Archives of Dermatological Research

, Volume 304, Issue 1, pp 39–45

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

  • Keiichi Hiramoto
  • Yurika Yamate
  • Hiromi Kobayashi
  • Masamitsu Ishii
Original Paper

DOI: 10.1007/s00403-011-1183-3

Cite this article as:
Hiramoto, K., Yamate, Y., Kobayashi, H. et al. Arch Dermatol Res (2012) 304: 39. doi:10.1007/s00403-011-1183-3

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/m2 using a FL20SBLB-A lamp for 60 days. The plasma α-melanocyte stimulating hormone (α-MSH), nitrogen oxides (NO2/NO3), tumor necrosis factor-α (TNF-α), and the prostaglandin E2 (PGE2) content all increased after UVA irradiation. The levels of NO2/NO3, TNF-α, and PGE2 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.

Keywords

Ultraviolet A Mast cell Fibroblast Collagen α-MSH 

Abbreviations

UVA

Ultraviolet A

α-MSH

α-melanocyte stimulating hormone

MC1R

Melanocortin receptor 1

TNF-α

Tumor necrosis factor-α

PGE2

Prostaglandin E2

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Keiichi Hiramoto
    • 1
    • 2
  • Yurika Yamate
    • 3
  • Hiromi Kobayashi
    • 1
  • Masamitsu Ishii
    • 1
  1. 1.Department of DermatologyOsaka City University Graduate School of MedicineAbenoJapan
  2. 2.Brain Science InstituteOsaka City University Medical SchoolAbenoJapan
  3. 3.Department of PhysiologyOsaka City University Graduate School of MedicineAbenoJapan