title: Differences in production of reactive oxygen species and mitochondrial uncoupling as events in the preconditioning signaling cascade between desflurane and sevoflurane.
abstract: BACKGROUND
  Signal transduction cascade of anesthetic-induced preconditioning has been extensively studied, yet many aspects of it remain unsolved. Here, we investigated the roles of reactive oxygen species (ROS) and mitochondrial uncoupling in cardiomyocyte preconditioning by two modern volatile anesthetics: desflurane and sevoflurane.
  
  
  METHODS
  Adult rat ventricular cardiomyocytes were isolated enzymatically. The preconditioning potency of desflurane and sevoflurane was assessed in cell survival experiments by evaluating myocyte protection from the oxidative stress-induced cell death. ROS production and flavoprotein fluorescence, an indicator of flavoprotein oxidation and mitochondrial uncoupling, were monitored in real time by confocal microscopy. The functional aspect of enhanced ROS generation by the anesthetics was assessed in cell survival and confocal experiments using the ROS scavenger Trolox.
  
  
  RESULTS
  Preconditioning of cardiomyocytes with desflurane or sevoflurane significantly decreased oxidative stress-induced cell death. That effect coincided with increased ROS production and increased flavoprotein oxidation detected during acute myocyte exposure to the anesthetics. Desflurane induced significantly greater ROS production and flavoprotein oxidation than sevoflurane. ROS scavenging with Trolox abrogated preconditioning potency of anesthetics and attenuated flavoprotein oxidation.
  
  
  CONCLUSIONS
  Preconditioning with desflurane or sevoflurane protects isolated rat cardiomyocytes from oxidative stress-induced cell death. Scavenging of ROS abolishes the preconditioning effect of both anesthetics and attenuates anesthetic-induced mitochondrial uncoupling, suggesting a crucial role for ROS in anesthetic-induced preconditioning and implying that ROS act upstream of mitochondrial uncoupling. Desflurane exhibits greater effect on stimulation of ROS production and mitochondrial uncoupling than sevoflurane.
authors.affiliation: Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA. fsedlic@mcw.ed
authors.forename: Filip
authors.initials: F
authors.lastname: Sedlic
authors.forename: Danijel
authors.initials: D
authors.lastname: Pravdic
authors.forename: Marko
authors.initials: M
authors.lastname: Ljubkovic
authors.forename: Jasna
authors.initials: J
authors.lastname: Marinovic
authors.forename: Anna
authors.initials: A
authors.lastname: Stadnicka
authors.forename: Zeljko J
authors.initials: ZJ
authors.lastname: Bosnjak
mesh_terms: D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002839:Chromans / Q000494:pharmacology; D000077335:Desflurane; D005420:Flavoproteins / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial; D007530:Isoflurane / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D000077149:Sevoflurane; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D018685:Anesthetics, Inhalation; D002839:Chromans; D005420:Flavoproteins; D016166:Free Radical Scavengers; D008738:Methyl Ethers; D017382:Reactive Oxygen Species; D000077149:Sevoflurane; D000077335:Desflurane; D007530:Isoflurane; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid