Effect of gamma-irradiation on prenatal development of the nasal septal cartilage in CD-1 mice.

The effects of gamma-rays on nasal septum development in CD-1 mouse fetuses subsequent to irradiation of their mothers were studied. Pregnant CD-1 mice exposed to 400 rads of whole body gamma-irradiation 12 days after gestation were sacrificed on day 18, post coitum. The fetuses were removed via laparotomy and analyzed. Data on head dimensions, including head height, width, and circumference were recorded. Fetal heads were then routinely prepared for histologic examination of the developing nasal septal cartilage. Analysis of data revealed significant reduction in litter size (p < .0025) and head measurements (p < .0005) of irradiated animals. Histologically, the nasal septa of irradiated fetuses had retarded growth, were less differentiated, and smaller than those of control mice. Results suggest that gamma-irradiation has detrimental effects on litter and head sizes and may interfere with the cellular maturation process of nasal septal cartilage as well as other structures.