Correction of amino acid metabolism by recombinant human erythropoietin therapy in hemodialysis patients.

We assessed the effect of correction of anemia with recombinant human erythropoietin (rhEPO) on plasma amino acid levels in maintenance hemodialysis patients. The plasma amino acid pattern was estimated by high performance liquid chromatography in 18 healthy persons and 14 hemodialysis patients before and up to 12 weeks after rhEPO therapy. There was a correction of the plasma serine values (67 +/- 16 to 87 +/- 22; P less than 0.05) and a corresponding decrease in the serine precursors, glycine (317 +/- 113 to 228 +/- 56; P less than 0.05) and hydroxyproline (26 +/- 21 to 15 +/- 13; P less than 0.10). The low plasma branched-chain amino acids, valine (137 +/- 33 to 154 +/- 50; P less than 0.10) and leucine (72 +/- 22 to 80 +/- 27; P less than 0.20), also were corrected. The elevated values of ornithine (78 +/- 16 to 62 +/- 19; P less than 0.1) and arginine (94 +/- 14 to 72 +/- 14; P less than 0.1) fell. The diminished glutamine values (470 +/- 125 to 563 +/- 115; P less than 0.1) and the decreased tyrosine/phenylalanine ratio (0.78 +/- 0.17 to 0.98 +/- 0.21; P less than 0.05) rose. Thus, the administration of rhEPO not only affects erythropoiesis, but also corrects the plasma amino acid pattern towards normal.