The effect of human recombinant erythropoietin on iron absorption and hepatic iron in a rat model.

In order to ascertain whether recombinant human erythropoietin (EPO) therapy would result in further intestinal iron absorption in the setting of systemic iron loading, iron absorption was measured in iron-loaded rats receiving EPO therapy and a control group of iron-loaded rats. Parenteral iron dextran (100 mg) resulted in hepatic siderosis with predominantly a reticuloendothelial distribution. EPO was given by intraperitoneal injection (100 U/kg) for 10 days. Radioiron absorption was measured by total body counting. Iron absorption in EPO-treated rats was 4.8 +/- 2.0% (n = 12) and 4.5 +/- 2.2% (n = 10) in the control rats (p greater than 0.05). Mean hemoglobin in the EPO rats was 201 +/- 12.5 g/L and 140 +/- 18.2 g/L in the control rats (p less than 0.001). Mean hepatic iron concentration was 73 +/- 16 mumol/g in the control rats and 34 +/- 9.1 mumol/g in the EPO-treated rats (p less than 0.001). This study suggests that iron-loaded rats do not demonstrate an increase in intestinal iron absorption with EPO therapy despite a significant erythropoiesis. The reduction in hepatic iron concentration suggests that reticuloendothelial iron is accessible and mobilized to produce new red blood cells.