title: Melatonin localization in human salivary glands.
abstract: BACKGROUND
  Circulating melatonin is believed to reach body fluids by crossing passively the cell membranes, but alternative ways for melatonin transport also are hypothesized. This investigation was carried out to furnish ultrastructural evidences for melatonin transport by salivary gland cells in order to indicate plausible routes by which circulating melatonin can reach saliva.
  
  
  METHODS
  Bioptic samples of parotid, submandibular and labial glands were processed for the electron microscopy and treated to demonstrate melatonin reactivity by the immunogold staining method.
  
  
  CONCLUSIONS
  The preferential sites of melatonin reactivity were the granules and vesicles of serous cells. Our results suggested that the acinar cells are able to store melatonin and that the hormone can be released into saliva through granule and vesicle exocytosis. The quantitative evaluation of labelling showed that the parotid gland is the most involved in the release of melatonin in saliva.
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Isola
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy.
authors.forename: Maria Alberta
authors.initials: MA
authors.lastname: Lilliu
mesh_terms: D061354:Acinar Cells / Q000378:metabolism; D000368:Aged; D002462:Cell Membrane / Q000378:metabolism; D005089:Exocytosis; D006801:Humans; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D010306:Parotid Gland / Q000378:metabolism; D012463:Saliva / Q000378:metabolism; D012469:Salivary Glands / Q000378:metabolism*; D012470:Salivary Glands, Minor / Q000378:metabolism; D013363:Submandibular Gland / Q000378:metabolism
chemical_list: D008550:Melatonin
keywords: immunogold method; melatonin; salivary gland