Recovery of hematopoiesis in bone marrow of mice after continuous irradiation with dose rate 4.8 Gy/day.

In this paper the morphological changes in mouse bone marrow till day 60 after the termination of continuous irradiation with the dose rate 4.8 Gy/day (480 rad/day) and the total accumulated doses 9.6 Gy (960 rad) and 19.2 Gy (1920 rad) are evaluated. Many mononuclear cells of the morphologically lymphoid type appear in the bone marrow on day 9 of the recovery and later on extensive granulopoiesis recovery occurs reaching the control level, as early as on day 21--28 after the irradiation. The recovery of erythropoiesis and megakaryocytopoiesis proceeds more slowly and their total recovery occurs within the period of 28--60 days after the irradiation. The total accumulated dose 19.2 Gy (1920 rad) causes irreversible damage in the bone marrow and the death of all experimental animals occurs within 11 days after irradiation.