title: Sevoflurane post-conditioning reduces rat myocardial ischemia reperfusion injury through an increase in NOS and a decrease in phopshorylated NHE1 levels.
abstract: The protective effects of sevoflurane post-conditioning against myocardial ischemia/reperfusion (I/R) injury (MIRI) have been previously reported. However, the mechanisms responsible for these protective effects remain elusive. In this study, in order to investigate the molecular mechanisms responsible for the protective effects of sevoflurane post-conditioning on isolated rat hearts subjected to MIRI, Sprague-Dawley rat hearts were randomly divided into the following 6 groups: i) the sham-operated control; ii) 2.5% sevoflurane; iii) ischemia/reperfusion (I/R); iv) 2.5% sevoflurane post-conditioning plus I/R; v) 2.5% sevoflurane post-conditioning + NG-nitro-L-arginine methyl ester (L-NAME) plus I/R; and vi) L-NAME plus I/R. The infarct size was measured using 2,3,5-triphenyl tetrazolium chloride (TTC) staining. Additionally, the myocardial nitric oxide (NO), NO synthase (NOS) and nicotinamide adenine dinucleotide (NAD+) levels were determined. Autophagosomes and apoptosomes in the myocardium were detected by transmission electron microscopy. The levels of Bcl-2, cleaved caspase-3, Beclin-1, microtubule-associated protein light chain 3 (LC3)‑I/II, Na+/H+ exchanger 1 (NHE1) and phosphorylated NHE1 protein were measured by western blot analysis. NHE1 mRNA levels were measured by reverse transcription-quantitative polymerase chain reaction. Compared with the I/R group, 15 min of exposure to 2.5% sevoflurane during early reperfusion significantly decreased the myocardial infarct size, the autophagic vacuole numbers, the NHE1 mRNA and protein expression of cleaved caspase-3, Beclin-1 and LC3-I/II. Post-conditioning with 2.5% sevoflurane also increased the NO and NOS levels and Bcl-2 protein expression (p<0.05 or p<0.01). Notably, the cardioprotective effects of sevoflurane were partly abolished by the NOS inhibitor, L-NAME. The findings of the present study suggest that sevoflurane post-conditioning protects the myocardium against I/R injury and reduces the myocardial infarct size. The underlying protective mechanisms are associated with the inhibition of mitochondrial permeability transition pore opening, and with the attenuation of cardiomyoctye apoptosis and excessive autophagy. These effects are mediated through an increase in NOS and a decrease in phopshorylated NHE1 levels.
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Jianfang
authors.initials: J
authors.lastname: Cao
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xie
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Ming
authors.initials: M
authors.lastname: Ying
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Shigang
authors.initials: S
authors.lastname: Qiao
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Shao
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Haorong
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
mesh_terms: D018685:Anesthetics, Inhalation / Q000494:pharmacology; D000818:Animals; D001343:Autophagy / Q000187:drug effects; D015153:Blotting, Western; D002316:Cardiotonic Agents / Q000494:pharmacology; D053148:Caspase 3 / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D057775:Ischemic Postconditioning / Q000379:methods*; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D046529:Microscopy, Electron, Transmission; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D009203:Myocardial Infarction / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control; D015428:Myocardial Reperfusion Injury / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D010766:Phosphorylation / Q000187:drug effects; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077149:Sevoflurane; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*
chemical_list: D018685:Anesthetics, Inhalation; D002316:Cardiotonic Agents; D053148:Caspase 3; D004791:Enzyme Inhibitors; D008738:Methyl Ethers; D008869:Microtubule-Associated Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase; D000077149:Sevoflurane; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers; C526109:Anxa3 protein, rat; C452850:Slc9a1 protein, rat