Cytochemical Localization of NAD (P) H Oxidase in the Myoepithelial Cells of Salivary and Other Exocrine Glands

Cytochemical localization of NAD (P) H oxidase, a hydrogen-peroxide generating enzyme, has been investigated using the cerium method in several mammalian exocrine glands: (a) salivary glands of the rat, Mongolian gerbil, house musk shrew and man, (b) lactating mammary glands of the rat and Mongolian gerbil and (c) exorbital lacrimal gland of the rat. The NAD (P) H oxidase activity could be exclusively localized in association with the myoepithelial cells (MEC) of all the exocrine glands examined. The reaction products in the MEC were found mostly on the plasma membranes facing the neighboring cells (acinar cells, ductal cells and MEC) and in the caveolae. These localizations imply that a membrane-bound NAD (P) H oxidase specific for the MEC could exist in mammalian exocrine glands, and that it may be involved in some intercellular regulatory system between MEC and other parenchymal cells of the glands. With regard to the reactivities on MEC, there were apparent diversities among different glands. Intense and constant activities were found in both the lactating mammary glands of the rat and Mongolian gerbil and the salivary glands of house musk shrew, in which the MEC are extremely developed. The usefulness of NAD (P) H oxidase as a marker enzyme of MEC and the significance of its localization in MEC are discussed

Cytochemical Localization of NAD (P) H Oxidase in the Myoepithelial Cells of Salivary and Other Exocrine Glands

Cytochemical localization of NAD (P) H oxidase, a hydrogen-peroxide generating enzyme, has been investigated using the cerium method in several mammalian exocrine glands: (a) salivary glands of the rat, Mongolian gerbil, house musk shrew and man, (b) lactating mammary glands of the rat and Mongolian gerbil and (c) exorbital lacrimal gland of the rat. The NAD (P) H oxidase activity could be exclusively localized in association with the myoepithelial cells (MEC) of all the exocrine glands examined. The reaction products in the MEC were found mostly on the plasma membranes facing the neighboring cells (acinar cells, ductal cells and MEC) and in the caveolae. These localizations imply that a membrane-bound NAD (P) H oxidase specific for the MEC could exist in mammalian exocrine glands, and that it may be involved in some intercellular regulatory system between MEC and other parenchymal cells of the glands. With regard to the reactivities on MEC, there were apparent diversities among different glands. Intense and constant activities were found in both the lactating mammary glands of the rat and Mongolian gerbil and the salivary glands of house musk shrew, in which the MEC are extremely developed. The usefulness of NAD (P) H oxidase as a marker enzyme of MEC and the significance of its localization in MEC are discussed

Comparative Study of the Proliferative Activity of Serous- and Mucous-type Acinar Cells in Developing Mongolian Gerbil Mixed Salivary Glands

We estimated the proliferative activity of serous and mucous acinar cells in mixed-type salivary glands of sucking Mongolian gerbils, using immunohistochemistry with proliferating cell nuclear antigen (PCNA) and in vivo labeling of S-phase cells with the thymidine analog bromodeoxyuridine (BrdU). In both sublingual and Weber\u27s (postlingual) salivary glands, acinar secretory cells showing immunoreactivity for anti-PCNA and anti-BrdU were restricted to serous-type cells that were also positive for a serous component, lysozyme. Some less-differentiated cells found in the serous demilunes or acini, which were negative for lysozyme, also showed proliferative activity, while mucous-type cells never did. These results suggest that in the histogenesis of the mixed gland endpieces, the serous-type cells include immature, differentiating cells, while the mucous-type cells consist of only mature, well-differentiated cells