IMMUNOCYTOCHEMICAL IDENTIFICATION OF DIFFERENT CELL-TYPES IN BOVINE NASOLABIAL GLANDS WITH PARTICULAR EMPHASIS ON CYTOSKELETAL PROTEIN EXPRESSION

Nasolabial glands are serous glands forming a thick subcutaneous layer in the bovine muzzle. In order to identify the different epithelial c ell types, both immunofluorescent and immunoperoxidase techniques were employed on frozen and fixed sections using monoclonal antibodies to cytoskeletal proteins and S-100. Actin was also detected with phalloid in. The results show that four cell types can be identified on the gro und of the different composition of the cytoskeletal filaments: acinar , basket, luminal duct and basal duct cells. Acinar, luminal duct cell s and basal duct cells express different patterns of cytokeratins, as shown by the 12 anti-cytokeratin monoclonal antibodies used, and both basket cells and the basal cells of intercalated ducts are also reacti ve to phalloidin and anti-alpha-smooth muscle actin monoclonal antibod y. The presence of actin supports the conclusion that basal duct cells are also contractile elements, i.e. myoepithelial cells. Vimentin, gl ial fibrillary acidic protein (GFAP): and S-100, molecules considered to be markers of myoepithelial cells by many AA., were not found. The intermediate filaments of the duct epithelium appear more complex and heterogeneous in comparison with those present in the acinar cells.