Hormonal Factors Influencing Erythropoiesis

Abstract

Removal of thyroid, adrenals or gonads individually or in combination results in only a mild anemia. Removal of these organs does not interfere with the erythropoietic response of the animal to hypoxia. Admn. of the hormones of these target organs has a beneficial effect when these hormones are not present but does not result in a polycythemia when given to normal animals. Evidence is presented that the anterior pituitary plays an important role in the control of circulating red cell volume. Hypophysectomy is followed by a severe anemia and by interference with the erythropoietic response to hypoxia. Oral admn. of fresh anterior lobe of pituitary stimulates erythropoiesis in normal, in adrenalectomized and in hypophysectomized rats. This is considered good evidence that this stimulation is not mediated predominantly through the thyroid, adrenals or testes and that the bone marrow is the target organ of a distinct pituitary hormone.