title: Long-term intermittent hyperoxic exposures do not enhance erythropoiesis.
abstract: BACKGROUND
  Based on a report of a marked increase in the erythropoietin concentration ([EPO]) a few hours after the cessation of a single 2-h session of O(2) breathing, short periods of O(2) administration have been advocated as a therapy for anaemia. Accordingly, the purpose of the present study was to evaluate this theory by investigating the effect of 10 daily short-term exposures to normobaric O(2) over a 2-week period on the plasma [EPO] in healthy individuals.
  
  
  METHODS
  Twenty men were assigned to either an experimental (NBO(2)) or to a control (AIR) group. The NBO(2) group breathed 100% normobaric O(2) for 2 h every weekday over a 2-week period. The AIR group breathed air within the same time protocol. Blood samples were collected at the pre-, mid- and post-intervention periods to determine [EPO].
  
  
  RESULTS
  [EPO] of the NBO(2) group was significantly lower than that of the AIR group during the mid- and post-periods (P < 0·001). [EPO] of the NBO(2) group showed a slight, albeit statistically nonsignificant, decrease during the mid (∼11%)- and post (∼16%)-periods.
  
  
  CONCLUSIONS
  Daily short-term exposures to normobaric hyperoxia do not increase the [EPO] in healthy individuals. The increased O(2) tension suppresses [EPO]. Hence, administration of pure O(2) to enhance erythropoiesis is not warranted.
authors.affiliation: Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia. mkeram@phed.uoa.gr
authors.forename: Michail E
authors.initials: ME
authors.lastname: Keramidas
authors.forename: Barbara
authors.initials: B
authors.lastname: Norman
authors.forename: Thomas
authors.initials: T
authors.lastname: Gustafsson
authors.forename: Ola
authors.initials: O
authors.lastname: Eiken
authors.forename: Igor B
authors.initials: IB
authors.lastname: Mekjavic
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004920:Erythropoiesis / Q000502:physiology*; D004921:Erythropoietin / Q000097:blood* / Q000378:metabolism; D006801:Humans; D006931:Hyperbaric Oxygenation / Q000379:methods; D018496:Hyperoxia / Q000097:blood* / Q000378:metabolism; D008297:Male; D010100:Oxygen / Q000097:blood* / Q000378:metabolism; D013997:Time Factors; D055815:Young Adult
chemical_list: D004921:Erythropoietin; D010100:Oxygen