^(99m)Tc标记的抗心肌肌钙蛋白Ⅰ单克隆抗体在心肌损伤大鼠体内的分布

Distribution of ^(99m)Tc-AcTnI MA in rats with myocardial injury

目的研究99mTc标记的抗心肌肌钙蛋白I单克隆抗体(AcTnIMA)在实验性心肌损伤大鼠体内的分布,探讨99mTc-AcTnIMA是否可以作为心脏放射免疫显像剂。方法第一批大鼠实验组:20只急性心肌损伤大鼠注射99mTc-AcTnIMA0.2mci,分别于注射后2、4、6、8h处死(每次5只),取血液、肝、脾、肾、正常肌肉、肺、心脏,计算每克组织计数占总注入计数的百分比(ID%/g)及心-肺ID%/g比(HLR);药物对照组:20只急性心肌损伤大鼠注射99mTc标记的非特异性免疫球蛋白(N-IgG)0.2mci,处死方法同实验组。取肺及心脏,计算ID%/g及HLR;空白对照组:20只正常大鼠注射99mTc-AcTnIMA0.2mci,处理方法同药物对照组。第二批50只心肌损伤大鼠分别于发生心肌损伤后2、4、6、8、12、24h,3、5、10、15d分10次静脉注射99mTc-AcTnIMA0.2mci(每次5只),注射后4h处死,计算出ID%/g及HLR。结果损伤心肌摄取99mTc-AcTnIMA为特异性摄取,摄取的高峰时间为4h;损伤心肌摄取99mTc-AcTnIMA与损伤发生时间无关。结论99mTc-AcTnIMA有望作为心脏放射免疫显像剂诊断心肌损伤。

Objective To study the distribution pattern of ^99mTc-AcTnIMA in rats with experimental myocardial injury, thereby determining the possibility of ^99mTc-AcTnIMA to be a tracer of myocardial radioimmunoimaging. Method The first 60 rats were divided into three groups. In the experimental group, 20 rats with acute myocardial lesion were injected with 0. 2 mci ^99mTc-AcTnIMA, and killed at 2,4,6 and 8 h after injection respectively （5 rats each time）. Blood, liver, spleen, kidneys, healthy muscles, lungs and heart were taken,and injection dose%/g（ID%/g） and the ID%/g ratio of heart to lung（ HLR） were calculated. In the pharmic control group,20 rats with acute myocardial lesion were injected with 0. 2 mci ^99mTc-N-IgG and were killed in the same way as the experimental group. The lungs and hearts were taken, and ID%/g and HLR calculated. In the blank control, 20 healthy rats were injected witty0. 2 mci ^99mTc-AcTnIMA and the subsequent procedures were just the same as the pharmic group. The second 50 rats with myocardial lesion were injected with 0. 2 mci ^99mTc-AcTnIMA at 2,4,6,8,12, and 24 h, and on the 3 rd, 5 th, 10 th and 15 th day after myocardial injury, respectively （5 rats each time）, and killed at 4 h after injection, and then ID%/g and HLR were calculated. Result It showed specific uptake of ^99mTc-AcTnIMA by compromised cardiac muscles with the peak time of 4 h, and the uptake had nothing to do with the time after lesiorL Conclusion ^99mTc-AcTnIMA can hopefully be a tracer of myocardial radioimmunoimaging to diagnose myocardial injury.