Dose-Response Relationships for Erythropoietin Given in Serum or in Saline.

Abstract

Summary Dose-response curves for sheep erythropoietin given subcutaneously to polycythemic mice are presented comparing saline to serum as a vehicle. The response observed in radioiron incorporation into red cells is greater for a particular dose of erythropoietin when that dose is given in serum. However, if erythropoietin dissolved in saline is given in fractionated doses over a period of time, the response of a given dose of erythropoietin will increase to that observed with the same dose given in serum. It is suggested that the plasma protein may slow down the absorption of erythropoietin from the subcutaneous site, resulting in a more continuous exposure of erythropoietin sensitive cells to erythropoietin.