腺苷对大鼠离体心脏功能及心肌细胞凋亡的影响

目的 探讨腺苷预处理对离体灌流大鼠心脏功能及心肌细胞凋亡的影响.方法 将30只雄性Wistar大鼠随机分为对照组、缺血—再灌注（IR）组、腺苷组,各10只.采用戊巴比妥钠腹腔注射麻醉,同时腹腔注射肝素,麻醉后开胸暴露心脏,快速取出心脏.用Langehdorff离体灌注大鼠心脏K-H液,腺苷组、IR组建立心肌缺血—再灌注损伤模型.对照组灌注时间为120 min;IR组灌注K-H液30min,缺血30 min,K-H液60 min;腺苷组灌注K-H液10 min,给予腺苷20 min,缺血30 min,K-H液60 min.记录实验初始和结束时左室发展压（LVDP）和平均冠脉流量（CSF）,测定心肌组织丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性,TUNEL方法检测细胞凋亡.结果 IR组和腺苷组实验结束时LVDP、CSF低于实验初始（P均＜0.01）;实验结束时腺苷组、对照组的CSF均高于IR组,LVDP水平IR组＜腺苷组＜对照组,P均＜0.05.大鼠心肌组织中MDA水平IR组＞腺苷组＞对照组,P均＜0.01,腺苷组及对照组心肌组织SOD活性高于IR组,P均＜0.01.心肌细胞凋亡率IR组＞腺苷组＞对照组P＜0.01.结论 腺苷预处理能改善离体灌流大鼠心功能,其机制可能与减轻缺血-再灌注损伤和抑制心肌细胞凋亡有关.

Effects of adenosine on cardiac function and myocardial apoptosis of isolated rat heart

Objective To explore the effects of adenosine preconditioning on cardiac function and myocardial apoptosis of isolated perfused rat heart.Methods Thirty male Wistar rats were randomly divided into 3 groups,10 rats in each group：the control group,ischemia-reperfusion group （IR group） and adenosine group.Pentobarbital sodium was intraperitoneally injected into rats for anesthesia,and at the same time heparin was injected into abdominal cavity.After anesthesia,hearts were obtained by thoracotomy.The isolated rat hearts were perfused with K-H solution on a Langendorff device,and the models of myocardial ischemia-reperfusion injury were established in the IR group and adenosine group.The isolated rat hearts were perfused for 120 min in the control group; IR group was perfused with K-H solution for 30min,ischemia for 30 min,and then with K-H solution for 60 min; adenosine group was perfused with K-H solution for 10 min and adenosine for 20 min,ischemia for 30 min,and then with K-H solution for 60 min.The left ventricular developed pressure （LVDP） and the average coronary flow （CSF） were recorded at the beginning and at the end of the process,respectively.The myocardial malondialdehyde （MDA） content and superoxide dismutase （SOD） activity were measured and myocardial apoptosis was detected by TUNEL method.Results Compared with the beginning,LVDP and CSF in both IR group and adenosine group were decreased at the end of the experiment （all P 〈 0.01）,LVDP and CSF in the adenosine group were lower than those of the IR group （all P 〈 0.05）.Compared with the control group,the MDA content in the myocardial tissue in both IR group and adenosine group increased,and the MDA content in the adenosine group was higher than that in the IR group （all P 〈 0.01）.SOD activity of myocardial tissue in the adenosine group and control group was higher than that in the IR group （all P 〈 0.01）.The myocardial apoptosis rate：IR group （0.287 ± 0.072） 〉 adenosine group （0.101 ±0.024,n=10） 〉 control group （0.015±0.004） （allP〈0.01）.Conclusion Adenosine preconditioning can improve the cardiac function of isolated perfused rat heart,whose mechanism may be associated with the reduction of ischemia-reperfusion injury and inhibition of myocardial apoptosis.