Direct measurements of the early erythropoietic effect of anemia

¹ Charlotte Drake Cardeza Foundation; and Department of Internal Medicine, Jefferson Medical College, Philadelphia, Pennsylvania

Measurements were made in normal rabbits of the early effect of acute anemic anoxia on the level of erythropoietic factor and on erythropoietic tissue. The erythropoietic factor was found to be increased 3 hr after the onset of anemic anoxia and before measurable changes could be detected in the erythropoietic tissue. The subsequent production and release appeared to be directly proportional to time. Bone marrow changes during the 8-hr experimental period were more difficult to measure. The best technique appeared to be a simple differential count with the measurement of the ratio between early and late nucleated red blood cells. In vitro bone marrow incorporation of Fe⁵⁹ could be used only if the bone marrow volumes studied were of identical size, a requirement difficult to fulfill. Plasma iron turnover was not sensitive enough to measure early bone marrow changes.