Systemic protection against radiation. I. Effect of an elemental diet on hematopoietic and immunologic systems in the rat

Rats were fed the Mead-Johnson elemental diet 3200-BD or the normal laboratory pellet food. The former group was found more resistant to a 700-rad total-body exposure of 60Co γ radiation. In these animals, [3H]TdR incorporation was higher in the thymus, spleen, and bone marrow. They could also respond better to an antigenic stimulation by producing a larger amount of antibody. The radioprotective action of the diet might be explained in terms of an enhanced cellular proliferation of the hematopoietic tissues. Finally, a relation seems to exist between this enhancement and a more efficient immune response in diet-fed animals. (U.S.)