title: Direct evidence for inhibition of mitochondrial permeability transition pore opening by sevoflurane preconditioning in cardiomyocytes: comparison with cyclosporine A.
abstract: To assess whether sevoflurane preconditioning is associated with inhibition of mitochondrial permeability transition pore (MPTP), the effects of sevoflurane were compared with those of cyclosporine A, a known inhibitor of MPTP opening. Isolated perfused guinea pig hearts underwent 30 min global ischemia and 120 min reperfusion (control). Sevoflurane preconditioning was elicited by administration of 2% sevoflurane for 10 min with 10 min washout before ischemia (sevoflurane). A preconditioning-like cardioprotection was also induced by administering cyclosporine A (0.2 μM) for 15 min, starting 5 min before ischemia and for 10 min after the onset of reperfusion (cyclosporine A). Left ventricular developed and end-diastolic pressures, coronary flow and infarct size were measured. Expressions of Akt and glycogen synthase kinase 3β (GSK3β), known mediators of inhibition of MPTP opening, were determined by Western blot analysis. GSK3β inhibition was achieved with LY294002. The effects of sevoflurane and cyclosporine A on calcium-induced MPTP opening in isolated calcein-loaded mitochondria were assessed. After ischemia-reperfusion, sevoflurane and cyclosporine A had higher left ventricular developed pressure. Infarct size was significantly reduced in sevoflurane and cyclosporine A vs. control. This was abolished by LY294002 in sevoflurane, but not in cyclosporine A. Akt and GSK3β phosphorylation after reperfusion were significantly increased in sevoflurane and cyclosporine A. Ca²⁺-induced reduction in calcein fluorescence was significantly attenuated in sevoflurane and cyclosporine A. Preconditioning agents, sevoflurane and cyclosporine A increase the threshold of calcium-induced MPTP opening to a similar extent. This effect by sevoflurane, but not cyclosporine A is at least partially mediated by GSK3β inactivation.
authors.affiliation: Graduate School, Dentistry (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: Kazuhiro
authors.initials: K
authors.lastname: Kaneda
authors.forename: Junichiro
authors.initials: J
authors.lastname: Kotani
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Figueredo
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002867:Chromones / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006168:Guinea Pigs; D007166:Immunosuppressive Agents / Q000494:pharmacology; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D009025:Morpholines / Q000494:pharmacology; D009203:Myocardial Infarction / Q000473:pathology / Q000517:prevention & control; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D000077149:Sevoflurane; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D002316:Cardiotonic Agents; D002867:Chromones; D004791:Enzyme Inhibitors; D007166:Immunosuppressive Agents; D008738:Methyl Ethers; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D009025:Morpholines; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D000077149:Sevoflurane; D016572:Cyclosporine; D000071679:Glycogen Synthase Kinase 3 beta; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3