| Project/Area Number |
12672168
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
医薬分子機能学
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| Research Institution | National Institute of Radiological Sciences |
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Principal Investigator |
UEDA Jun-ichi National Institute of Radiological Sciences, Redox Regulation Research Group, Team Leader, 放射線安全研究センター・レドックス制御研究グループ, チームリーダー (90160168)
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| Co-Investigator(Kenkyū-buntansha) |
OZAWA Toshihiko National Institute of Radiological Sciences, Executive Director, 理事 (40160858)
KEIZO Takeshita National Institute of Radiological Sciences, Redox Regulation Research Group, Senior Researcher, 放射線安全研究センター・レドックス制御研究グループ, 主任研究員 (70175438)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | ultraviolet light / skin / reactive oxygen species / free radical / in vivo ESR / surface-soil-type resonator / hairless mouse / PBN / In vitro ESR / ニトロキシルラジカル / スピンプローブ / サーフェイス・コイル型共振器 |
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| Research Abstract |
Distinct electron spin resonance(ESR) signal of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) adduct of hydroxyl radical (OH) was observed in uroporphyrin or hematoporphyrin photodynamic reactions in the presence of reducing reagents, although no adduct of OH was observed using 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO) as a spin-trapping agent. Both DMPO and DEPMPO adducts of OH appeared, as the spin-trapping was performed with DEPMPO in the presence of DMPO. The results indicate that the DMPO-mediated generation of OH occurs during the spin-trapping in photodynamic reactions. Thus, in vivo ESR spectroscopy with a nitroxyl spin probe was employed to detect reactive oxygen species generated in skin.
An aqueous solution of carbamoyl-PROXYL was injected intravenously to an anesthetized hair-removed ddY mouse or hairless mouse, and L-band ESR spectra of the probe were recorded at the dorsal region of the mice. A surface-coil-type resonator was used to detect carbamoyl-PROXYL in skin. The decay rate of the ESR signal increased by irradiation with UV light (UVA+B). The enhancement of signal decay was suppressed by pre-administration of a spin-trapping reagent, N-t-butyl-α-phenylnitrone (PBN), while PBN did not change the decay rate for non-irradiated mouse. Peroxyl radical caused the decay of carbamoyl-PROXYL signal in vitro, and the decay was inhibited by PBN. These observations suggest that peroxyl radical was generated in skin of mouse under ultraviolet light irradiation.
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