American Journal of Clinical Nutrition, Vol 5, 461-472, Copyright © 1957 by The American Society for Clinical Nutrition, Inc.

Influence of Humoral Factors on Erythropoiesis

¹ From the Department of Biology, Graduate School of Arts and Science, New York University, N. Y.

It has been shown that although the endocrine glands, including the anterior pituitary, thyroid and adrenal, exert significant effects upon erythropoiesis, their role is a subsidiary one. They operate probably by altering the rate rather than by exerting an absolute control over the erythropoietic processes.

There can be no doubt that erythropoietic stimulating activity appears in the blood of animals and man under anoxic conditions. The factor(s) evoked by anoxia is heat-stable and appears in greater concentration in the plasma than in a variety of organs examined. Its presence in large concentration in the blood of human subjects with Cooley's anemia and its absence in a case of chronic hypoplastic anemia suggest that it plays a part in erythropoiesis in man and presents the possibility of its utilization in the treatment of certain types of anemia.

Opinion is divided concerning the chemical nature of the erythropoietic factor. A lipoidal substance (e.g., fatty-acid ester or steroid) is suggested by some experiments whereas others indicate that it may be protein in nature. Our chromatographic studies show a good positive correlation between the degree of metachromasia and erythropoietic stimulating activity in boiled filtrates of plasma obtained from subjects with Cooley's anemia, rabbits treated with phenylhydrazine and from control subjects. This would support the contention that the erythropoietic factor is a mucoprotein or a moiety associated with this fraction.

There is need at the present for more information concerning the site of production of the erythropoietic factor, its chemical nature and mode of action, and its possible application to the treatment of a variety of blood dyscrasias in man and laboratory animals.