Free radicals in human skin before and after exposure to light.

@article{Pathak1968FreeRI,
  title={Free radicals in human skin before and after exposure to light.},
  author={M. Pathak and K. Stratton},
  journal={Archives of biochemistry and biophysics},
  year={1968},
  volume={123 3},
  pages={
          468-76
        }
}
Human skin exhibited a stable electron spin resonance (ESR) signal before irradiation, only if the samples were pigmented. The single almost symmetrical absorption peak with g = 2.003 and a line width of 5–6 gauss at 77 °K is associated with melanin. It was also observed in pigmented human and guinea pig hair, melanosomes, and melanin granules obtained from B-16 mouse melanoma and DOPA-melanin. Irradiation with wavelengths greater than 320 mμ, including ruby laser (λ = 694 mμ) and incoherent… Expand
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Observations show that irradiation of cells in the presence of pheomelanin could produce cytotoxic effects, and may have application in the development of in vitro models for the study of UV radiation-induced cutaneous carcinogenesis. Expand
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Abstract Photoenhancement of the electron spin resonance signals from pigmented human skin, black hair, and synthetic DOPA-melanin preparations has been studied both at room temperature and atExpand
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By electron-spin resonance measurements, the melanin granules of the mammalian eye have been shown to generate free radicals when irradiated with visible light under approximately physiological conditions, and the anatomical proximity of the melanIn granules to the rods and cones and their response to light suggests that the melanins may play an important role in the visual process. Expand
APPARENT ESR PHOTOSIGNALS IN MELANIN
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The effect of U.V. radiation on the ESR in squid melanin was investigated and found under certain conditions an apparent photo-enhancement of the melanin resonance and the photoenhanced ESR was found to have a TI shorter than that of the normal ESR. Expand
ELECTRON SPIN RESONANCE STUDIES OF ULTRAVIOLET IRRADIATED KERATIN AND RELATED PROTEINS
Abstract— The formation of free radicals in keratin and related proteins by exposure to u.v. light has been examined by electron spin resonance spectroscopy. From a comparison of the spectra obtainedExpand
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It is concluded that the unpaired electrons observed are associated with trapped free radicals in the melanin polymer, that the biosynthesis of melanin may involve a free radical mechanism, and that these physical data are in accord with the concept of Nicolaus that melanin is a highly irregular, three-dimensional, polymer. Expand
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Understanding of the biochemical changes occurring in the epidermal cell following irradiation remains limited, but there is increasing interest in studying mammalian tissues. Expand
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Abstract A comparative study on sepiomelanin and three synthetic pigments, namely dopa melanin, 5,6-dihydroxyindole melanin and pyrrole black, has been carried out. Sepiomelanin is structurallyExpand
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The electron spin resonances of Calliphora puparia, of Sepia ink, of human hair, and of 3,4-dihydroxyphenylalanine melanin have been determined and the free radical property of these melanins is ascribed to a stabilized semiquinonoid form of the polymeric pigment. Expand
Carcinogenesis by Ultraviolet Light
Feel lonely? What about reading books? Book is one of the greatest friends to accompany while in your lonely time. When you have no friends and activities somewhere and sometimes, reading book can beExpand
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