eumelanin


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eumelanin

(juːˈmɛlənɪn)
n
(Biochemistry) a form of melanin found in human skin and hair, more common in people with dark skin
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References in periodicals archive ?
Release date- 14082019 - Eumelanin - a natural pigment found for instance in human eyes - has, for the first time, been identified in the fossilized compound eyes of 54-million-year-old crane-flies.
Among the genes that are known to be involved in pigmentation, tyrosinase-related protein (TYRP1), Melanogenesis associated transcription factor (MITF), and KIT ligand (KITLG) genes could directly or indirectly affect the production of two types of pigments, pheomelanin (yellow/red or white color) and eumelanin (dark color) in mammals [5].
Melanin comes in two forms, eumelanin (black or brown) and pheomelanin (reddish-yellow).
People with skin type IV are primarily brown-skinned.19 Skin type IV has more eumelanin and has greater photoprotectant abilities.20
In this work, we follow the proposal of Van Grouw (2006), who considers leucism as a partial or total lack of eumelanin and phaeomelanin due to an inherited disorder in pigment transfer, which causes fail in melanin deposition within cells, although maintaining pigments in the back of the eyeball but not in the iris.
[alpha]-MSH then binds to the melanocortin 1 receptor on melanocyte cells, inducing a switch from the production of the pale skin pigment pheomelanin to eumelanin which is the darker (brown or black) pigment (7).
The first-degree target in laser hair removal is eumelanin contained in the bulb of hair follicles, she said, but the heat must diffuse to a secondary target--follicular stem cells in the bulge of the outer root sheath.
Reasons for its skin lightening effect include: its antioxidant properties, ability to switch eumelanin to pheomelanin which is the type of melanin found in lighter skin-toned individuals and the inhibitory effect it has on tyrosinase which is a key enzyme in melanogenesis.2
Redheads have a particularly high abundance of pheomelanin, with very little eumelanin, which ranges from brown to black.
The color of these organs depends on the amount, distribution, and quality of melanin, which occurs in 3 forms: neuromelanin (brown-black), eumelanin (brownblack), and pheomelanin (golden yellow-red) (Figure 5, B through D).