Attenuation of DNA damage in the dermis and epidermis of the albino hairless mouse by chronic exposure to ultraviolet-A and -B radiation.
Mammalian skin is vulnerable to the photocarcinogenic and photoaging effects of solar UV radiation and defends itself using a variety of photoprotective responses including epidermal thickening, tanning and the induction of repair and antiradical systems. We treated Skh-1 albino hairless mice for 60 days with ultraviolet-A (UVA) or ultraviolet-B (UVB) radiation and measured the frequency of cyclobutane pyrimidine dimers and pyrimidine(6-4)pyrimidone photoproducts induced by a single acute sunburn dose of UVB at different stages of the chronic treatment. We found that both UVA and UVB exposure produced a photoprotective response in the dermis and epidermis and that the degree of photoproduct attenuation was dependent on dose, wavelength and the type of damage induced. Although epidermal thickening was important, our data suggest that UV protective compounds other than melanin may be involved in mitigating the damaging effects of sunlight in the skin.
Mitchell
D L
DL
Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park/Research Division, P.O. Box 389, Smithvilie, TX 78957, USA. dmitch@io.com
Byrom
M
M
Chiarello
S
S
Lowery
M G
MG
D000818:Animals; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D005260:Female; D051379:Mice; D008812:Mice, Hairless; D011740:Pyrimidine Dimers / Q000378:metabolism / Q000528:radiation effects; D012867:Skin / Q000293:injuries / Q000378:metabolism / Q000528:radiation effects*; D012878:Skin Neoplasms / Q000517:prevention & control; D014466:Ultraviolet Rays
D011740:Pyrimidine Dimers