Hemoglobin content is increased in the human erythroleukemia K562 cell line by a 56.2-kD peptide from uremic plasma.

Background: Some abnormalities in porphyrin metabolism have been described in erythrocytes from patients with end-stage renal failure. A peptidic fraction of 56.2 kD isolated from plasma of these patients was previously identified as an aminolevulinate dehydratase inhibitor.