Effect of Bone Marrow Therapy on the Volitional Activity of Whole-Body X-Irradiated Rats

¹ From the U. S. Naval Radiological Defense Laboratory, San Francisco, California

Postirradiation injection of bone marrow suspension was used to test the hypothesis that the decrease in volitional activity seen during the 2nd and 3rd weeks after whole-body x-irradiation in the lethal range is related to damage of the hematopoietic system. The marrow preparation used was found to afford statistically significant protection in terms of lethality. Surviving irradiated animals treated with bone marrow suspension showed no decrease in activity during the 2nd and 3rd weeks postirradiation, even though the radiation dose used (650 r) was in excess of that required to produce such a decrease in the volitional activity of nontreated irradiated animals. Since the bone marrow treatment apparently affects hematopoiesis specifically, it appears that the volitional activity decrement during the 2nd and 3rd weeks after whole-body irradiation is related to hematopoietic damage. Further, it appears that a greater functional hematopoietic capacity is necessary to maintain normal volitional activity levels than is required to survive after x-irradiation.