title: Photoreversal of the ultraviolet radiation-induced disappearance of ATPase-positive Langerhans cells in the epidermis of Monodelphis domestica.
abstract: The present study was undertaken to explore the possible causes of ultraviolet radiation (UVR)-induced disappearance of ATPase-positive, epidermal Langerhans cells (LC). Monodelphis domestica was used because it has the capacity for photoreactivation of UVR-induced pyrimidine dimers in epidermal DNA. Single, 330 J/m2 (ears) or 500 J/m2 (back) UVR exposures (FS-40 sunlamps) reduced the numbers of ATPase-positive epidermal LC in M. domestica ears to approximately 15% of those in unirradiated ears and approximately 37% of those in unirradiated dorsal skin. Immediate 90-minute exposures to photoreactivating light (PRL, 320-400 nm) post-UVR reversed the effects of UVR, resulting in ATPase-positive LC numbers not being significantly different from controls. Exposure to PRL immediately preceeding UVR did not prevent ATPase-positive LC disappearance. The photoreactivation of UVR-induced ATPase-positive LC disappearance indicates that DNA damage (pyrimidine dimers) is involved in the loss of ATPase-positive LC.
authors.affiliation: Biomedical Research Division, Lovelace Medical Foundation, Albuquerque, New Mexico.
authors.forename: G J
authors.initials: GJ
authors.lastname: LeVee
authors.forename: L A
authors.initials: LA
authors.lastname: Applegate
authors.forename: R D
authors.initials: RD
authors.lastname: Ley
mesh_terms: D000251:Adenosine Triphosphatases / Q000032:analysis*; D000818:Animals; D000078404:Epidermal Cells; D004817:Epidermis / Q000528:radiation effects*; D007801:Langerhans Cells / Q000201:enzymology / Q000528:radiation effects*; D009893:Opossums; D014466:Ultraviolet Rays
chemical_list: D000251:Adenosine Triphosphatases