Erythropoietin research, 80 years after the initial studies by Carnot and Deflandre.

The discovery and present state of knowledge of the specific hormonal mechanism controlling erythropoiesis are briefly reviewed. 80 years ago, Carnot and Deflandre postulated the existence of a humoral erythropoietic factor ('hémopoïétine') produced in response to anemia. The general approval of this concept required almost 50 years, when the factor was recognized to be a glycoprotein hormone and termed 'erythropoietin'. Very recently, human erythropoietin has been purified and its amino acid sequence been identified. The hormone is mainly of renal origin. Its production is stimulated by tissue hypoxia of different causes. The mechanism of O2 sensing and the exact site of erythropoietin synthesis in the kidney still remain to be clarified.