1992 Volume 111 Issue 6 Pages 693-695
To elucidate the mechanism of sunlight-induced skin damage, guinea pigs were exposed to UV light (280-320nm, UV B, 4J/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 (0.5J/cm2). An ESR signal obtained only with irradiation comprised a 1:2:2:1 quartet [a(N)=a(βH)=1.49mT] 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.
