In vitro leucine incorporation into protein of normal and x-irradiated rabbit bone marrow cells

¹ Atomic Energy Medical Research Project, Western Reserve University School of Medicine, Cleveland, Ohio

When compared with nonirradiated controls, the isolated bone marrow cells of x-irradiated rabbits showed a decrease (ca. 40%) in the in vitro uptake of labeled leucine into proteins 1 and 2 days after exposure to 400 r and 800 r. A similar magnitude of inhibition of leucine incorporation was observed in hemibody x-irradiated rabbits in which the marrow cells from the irradiated femur were compared with that from the nonirradiated side. The decreased uptake of leucine into protein after radiation may be due to an interruption in the supply of young forms during the postirradiation period, and hence, the decreased uptake of amino acids into proteins may be characteristic of the mature cells of the surviving cellular elements.