Studies on the Biochemical Alterations of the Protein Synthesizing Apparatus in Maturing Rabbit Reticulocytes : I. Maturation in Vivo

The study of maturation of rabbit reticulocytes in vivo revealed an essential correlation between the degree of reticulocytosis, the RNA content of the circulating red blood cells and their ability to carry out amino acid incorporation into protein. The nevertheless frequent occurrence of considerable quantitative discrepancies between these parameters during the progress of maturation appears to be attributable to fluctuations in the reticulocyte population due to intrinsic difference in the life span of these cells and to release of young reticulocytes from the hyperplastic bone marrow into the circulation. The distortions in the pattern of maturation kinetics by the continued contribution of the bone marrow seem to be largely eliminated by blocking erythropoiesis at the height of reticulocytosis with the aid of actinomycin D treatment.