Localization of Radiolabeled Cardiac Myosin‐Specific Antibody in Myocardial Infarcts: Comparison with Technetium‐99m Stannous Pyrophosphate
Localization of Radiolabeled Cardiac Myosin‐Specific Antibody in Myocardial Infarcts: Comparison with Technetium‐99m Stannous Pyrophosphate
复制标题
放射性标记心肌肌球蛋白特异性抗体在心肌梗塞中的定位：与 Technetium-99m 焦磷酸亚锡的比较
作者：
G. Beller;B. Khaw;E. Haber;T. Smith
摘要：将抗肌球蛋白抗体 [125I-(Fab')2] 的放射性碘化 (Fab')2 片段的心肌摄取与同时给予冠状动脉闭塞 24 (N = 6) 或 72 小时 (N = 5) 的狗的 99mTc-焦磷酸盐 (Tc-PYP) 进行比较。正常和梗塞心肌中这两种药物的相对浓度与区域血流相关，这通过相同动物中 35Sr 标记微球的分布来确定。在 24 小时 (r = -0.64) 和 72 小时 (r = -0.80) 闭塞动物中，125I-(Fab')2 定位与区域血流之间存在反指数关系。 135I-(Fab')2 的最大摄取出现在梗塞中心的心内膜下层，此处区域血流受损最严重（正常血流的 1-10%）。在梗塞周围样本的心外膜下层中观察到 Tc-PYP 的最大定位，其中流量仅适度减少（正常值的 31-50%）。这两种药物在缺血心肌中分布的差异可能与从血池排出的动力学差异有关。
SUMMARYThe myocardial uptake of radioiodinated (Fab')2 fragments of antimyosin antibody [125I-(Fab')2] was compared with simultaneously administered 99mTc-pyrophosphate (Tc-PYP) in dogs undergoing coronary occlusion for 24 (N = 6) or 72 hours (N = 5). Relative concentrations of both agents in normal and infarcted myocardiuni were related to regional blood flow as determined by distribution of 35Sr-labeled microspheres in the same animals.There was an inverse exponential relationship between 125I-(Fab')2 localization and regional blood flow in 24 hr (r = −0.64) and 72 hr (r = −0.80) occluded animals. The greatest uptake of 135I-(Fab')2 was observed in subendocardial layers of the center of the infarct where regional flow was most severely impaired (1–10% of normal flow). Maximal localization of Tc-PYP was observed in subepicardial layers in samples from the periphery of the infarct where flow was only moderately reduced (31–50% of normal). Differences in distribution of these two agents in ischemic myocardium are probably related to differences in kinetics of exit from the blood pool.