IMMUNOHISTOCHEMICAL INVESTIGATION INTO THE DISTRIBUTION PATTERN OF MYOEPITHELIAL CELLS IN THE BOVINE MAMMARY-GLAND

The distribution pattern of myoepithelial cells in the bovine mammary gland was investigated by an immunohistochemical technique, using mono clonal antibodies against cytokeratins 5, 6 and 18 and cytokeratins 8 and 14 and against a-smooth-muscle actin filaments. Myoepithelial cell s were shown to be present as a continuous basal cell layer in the int ralobular ducts, as discontinuous cell rows in the basal cell layer of the interlobular ducts, and as single cells dispersed in the basal ce ll layer of the quarter cisterns, while they were apparently absent in the teat cisterns. Unlike the case with myoepithelial cells of the hu man breast, anticytokeratin 14 was less specific as a marker of bovine myoepithelial cells than was anti-cz-smooth-muscle actin.