Increased Erythropoietic Stimulant in Plasma of Pregnant Rats.

Abstract
Plasma of normal adult female rats contains a factor capable of stimulating erythropoiesis in hypophysectomized rats and also in newborn rats, as judged by increased circulating red cell volume and hemoglobin. This humoral erythropoietic factor is markedly increased during pregnancy. Plasma and blood volumes of both hypophysectomized and newborn recipients were also increased by the injection of plasma from pregnant and non-pregnant rats.