^(125)I-BMIPP检测缺血和再灌注区存活心肌及其与局部血流的关系

Detection of viable myocardium in canine model with myocardial ischemia and ischemiareperfusion by 125 IBMIPP: relation to regional blood flow

目的通过犬心肌梗死及缺血再灌注模型，观察碘标β甲基碘苯脂十五烷酸（ＢＭＩＰＰ）检测缺血区存活与坏死心肌的作用及其与局部血流的关系。方法１２条实验犬结扎左回旋支冠状动脉后分成２组，即单纯缺血组与缺血再灌注组。静脉注射１２５ＩＢＭＩＰＰ和９９Ｔｃｍ右旋糖酐微球（ＴＭ），３０ｍｉｎ后处死实验犬，摘除心脏，分别进行ＥＶＡＮＳ蓝和ＮＢＴ染色，确定正常、缺血和坏死心肌范围，并分别测定同一组织块１２５Ｉ和９９Ｔｃｍ的放射性计数，各局部心肌血流量与ＢＭＩＰＰ摄取量以左心室组织块峰计数的百分率表示。结果在单纯缺血组中，缺血心肌局部ＢＭＩＰＰ的摄取量为（６７±２３）％，明显高于局部血流（４２±１９）％，但与正常心肌组比较，局部血流和ＢＭＩＰＰ摄取量均明显减低；坏死心肌局部血流为（２６±１１）％，与ＢＭＩＰＰ摄取量（２５±１３）％差异无显著性，但明显低于缺血心肌组的局部血流和ＢＭＩＰＰ浓聚量；缺血心肌再灌注后，无论缺血或坏死心肌，局部血流均见明显恢复，但局部ＢＭＩＰＰ的摄取量与单纯缺血组比较无明显增加。结论在血流灌注减低区，ＢＭＩＰＰ浓聚量相对增高可能是缺血区心肌存活的标志；而血流量与ＢＭＩＰＰ浓聚量一致性严重减低的部位?

bjective The effects of BMIPP (methyliodophenyl pentadecanoic acid) on detecting viable myocardium and the relation between regional blood flow and the uptake of BMIPP were evaluated in canine model of myocardial ischemia and ischemiareperfusion Methods 12 openchest dogs under anesthesia were divided into two groups Group (ischemia group) had left circumflex coronary arterial occlusion for 2 h and group (ischemiareperfusion group) was occlused for 1 h and followed by 2 h reperfusion Myocardial blood flow was measured with 99 Tcmmicrospheres 30 min after intravenous injection of 125 IBMIPP and 99 Tcmmicrospheres, the heart was excised rapidly and stained with Evans blue and NBT Tissue samples (divided into approximately 1 g) of left ventricle were obtained, weighed and counted for 125 I and 99 Tcm Regional blood flow and the uptake of BMIPP were expressed as percentages of average values in nonischemic myocardium (two to three tissue samples) from the normal myocardium Results In ischemic myocardium (NBT positive samples), the uptake of BMIPP was relatively higher compared with regional blood flow 23)% vs (4219)%, P <0001] and remarkably higher than that in necrotic samples, but was lower than that in normal myocardium However, a concordant reduction of regional blood flow and BMIPP uptake was showed in necrotic myocardium P >005] In ischemiareperfusion group, regional blood flow was increased in ischemic and necrotic tissues, but the uptake of BMIPP was not enhanced with the increasing blood flow Conclusions BMIPP uptake seems to provide metabolic information independent of regional blood flow The mismatching between regional blood flow and BMIPP uptake may indicate myocardial viability in the regions of hypoperfusion and the uptake of BMIPP in ischemic myocardium was related to existence of cellular metabolism