group and experimental group C showed thickening and stiffness of the middle and lower esophageal mucosa, indicating localized stenosis. It was difficult for the contrast medium to pass, while the esophageal mucosa in experimental groups A and B was not smooth, and the contrast medium was passable. Hematoxylin eosin staining reveals mucosal and submucosal necrosis, with inflammatory cell infiltration mainly composed of eosinophils and lymphocytes. Immunohistochemistry showed deposition of collagen fibers and expression of smooth muscle actin. The inflammatory indicators and protein expression in the control group were higher than those in experimental groups A, B and C, with statistically significant differences (P < 0.01).

Early administration of rapamycin can significantly reduce the degree of corrosive esophageal inflammatory stenosis in rabbits, alleviate inflammatory reactions and protein expression, and thus inhibit scar formation.