Table 2. Radiation-induced base damage in cellular DNA.
| Product/DNA basea | 5mC (1a) | C (1c) | T (1b) | Guanine |
|---|---|---|---|---|
| Gly (2) | n.d. | 1.48 ± 0.14 | 7.75 ± 0.10 | |
| Hyd (3) | 0.37 ± 0.01 | 5.71 ± 0.48 | 0.85 ± 0.14 | |
| Imid (4) | n.d.b | 2.12 ± 0.06 | ||
| 5hmC/5hmU (5) | 1.20 ± 0.14 | 13.26 ± 1.64 | ||
| 5fC/5fU (6) | 0.47 ± 0.05 | 19.47 ± 1.15 | ||
| 8oxoG | 8.72 ± 0.72 |
aRate of formation of pyrimidine oxidation products in cellular DNA in units of lesions per 106 non-modified DNA bases per kGy of ionizing radiation. The values were obtained from the graphs presented in Figure 5. Levels of modifications in non-irradiated cells were 7.5 5hmC, 0.5 5fC, 5.6 5hmU, 24.5 5fU, 3.7 T-Gly and 2.5 8oxoG lesions per 106 nonmodified DNA bases modifications; the other lesions were not detected in non-irradiated cellular DNA (<0.1).