Electron microscopic immunogold localization of statherin in human minor salivary glands

In this study, which supplements a recent article on the localization of statherin in human major salivary glands, we investigated the intracellular distribution of this peptide in minor salivary glands by immunogold cytochemistry at the electron microscopy level. In the lingual serous glands of von Ebner, gold particles were found in serous granules of all secreting cells, indicating that statherin is released through granule exocytosis. In buccal and labial glands, mostly composed of mucous tubuli, statherin reactivity was detected in the serous element, which represents only a small population of the glandular parenchyma. In these serous cells, however, statherin labeling was absent in secretory granules and restricted to small cytoplasmic vesicles near or partially fused with granules. Vesicle labeling could be related to the occurrence of an alternative secretory pathway for statherin in buccal and labial glands.