Cardioprotective effects of morphine on rat heart suffering from ischemia and reperfusion.
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.
Shi
Enyi
E
Department of Cardiac Surgery, the First Affiliated Hospital, China Medical University, Shenyang 110001, China.
Jiang
Xiaojing
X
Bai
Han
H
Gu
Tianxiang
T
Chang
Yetian
Y
Wang
Junke
J
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
D002316:Cardiotonic Agents; D009270:Naloxone; D009020:Morphine; D005905:Glyburide