Mouse Bone-marrow Response to Low Doses of Whole-body Gamma Irradiation: Induction of Micronuclei

Summary

The induction of micronuclei in mouse bone marrow was studied after whole-body exposure to low doses of gamma radiation, ranging from 5 to 75 cGy. Micronuclei were scored at 10 and 30 h after irradiation. A linear dose response was obtained at both postirradiation times. However, the number of micronuclei per 100 nuclei was lower at 30 h than at 10 h, and the dose—response curve for the former had a shallower slope. When fitted to the αD + βD² model, a negative β value was obtained. This could be due to division delay, combined with elimination of damaged cells by death at higher doses.