Background: This paper aims to comparatively observe similarities of squamous-columnar junction (SCJ) at the opening of Von Ebner's glandular ducts at the vallate papillae in dogs, mice, rats and humans, lay a foundation for the selection of the model in future study of the carcinogenesis in SCJ at vallate papillae.
Materials and methods: The localization of the vallate papillae in three laboratory animals and humans was comparatively observed. The differences of SCJ at vallate papillae were comparatively observed by Alcian blue, immunohistochemistry and HE staining.
Results: Anatomically, the canine vallate papillae were most similar to those of humans in location, whereas mice and rats only had a single, Ω-shaped, vallate papilla lying directly anterior to the posterior border of the intermolar eminence. In histology, the SCJ of dogs lacked a transition zone similar to that of the human SCJ, and there was glandular epithelium secreting acidic mucus at the opening of the rats' Von Ebner's glandular ducts. All of this suggested that the histological structure of SCJ in rats and dogs is more distinct from that of humans, whereas the histological structure of SCJ at vallate papilla in mice was more similar.
Conclusions: The structure of SCJ at vallate papilla in mice is most similar to that of humans, so we conclude that mouse is the most suitable model for studying tumorigenesis in SCJ at vallate papillae in these three common laboratory animals.
Keywords: Vallate papillae; Von Ebner's glands; squamous-columnar junction (SCJ).