Adaptive response of the mutagenicity of the somatic and germ cells in mice induced by in vivo 147Pm radiation

Effects of pretreatment of mouse with low doses of internally deposited 147Pm on the mutagenicity of both the bone marrow lymphocytes and the spermatoblasts induced by subsequent high dose of internally deposited 147Pm were studied. Kunming male mice were injected from the tail vein with low doses of 147Pm(NO3)3 of 0.37, 3.7 and 37 Bq/g body weight. Three days later the mice were injected with a high dose of 147Pm(NO3)3 of 18.5 kBq/g body weight. The animals were sacrificed at 24h after the high dose injection. The results show that the bone marrow lymphocytes and the spermatoblasts pre-exposed in vivo to low doses of 147Pm can produce an adaptive response. The radio-adapted cells had a resistance to the mutagenicity induced by the subsequent high dose of 147Pm, that is, the proportion of both the bone marrow lymphocytes containing micronuclei and the sperm shape abnormalities was significantly lower than those for the pure high dose group (P<0.01). In addition, the induction of the adaptive response of the cells possesses the different dose ranges for the different biological parameters. The 147Pm dose ranges of the adaptive response are 0.37-3.7 and 0.37-37 Bq/g body weight for the frequency of micro-nucleated bone marrow lymphocytes and abnormal sperms, respectively