title: Cardioprotective effects of morphine on rat heart suffering from ischemia and reperfusion.
abstract: OBJECTIVE
  To investigate the cardioprotective effects of morphine on ischemic reperfused rat heart in vitro and its mechanism.
  
  
  METHODS
  The isolated rat heart was perfused in a Langendorff apparatus. Infarct myocardium was determined by TTC. Coronary flow (CF), heart rate (HR), left ventricular pressure (LVP), the first derivative of ventricular pressure (LVP/dtmax) and infarct size after ischemia and reperfusion in rat heart given 0.3 micro mol/L morphine were observed. The effects of naloxone and glibenclamide on the cardioprotection of morphine were also measured.
  
  
  RESULTS
  After ischemia and reperfusion, CF, HR, LVP and LVP/dtmax of isolated rat hearts decreased significantly (P < 0.01). After morphine preconditioning, HR, LVP and LVP/dtmax increased (P < 0.01) and infarct size was reduced significantly (P < 0.01), while no significant change in CF (P > 0.05). The cardioprotective effects of morphine were abolished by naloxone or glibenclamide completely.
  
  
  CONCLUSIONS
  Morphine can reduce ischemia-reperfusion injuries in isolated rat heart. The cardioprotective effects of morphine are mediated by a local opioid receptor-K(ATP) channel linked mechanism in rat hearts.
authors.affiliation: Department of Cardiac Surgery, the First Affiliated Hospital, China Medical University, Shenyang 110001, China.
authors.forename: Enyi
authors.initials: E
authors.lastname: Shi
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Jiang
authors.forename: Han
authors.initials: H
authors.lastname: Bai
authors.forename: Tianxiang
authors.initials: T
authors.lastname: Gu
authors.forename: Yetian
authors.initials: Y
authors.lastname: Chang
authors.forename: Junke
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D005905:Glyburide / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002316:Cardiotonic Agents; D009270:Naloxone; D009020:Morphine; D005905:Glyburide