Renal mechanisms in erythropoiesis regulation.

The kidneys, which a high content of renal erythropoietic profactor, represent an important organ in the formation of erythropoietin in hypoxia. There is, however, an extrarenal mechanism, too, for its formation. The mechanism of erythropoietin secretion could be a central nervous action of hypoxia and a direct cellular one. In the first situation, moderate hypoxia acts upon the nervous centers, whose connexions with the effector cells are made by the beta-adrenergic sympathetic nerves, determining the release in certain kidney cells and in structures outside this organ, of the proerythropoietic factor of lysosomal nature. In the second situation, long-term intense hypoxia would exert its action directly on the cells, releasing the profactor participating in the formation of erythropoietin from the kidney lysosomes or those of other organs.