Radiosensitivity of lymphocytes of mice irradiated in utero and its modification as a function of exposure dose

Pregnant Swiss albino mice were exposed to three different doses of gamma rays i.e. 0.5, 1.5 and 2.5 Gy at different gestation days (14 1/4, 16 1/4, 18 1/4) with or without a prior injection of the radioprotective drug MPG. The animals were bred and lymphocyte count was performed in the offsprings at one week post-partum. The lymphocyte number was significantly depleted in all the exposure groups. Significantly higher counts were noticed in the offsprings of the drug-treated mice irradiated at 14 1/4 days post-conception (p.c.) in all the exposure groups and in those exposed at 16 1/4 p.c. only after the lower doses (0.5 and 1.5 Gy); in the 18 1/4 p.c. group no significant difference in lymphocyte number was observed between the protected and non-protected animals. (author)