Carnot and Deflandre , in 1906 , were the first researchers who dealt with the study of humoral factor , which they called haemopoietin later experimental work was done on animals by bleeding and falling barometric pressure , suggesting that the stimulus would occur from these causes. Later Reissman ( 1) , in their experience is that humoral mechanism for hypoxia stimulates erythropoiesis . Stohlman ( 2) , and others , in patients with ductus arteriosus , did a study on saturation and oxygen tension , supporting the mechanism mentioned above. In 1953 , Erslev ( 3) plasma transfused to normal recipients anemic getting reticulocytosis ( 6 to 10 % ) and a significant increase in hematocrit . Van Dyke (8 ) studied this factor in several clinical cases of anemia, finding positive in some cas.os of aplastic anemia. These facts suggested us to perform this study on erythropoietin, which was fir...