title: UVA does not photoreactivate pyrimidine dimers in cultured human fibroblasts.
abstract: Pyrimidine dimers were induced in duplicates of cultured human skin fibroblasts by irradiation with various doses of UVB radiation. Subsequently, one set of cells was further exposed to either 5 or 10 J/cm2 of UVA radiation to assess the photoreactivating activity of this spectral range in a human cell system. Following irradiation, pyrimidine dimers were quantified in all cells by determining the number of endonuclease-sensitive sites (ESS). No difference in the yield of ESS was observed between cells which had been irradiated with UVB only as compared to cells which subsequently had been exposed to 5 or 10 J/cm2 UVA. In contrast, subsequent exposure of UVB-irradiated cells of Monodelphis domestica to 10 J/cm2 UVA resulted in an almost 50% reduction of UVB-induced pyrimidine dimers. These data indicate that UVA does not induce photoenzymatic repair in human fibroblasts.
authors.affiliation: Division of Special and Environmental Dermatology, University of Vienna, Medical School, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Tanew
authors.forename: B
authors.initials: B
authors.lastname: Ortel
authors.forename: H
authors.initials: H
authors.lastname: Hönigsmann
mesh_terms: D000328:Adult; D000818:Animals; D002478:Cells, Cultured; D004249:DNA Damage; D004260:DNA Repair / Q000528:radiation effects*; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000378:metabolism*; D004790:Enzyme Induction / Q000528:radiation effects; D000078404:Epidermal Cells; D005347:Fibroblasts / Q000201:enzymology / Q000528:radiation effects*; D006801:Humans; D009893:Opossums / Q000378:metabolism; D011740:Pyrimidine Dimers / Q000528:radiation effects*; D013045:Species Specificity; D014466:Ultraviolet Rays
chemical_list: D011740:Pyrimidine Dimers; D004255:Deoxyribodipyrimidine Photo-Lyase