title: Biological consequences of oxygen desaturation and respiratory effort in an acute animal model of obstructive sleep apnea (OSA).
abstract: BACKGROUND
  An animal model mimicking all the factors involved in obstructive sleep apnea (OSA) is useful for investigating mechanisms because the associated comorbidity usually present in such patients is an important limitation.
  
  
  OBJECTIVE
  To test the hypothesis that hypoxia/normoxia and respiratory effort have different effects on the induction of inflammatory response and endothelial dysfunction in an acute rat model of OSA.
  
  
  METHODS
  Four groups of anesthetized rats were studied (n=8): (1) sham; (2) apnea: obstructions (15s each, 60/h, for 3h); (3) apnea+O(2): obstructions and breathing oxygen-enriched air to avoid hypoxia and (4) intermittent hypoxia/normoxia. Inflammatory and endothelial mediators were measured as outcomes along with NF-kappaB in the lung and diaphragm.
  
  
  RESULTS
  TNF-alpha and IL-1beta significantly increased in all groups compared with sham. NF-kappaB in the lung was increased in apnea and hypoxia/normoxia groups, but not in apnea+O(2) group. In diaphragm tissue, NF-kappaB was only significant in apnea compared to sham. Significant differences were found in the ratio thromboxane-B2/6-keto-Prostaglandin-F1alpha between apnea and hypoxia/normoxia compared to sham but not in apnea+O(2).
  
  
  CONCLUSIONS
  Oxygen desaturations and respiratory efforts play a role in the induction of systemic inflammation but only hypoxia/normoxia induces endothelial dysfunction. These data suggest a potential role for oxygen therapy in patients with OSA.
authors.affiliation: Laboratori de la Son. Servei de Pneumologia, Sleep Lab, Hospital Clinic Provincial-IDIBAPS, C/Casanoves 170, Barcelona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Nácher
authors.forename: Ramon
authors.initials: R
authors.lastname: Farré
authors.forename: Josep M
authors.initials: JM
authors.lastname: Montserrat
authors.forename: Marta
authors.initials: M
authors.lastname: Torres
authors.forename: Daniel
authors.initials: D
authors.lastname: Navajas
authors.forename: Oriol
authors.initials: O
authors.lastname: Bulbena
authors.forename: Anna
authors.initials: A
authors.lastname: Serrano-Mollar