Humbert T, Luu-Duc C, Comet M, Demenge P
Université Joseph Fourier, URA CNRS 1287, Grenoble, France.
Eur J Nucl Med. 1991;18(11):870-8. doi: 10.1007/BF02258452.
Previous studies led us to hypothesize that a fatty acid analogue, 15-p-iodophenyl-beta-methyl pentadecanoic acid (IMPPA or BMIPP), which is taken up but not quickly metabolized by heart cells, would be a more suitable tracer of cellular viability than thallium-201. Biodistribution studies of 1-14C-IMPPA in conscious, freely moving rats showed that the concentration ratio of radioactivity in the heart with respect to the blood was about 8 for at least 60 min after intravenous administration, permitting its use as a putative tracer in these conscious, freely moving rats. Thereafter, the myocardial uptake of 14C-IMPPA was studied in isoproterenol-treated rats (daily treatment for 10 days in order to induce cardiac hypertrophy and necrotic foci) with respect to control ones. Comparison of myocardial localizations by quantitative autoradiography of the uptake of 201Tl and 14C-IMPPA with that of triphenyltetrazolium chloride (TTC) staining enabled comparative evaluation of nutritional blood flow, localization and uptake of 14C-IMPPA and necrotic foci size. Distributions of 14C-IMPPA and 201Tl in control rats' hearts were homogeneous, like TTC staining. In infarcted hearts, areas of decreased 14C-IMPPA uptake were nearly the same (100% +/- 5%) as those unstained by TTC. These areas were larger than those showing a decrease in thallium uptake (about 70% +/- 5% of the total scar size). Therefore, IMPPA seems to be a more accurate and sensitive indicator of necrosis localization compared with thallium. It may be a useful agent for assessment of myocardial viability by single photon emission tomography (SPET) imaging.
以往的研究使我们推测，一种脂肪酸类似物，即15-对碘苯基-β-甲基十五烷酸（IMPPA或BMIPP），它能被心肌细胞摄取但代谢缓慢，可能是一种比铊-201更适合的细胞活力示踪剂。对清醒、自由活动的大鼠进行的1-14C-IMPPA生物分布研究表明，静脉注射后至少60分钟内，心脏与血液中放射性的浓度比约为8，这使得它可作为这些清醒、自由活动大鼠的一种假定示踪剂。此后，研究了异丙肾上腺素处理的大鼠（每日处理10天以诱导心肌肥大和坏死灶）与对照大鼠相比14C-IMPPA的心肌摄取情况。通过对201Tl和14C-IMPPA摄取的定量放射自显影与氯化三苯基四氮唑（TTC）染色进行心肌定位比较，能够对营养血流、14C-IMPPA的定位和摄取以及坏死灶大小进行比较评估。14C-IMPPA和201Tl在对照大鼠心脏中的分布是均匀的，与TTC染色情况相似。在梗死心脏中，14C-IMPPA摄取减少的区域与未被TTC染色的区域几乎相同（100%±5%）。这些区域比铊摄取减少的区域更大（约占总瘢痕大小的70%±5%）。因此，与铊相比，IMPPA似乎是一种更准确、更敏感的坏死定位指标。它可能是一种通过单光子发射断层扫描（SPET）成像评估心肌活力的有用试剂。
