Exposure time effect on radiation damage and recovery of hemopoiesis in mice

In experiments on F1 hybrid mice (CBAsup(x)-C57B1) exposed to doses of 800 R over a period of 123 sec in one case and 47 hr in the other, changes in the cellular make-up of bone marrow, thymus, spleen and peripheral blood were studied. Following the prolonged irradiation larger numbers of cells were preserved in the organs studied; repopulation processes began earlier and ended with more complete regeneration than was observed in the animals subjected to the short irradiation. Cell regeneration processes following both prolonged and short irradiation were modelled by an exponential function. The regeneration time in mice subjected to the short irradiation was 1.1-3.6 times that observed in the other animals. (author)