用^99Tc^m-MIBI评价腺苷预适应对缺血心肌细胞的保护作用  

Study on evaluating the importance and mechanism of adenosine preconditioning in mediating myocardial protection from ischemic myocardial injury with ^99Tc^m-MIBI

作　　者：梁君[1] 林国生[2] 蔡军[2] 周逸[3] 陈辉霖[1] 

机构地区：[1]武汉大学人民医院核医学科,430060 [2]武汉大学人民医院心内科,430060 [3]武汉市中心医院心内科

出　　处：《中华核医学杂志》2008年第2期134-136,共3页Chinese Journal of Nuclear Medicine

基　　金：国家自然科学基金（30600337）

摘　　要：目的探讨辨^99Tc^m-甲氧基异丁基异腈（MIBI）评价腺苷预适应对心肌缺血／再灌注（L／R）损伤的保护作用及其机制。方法应用Langendorff装置建立离体兔心脏I／R模型，18只离体灌注兔心脏随机分成I／R组6只、腺苷预适应＋I／R组（AD）6只、缺血预适应＋I／R组（IPC）6只。用含^99Tc^m-MIBI（55．5MBq）的Krebs-Henseleit（KH）液灌注40min，测定^99Tc^m-MIBI摄取相和洗脱相心肌的放射性变化。观察左心室血流动力学变化、心肌细胞肌酸激酶（CK）和乳酸脱氢酶（LDH）漏出量的变化、心肌梗死面积，用透射电镜观察心肌受损程度。采用SPSS11．5软件和Excel软件对数据进行分析。结果AD和IPC组MIBI摄取率和滞留分数明显高于I／R组（t=2．614—7．730，P均〈0．05）。而AD和IPC组摄取率和滞留分数差异均无统计学意义（t=0．614—2．227，P均〉0．05）。左心室功能恢复、心肌CK和LDH漏出量、心肌梗死面积、电镜分析结果均表明，AD和IPC组心肌受损程度较I／R组轻。心肌^99Tc^m-MIBI放射性与心肌冠状动脉血流量呈明显正相关（r=0．793，P〈0．001）；而与梗死心肌／缺血心肌质量百分比呈明显负相关（r=-0．86，P〈0．0001）。结论腺苷预适应与缺血预适应对I／R心肌具有相似的心脏保护效应。心肌^99Tc^m-MIBI血流动力学变化与心肌活力密切相关，可以作为评价心肌腺苷预适应及其机制的有效指标。Objective Recently, many investigators are interested in the study on mechanism of adenosine preconditioning in mediating myocardial protection from ischemic myocardial injury. The aim of this paper was to investigate the feasibility of the protective effects and possible mechanism of adenosine preconditioning on myocardium injured by ischemic/reperfusion （I/R） with ^99Tc^m-methoxyisobutylisonitrile （MIBI）. Methods The isolated I/R rabbit heart models were established with Langendorff. Eighteen Krebs-Henseleit（KH） perfused rabbit hearts were randomly assigned to three groups： I/R （n = 6） group, adenosine preconditioning （ AD, n = 6 ） group and ischemic preconditioning （ IPC, n = 6 ） group. KH rabbit hearts were perfused with 55.5 MBq ^99Tc^m-MIBI for 40 min. The changes of myocardial activity were recorded to get the data of uptake and washout. Cardiac function recovery, creatine kinase （CK） and lactate dehydrogenase （LDH） leakage, myocardial infarct size were measured and the transmission electron microscope analysis was performed to assess myocardial injury. SPSS 11.5 and Excel were used for data analysis. Results Based on the myocardial assessment data, the degree of myocardial injury was also less in AD and IPC than in I/R groups. Significantly higher ^99Tc^m-MIBI myocardium uptake rates and retention fractions were observed in AD and IPC than in I/R （ t = 2. 614 ;7.730, P 〈 0.05 ） groups, though no statistic difference was noted between AD and IPC groups in either myocardium uptake rates or retention fractions （ t = 0. 614 -2. 227, P 〉0.05）. The ^99Tc^m-MIBI activity was positively correlated with coronary artery blood flow（ r =0.79, P 〈0. 001 ） and negatively correlated with severity of myocardial infarction（ r = -0.86, P 〈 0.0001 ）. Conclusion ^99Tc^m-MIBI was potentially useful to study the protective effects and possible mechanism of adenosine preconditioning on I/R myocardium.

关 键 词：心肌缺血 腺苷 MIBI 心肌再灌注 体外循环 兔 

分 类 号：R686[医药卫生—骨科学]