Extra-Renal Production of Erythropoietin in Man

Pathogenetic Aspects of Anemia in Long-Term Hemodialyzed Patients

“…The observation that the anemia in a dialyzed patient shows a nor mal reticulocyte count and that reticulocytosis can, however, follow a fur ther critical fall of red cells, induces us to suppose a varying change of the erythropoietin feedback mechanism. In support is the fact that the kidney is not the only site of erythropoietin production [19,21], while it certainly induces a normal erythropoietin feedback mechanism [18]. On the other hand, the increase of 2,3-DPG and ATP of the erythrocytes between the dialyses [15,23], may shift the oxygen dissociation curve of the hemoglo bin rightward, providing an increased amount of oxygen to the tissues, so as to 'deceive' the structures that produce erythropoietin.…”

Erythropoietm and the Kidney

“…Accordingly, the amount of erythroid activity in the marrow of a patient with chronic renal failure and severe anemia might be quite normal or even slightly increased; however, it is never as great as one would expect from a normal response to a comparably severe anemia. In accord with this concept, EP levels have reached values which are detectable in the plasma of severely anemic uremic subjects and even occasionally in anephric subjects [22,37,115,122]. It has been estimated that the EP levels are only approximately 10% as high as expected but are still roughly proportional to the intensity of the hypoxic (anemic) stimulus.…”

Erythropoietin activity in anephric humans given prolonged androgen treatment

“…More recently, we and others have demonstrated that ESF levels and/or erythropoiesis are present in anephric man Mirand, 1968;Mirand et al, 1968;Naets and Wittek, 1968;Nathan et al, 1964;Erslev et al, 1968;Murphy et al, 1968). Moreover, findings from our laboratory have shown that the extrarenal ESF can be increased on a short-term basis in selected anephric patients exposed to low-dose androgen treatment .…”