title: Iron release analyses from ferritin by visible light irradiation.
abstract: We investigated the iron release from ferritin by irradiation from a white fluorescent light in the absence or presence of ADP. Irradiation of a ferritin solution at 17,000 lx in the absence of ADP slightly induces iron release from ferritin but only at acidic pH conditions (pH 5.0 or pH 6.0). Irradiation in the presence of ADP markedly enhances iron release from ferritin under the same conditions. In the absence of irradiation, the iron release from ferritin was low even in the presence of ADP. The induction of the iron release by irradiation in the presence of ADP was also affected by various factors such as irradiation dose and acidity, but not temperature (4-47 degrees C), oxygen concentration, or free radical generations during the irradiation. The iron release during the irradiation ceased to increase by turning off the light and was found to increase again after additional irradiation. These results suggest that visible light directly induces iron release from ferritin via the photoreduction of iron stored inside ferritin.
authors.affiliation: Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ohishi
authors.forename: Xiao Mei
authors.initials: XM
authors.lastname: Zhang
authors.forename: Shinichi
authors.initials: S
authors.lastname: Moriwaki
authors.forename: Tadahisa
authors.initials: T
authors.lastname: Hiramitsu
authors.forename: Seiichi
authors.initials: S
authors.lastname: Matsugo
mesh_terms: D000244:Adenosine Diphosphate / Q000737:chemistry*; D000818:Animals; D000975:Antioxidants / Q000737:chemistry; D005293:Ferritins / Q000737:chemistry* / Q000528:radiation effects*; D005609:Free Radicals / Q000737:chemistry; D006736:Horses; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008027:Light; D010100:Oxygen / Q000737:chemistry; D010777:Photochemistry; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D000244:Adenosine Diphosphate; D005293:Ferritins; D007501:Iron; D010100:Oxygen