title: Sevoflurane confers additive cardioprotection to ethanol preconditioning associated with enhanced phosphorylation of glycogen synthase kinase-3β and inhibition of mitochondrial permeability transition pore opening.
abstract: OBJECTIVE
  The purposes of this study were to investigate whether sevoflurane (SEVO) enhances moderate-dose ethanol (EtOH) preconditioning and whether this additional cardioprotection is associated with glycogen synthase kinase-3β (GSK-3β), protein kinase B (Akt), mammalian target of rapamycin (mTOR), 70-kDa ribosomal s6 kinase-1 (p70s6K), and/or mitochondrial permeability transition pore (MPTP) opening.
  
  
  METHODS
  In vitro study using an isolated heart Langendorff preparation.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Male guinea pigs (n = 170).
  
  
  METHODS
  Isolated perfused guinea pig hearts underwent 30-minute ischemia and 120-minute reperfusion (control). The EtOH group received 5% EtOH in the drinking water for 8 weeks. Anesthetic preconditioning was elicited by a 10-minute exposure to 2% SEVO in EtOH (EtOH + SEVO group) or non-EtOH (SEVO group) hearts. The inhibition of GSK-3β phosphorylation and mTOR was achieved with LY294002 and rapamycin, respectively. GSK-3β, Akt, mTOR, and p70s6K expressions were determined by western blot. Calcium-induced MPTP opening was assessed in isolated calcein-loaded mitochondria.
  
  
  RESULTS
  After ischemia-reperfusion, the EtOH, SEVO, and EtOH + SEVO groups had higher left ventricular developed pressure recovery and lower end-diastolic pressure versus the control group. Infarct size was smaller in the EtOH and SEVO groups versus control and even smaller in the EtOH + SEVO group. Phosphorylation of GSK-3β and Akt, but not mTOR and p70s6K, was increased in the EtOH and SEVO groups. Phosphorylation of GSK-3β, but not mTOR and p70s6K, was further increased in the EtOH + SEVO group. The EtOH and SEVO groups exhibited a smaller calcium-induced MPTP opening, and the EtOH + SEVO presented an even smaller MPTP opening.
  
  
  CONCLUSIONS
  SEVO and chronic EtOH preconditioning offer additive cardioprotection. This effect is associated with an increased GSK-3β phosphorylation and an inhibition of MPTP opening.
authors.affiliation: Department of Anesthesiology, Osaka Dental University, Osaka, Japan.
authors.forename: Anna
authors.initials: A
authors.lastname: Onishi
authors.forename: Masami
authors.initials: M
authors.lastname: Miyamae
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inoue
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kaneda
authors.forename: Chika
authors.initials: C
authors.lastname: Okusa
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Inamura
authors.forename: Mayumi
authors.initials: M
authors.lastname: Shiomi
authors.forename: Shizuka
authors.initials: S
authors.lastname: Koshinuma
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Momota
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Figueredo
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000008:administration & dosage*; D004359:Drug Therapy, Combination; D000431:Ethanol / Q000008:administration & dosage*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006168:Guinea Pigs; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage*; D033681:Mitochondrial Membrane Transport Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D009924:Organ Culture Techniques; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D000077149:Sevoflurane
chemical_list: D002316:Cardiotonic Agents; D008738:Methyl Ethers; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D000077149:Sevoflurane; D000431:Ethanol; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3