Abstract
Production of 8-hydroxy-2'-deoxyguanosine (8-OHdG) was examined in 2'-deoxyguanosine (dG) solution irradiated with X-rays, carbon ions, neon ions or silicon ions. The range of LET was 2-300keV/micrometer. The dG solution was saturated with air or with the mixture of 95% nitrogen and 5% carbon dioxide for a hypoxic condition during irradiation. 8-OHdG was detected by an HPLC-ECD system. In both conditions, the yield of 8-OHdG decreased with increasing LET, which can be explained by the lower yield of OH radicals in the high LET region. However, the yield showed constant or rather increasing tendency above 100 keV/micrometer under the hypoxic condition. Consequently the ratio of 8-OHdG yields between the air-saturated and the hypoxic condition became small. These results are consistent with oxygen-in-the-track hypothesis that proposes the oxygen production along ion tracks at the high LET region. [J Radiat Res 44:435 (2003)]
