Abstract
The effects of low-dose iron ion beam (500 MeV/n, LET=220 keV/μ
m) on the postnatal and prenatal development of mice as well as on the differentiation of neural crest cells were investigated. Pregnant females of C57BL/10JHir mice at 9 days of gestation were whole-body irradiated with a single acute dose of iron ions. The effect was studied by scoring changes in the postnatal development of mice and in the pigmentation (white spot) in cutaneous coats 22 days after birth. The percentage of birth, survival to day 22 and body weight at day 22 decreased in irradiated mice. The effect of iron ions on the survival to day 22 was greater than that of γ-rays (Hirobe, 1994). Iron ions were more effective than γ-rays. The frequency and size of white spots in the mid-ventrum increased in irradiated mice. In irradiated embryos, the frequency of abnormalities in fore and hind legs, tails and eyes as well as of hemorrhage increased with increasing dose and the number of embryos as well as the body weight at 18 days of gestation decreased. Moreover, the number of hair bulb melanocytes in the dorsal and ventral skins decreased from 0.1 Gy-treated mice, and as gradually decreased with increasing dose. These results suggest that low-dose iron ions have a greater effect on the prenatal and postnatal development of mice as well as on the neural crest cell differentiation.
