Transplantation of Rat Bone Marrow in Irradiated Mice: Effect of Exposure Rate

Mice were irradiated at several different exposure rates so that they received a total of 900 roentgens over the whole body. Within 2 hours they were injected with rat bone marrow. The success of the transplantation depended upon the rate at which the animals had been irradiated: the higher the rate, the greater the success of the grafts. Failure of grafts in mice subjected to low exposure-rates was associated with antibody formation. The data indicate existence of an immune mechanism which is dependent on the radiation exposure-rate.