title: In vivo oxygen radical generation in the skin of the protoporphyria model mouse with visible light exposure: an L-band ESR study.
abstract: Although oxygen radicals are thought to play a key role in the skin injury that is caused by protoporphyria, there is no direct evidence of generation of these radicals in vivo. This study measured the generation of oxygen radicals caused by visible light non-invasively in the skin of griseofulvin-induced protoporphyria model mice, using an in vivo electron spin resonance spectrometer equipped with a surface-coil-type resonator that could detect radicals within about 0.5 mm of the skin surface. A durable nitroxyl radical was administered intravenously as a probe. Light irradiation enhanced the decay of the nitroxyl signal in griseofulvin-treated mice, whereas light irradiation did not enhance the signal decay in control mice. The enhanced signal decay was completely suppressed by intravenous administration of hydroxyl radical scavengers, superoxide dismutase or catalase, or the intraperitoneal administration of desferrioxamine. The enhanced signal decay with illumination was reversible, and quickly responded to turning the light on and off. These observations suggest that the hydroxyl radical is generated via an iron-catalyzed reaction in the skin. This paper demonstrates, for the first time, the specific generation of oxygen radicals in response to light irradiation of the skin of protoporphyria model mice.
authors.affiliation: Department of Biophysics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Keizo
authors.initials: K
authors.lastname: Takeshita
authors.forename: Tokuko
authors.initials: T
authors.lastname: Takajo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hirata
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Ono
authors.forename: Hideo
authors.initials: H
authors.lastname: Utsumi
mesh_terms: D000818:Animals; D000935:Antifungal Agents; D002374:Catalase / Q000494:pharmacology; D003676:Deferoxamine / Q000494:pharmacology; D004195:Disease Models, Animal; D004578:Electron Spin Resonance Spectroscopy; D006118:Griseofulvin; D017665:Hydroxyl Radical / Q000378:metabolism; D007502:Iron Chelating Agents / Q000494:pharmacology; D008027:Light / Q000009:adverse effects*; D008297:Male; D051379:Mice; D017121:Porphyria, Hepatoerythropoietic / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012867:Skin / Q000378:metabolism* / Q000528:radiation effects*; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D007502:Iron Chelating Agents; D017382:Reactive Oxygen Species; D006118:Griseofulvin; D017665:Hydroxyl Radical; D002374:Catalase; D013482:Superoxide Dismutase; D003676:Deferoxamine