99锝m N-2-巯基吡啶-N-氧化物与99锝m-甲氧基异丁基异腈对犬急性心肌梗死模型的对照研究  

A comparative study of 99Tcm N-mercaptopyridine-N-oxide and 99Tcm-sestamibi myocardial perfusion imaging on acute myocardial infarction canine model

作　　者：沙非[1] 温晓斐[1] 卜丽红[1] 李任飞[1] 张同[1] 金钟男[1] 申宝忠[1] 

机构地区：[1]哈尔滨医科大学第四临床医学院医学影像科,150001

出　　处：《中华放射学杂志》2011年第4期392-398,共7页Chinese Journal of Radiology

基　　金：基金项目：科技部国际科学合作项目（2009DFB30040）;国家自然科学基金资助项目（30970807）;哈尔滨市科技攻关计划项目（2007AA3CS085）;中国博士后科学基金特别资助项目（200801305）;第42批中国博士后科学基金面上资助项目（20070420165）;黑龙江省卫生厅资助项目（2007-446）;教育部春晖计划合作项目（2005-1-23003）;黑龙江省教育厅基金资助项目（11511213）;黑龙江省青年基金资助项目（QC07C79）

摘　　要：目的 在正常和心肌梗死犬模型上,研究99TcmN-2-巯基吡啶-N-氧化物（99TcmN-MPO）的药物代谢动力学特征、生物学分布特征和对急性心肌梗死的诊断能力,并与传统示踪剂99锝m-甲氧基异丁基异腈（99Tcm-MIBI）进行对比研究.方法 正常杂种犬12只.静脉注射99TcmN-MPO,于不同时间点（30 s及1、2、3、4、5、10、20、30、40、60和90 min）静脉分别采血1 ml,经γ探测器测量其放射活性;注药后10、20、30、60、90及120 min行全身SPECT显像,并于不同器官上各取同样大小的ROI,测量其放射性计数进行定量研究.每只犬均注射相同剂量的99TcmMIBI,进行相同的实验作为对照.介入学方法构建犬急性心肌梗死模型,24 h后,静脉注入99TcmN-MPO（5只）和99Tcm-MIBI（5只）,并于注药后30、60min进行心肌SPECT显像.结果 在静脉注射90 min内,99TcmN-MPO和99Tcm-MIBI均表现为快速的血液清除.两种示踪剂的初始注射剂量均为370 MBq.注射后1 min,每毫克血浆的放射活性小于初始注射剂量的50%[99TcmN-MPO为（35.77±6.31）%ID/mg;99Tcm-MIBI为（34.46±6.83）%ID/mg],30 min时＜5%[99TcmN-MPO：（3.11±1.44）%ID/mg;99Tcm-MIBI：（2.93±0.39）%ID/mg].99TcmN-MPO在心脏的浓聚明显,且存留时间很长,由于其在肝脏清除的速度较快,因此可获得良好的心/肝摄取比值,注射后10 min为0.54±0.06,30 min为1.02±0.06,60 min上升到1.38±0.06.相比之下,99Tcm-MIBI的心/肝摄取比值上升较为缓慢（注射后10 min为0.46±0.03,30 min为0.63±0.03,60 min为0.62±0.12）.犬心肌梗死后SPECT心肌断层扫描显示,在注射99TcmN-MPO 30 min后,心脏与肝脏分界清楚,可清楚显示心肌缺血、梗死灌注缺损区域、范围和程度;而99Tcm-MIBI注射后60 min,心脏和肝脏的分界依然不清,尤其是肝脏的高放射性对心脏下壁和左心室壁的影响很大,对心脏左心室壁的心肌梗死灌注缺损区域的显示不佳.结论 99TcmN-MPO具有心肌摄取量较高,肝脏代谢快的Objective The purpose of the present study is to compare the pharmacokinetic and biodistribution properties of 99Tcm N-mercaptopyridine-N-oxide （99 Tcm N-MPO） with 99 Tcm-sestamibi （99 Tcm-MIBI） in normal dogs, and to investigate the potential of 99TcmN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Methods Twelve healthy mongrel dogs were injected intravenously with 99TcmN-MPO （n = 6） or 99Tcm-MIBI （n = 6）. Tracer kinetics in body fluids were determined by collecting blood of 1 ml via a femoral vein catheter at 30 s, 1,2,3,4,5, 10, 20, 30, 40, 60and 90 min post-injection （p. i.）. The collected blood samples were weighed and counted for radioactivity in a γ-counter. Anterior and posterior planar γ-camera images were collected at 10, 20, 30, 60, 90, and 120 min after injection, with organ uptake quantified by region-of-interest （ROIs） analysis. For comparison, 99Tcm-MIBI was also evaluated in the same twelve dogs. Canine infarct models were set up by micro-invasive interventional embolization. SPECT images in the canine infarct model were collected 24 hours after myocardial infarction at 30 min and 60 min after the administration of 99Tcm N-MPO （n = 5） or 99Tcm-MIBI （n = 5）. Results Both of 99Tcm N-MPO and 99Tcm-M1BI had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min [99TcmN-MPO： （35. 77 ± 6. 31）% ID/mg ,99Tcm-MIBI （34. 46 ± 6. 83） % ID/mg] and less than 5% at 30 min p. i. [99Tcm N-MPO（3. 11 ± 1.44） % ID/mg,99Tcm-MIBI （2.93 ±0. 39）% ID/mg] . After injection, 99TcmN-MPO showed significant accumulation in the myocardium and prolonged retention. This rapid liver clearance of 99TcmN-MPO led to favorable heart-to-liver ratios, reaching values of 0. 54 ±0. 06 at 10 min, 1.02 ±0. 06 at 30 min, and 1.38 ±0. 06 at 60 min p. i.In contrast, the heart/liver ratio of 99Tcm-MIBI remained low at all time points （0. 46 ± 0. 03 at 10 min,0. 63 ±0. 03 at 30 min, and 0. 62 ± 0. 12 at 60 min p. i.�

关 键 词：心肌梗死 放射性同位素 体层摄影术 发射型计算机 单光子 

分 类 号：R542.22[医药卫生—心血管疾病]