Immunohistochemical changes in an in vitro rat model of celiac disease

Dietary wheat gluten is the etiologic cause of celiac disease. Its ingestion induces changes in the mucosal architecture of the jejunum in susceptible individuals. The aim of this study was to improve the in vitro rat embryo model for testing toxicity of gluten peptides. In the experiment, a modified rat embryo small intestinal model was used. Cultured jejunal tissue was exposed to peptic-tryptic digest of gliadin and its effect was compared to lactalbumin; the control was not exposed to any material. The effects on the intestinal tissue were assessed by light microscopy, using the following staining methods: hematoxylin and eosin, proliferating cell nuclear antigen-staining to assess cell proliferation; cytokeratin staining to determine the stage of cell differentiation; and alkaline phosphatase activity was assayed to determine maturity and viability of the epithelium. Marked changes in both proliferation and villar differentiation parameters were noted in the fractions of the rat embryo small intestine. Gluten treatment was toxic to the villar epithelium, whereas lactalbumin was not. The present work indicates that the use of different immunohistochemical staining methods to detect cell differentiation and proliferation in rat embryo small intestine serves as a good model for examining toxic effects of gliadin fractions in vitro.