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The most abundant type of human melanin, found in brown and black skin and hair; cross-linked polymers of 5,6-dihydroxyindoles, usually linked to proteins; levels are decreased in certain types of albinism.
[eu- + G. melos (melan-), black]
Farlex Partner Medical Dictionary © Farlex 2012
References in periodicals archive ?
Studies have shown that dysplastic nevi can contain higher amounts of pheomelanin compared with eumelanin, which suggests a disruption of melanogenesis.
homochromy, crypsis, color change, image analysis, habitat choice, pheomelanin, eumelanin
In the feathers, the researchers spotted the skinny sausages of iridescent melanosomes and chemical signs of the pigment eumelanin. Shawkey thinks the chemical evidence could help "head off any criticism that we might encounter."
Further more, since GSH causes a switch from eumelanin to phaeomelanin, it may increase UV photosensitivity, DNA damage and skin cancers in previously protected populations.
Hair has two types of pigments: eumelanin (dark brown or black pigment) and phaeomelanin (light, reddish-yellow pigment).
The scientists found granules in the fossil that, when compared to modern fish eyes, are made of eumelanin a pigment that absorbs light and helps animals see, Press Tv reported.
he melanocytes, which produce the melanin, can either produce a red melanin -- pheomelanin -- or dark brown -- eumelanin. Melanin can take the form of sunburn, a tan or freckles.
It's the combination of yellow, red and blue pigmentation called pheomelanin and black to brown pigmentation called eumelanin that gives mammals and birds their skin color.
cooperation of dopachrome conversion factor with phenoloxidase in the eumelanin pathway in haemolymph of Locusta migratoria (Insecta).
For example, given the strong optical absorption of melanin, tyrosinase genes were transferred to non-melanogenic cells to encode eumelanin as the contrast agent for PA imaging [52, 54,163,164].
Theconstitutive skin pigmentation is regulated by a number of factors including the relative amounts of eumelanin (brown- black pigment) and pheomelanin (red-yellow pigment) synthesized within melanosomes melanocyte dendricity transport of melanosomes to dendrites and the rate of melanosome transfer to the surrounding keratinocytes (Abdel-Malek and Kadekaro2006).It is also reported that autophagy plays a role in skin colour in humans by regulating melanosome degradation in keratinocytes and thereby contributes to the ethnic diversity of skin color (Murase et al.
There are two types of melanin pigments that can be produced by the melanocytes, namely, "eumelanin" (black or brown) and "pheomelanin" (red or yellow) as shown in Figure 4.