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Long-term ultraviolet A irradiation of the eye induces photoaging of the skin in mice.

Abstract

Irradiation by long-term ultraviolet (UV) A initiates the induction of photoaging. However, the mechanisms responsible for the structural changes of skin induced by UVA irradiation of the eye are still unknown. Male hairless mice were used in this study. The eye or dorsal skin was locally exposed to UVA after covering the remaining body surface with aluminum foil at a dose of 110 kJ/m(2) using a FL20SBLB-A lamp for 60 days. The plasma α-melanocyte stimulating hormone (α-MSH), nitrogen oxides (NO(2)/NO(3)), tumor necrosis factor-α (TNF-α), and the prostaglandin E(2) (PGE(2)) content all increased after UVA irradiation. The levels of NO(2)/NO(3), TNF-α, and PGE(2) also increased more after UVA skin irradiation than after UVA eye irradiation. However, the level of α-MSH increased more by eye irradiation than skin irradiation. In addition, UVA irradiation of the eye and dorsal skin increased the number of mast cells and fibroblasts. Furthermore, the expression of the melanocortin-1 receptor (MC1R) was increased on the fibroblast surface by UVA irradiation of the eye. These results indicate that the signal evoked by UVA irradiation of the eye, through the hypothalamo-pituitary proopiomelanocortin system, up-regulated the production of α-MSH. This hormone controls the collagen generation from fibroblasts, thus suggesting that photoaging was induced by UVA irradiation of the eye.

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  • Publisher Full Text
  • Authors

    Hiramoto K, Yamate Y, Kobayashi H, Ishii M

    Institution

    Department of Dermatology, Osaka City University Graduate School of Medicine, Abeno, Japan. hiramoto@msic.med.osaka-cu.ac.jp

    Source

    Archives of dermatological research 304:1 2012 Jan pg 39-45

    MeSH

    Animals
    Dinoprostone
    Eye
    Fibroblasts
    Immunohistochemistry
    Male
    Mast Cells
    Mice
    Mice, Hairless
    Nitrogen Oxides
    Receptor, Melanocortin, Type 1
    Skin Aging
    Time Factors
    Tumor Necrosis Factor-alpha
    Ultraviolet Rays
    alpha-MSH

    Pub Type(s)

    Journal Article

    Language

    eng

    PubMed ID

    22033528