Iron for Erythropoiesis

Rabbits were rendered anemic by phlebotomy, by parenteral administration of phenylhydrazine and by phlebotomy coupled with transfusion of nonviable erythrocytes. Measurements were made of the number and iron uptake of immature erythroid cells, and the size and hemoglobin content of the circulating erythrocytes. All groups of animals showed the same degree of erythroid cellular proliferation in response to anemia. The total amount of hemoglobin synthesized was determined by the supply of iron to the marrow and was reflected in variations in hemoglobin content within the individual erythrocyte. For maximal production of hemoglobin in the animal with increased cellular proliferation, an increased plasma iron level is required.