Ultrastructural and histochemical demonstration of myoepithelium in the normal canine mammary gland
Pulley, L.T.
American Journal of Veterinary Research 34(12): 1505-1512
1973
ISSN/ISBN: 0002-9645 PMID: 4128460 Document Number: 65134
Myoepithelial cells were demonstrated in normal canine mammary gland by means of the phosphotungstic acid-haematoxylin, Heidenhain's iron-haematoxylin and tannic acid-phosphomolybdic acid-amido black histological staining techniqes, the azo dye method for alkaline phosphatase activity, and electron microscopy. The alkaline phosphatase reaction was the most reliable light microscopic technique for identifying myoepithelium, since alkaline phosphatase activity was demonstrated only in myoepithelial cells and not in any of the surrounding cells. Ultrastructurally, myoepithelial cells were always identified between the epithelial cells and the basement membrane. A discontinuous layer of myoepithelial cells was around alveoli and some ductules, and a continuous layer was always around ducts. The main identifying ultrastructural feature was the numerous 60- to 80-A filaments in the cytoplasm. Other organelles were scarce and usually limited to the perinuclear area.