title: Eumelanin and pheomelanin concentrations in human epidermis before and after UVB irradiation.
abstract: Pheomelanin is widely thought to be causally related to susceptibility to the harmful effects of ultraviolet radiation: epidemiological studies show that those with a higher ratio of pheomelanin to eumelanin in hair have higher rates of melanoma, and work in mouse and cell culture shows that pheomelanin generates excess free radicals after UVR exposure. By contrast, based on measurements of eumelanin and pheomelanin in human skin, before and following irradiation, we now report that both pheomelanin and eumelanin are positively related to skin colour, and by inference, inversely with cancer susceptibility. The ratio of melanin classes is similar in people with widely different cancer rates and UVR sensitivity. Although our numbers are small, our results extend previous work in man, and lead us to speculate that factors other than the amount of pheomelanin may be important in determining UVR susceptibility in persons with red hair.
authors.affiliation: Department of Dermatology, University of Edinburgh, UK.
authors.forename: Alison
authors.initials: A
authors.lastname: Hennessy
authors.forename: Carol
authors.initials: C
authors.lastname: Oh
authors.forename: Brian
authors.initials: B
authors.lastname: Diffey
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Wakamatsu
authors.forename: Shosuke
authors.initials: S
authors.lastname: Ito
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rees
mesh_terms: D004817:Epidermis / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects*; D006801:Humans; D008543:Melanins / Q000032:analysis / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D008543:Melanins; C018362:pheomelanin; C041877:eumelanin