SMT对大鼠在体心脏缺血-再灌注损伤超微结构的保护作用.doc

???? SMT对大鼠在体心脏缺血-再灌注损伤超微结构的保护作用 ???? ???? 摘要 目的：研究SMT对心脏缺血-再灌注损伤(IRI)心肌超微结构的影响。方法 ：SD大鼠18只，体重320～380 g，随机分为三组：①缺血-再灌注组(IR)：夹闭冠状 动脉左前降支60 min，松夹20 min；②缺血-再灌注+SMT组(SMT)：再灌注前5 min，股静脉 注射iNOS抑制剂S-methylisothiourea sulfate(SMT 5 mg／kg w )，余同IR组；③对照组( C)：暴露心脏后，不做任何处理，观察80 min。测量Ⅱ导联心电，测定心肌NO2-+NO 3-、实验前后血清NO2-+NO3-含量，心肌组织透射电镜检查。结果：IR组血清NO2-+NO3-较实验前明显增高(P＜0．01)，心肌组织NO2-+NO3 -高于C组(P＜0．05)。电镜观察，心肌纤维过度收缩，线粒体肿胀、嵴断裂，排列紊 乱、空泡形成。SMT组实验后血清NO2-+NO3-较实验前降低(P＜0．05)，心肌组 织NO2-+NO3-接近C组(P＞0．05)、低于IR组(P＜0．05)。电镜下，心肌超 微结构损伤明显改善。线粒体群集，电子密度增高，嵴密集、排列整齐，肿胀及空泡明显减 轻。结论：SMT对IRI的心肌超微结构有保护作用。关键词：　心脏；　缺血-再灌注损伤；　一氧化氮合酶;　超微结构中分类号：　Q463；R331．3文献标识码: A文章编号: 1 000-6834(2000)04-0314-04 PROTECTIVE EFFECTS OF SMT ON MYOCARDIALULTRASTRUCTURE OF ISCHEMIA REPERFUSION INJURY IN HEART OF RAT ZHENG Hui-zhen（Department of Physiology）CAI Bo（Department of Physiology）FENG You-hui（Department of Physiology）SUN Hong（ Histology and Embryology）CAI Ka ng-rong（Analysis center, Gu angdong Medical College, Zhanjiang 524023） ABSTRACT　　Aim: To Investigate the myocardial ultrastructure effects of SMT on 　the ischemia reperfusion injury (IRI) in the rat heart. Methods: Eighteen　Spraqua-Dawley rats were randomly divided into three groups: ische mia　reperfusion group (IR), subjected to 60 min of o-cclusion and 20 min o f　reperfusion of the anterior descending branch of left coronary artery;　IR+SM T group (SMT) , given the selective iNOS inhibitor S-methylisothiourea　sulfate (SMT, 5mg/kg, Ⅳ) before reperfusion; control group (C), didnt　occlude corona ry artery after exposing heart and observed 80 min.Electrocardiogram (ECG) was r ecorded. Nitrite and nitrate content were　measured in myocardium and blood seru m. The changes of myocardial ultrastructure were observed with electron microsco pe. Results: Ischemia　reperfusion induced ST segment elevation and T waves inversion or tallness　in ECG, damaged myocardial ultrastructure, increa sed nitrite and nitrate　content in myocardium and blood serum after IR compare d w