title: Eicosapentaenoic acid reduces pulmonary edema in endotoxemic rats.
abstract: BACKGROUND
  Recently, eicosapentaenoic acid (EPA) was found to have an anti-inflammatory effect attributable to diminished synthesis of arachidonic acid metabolites that initiate acute lung injury. We evaluated the ability of dietary EPA supplementation to prevent endotoxin-induced acute lung injury in rats.
  
  
  METHODS
  Rats fed a standard diet were divided randomly into two groups: for 2 weeks one group additionally was fed 1000 mg/kg/day of EPA ethyl ester emulsion (EPA rats), while in the other group the diet was supplemented with vehicle alone (control rats). Fatty acid components of alveolar macrophages (AM) were measured, as well as leukotriene (LT) B(4) and LTB(5) production by AM exposed in vitro to calcium ionophore A23187. Plasma concentrations of thromboxane (Tx) B(2), a stable metabolite of TxA(2), were examined 1 h after inducing lung injury with endotoxin (2 mg/kg iv). At 6 h, wet/dry (W/D) weight ratios were calculated for the lungs to assess pulmonary edema, and neutrophils were counted in pulmonary parenchyma and peripheral blood.
  
  
  RESULTS
  Arachidonic acid content and LTB(4) generation in AM were significantly lower in EPA rats than in controls; conversely, EPA content and LTB(5) generation in AM were significantly higher in the EPA group. Neutrophil counts in lung parenchyma and peripheral blood did not differ between groups, but W/D and plasma TxB(2) concentrations were significantly lower in EPA rats.
  
  
  CONCLUSIONS
  EPA supplementation depressed arachidonic acid content and LTB(4) generation in AM and plasma TxB(2) in our model, leading to decreased pulmonary edema.
authors.affiliation: First Department of Surgery, Kagoshima University School of Medicine, 8-35-1, Sakuragaoka, Kagoshima, 890-8520, Japan. soujisane@po2.synapse.ne.jp
authors.forename: S
authors.initials: S
authors.lastname: Sane
authors.forename: M
authors.initials: M
authors.lastname: Baba
authors.forename: C
authors.initials: C
authors.lastname: Kusano
authors.forename: K
authors.initials: K
authors.lastname: Shirao
authors.forename: T
authors.initials: T
authors.lastname: Andoh
authors.forename: T
authors.initials: T
authors.lastname: Kamada
authors.forename: T
authors.initials: T
authors.lastname: Aikou
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000627:therapeutic use*; D019446:Endotoxemia / Q000150:complications; D005227:Fatty Acids / Q000096:biosynthesis; D007975:Leukotriene B4 / Q000096:biosynthesis; D008297:Male; D009504:Neutrophils / Q000502:physiology; D011654:Pulmonary Edema / Q000517:prevention & control*; D051381:Rats; D017208:Rats, Wistar; D012128:Respiratory Distress Syndrome / Q000517:prevention & control; D013929:Thromboxane B2 / Q000097:blood
chemical_list: D005227:Fatty Acids; D007975:Leukotriene B4; D016718:Arachidonic Acid; D013929:Thromboxane B2; D015118:Eicosapentaenoic Acid