Studies on splenic population size feedback control regulatory mechanisms.

In previous studies, experimental splenosis was produced in normal rodents and in animals following splenectomy. Splenosis was more in splenectomised than in normal animals. In the present study, in animals into whom splenic fragments were implanted subcutaneously, there were less peritoneal splenic growth areas than in controls. The hypothesis is presented that there is a population size feedback control regulatory mechanism operating in splenic growth and regeneration. If such regulators are present in the circulation, administration of normal plasma should inhibit splenosis and this may serve as a model to isolate such regulators. This was not the case in these experiments.

Studies on the radioprotective effect of etiocholanolone.

One-hundred forty male mice of an inbred strain (C3H/St) were divided into four groups of thirty-five each and were given total body irradiation of 750 cGy. After X-irradiation, one group was given etiocholanolone alone, the other was given bone marrow alone, a third was given both of these. One group was used as a control and was given no treatment after irradiation. The bone marrow used was obtained from the same inbred strain of mice. The most remarkable hematologic recovery was seen in the group which was given both etiocholanolone and bone marrow. The groups given only etiocholanolone or only bone marrow recovered better than the control group. Overall survival was best for the group receiving both modes of treatment and worst for the control group. Survival for the groups receiving a single mode of treatment lay in between the other two mentioned above.