Role of delta and kappa opioid receptors in sufentanil preconditioning-induced attenuation of myocardial ischemia-reperfusion injury in rats

Abstract

Objective To evaluate the role of delta and kappa opioid receptors in sufentanil preconditioning (SPC)-induced attenuation of myocardial ischemia-reperfusion (I/R) injury in rats.Methods Forty adult male Sprague-Dawley rats,aged 2-3 months,weighing 250-330 g,were randomly divided into 5 groups (n =8 each) using a random number table:sham operation group (group S),group I/R,group SPC,δ receptor antagonist naltrindole + SPC group (NTD + SPC group),and κ receptor antagonist nor-binaltorphimine (nor-BNI) + SPC group (BNI + SPC group).Myocardial I/R was induced by 30 min occlusion of left anterior descending branch of coronary artery followed by 120 min reperfusion.In group SPC,5 min infusion of sufentanil 3μg/kg was repeated 3 times at 5 min interval before myocardial ischemia.In NTD + SPC group,naltrindole 5 mg/kg was intravenously injected,at 10 before SPC.In BNI + SPC group,nor-BNI 5 mg/kg was injected intravenously at 15 min before SPC.Arterial blood samples were collected at 120 min of reperfusion for measurement of the serum cardiac troponin I (cTnI) and creatine kinase isoenzyme-MB (CK-MB) concentrations.The rats were then sacrificed and hearts removed for determination of myocardial infarct size (IS) and area at risk (AAR).IS/AAR ratio was calculated.Results Compared with S group,the serum cTnI and CK-MB concentrations were significantly increased in I/R,NTD + SPC and BNI + SPC groups,and the serum CK-MB concentrations were increased in SPC group,and IS/AAR ratio was increased in I/R group (P ＜ 0.05 or 0.01).The serum cTnI and CK-MB concentrations were significantly lower in SPC,NTD + SPC and BNI + SPC groups and IS/AAR ratio was lower in SPC and BNI + SPC groups than in I/R group,and higher in NTD + SPC and BNI + SPC groups than in SPC group (P ＜ 0.05 or 0.01).Conclusion Both κ and δ opioid receptors mediate SPC-induced attenuation of myocardial I/R injury in rats. Key words: Receptors, opioid ; Sufentanil ; Ischemic preconditioning; Myocardial reperfusion injury