Establishment and characterization of an epithelial cell line from the rat submandibular gland.

An epithelial cell line, RSMTx, has been established from the submandibular gland of weanling Fisher 344 rats by treatment of explanted tissue clumps with 3-methylcholanthrene. These cells exhibit a polygonal shape on light microscopy and a polar appearance, with desmosomes, terminal bar-like structures, surface microvilli and cytoplasmic interdigitations, when examined by electron microscopy. The cells react positively with an antiserum to cytoskeletal keratin, and a commercial monoclonal antibody to an "epithelial membrane antigen." An antiserum, prepared against early passage cells in hamsters, reacts primarily with ductal elements in tissue sections of submandibular gland, as does an antiserum prepared in mice with late passage cells. The cells are easily passaged and have been maintained for more than two years in continuous culture.