title: Bradykinin and adenosine receptors mediate desflurane induced postconditioning in human myocardium: role of reactive oxygen species.
abstract: BACKGROUND
  Desflurane during early reperfusion has been shown to postcondition human myocardium, in vitro. We investigated the role of adenosine and bradykinin receptors, and generation of radical oxygen species in desflurane-induced postconditioning in human myocardium.
  
  
  METHODS
  We recorded isometric contraction of human right atrial trabeculae hanged in an oxygenated Tyrode's solution (34 degrees Celsius, stimulation frequency 1 Hz). After a 30-min hypoxic period, desflurane 6% was administered during the first 5 min of reoxygenation. Desflurane was administered alone or with pretreatment of N-mercaptopropionylglycine, a reactive oxygen species scavenger, 8-(p-Sulfophenyl)theophylline, an adenosine receptor antagonist, HOE140, a selective B2 bradykinin receptor antagonist. In separate groups, adenosine and bradykinin were administered during the first minutes of reoxygenation alone or in presence of N-mercaptopropionylglycine. The force of contraction of trabeculae was recorded continuously. Developed force at the end of a 60-min reoxygenation period was compared (mean +/- standard deviation) between the groups by a variance analysis and post hoc test.
  
  
  RESULTS
  Desflurane 6% (84 +/- 6% of baseline) enhanced the recovery of force after 60-min of reoxygenation as compared to control group (51 +/- 8% of baseline, P < 0.0001). N-mercaptopropionylglycine (54 +/- 3% of baseline), 8-(p-Sulfophenyl)theophylline (62 +/- 9% of baseline), HOE140 (58 +/- 6% of baseline) abolished desflurane-induced postconditioning. Adenosine (80 +/- 9% of baseline) and bradykinin (83 +/- 4% of baseline) induced postconditioning (P < 0.0001 vs control), N-mercaptopropionylglycine abolished the beneficial effects of adenosine and bradykinin (54 +/- 8 and 58 +/- 5% of baseline, respectively).
  
  
  CONCLUSIONS
  In vitro, desflurane-induced postconditioning depends on reactive oxygen species production, activation of adenosine and bradykinin B2 receptors. And, the cardioprotective effect of adenosine and bradykinin administered at the beginning of reoxygenation, was mediated, at least in part, through ROS production.
authors.affiliation: Laboratory of Experimental Anesthesiology and Cellular Physiology, IFR 146 ICORE, Université de Caen Basse Normandie, CHU Caen, Avenue de la Cote de Nacre, 14033 Caen, France. sand.lemoine2@wanadoo.fr.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Lemoine
authors.forename: Clément
authors.initials: C
authors.lastname: Buléon
authors.forename: René
authors.initials: R
authors.lastname: Rouet
authors.forename: Calin
authors.initials: C
authors.lastname: Ivascau
authors.forename: Gérard
authors.initials: G
authors.lastname: Babatasi
authors.forename: Massimo
authors.initials: M
authors.lastname: Massetti
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Gérard
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Hanouz