title: Acidic buffer or plus cyclosporine A post-conditioning protects isolated rat hearts against ischemia-reperfusion injury.
abstract: BACKGROUND
  It is well documented that transient acidosis during reperfusion is protective. The aim of this study was to evaluate the cardioprotection of acidic buffer or plus cyclosporine A in isolated rat hearts after cardioplegic arrest.
  
  
  METHODS
  Langendorff-perfused Sprague-Dawley rat hearts were perfused for 20 min with Krebs-Henseleit (K-H) buffer followed by 30 min of crystalloid cardioplegia and 60 min of reperfusion. Control hearts were perfused with Krebs-Henseleit buffer. Acidic buffer post-conditioning hearts were perfused with acidic K-H buffer (pH 6.8) for the first 3 min of reperfusion. Acidic buffer plus cyclosporine A hearts were perfused with K-H acidic buffer (pH 6.8) containing cyclosporine A (0.2 μmol/L) for the first 3 min of reperfusion.
  
  
  RESULTS
  Compared with the control group, acidic buffer or plus cyclosporine A post-conditioning significantly improved myocardial performance, decreased cytochrome C release into the cytosol, increased Bcl-2 expression and decreased Bax expression, decreased sensitivity of mPTP-opening to [Ca2+] and the rate of apoptosis after reperfusion.
  
  
  CONCLUSIONS
  These findings suggested that acidic buffer or plus cyclosporine A post-conditioning prevented apoptosis-related mitochondrial permeabilization and provided the myocardial protection after cardioplegic arrest.
authors.affiliation: Fuwai Hospital & Cardiovascular Institute, Chinese Academy of Medical Science, Peking Union Medical College, 167 Bei li shi Road, Fuwai Da Jie, Xi Cheng, Beijing, Peoples Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Duan
authors.forename: Bingyang
authors.initials: B
authors.lastname: Ji
authors.forename: Kun
authors.initials: K
authors.lastname: Yu
authors.forename: Feilong
authors.initials: F
authors.lastname: Hei
authors.forename: Jinping
authors.initials: J
authors.lastname: Liu
authors.forename: Cun
authors.initials: C
authors.lastname: Long
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D016572:Cyclosporine / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D009124:Muscle Proteins / Q000378:metabolism; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009206:Myocardium; D019188:Organ Preservation Solutions / Q000494:pharmacology*; D017680:Potassium Compounds / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D007166:Immunosuppressive Agents; D009124:Muscle Proteins; D019188:Organ Preservation Solutions; D017680:Potassium Compounds; C018369:potassium cardioplegic solution; D016572:Cyclosporine