Local variations in the staining patterns of keratin antigens and blood group antigens in normal rodent oral epithelia.

All rodent oral epithelia are orthokeratinized. However, morphological, immunohistochemical and biochemical studies have shown that regional differences exist. In the present study, intraregional variations in differentiation patterns of rat oral epithelia are demonstrated using monoclonal anti-keratin antibodies AE1 and AE2 and antibodies to blood group antigens B and H. Well-defined areas of rat buccal and hard palate epithelium differed from the general staining patterns of these epithelia. These areas were associated with a papillary surface contour. These local variations were not found in the strain of mice examined. The results suggest that physiologically different vertical compartments of keratinocytes exist within one and the same region of rat oral mucosa, a phenomenon previously recognized in detail only in the epithelium of dorsal tongue. The papillary structures may have some functional significance related to the processing of food similar to that suggested for lingual filiform papillae.