Changes in the alpha adrenergic system and increase in blood pressure with recombinant human erythropoietin (rHuEpo) therapy for renal anemia.

Recombinant human erythropoietin (rHuEpo) is effective in correcting renal anemia with the development of hypertension as the most frequent side-effect. Compared to hemodialysis patients with normal hemoglobin concentration, nine examined patients with transfusion-dependent renal anemia had low blood pressure in the context of high alpha 2-receptor densities and high plasma levels of catecholamines. This constellation can be explained by a defective receptor-ligand-interaction. During treatment with rHuEpo all patients showed an increase in blood pressure due to increased peripheral resistance, accompanied by a significant fall in plasma noradrenaline and alpha 2-receptor-density. There was a significant negative correlation between hemoglobin concentration and alpha 2-receptor density. We conclude that correction of renal anemia abolishes anemia-mediated disturbance of alpha 2-receptor function with the consequence of receptor down-regulation and increased vasoconstriction, which contributes to the rise in arterial blood pressure.