STUDY OF BIOLOGICAL EFFECTS OF TRITIUM IN MICE

The mutation, apoptosis and chromosomal aberration induced by tritiated water (HTO) in spleen T lymphocytes of mice were investigated and compared with those by acute or chronic 137Cs gamma irradiation. p53 wild-type (p53+/+) and null (p53−/−) mice were exposed to tritium (3H) beta rays via a single injection of HTO. 137Cs gamma irradiation was carried out at dose-rate of 0.86Gy min−1 (acute) and at a low dose-rate (0.71–0.09 mGy min−1) that mimicked internal exposure (gamma simulation-irradiation). Each dose of irradiation was 3Gy. When compared on the basis of the induced TCR variant fractions in p53−/− mice at 3Gy, 3H beta rays appeared to be more mutagenic than chronic gamma ray reference. On the other hand, both of the frequency chromosomal aberration was not different significantly between HTO injected and 137Cs gamma irradiated mice.