The Effect of Plethora on Erythropoietin Levels 1 2

Summary The mechanism by which plethora suppresses erythropoiesis in experimental animals has been assumed to be related to a decrease in erythropoietin (Ep) levels. Prior to the advent of a radioimmunoassay (RIA) for Ep this theory could not be confirmed because of the insensitivity of the bioassay for Ep. In the present study hypertransfusion induced plethora was associated with approximately a 50% reduction in plasma Ep levels in CF1 mice. The technical assistance of Ms. Greta Duke and Mr. David Wei is gratefully acknowledged.