Erythropoietin Assays Using Iron 59 Incorporation into Blood and Spleen of the Polycythemic Mouse

Summary

Incorporation of Fe⁵⁹ with blood and spleen of transfused polycythemic mice at various intervals has been used to find sensitive assay systems for erythropoietin. Transfusion polycythemia markedly reduces erythropoiesis as judged by low levels of Fe⁵⁹ uptake into the spleen and into the blood after 16 hours. In polycythemic mice receiving injections of erythropoietin, incorporation of Fe⁵⁹ is maximal in the spleen at 8 hours and in the blood at 48 hours after injection of the isotope. Incorporation of Fe⁵⁹ into the blood of the polycythemic mouse 48 hours after giving the isotope was found to be the most sensitive assay when compared to the starved rat assay and other polycythemic mouse assays.