Alkaline phosphatase and myoepithelial cells in the parotid gland of the rat

Synopsis Alkaline phosphatase activity has been studied in the parotid glands of rats at the light and electron microscopical levels. Reaction product was found to outline the plasma membranes of myoepithelial cells. It was also found in the walls of many capillaries and on the luminal surface and between apposing cells in some intercallary ducts.The distribution of myoepithelial cells in the rat parotid is unusual. The cells run longitudinally around intercalary ducts and send processes on to the bases of adjoining acini but do not embrace the acini. The possible functions of these myoepithelial cells are discussed.