@misc{oai:repo.qst.go.jp:00069014,
 author = {Moritake, Takashi and Anzai, Kazunori and Manda, Kailash and Ueno, Megumi and Takusagawa, Mitsuko and Iwakawa, Mayumi and Imai, Takashi and 盛武 敬 and 安西 和紀 and Ｍａｎｄａ Ｋａｉｌａｓｈ and 上野 恵美 and 田草川 光子 and 岩川 眞由美 and 今井 高志},
 month = {Jul},
 note = {[Purpose]
The aim of this study was to quantitatively evaluate the generation of hydroxyl radicals (OH) in water and 8-hydroxydeoxyguanosine (8-OHdG) in DNA during high linear energy transfer (LET) ion irradiation. In addition, the effect of oxygen on OH and 8-OHdG generation was evaluated.
[Materials and Methods]
Pure water containing 200 mM 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and pure water containing 1.0 mg/ml salmon sperm DNA were irradiated with heavy-ion beams at dose levels of 20 Gy and 10 Gy, respectively. In order to investigate the effect of oxygen on the generation of OH and 8-OHdG, the samples were irradiated under atmospheric and deaerated conditions. Irradiation using four ion species at five different energies (carbon, 290 MeV/n and 135 MeV/n; neon, 400 MeV/n; silicon, 490 MeV/n; and argon, 500 MeV/n) was carried out at NIRS-HIMAC in Japan. Each type of ion was irradiated at three different LET values, using PMMA plates of varying thickness to attenuate the irradiation energy: carbon (290), 20-80 keV/um; carbon (135), 25-95 keV/um; neon, 30-100 keV/um; silicon, 80-300 keV/um; and argon, 100-230 keV/um. In order to compare the effects of high-LET heavy-ion irradiation and low-LET photon irradiation, identical samples were also irradiated with x-rays (200 kV, 20 mA; approximately 2 keV/um) under the same conditions. Yields of OH were measured using an electron spin resonance (ESR) spectrometer. Levels of 8-OHdG in DNA were measured by HPLC with an electrochemical detector (ECD) after each irradiation.
[Results]
For each type of ion irradiation, the amounts of both OH and 8-OHdG formed decreased logarithmically as LET (keV/um) increased. The amounts of both species formed at each LET value tended to become greater as the atomic number of the irradiating species (carbon, neon, silicon, or argon) increased. The results obtained for aerated and deaerated samples revealed the same pattern; however, significantly smaller amounts of OH and 8-OHdG were formed under deaerated conditions., The 13th International Congress of Radiation Research},
 title = {Measurement of hydroxyl radicals and 8- hydroxydeoxyguanosine induced by high-LET heavy-ion irradiation},
 year = {2007}
}