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