Serum erythropoietin levels in healthy humans after a short period of normobaric and hyperbaric oxygen breathing: the "normobaric oxygen paradox"

• Published in: Journal of applied physiology (1985) Vol. 100; no. 2; pp. 512 - 518
• Main Authors: Balestra, Costantino, Germonpre, Peter, Poortmans, Jacques R, Marroni, Alessandro
• Format: Journal Article
• Language: English
• Published: United States Am Physiological Soc 01.02.2006; American Physiological Society
• Subjects: Blood Gas Monitoring, Transcutaneous; Erythropoietin - blood; Female; Hormones; Humans; Hyperbaric Oxygenation; Hyperoxia - blood; Hypoxia; Hypoxia - blood; Kidneys; Male; Oxygen; Oxygen - blood; Respiratory system; Time Factors
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00964.2005

1 Divers Alert Network Europe Research Division, 2 Université Libre de Bruxelles Institut Supérieur d'Éducation Physique et de Kinésithérapie; 3 Department of Environmental & Occupational Physiology, Haute Ecole Paul Henri Spaak; and 4 Center for Hyperbaric Oxygen Therapy, Military Hospital Queen Astrid, Brussels, Belgium Submitted 8 August 2005 ; accepted in final form 10 October 2005 Renal (peritubular) tissue hypoxia is a well-known physiological trigger for erythropoietin (EPO) production. We investigated the effect of rebound relative hypoxia after hyperoxia obtained under normo- and hyperbaric oxygen breathing conditions. A group of 16 healthy volunteers were investigated before and after a period of breathing 100% normobaric oxygen for 2 h and a period of breathing 100% oxygen at 2.5 ATA for 90 min (hyperbaric oxygen). Serum EPO concentration was measured using a radioimmunoassay at various time points during 24–36 h. A 60% increase ( P < 0.001) in serum EPO was observed 36 h after normobaric oxygen. In contrast, a 53% decrease in serum EPO was observed at 24 h after hyperbaric oxygen. Those changes were not related to the circadian rhythm of serum EPO of the subjects. These results indicate that a sudden and sustained decrease in tissue oxygen tension, even above hypoxia thresholds (e.g., after a period of normobaric oxygen breathing), may act as a trigger for EPO serum level. This EPO trigger, the "normobaric oxygen paradox," does not appear to be present after hyperbaric oxygen breathing. erythropoietin stimulus; erythropoietin; hypoxia Address for reprint requests and other correspondence: C. Balestra, Environmental & Occupational Physiology Dept., Haute Ecole Paul Henri Spaak, Pôle Universitaire de Bruxelles Wallonie, 91 Ave. C. Schaller, 1160 Bruxelles, Belgium (e-mail: balestra@daneurope.org)