An electron microscopic study of the secretory granules in the acinar and duct cells of von Ebner's glands

Abstract

The fine structure of von Ebner's gland was studied in the rat, the mouse, the hamster, the monkey and the human fetus.The histological architecture of the glands in these animals is similar to that reported for the exocrine serous glands. In the rat, the mouse and the hamster, the apical portion of the acinar cell is filled with dense homogeneous secretory granules, which are poor in mucosubstance (weakly positive to PA-TCH staining). The duct cells contain secretory granules which are intensely positive to PA-TCH. In the monkey, the secretory granules of the acinar cells often show a bipartite structure consisting of a centrally-located less dense granular spherule and the peripheral rim of a dense homogeneous matrix. The latter is positive to PA-TCH, in contrast to an weaker reaction in the central spherule. The secretory granules of the duct cells are more intensely positive to PA-TCH than those of the acinar cells. In the 6-months-old human fetus, the acinar cells stain metachromatically with toluidine blue in the apical portion. Many of the secretory granules are less electron dense, and exhibit an intense reaction with PA-TCH in the peripheral rim of the granules. It is, therefore, that these secretory granules are rich in acid mucosubstance. At the end of 7-months of fetal age no metachromasia is found in the apical portion of acinar cells and their secretory granules are rather high in electron density.