Effects of low doses of gamma radiation on DNA synthesis in the developing rat brain.
Rats of one or ten days of age were irradiated with low doses of gamma radiation, and synthesis of DNA was examined by the incorporation of 3H-thymidine in the cerebellum and the rest of the brain in vivo. DNA synthesis was depressed in both parts of the brain but the effects were larger in cerebellum. A minimum was found about 10 hours after irradiation in the older rats and later (18 h) in the younger ones. The dose response, in 10-day-old rats, was biphasic and showed that cerebellum was more affected. Autoradiographs showed that fewer cells entered the cycle and those synthesizing showed a depressed rate of synthesis. These findings are discussed in relation to induction of cell death.
D000367:Age Factors; D000818:Animals; D001921:Brain / Q000378:metabolism / Q000528:radiation effects*; D002531:Cerebellum / Q000378:metabolism / Q000528:radiation effects; D003037:Cobalt Radioisotopes / Q000009:adverse effects*; D004247:DNA / Q000096:biosynthesis / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D003037:Cobalt Radioisotopes; D004247:DNA