Researches On Morphine-induced Cardioprotection Against Hypoxia-reoxygenation Injury Of Cultured Myocardial Cells In New-born Rats

Backgroud: Myocardium will suffer ischemia and hypoxia after aortic clamping during cardiopulmonary bypass (CPB).And reperfusion injury in heart cells maybe occur after aortic unclamping. According to many researches, the postoperative complications and ortality rate were related to the severity of myocardial injury. Recently more and more cardiac diseases can be cure by operation, therefore the cardiac surgery are becoming more and more complicated. So, how to protect the myocardium from ischemia-reperfusion injury during CPB, except of depending to shortening the operative time , is an essential problem that must to be solve.Morphine, as the active ingredient of opium, was isolated firstly in 1803 from opium .And its chemical structure was identified in 1925.Morphine have been administered for hundreds of years to reduce the pain associated with surgery mainly because of its μ-opioid receptor agonist characteristic. Administration of large dose morphine (1 mg/kg) by IV was ever used as compounded general anesthesia in cardiac surgery, but now is replaced by fentanyl and other synthetic opioids.Previous studies indicate that opioid receptors agonist such as morphine have the cardioprotective effects against myocardial ischemia-reperfusion injury. Peart JN and Shi E discovered that morphine improve function of isolated rat heart subjected to global ischemia and...