Inhibition of Erythropoietic Effects of Hormones by Erythropoietin Antisera in Mildly Plethoric Mice. ∗

Summary

Antisera to erythropoietin (Anti-ESF) was found to block completely the erythropoietic effects of 3,5,3′-triiodothyronine (T₃), ACTH, and testosterone in mildly plethoric mice. The effects of T₃, ACTH, and testosterone were also markedly dampened by increased plethora. The hormones studied increased radioactive iron in red cells of mildly plethoric mice without producing a significant alteration in plasma iron. These findings indicate that ACTH, testosterone and T₃ stimulate erythropoiesis indirectly by increasing the elaboration of endogenous erythropoietin, or else they require a certain level of erythropoietin in the recipient animal for their erythropoietic effects.