Common immunophenotypic features of submandibular salivary glands and thymus in rats

Introduction. Submandibular salivary gland is a part of the neuro-immune-endocrine system. It contains biological factors which regulate a number of functions in the body including the modulation of thymus function. Objective. The aim of the study was to investigate immunophenotypic characteristics of submandibular salivary glands of rats during ontogenesis, using the panels of monoclonal antibodies and to compare with the phenotypic characteristics of epithelial components of the thymus. Methods. Submandibular salivary glands and thymus were obtained from 1, 30 and 60 days old male AO (Albino, Oxford) rats. Streptavidin-biotin peroxidase method was used for staining. Results. Immunohistochemical analysis of rat submandibular salivary glands showed phenotypic heterogeneity of particular components of this gland during the postnatal development. We demonstrated that rat submandibular salivary glands share common antigens with rat thymic epithelial cells, but the observed phenotypic similarity between the individual regions was considered much more significant. Our data showed that the phenotypic similarity between duct epithelial cells and subcapsular epithelial cells and most medullary cells, whereas cortical epithelial cells are phenotypically similar to acinar cells. Conclusion. This immunohistological study showed phenotypic complexity of the submandibular salivary gland and similarity to the thymus that opens new perspectives in studying phenotypic similarities between this gland and lymphatic organs