Agents that give rise to skin color are skin thickness, the skin’s light refraction and absorption properties, vascular status, levels of oxidized and reduced hemoglobin, carotenoid content and, most importantly, the pigment melanin. Melanocytes, cells responsible for pigment formation, are present in the basal layer. Melanocytes are most concentrated in the central part of the face and most sp...

Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not wel...

Melanin pigmentation of the gingiva is a common occurrence. Depending on the gingival display during smiling, corrective measures may be needed for an esthetic purpose. Diode laser is a minimally invasive treatment option for the treatment of gingival melanin pigmentation. Three case reports of gingival depigmentation procedure performed using a 980 nm diode laser are presented here.

PURPOSE To study melanogenesis by cultured human uveal melanocytes, and the relationship between melanin production by uveal melanocytes in vitro with the degree of iris pigmentation in vivo. METHODS Melanin content, melanin production, and tyrosinase activity of cultured uveal melanocytes derived from eyes of various iris color were measured at different stages of cultivation. RESULTS Cult...

Intracellular organelles mediate complex cellular functions that often require ion transport across their membranes. Melanosomes are organelles responsible for the synthesis of the major mammalian pigment melanin. Defects in melanin synthesis result in pigmentation defects, visual deficits, and increased susceptibility to skin and eye cancers. Although genes encoding putative melanosomal ion tr...

Mutation of the tyrosinase gene (TYR) causes oculocutaneous albinism, type 1 (OCA1), a condition characterized by reduced skin and eye melanin pigmentation and by vision loss. The retinal pigment epithelium influences postnatal visual development. Therefore, increasing ocular pigmentation in patients with OCA1 might enhance visual function. There are 2 forms of OCA1, OCA-1A and OCA-1B. Individu...

Excessive gingival pigmentation is a major esthetic concern for many people. Melanin pigmentation is known to be caused by melanin granules within the gingival epithelium. Though it is not a medical pathology, many people complain of dark gums as unesthetic. A case is reported here of hyperpigmentation treated with scalpel, diode laser and electrosurgical procedure in a split mouth design with ...

In Drosophila, the pattern of adult pigmentation is initiated during late pupal stages by the production of catecholamines DOPA and dopamine, which are converted to melanin. The pattern and degree of melanin deposition is controlled by the expression of genes such as ebony and yellow as well as by the enzymes involved in catecholamine biosynthesis. In this study, we show that the conserved TSC/...

Effects of histamine per se along with its specific agonists and antagonists were studied on the skin melanophores of Hemidactylus flaviviridis to study the role of histamine receptors in pigmentation. Histamine and 2-methyl histamine induced powerful melanin aggregation effects, leading to paling of the skin through stimulation of H1 receptors. On the other hand, 4-methyl histamine, a specific...