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Detecting free radical reactions induced by low LET irradiation: Reactions of nitroxyl free radical probes and hydrogen donors
https://repo.qst.go.jp/records/69185
https://repo.qst.go.jp/records/6918559211baa-12c6-4b86-80b7-208c0e699437
| アイテムタイプ | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2007-11-22 | |||||
| タイトル | ||||||
| タイトル | Detecting free radical reactions induced by low LET irradiation: Reactions of nitroxyl free radical probes and hydrogen donors | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference output | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Matsumoto, Kenichiro
× Matsumoto, Kenichiro× et.al× 松本 謙一郎 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Free radical reaction/generation may not simply depend linearly on the dose and LET when heavy ion beam was irradiated to a biological samples. Oxygen effect is being a problem even in a radiation therapy using carbon ion beam. Since generation of reactive oxygen species/bioorganic free radicals can be considered as a main reason of the oxygen effect, a method to quantify amount of free radical reaction/generation in a biological sample is requred. In this study, stability and reactivity of reaction mixtures containing 0.1 mM of a nitroxyl free radical probe, i.e. 4-hydroxyl-TEMPO (TEMPOL) or 3-carbamoyl-PROXYL (CmP), and 1 M of a hydrogen donor (H-donor), i.e. GSH, NADH, or NADPH were tested. X-band EPR measurements of several reaction mixtures were performed to find a suitable condition to detect free radical reactions using low linear-energy-transfer (LET) irradiation at relatively low dose (< 16 Gy). The EPR signal intensity of nitroxyl radicals were decreased by X-ray irradiation when the hydrogen donor was coexisting in the reaction mixture. It was found that presence of H-donor, such as GSH or NAD(P)H, was indispensable to detect reduction of nitroxyl radicals by a relatively low dose irradiation. It was strongly suggested the formation of ROS, such as ∙OH and/or ∙O2-, in aqueous solution by radiation. The main reaction of NAD(P)H and nitroxyl radicals may be the one-electron reduction of nitroxyl radical to corresponding hydroxylamine, which may be two-step reaction via oxoamonium cation. The reaction of GSH and nitroxyl radicals may have both one-electron reduction passway and an another unknown pass, which may be irreversible. The combination of TEMPOL and GSH was most preferable to detect free radical reaction caused by radiation quantitatively among the conditions tested in this study, because of the sensitivity and irreversibity of the reaction. This combination can also be applied to test effects of other radiation sources, i.e. beta-, and gamma-ray. This method will be applied to estimate free radical reaction caused by heavy-ion beams in a future study. | |||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | The 4th JSPS Core-to-Core Program Seminar International In Vivo Redox Symposium | |||||
| 発表年月日 | ||||||
| 日付 | 2007-11-05 | |||||
| 日付タイプ | Issued | |||||
