MACROMOLECULAR CARBONYLS IN HUMAN STRATUM-CORNEUM - A BIOMARKER FOR ENVIRONMENTAL OXIDANT EXPOSURE

The presence of stratum corneum carbonyls may serve as an intrinsic do simeter for environmental oxidative damage to skin, To investigate the accumulation of carbonyls in human stratum corneum, skin was tape-str ipped, then tapes were sequentially incubated with 2,4-dinitrophenyl h ydrazine (DNPH), rat anti-DNP, mouse anti-rat IgG conjugated with alka line phosphatase, p-nitrophenyl phosphate and absorbance (405 nm) meas ured and carbonyls estimated, Stratum corneum exposed in vitro to oxid ants: hypochlorous acid (1, 10, 100 mM), ozone (0, 1, 5, 10 ppm for 2 h) or UV light (280-400 nm; 0, 4, 88, or 24 J/cm(2)) contained increas ed carbonyls, Furthermore, stratum corneum carbonyls were elevated in tanned compared with untanned sites: dorsal hand (0.43 +/- 0.06 nmol/c m(2)) vs, lower arm (0.32 +/- 0.04, mean +/- S.E.M., n = 11; P < 0.003 ) and lower back (0.26 +/- 0.02) vs, buttock (0.21 +/- 0.02; n = 6, P < 0.01) indicating in vivo oxidative damage. (C) 1998 Federation of Eu ropean Biochemical Societies.