title: Melanin: the biophysiology of oral melanocytes and physiological oral pigmentation.
abstract: The presence of melanocytes in the oral epithelium is a well-established fact, but their physiological functions are not well defined. Melanin provides protection from environmental stressors such as ultraviolet radiation and reactive oxygen species; and melanocytes function as stress-sensors having the capacity both to react to and to produce a variety of microenvironmental cytokines and growth factors, modulating immune, inflammatory and antibacterial responses. Melanocytes also act as neuroendocrine cells producing local neurotransmitters including acetylcholine, catecholamines and opioids, and hormones of the melanocortin system such as proopiomelanocortin, adrenocorticotropic hormone and α-melanocyte stimulating hormone, that participate in intracellular and in intercellular signalling pathways, thus contributing to tissue homeostasis.There is a wide range of normal variation in melanin pigmentation of the oral mucosa. In general, darker skinned persons more frequently have oral melanin pigmentation than light-skinned persons. Variations in oral physiological pigmentation are genetically determined unless associated with some underlying disease.In this article, we discuss some aspects of the biophysiology of oral melanocytes, of the functions of melanin, and of physiological oral pigmentation.
authors.affiliation: Department of Periodontology and Oral Medicine, University of Limpopo (Medunsa Campus), Pretoria, South Africa. liviu.feller@ul.ac.za.
authors.forename: Liviu
authors.initials: L
authors.lastname: Feller
authors.forename: Aubrey
authors.initials: A
authors.lastname: Masilana
authors.forename: Razia A G
authors.initials: RA
authors.lastname: Khammissa
authors.forename: Mario
authors.initials: M
authors.lastname: Altini
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Jadwat
authors.forename: Johan
authors.initials: J
authors.lastname: Lemmer
mesh_terms: D006801:Humans; D008543:Melanins / Q000502:physiology*; D008544:Melanocytes / Q000502:physiology*; D009061:Mouth Mucosa / Q000502:physiology*; D009909:Oral Health; D012880:Skin Pigmentation / Q000235:genetics / Q000502:physiology*; D013234:Stem Cells / Q000502:physiology; D020390:Tooth Socket / Q000502:physiology
chemical_list: D008543:Melanins