Hydroxyl radical formation by UV-irradiated epidermal cells.
To elucidate the mechanism of sunlight-induced skin damage, guinea pigs were exposed to UV light (280-320 nm, UV B, 4 J/cm2) and a homogenate of the epidermis was examined by means of the thiobarbituric acid (TBA) test. Three hours after the exposure, TBA-malondialdehyde adducts had increased while glutathione reductase activity had decreased, indicating lipid peroxidation. To detect the initial species, spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was applied to a suspension of illuminated epidermal cells (0.5 J/cm2). An ESR signal obtained only with irradiation comprised a 1:2:2:1 quartet [a(N)= a(beta H) = 1.49 mT] attributable to a spin adduct of hydroxyl radicals. These results suggest that sunlight exposure of skin may lead to hydroxyl radical generation and simultaneous lipid peroxidation.
Taira
J
J
Cosmetics Laboratory, Kanebo Ltd., Odawara.
Mimura
K
K
Yoneya
T
T
Hagi
A
A
Murakami
A
A
Makino
K
K
D000818:Animals; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D006168:Guinea Pigs; D006878:Hydroxides / Q000378:metabolism / Q000528:radiation effects*; D017665:Hydroxyl Radical; D015227:Lipid Peroxidation / Q000528:radiation effects; D008297:Male; D012867:Skin / Q000378:metabolism / Q000528:radiation effects*; D013113:Spin Labels; D014466:Ultraviolet Rays / Q000009:adverse effects
D003497:Cyclic N-Oxides; D005609:Free Radicals; D006878:Hydroxides; D013113:Spin Labels; D017665:Hydroxyl Radical; C017245:5,5-dimethyl-1-pyrroline-1-oxide