title: Erythropoetin treatment can increase 2,3-diphosphoglycerate levels in red blood cells.
abstract: Some patients experience an improved well-being during treatment with recombinant human erythropoietin even with an unchanged Hb level. We have hypothesized that this may not be only a placebo effect. 2,3-diphosphoglycerate (2,3-DPG) in red blood cells increases in response to anaemia/hypoxia and causes a shift of the oxygen dissociation curve, allowing a more effective oxygen delivery. We have investigated red cell 2,3-DPG concentrations during erythropoietin treatment in healthy volunteers as a mediator of a possible physiological explanation. Thirteen healthy subjects with no iron deficiency were recruited and randomly assigned to a treatment group comprising five males and three females and a control group including three males and two females. The treatment group was treated with erythropoietin (Recormon), 20 IE/kg subcutaneously three times/week for 4 weeks. Blood samples were collected at each injection day and 10 days after the last injection and at corresponding times in the control group. B-Hb, red cell 2,3-DPG and P50 were measured by standard techniques and oxygen-releasing capacity was calculated.
  
  
  RESULTS
  due to the sampling (26 ml each time, three times/week) the mean Hb level was lowered from 140.5 +/- 5.9 to 128.6 +/- 10.4 g/L in the control group whereas the erythropoietin treatment group maintained a mean Hb level of about 142 g/L (p<0.002). The 2,3-DPG mean level curve as well as that for oxygen releasing capacity also differed significantly between the two groups (p < 0.002), the treatment group showing higher levels.
  
  
  CONCLUSIONS
  treatment with erythropoietin causes an increase in red cell 2,3-DPG levels.
authors.affiliation: Department of Medical Sciences. University Hospital, Uppsala, Sweden. gunnar.birgegard@medsci.uu.se
authors.forename: G
authors.initials: G
authors.lastname: Birgegård
authors.forename: B
authors.initials: B
authors.lastname: Sandhagen
mesh_terms: D019794:2,3-Diphosphoglycerate / Q000097:blood*; D000328:Adult; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D004921:Erythropoietin / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D006454:Hemoglobins; D011994:Recombinant Proteins; D004921:Erythropoietin; D019794:2,3-Diphosphoglycerate