title: Influence of controlled hypoxia and radical scavenging agents on erythropoietin and malondialdehyde concentrations in humans.
abstract: The present study was carried out to evaluate a model of a hypoxic stimulus of erythropoietin (EPO) production in humans and to investigate the role of free oxygen radicals in human EPO production. The study was conducted as an open, randomized, parallel, placebo-controlled trial. Thirty-six healthy male volunteers received a hypoxic treatment (13% O(2)) with a respiration mask for 6 h. During the period of hypoxia, the volunteers received as a short-term treatment either 1200 mg thioctic acid, or N-acetylcysteine 600 mg or placebo (0.9% sodium chloride). The EPO concentration in plasma increased up to 290% of the baseline level in all three groups. No statistically significant differences of AUC(EPO(0-48 h)) could be demonstrated between the groups. The malondialdehyde (MDA) concentration in plasma increased significantly (P < 0.001) 2 h after termination of hypoxia (mean 129.8 +/- 6.8% of the baseline) in all three groups.
  
  
  CONCLUSIONS
  Taken together, our in-vivo results do not support a gross modulatory effect of a short-term treatment with radical scavenging agents on EPO-production during or after hypoxia in humans, as derived from the detected changes of MDA-concentrations in peripheral plasma.
authors.affiliation: Department of Clinical Pharmacology, University of Tuebingen, Germany.
authors.forename: S M
authors.initials: SM
authors.lastname: Freudenthaler
authors.forename: K-H
authors.initials: KH
authors.lastname: Schreeb
authors.forename: A
authors.initials: A
authors.lastname: Wiese
authors.forename: J
authors.initials: J
authors.lastname: Pilz
authors.forename: C H
authors.initials: CH
authors.lastname: Gleiter
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000328:Adult; D000975:Antioxidants / Q000494:pharmacology; D019540:Area Under Curve; D004921:Erythropoietin / Q000097:blood*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006801:Humans; D000860:Hypoxia / Q000097:blood* / Q000503:physiopathology*; D008297:Male; D008315:Malondialdehyde / Q000097:blood*; D008063:Thioctic Acid / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D004921:Erythropoietin; D008315:Malondialdehyde; D008063:Thioctic Acid; D000111:Acetylcysteine