目的通过建立猪体外循环(cardiopulmonary bypass,CPB)心肌缺血再灌注模型,探讨δ-阿片受体激动剂脑腓肽([D-Ala2,D-Leu5]Enkephalin,[D-Ala2,D-Leu5],DADLE)的心肌保护作用。方法将12只成年猪(30~35kg)随机分为对照组(常规CPB)(n=6)和DADLE组(CPB前1h静脉应用DADLE,1mg/kg)(n=6)。常规建立体外循环模型,主动脉阻断同时灌注改良st.Thomas停搏液。每组于CPB前、主动脉开放时、CPB结束时、主动脉开放后1h、主动脉开放后2h检测冠状静脉窦血肌钙蛋白(TnT)和肌酸激酶同功酶(CK-MB)含量,相应时间点监测左室收缩压(LVSP),左室舒张末期压(LVEDP)、左室内压最大变化速率(±dp/±dtmax),主动脉开放后2h取左心室心肌,测定心肌ATP含量。结果(1)和预处理组相比,对照组心功能指标明显下降;(2)对照组的TnT和CK-MB较预处理组明显升高,相反,其ATP含量明显降低。结论在猪心肌缺血再灌注中,非选择性δ-阿片受体激动剂DADLE具有明显的心肌保护作用。
Objective To study the cardioprotective effects of δ-opioid receptor agonist [D-Ala2,D-LeuS]Enkephalin (DADLE) in swine cardiopulmonary bypass(CPB) model after ischemic-reperfusion. Methods 12 adult swine(30-35 kg) were randomly divided into 2 groups:control group and DADLE group ( n = 6). CPB was instituted routinely and the modified St. Thomas cold cardioplegic solution was administered into the root of aorta. Blood samples were taken from coronary sinus before CPB, at the beginning of reperfusion, at the end of CPB, one hour after reperfusion and two hours after reperfusion. Parameters including TnT and CK-MB were measured. LVSP, LVEDP and ± dp/± dtmax were meastared at the corresponding time points. Specimens of myocardium were taken for ATP determination. Results (1) Cardiac function were found to be decreased in both groups but more significantly in control group; (2) Concentrations of TnT and CK-MB increased significantly in control group as compared with DADLE group, and the value of ATP decreased significantly in control group. Conclusion This suggests that δ-opioid receptor agonist DADLE has cardioprotective effect in swine after CPB ischemic-reperfusion injury.