[Effect of fractionated thymocytes from intact and irradiated mice on CFU recovery in the bone marrow after sublethal irradiation].

In studying the influence of thymocytes fractionated by their size in the ficoll density gradient on the CFUs content of the irradiated mouse bone marrow, two subpopulations of T-cells were isolated: the administration of the first thymocyte subpopulation decreased the CFUs content during the postirradiation recovery period while thymocytes of the second subpopulation increased the content of CFUs in the bone marrow. When thymocytes of mice exposed to low-level radiation were separated a considerable stimulatory effect was produced by certain thymus cell fractions on the number of CFUs in the bone marrow of exposed recipients; no inhibitory effect was registered.