Melatonin ultrastructural localization in mitochondria of human salivary glands. Issue 2 (29th September 2022)

• Record Type: Journal Article
• Authors: Isola, Raffaella; Lai, Ylenia; Noli, Roberta; Masala, Carla; Isola, Michela; Loy, Francesco
• Is Part Of: Journal of anatomy. Volume 242:Issue 2(2023)
• Page Start: 146
• Page End: 152
• Publication Date: 2022-09-29
• Subjects: immunogold method -- melatonin -- mitochondria -- salivary glands; Anatomy -- Periodicals; 571.3
• DOI: 10.1111/joa.13775
• Languages: English
• ISSNs: 0021-8782

Abstract

Abstract: The hormone melatonin was initially believed to be synthesized exclusively by the pineal gland and the enterochromaffin cells, but nowadays its production and distribution were observed in several other tissues and organs. Among others, the ultrastructural localization of melatonin and its receptors has been reported in human salivary glands. In these glands, the fine localization of melatonin in intracellular organelles, above all in mitochondria, remains to be explored comprehensively. Bioptic samples of parotid and submandibular glands were treated to search for melatonin using the immunogold staining method by transmission electron microscopy. Morphometric analysis was applied to micrographs. The results indicated that, both in parotid and submandibular glands mitochondria, a certain melatonin positivity was present. Within glandular cells, melatonin was less retrieved in mitochondria than in secretory granules; however, its presence in this organelle was clearly evident. Inside striated duct cells, melatonin staining in mitochondria was more prominent than in glandular cells. Our data provide an ultrastructural report on the presence of melatonin in mitochondria of human major salivary glands and represent a fundamental prerequisite for a better understanding of the melatonin role in this organelle. Abstract : Melatonin was found in mitochondria of serous cells and striated ducts in both human parotid and submandibular glands. Mitochondrial melatonin intensity was similar in both glandular cells and its physiological significance might be connected to its antioxidant activity or efficiency.