Abstract
The effects of iron ion beam (500 MeV/u, LET=200 KeV/micronm) on the differentiation of melanocytes as well as on the prenatal and postnatal development of mice were investigated by scoring changes in the ventral pigmentation and in the organogenesis. Pregnant females of C57BL/10J 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 pigmentation in cutaneous coats 22 days after birth and in the prenatal and postnatal development of mice. The percentage of birth, survival to day 22 and body weight at day 22 were decreased in irradiated mice. The effect of iron ions on the survival to day 22 was greater than that of gamma-rays (Hirobe, 1994). The frequency and size of white spots in the mid-ventrum were increased in irradiated mice. Iron ions were more effective than gamma-rays. The frequency of abnormalities in the fore and hind legs, tails and eyes as well as of hemorrhage was increased as dose increased and the number of embryos as well as the body weight at 18 days of gestation was decreased. These results suggest that iron ions have a greater effect on the melanocyte differentiation as well as on prenatal and postnatal development of mice than gamma-rays.
