Late haematological changes in mice after 'in utero' exposure to diagnostic X-rays

Pregnant mice were exposed to single dose of diagnostic X-rays (∼9 mGy) at 3.5 day post-coitus (d.p.c.), 6.5 d.p.c. or 11.5 d.p.c. Peripheral blood changes were studied at 6 weeks and 3, 6 and 12 months of age in the offspring b y estimating total RBC, WBC and haemoglobin. Haemoglobin level and RBC count did not show any change in any of the groups. There was a reduction in the total WBC count at 3 months in the 6.5 d.p.c. exposed group and at 6 months in the 3.5 d.p.c. group, whereas a signficant increase in total leukocytes was observed at 12 months in the animals exposed on day 11.5 of intrauterine life. Differenti al leukocyte counts revealed that a change in the number of lymphocytes was respons ible for the increase or decrease in the total leukocyte counts. These findings could be significant in interpreting the excess leukemia cases reported in epidemiolog ical studies in the exposed populations. (author). 10 refs., 4 tabs