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Reactive Oxygen Species Generated in an Aqueous Gelatin Sample Irradiated by Carbon Ion Beam
https://repo.qst.go.jp/records/70092
https://repo.qst.go.jp/records/70092c4bc42cb-12af-4202-8e51-0ef56d4ce92d
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2010-05-10 | |||||
| タイトル | ||||||
| タイトル | Reactive Oxygen Species Generated in an Aqueous Gelatin Sample Irradiated by Carbon Ion Beam | |||||
| 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 object | |||||
| 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× Nakanishi, Ikuo× Anzai, Kazunori× 松本 謙一郎× 中西 郁夫× 安西 和紀 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | A paramagnetic nitroxyl radical was oxidized by superoxide (•O2-) or hydroxyl radical (•OH) to give the oxoamonium cation. The oxoamonium cation reacts with glutathione to make a stable diamagnetic compound (structure unidentified) or with NAD(P)H to become the hydroxylamine. The hydroxylamine can be re-oxidized mainly by •OH to give the corresponding nitroxyl radical. Hydrogen peroxide (H2O2) participates a reducing the nitroxyl radical during high dose irradiation, since this reduction of nitroxyl radical was restrained by catalase. In this study, amount and distribution of several ROS generated in a gelatin sample by carbon ion irradiation was estimated using a nitroxyl radical, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL), or its hydroxylamine form, i.e. TEMPOL-H as a redox probe. The reduction of TEMPOL in a reaction mixture containing a combination of TEMPOL and GSH can be an index of total reaction of ROS (mainly •OH and •O2-). The GSH-independent reduction of nitroxyl radical caused by high dose irradiation in a reaction mixture of TEMPOL alone can be an index of H2O2 generation. The oxidation of TEMPOL-H in a reaction mixture containing TEMPOL-H alone can be an index of OH. Each reaction mixture containing 0.1 mM TEMPOL or TEMPOL-H was caked using gelatin to test depth-dependent redox reactions. The gelatin sample was irradiated with a 290 MeV/nucleon carbon ion beam at a dose of 32 Gy with several different linear energy transfer (LET) setting. An aliquot of gelatin sample was sampled from surface using a glass capillary, and then increase or decrease of TEMPOL signal was measured by X-band EPR spectrometer. Amount of GSH-dependent reduction of TEMPOL was 400–1200 nmol/L/Gy, which decreased with increasing LET. Amount of GSH-independent reduction of TEMPOL was 30–300 nmol/L/Gy, which also decreased with increasing LET. The level of 30–300 nmol/L/Gy GSH-independent reduction of TEMPOL was estimated as around 60–600 nmol/L/Gy of H2O2 generation if it was simply correlated with X-ray. Amount of oxidation of TEMPOL-H was 2–4 nmol/L/Gy, which also decreased with increasing LET. This result is suggesting that •O2- and/or H2O2 may be an important species to regulate at lower LET part, which usually corresponds to a normal tissue at the carbon ion cancer therapy. |
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| 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 | EPR 2010 (A Joint Conference of the 14th In Vivo EPR Spectroscopy and Imaging and the 11th International EPR Spin Trapping/Spin Labeling) | |||||
| 発表年月日 | ||||||
| 日付 | 2010-05-06 | |||||
| 日付タイプ | Issued | |||||
