title: Lipid peroxidation, circulating cytokine and endothelin 1 levels in healthy volunteers undergoing hyperbaric oxygenation.
abstract: BACKGROUND
  The aim of the present study was to evaluate the effects of hyperbaric oxygenation on lipid peroxidation, on the release of circulating cytokines (TNFa, IL6, IL1b) and endothelin-1 (ET1).
  
  
  METHODS
  
  
  
  METHODS
  single arm, prospective study.
  
  
  METHODS
  ICU hyperbaric division of a University Hospital.
  
  
  METHODS
  fifteen healthy volunteers (10 male and 5 female, mean age 32+/-7 years) studied during hyperbaric oxygenation divided at random into two groups: group A (7 subjects) and group B (8 subjects).
  
  
  METHODS
  Both groups were consecutively pressurized at 2 atmospheres (2 atm abs) and 2.8 atm abs, with a constant descending rate of 1 m/min; in accordance with the experimental design, group A breathed pure oxygen continuously through facial masks and group B breathed chamber air during pressurization.
  
  
  METHODS
  Twenty millilitres of blood were drawn from all individuals at the following times: 1) basal, before HBO; 2) after 10 min at 2 atm abs; 3) after 10 min at 2.8 atm abs; 4) 30 min after the end of HBO. In all collected samples thiobarbituric reacting substances were evaluated, using the spectrophotometric technique, IL1 TNF and IL6 serum levels by ELISA and endothelin 1 plasma levels by radioimmunoassay.
  
  
  RESULTS
  In both groups, TBARS levels showed a twofold increase (p<0.05) in relation to the baseline, during and after hyperbaric oxygenation. Serum IL6 and IL1b values did not significantly change over the study in any of the volunteers. TNFa amounts significantly increased (p<0.05) during HBO, at 2 atm abs and 2.8 atm abs in both groups, with almost twofold increments. ET1 plasma values increased (p<0.05) in all volunteers during and after HBO: at 2 atm abs (range 7 to 24 pg/ml), 2.8 atm abs (range 7 to 19 pg/ml) and 30 min after (range 8 to 17 pg/ml) in relation to baseline (range 4 to 12 pg/ml). All the studied compounds had a similar trend in the two groups.
  
  
  CONCLUSIONS
  Hyperbaric oxygenation in healthy volunteers can induce not only lipid peroxidation, but also liberation of compounds such as TNFa and endothelins, no matter whether pure oxygen is breathed or not. These results suggest that the phenomenon behind this release might be leukocyte activation as induced by HBO. The possible role of ET1 in determining vasoconstriction occurring during HBO is also suggested.
authors.affiliation: Istituto di Anestesiologia e Rianimazione, University La Sapienza, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rocco
authors.forename: M
authors.initials: M
authors.lastname: Antonelli
authors.forename: V
authors.initials: V
authors.lastname: Letizia
authors.forename: D
authors.initials: D
authors.lastname: Alampi
authors.forename: G
authors.initials: G
authors.lastname: Spadetta
authors.forename: M
authors.initials: M
authors.lastname: Passariello
authors.forename: G
authors.initials: G
authors.lastname: Conti
authors.forename: P
authors.initials: P
authors.lastname: Serio
authors.forename: A
authors.initials: A
authors.lastname: Gasparetto
mesh_terms: D000328:Adult; D016207:Cytokines / Q000097:blood*; D019332:Endothelin-1 / Q000097:blood*; D005260:Female; D006801:Humans; D006931:Hyperbaric Oxygenation; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D016207:Cytokines; D019332:Endothelin-1; D017392:Thiobarbituric Acid Reactive Substances