Ultrastructural phosphatase cytochemistry of the intercalary ducts of the parotid and submandibular salivary glands of man.

Cells of the intercalary ducts showed concentrations of secretory granules adjacent to the luminal plasma membrane. Evidence of thiamine-pyrophosphatase activity was seen in the Golgi apparatus and of acid-phosphatase activity in GERL-like structure, lysosomes and immature secretory granules. Adenosine-triphosphatase reaction-product was present along surfaces of myoepithelial cells and to a lesser extent along contiguous surfaces of duct cells. The findings indicate secretory activity in the intercalary duct cells.