Postirradiation erythropoietic recovery in splenectomized mice

The influence of splenectomy on erythropoietic recovery of lethally X-irradiated mice injected with different doses of syngeneic bone marrow was studied. Splenectomized animals showed less activation than unoperated controls in the lower dose range; however, by increasing the number of injected cells the response obtained was similar in both groups. Providing an adequate number of stem cells is administered to the splenectomized recipients, an enhanced erythropoietic activity of the graft may compensate for the absence of the spleen, which is an important organ in postirradiation recovery. Suggested explanations for this observation are lack of an haematopoietic inhibitory effect of the irradiated spleen, or changes in the environment provided by the spleenless host.