梗塞心肌摄取锝标抗心肌肌凝蛋白轻链mAb^(99)Tc^m-AMLCA的影响因素

Influential factors of Technetium-99m labeled anticardiac myosin light mAb uptake in infarcted myocardium in rats

目的 :探讨注射锝标抗心肌肌凝蛋白轻链单克隆抗体 (99Tcm AMLCA)后不同时间 ,梗死时间和梗死区域对大鼠梗死心肌摄取99Tcm AMLCA的影响 .方法 :大鼠静脉注射99Tcm AMLCA 7.4MBq ,观察不同注射时间 (2 ,4 ,8,2 4h) ,不同梗死时间 (心梗后 6 ,12h ,1～ 14d)和不同梗死区域 (梗死中央、周边的内层心肌和外层心肌 )对梗死心肌 /正常心肌发射性比的影响 .结果 :注射后 2h梗死心肌开始摄取99Tcm AMLCA ,梗死心肌 /正常心肌发射性比是 1.6 7± 0 .96 ,4～ 8h摄取逐渐增加 ,2 4h达到高峰 ,梗死心肌 /正常心肌发射性比是 4 .38± 0 .80 .心肌梗死后 6h～ 14d ,梗死心肌均有很强的99Tcm AMLCA摄取 ,心梗后 5d摄取最强 ,梗死心肌 /正常心肌发射性比是3.82± 0 .6 7;梗死中央区内层心肌的放射性摄取比值是 4 .5 2± 0 .6 0 ,外层心肌是 3.32± 0 .5 8两者具有统计学显著意义 (P<0 .0 1) .结论 :急性心肌梗死大鼠梗死心肌特异性地摄取99Tcm AMLCA迅速持久 ,不受心梗时间影响 ,梗死中央区内层心肌摄取最强 ,为99Tcm AMLCA亲梗死心肌显像临床应用提供了实验依据 .

AIM: To study the influential factors of uptake of Technetium 99m labeled anticardic myosin light chain monoclonal antibody ( 99 Tc m AMLCA) in infarcted myocardium in rats. METHODS: The ratio was calculated between infarcted and normal myocardium after injecting certian dose of 99 Tc m AMLCA in the experimental myocardial infarction in rats and the relationship was observed between the radioactivity uptake in infarcted myocardium and injection time, infarction time and zone region of infracted myocardium. RESULTS: The infarcted myocardium uptook 99 Tc m AMLCA rapidly at the first 2 h, increased towards steady at 4～8 h and reached the peak at 24 h after injection. Compared with the ratios of 99 Tc m N IgG in the infarcted with normal myocardium, the ratios of 99 Tc m AMLCA were significantly higher at the same time after injection ( P <0.01). There were a greater uptake of 99 Tc m AMLCA in the infarcted myocardium during the phase of acute myocardium infarction (AMI).The uptake of 99 Tc m AMLCA in the infarcted myocardium in the endiocardial layers at the infarct center was greater than other zone regions of infracted myocardium. CONCLUSION: The uptake of 99 Tc m AMLCA is specific, rapid and long lasting in the infarcted myocardium and is hardly affected by infarct time. This may probably become a new approach to myocardial infarct imaging.