The human melanocytes of the skin, hair, eyes, inner ears, and covering of the brain provide physiologic functions important in organ development and maintenance. Melanocytes develop from embryonic neural crest progenitors and share certain traits with other neural crest derivatives found in the adrenal medulla and peripheral nervous system. The distinctive metabolic feature of melanocytes is the synthesis of melanin pigments from tyrosine and cysteine precursors involving over 100 gene products. These complex biochemical mechanisms create inherent liabilities for melanocytic cells if intracellular systems necessary for compartmentalization, detoxification, or repair are compromised. Melanocyte disorders may involve pigmentation, sensory functions, autoimmunity, or malignancy. Environmental factors such as ultraviolet radiation and chemical exposures, combined with heritable traits, represent the principal hazards associated with melanocyte disorders.
Acknowledgments
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Notes
a Adapted from Liu et al. [Citation96].
b Isolated using enzymatic method.
c Range of values from three hair samples.
d Sum of total amino acids from HCl hydrolysis.
e Soluene 350 extract, A 500× 1000.
f PTCA (pyrrole-2,3,5-tricarboxylic acid) generated from eumelanin with H2O2/OH−.
g AHP (aminohydroxyphenylalanine) formed from pheomelanin by Hl-hydrolysis.
a Compiled from reviews by Njoo and Westerhof (Am. J. Clin. Dermatol. 2001;2:167–181) and Boissy and Manga (Pigm. Cell Res. 2004;17:208–214).
a Compiled from Boissy and Manga (Pigm. Cell Res. 2004, 17: 208–214).