Biochemical analysis of cerebrum of fetal rat X-irradiated in utero--DNA, RNA, superoxide dismutase and lipid peroxide--.

Wistar rats were X-irradiated in utero and biochemical analysis of the cerebrum was performed on gestational day (g d) 21. The cerebral weight was significantly lower in the irradiated group on g d 13 with above 75R than in the control group. The contents of DNA, RNA and protein were decreased in the cerebrum of the fetuses irradiated with 100R on g d 13 when calculated per cerebrum, and DNA only was decreased occasionally when expressed as per gm wet weight. The lipid peroxide level of the cerebrum in the irradiated group was increased compared to that of the control group. The superoxide dismutase (SOD; E.C. 1.15.1.1.) activity was extremely low and lipid peroxidation in vitro was considerably enhanced in fetal cerebrum. The low activity of SOD may be one of the factors which cause the vulnerability of fetal brain to irradiation.