Effect of Exposure and Exposure-rate (γ-radiation) on the Brain of the Prenatal Rat

Summary

Pregnant rats were irradiated on day 18 of gestation, 160 R, ⁶⁰Co, gamma, at exposure-rates of 1, 3 and 47 R/min. Body weights of all irradiated animals were less than controls from day 19 (prenatal) through 63 days of age. Concentrations per cell of RNA and protein in the irradiated were not consistently different from controls. Although the cortex from the irradiated animals weighed less than controls and contained less DNA, RNA and protein (1 > 3 > 47 R/min), no exposure-rate effect was evident. In contrast, the remaining portion of the brain from the irradiated groups exhibited not only partial recovery (1 > 3 > 47 R/min) in total DNA in relation to controls but also exhibited an exposure-rate effect. The controls and 1 R/min group (not different) contained more (P < 0·01) DNA than the 3 and 47 R/min groups at day 63.