The effect of cystamine protection on postirradiation recovery of hemopoiesis as measured by 125I-iododeoxyuridine uptake in bone marrow, spleen and thymus of mice

The method of 125I-iododeoxyuridine labelling of hemopoietic cell populations was used to estimate the effect of cystamine protection on the proliferative activity in spleen, femoral bone marrow and thymus of sublethally gamma-irradiated mice. In the regenerating spleen (9-day period after irradiation) cystamine radioprotection resulted in enhanced proliferative activity, the organ weight regrowth being less evidently modified. In the femoral bone marrow radioprotection effectively enhanced the restitution of cellularity, whilst the proliferative activity was significantly elevated only up to the 5th day after irradiation. The bone marrow independent phase of thymus regeneration, as evidenced by the growth of thymus weight and proliferative activity up to the 9th postirradiation day, was not affected by cystamine radioprotection. The results are discussed from the point of view of the peculiarities of local proliferation control in irradiated hemopoietic organs. (author)