[Effect of immobilization of mice with different radiosensitivities and shielding of part of the bone marrow on survival and spleen colony formation following irradiation].

Experiments on linear F1 (CBA x C57BL) mice resistant to irradiation and random-bred white mice which are more sensitive to irradiation were made to study the relationship of the survival rate of the animals and spleen colony formation to the magnitude of x-ray doses during immobilization and shielding of the crus--factors which increase the resistance. It was shown that low colony formation typical for linear mice remained at a low level during the resistance-increasing immobilization, while in the course of shielding it increased in accordance with the animals' survival rate. In random-bred mice, the survival rate and colony formation were in good agreement in all the cases.