title: Flaxseed oil increases aortic reactivity to phenylephrine through reactive oxygen species and the cyclooxygenase-2 pathway in rats.
abstract: BACKGROUND
  Flaxseed oil has the highest concentration of omega-3 α-linolenic acid, which has been associated with cardiovascular benefit. However, the mechanism underlying the vascular effects induced through flaxseed oil is not well known. Thus, in the present study, we investigated the effects of flaxseed oil on vascular function in isolated rat aortic rings.
  
  
  METHODS
  Wistar rats were treated daily with flaxseed oil or a control (mineral oil) intramuscular (i.m.) for fifteen days. Isolated aortic segments were used to evaluate cyclooxygenase-2 (COX-2) protein expression, superoxide anion levels and vascular reactivity experiments.
  
  
  RESULTS
  Flaxseed oil treatment increased the vasoconstrictor response of aortic rings to phenylephrine. Endothelium removal increased the response to phenylephrine in aortic segments isolated from both groups, but the effect was smaller in the treated group. L-NAME incubation similarly increased the phenylephrine response in segments from both groups. The TXA2 synthase inhibitor furegrelate, the selective COX-2 inhibitor NS 398, the TP receptor antagonist SQ 29.548, the reactive oxygen species (ROS) scavenger apocynin, the superoxide anion scavengers tiron and the phospholipase A2 inhibitor dexamethasone partially reversed the flaxseed oil-induced increase in reactivity to phenylephrine.
  
  
  CONCLUSIONS
  These findings suggest that flaxseed oil treatment increased vascular reactivity to phenylephrine through an increase in ROS production and COX-2-derived TXA2 production. The results obtained in the present study provide new insight into the effects of flaxseed oil treatment (i.m.) on vascular function.
authors.forename: Dieli Oliveira
authors.initials: DO
authors.lastname: Nunes
authors.forename: Camila Cruz Pereira
authors.initials: CC
authors.lastname: Almenara
authors.forename: Gilson Brás
authors.initials: GB
authors.lastname: Broseghini-Filho
authors.forename: Marito Afonso Sousa Costa
authors.initials: MA
authors.lastname: Silva
authors.forename: Ivanita
authors.initials: I
authors.lastname: Stefanon
authors.forename: Dalton V
authors.initials: DV
authors.lastname: Vassallo
authors.affiliation: Department of Physiological Sciences, Federal University of Espirito Santo, Av, Marechal Campos, 1468, Maruípe, 29040-091 Vitória, ES, Brazil. ale_padilha@hotmail.com.
authors.forename: Alessandra S
authors.initials: AS
authors.lastname: Padilha
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology*; D002097:C-Reactive Protein / Q000378:metabolism; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D008043:Linseed Oil / Q000008:administration & dosage*; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D018384:Oxidative Stress; D010656:Phenylephrine / Q000494:pharmacology*; D011453:Prostaglandins / Q000494:pharmacology; D017208:Rats, Wistar; D013481:Superoxides / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D002317:Cardiovascular Agents; D011453:Prostaglandins; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D013481:Superoxides; D009599:Nitroprusside; D010656:Phenylephrine; D008043:Linseed Oil; D002097:C-Reactive Protein; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat