抗心肌肌凝蛋白轻链单克隆抗体亲大鼠梗死心肌放射免疫显像探讨

Imaging of ^(99m) Technetium labelled anticardiac myosin light monoclonal antibody(AMLCA) in experimental myocardial infarction in rats

目的 探讨抗心肌肌凝蛋白轻链单克隆抗体 ( AMLCA)亲梗死心肌显像的可行性。 方法 大鼠静脉注射99m Tc标记 AMLCA,观察梗死心肌摄取99m Tc-AMLCA的特异性及摄取与注射时间和梗死时间的关系。 结果 99m Tc-AMLCA在大鼠血中的清除呈双相 :注射后 ,99m Tc-AMLCA血浓度由 2 h的 ( 4.0 7± 0 .90 ) ID% / g组织迅速降至 4 h的 ( 2 .70± 0 .54) ID% / g组织 ;此后缓慢下降。注射后 6h、8h、2 4 h,肝脏均较梗死心肌摄取强。梗死心肌在注射后 2 h就开始摄取99m Tc-AMLCA,4～ 8h渐趋平衡 ,2 4 h达到高峰。梗死 6h至 1 4 d的不同梗死时间 99m Tc-AMLCA摄取差异无显著性( P>0 .0 5)。注射后相同时间 ,梗死心肌与正常心肌放射比 ,99m Tc-AMLCA明显大于 99m Tc-N-Ig G( P<0 .0 1 )。 结论 大鼠梗死心肌能特异地摄取 99m Tc-AMLCA,并且具有摄取时间早 ,持续时间长 ,受梗死时间影响较小的特点 ,为99m Tc-AMLCA亲梗死心肌显像的研究提供了初步的实验依据。

Objective To study the feasibility of imaging of myocardial infarcts by intravenous injection of 99m Tc labelled anticardic myosin light chain monoclonal antibody(AMLCA). Methods The percentage of injection dose (ID) per organ and the ratio between infarcted and normal myocardium were calculated after injection certain dose of 99m Tc AMLCA in the experimental myocardial infarction in rats. Results The circulating 99m Tc AMLCA at the first 4 hr decreased rapidly with only (2 70±0 54) ID%/g from (4 07±0 90) ID%/g at 2 hr,and decreased slowly during 6 24 hr with (1 30±0 61) ID%/g at 24 hr after injection The infarcted myocardium uptook 99m Tc AMLCA rapidly at the first 2 hr,tended towards steady at 4 8 hr and reached the peak at 24 hr after injection. Compared with the ratios of uptake of 99m Tc N IgG in the infarcted vs normal myocardium,the ratios of 99m Tc AMLCA were significantly greater at same time after injection( P <0.01).There were no significant differences of the ratios of uptake of 99m Tc AMLCA in the infarcted vs normal myocardium at different time of infarction( P >0 05). Conclusions These data suggest that the uptake of 99m Tc AMLCA may be specific,early,and long lasting in the infarcted myocardium and be hardly affected by infarct time.This may probably become a new approach to myocardial infarct imaging.