title: Sevoflurane postconditioning alleviates action potential duration shortening and L-type calcium current suppression induced by ischemia/reperfusion injury in rat epicardial myocytes.
abstract: BACKGROUND
  It has been proved that sevoflurane postconditioning (SpostC) could protect the heart against myocardial ischemia/reperfusion injury, however, there has been few research focused on the electrophysiological effects of SpostC. The objective of the study was to investigate the effects of SpostC on action potential duration (APD) and L-type calcium current (I(Ca, L)) in isolated cardiomyocytes.
  
  
  METHODS
  Langendorff perfused SD rat hearts were randomly assigned to one of the time control (TC), ischemia/reperfusion (I/R, 25 minutes of ischemia followed by 30 minutes of reperfusion), and SpostC (postconditioned with 3% sevoflurane) groups. At the end of reperfusion, epicardial myocytes were dissociated enzymatically for patch clamp studies.
  
  
  RESULTS
  Sevoflurane directly prolonged APD and decreased peak I(Ca, L) densities in epicardial myocytes of the TC group (P < 0.05). I/R injury shortened APD and decreased peak I(Ca, L) densities in epicardial myocytes of the I/R group (P < 0.05). SpostC prolonged APD and increased peak I(Ca, L) densities in epicardial myocytes exposed to I/R injury (P < 0.05). SpostC decreased intracellular reactive oxygen species (ROS) levels, reduced the incidence of ventricular tachycardia and ventricular fibrillation, and decreased reperfusion arrhythmia scores compared with the I/R group (all P < 0.05).
  
  
  CONCLUSIONS
  SpostC attenuates APD shortening and I(Ca, L) suppression induced by I/R injury. The regulation of APD and I(Ca, L) by SpostC might be related with intracellular ROS modulation, which contributes to the alleviation of reperfusion ventricular arrhythmia.
authors.affiliation: Department of Anesthesiology, Fuwai Hospital, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.
authors.forename: Jun-Song
authors.initials: JS
authors.lastname: Gong
authors.forename: Yun-Tai
authors.initials: YT
authors.lastname: Yao
authors.forename: Neng-Xin
authors.initials: NX
authors.lastname: Fang
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.forename: Li-Huan
authors.initials: LH
authors.lastname: Li
mesh_terms: D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004562:Electrocardiography; D008738:Methyl Ethers / Q000627:therapeutic use*; D018408:Patch-Clamp Techniques; D010496:Pericardium / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000188:drug therapy* / Q000378:metabolism*; D000077149:Sevoflurane
chemical_list: D008738:Methyl Ethers; D017382:Reactive Oxygen Species; D000077149:Sevoflurane; D002118:Calcium