Measurement of erythropoiesis by radio-iron incorporation: influence of iron- and cell kinetic changes.

59Fe blood appearance curves have been obtained in mice by injection of the isotope at various times after 850 rad whole body X-irradiation and bone marrow grafting in order to produce different levels of erythropoiesis. The results demonstrate that measurements at 24, 48 and 72 hours are not comparable and lead to different interpretations. Standardization of the time at which 59Fe uptake measurements are made is therefore recommended.