Pappata S, Samson Y, Chavoix C, Prenant C, Mazière M, Baron J C
Commissariat à l'Energie Atomique, Service Hospitalier Frédéric Joliot, Département de Biologie, Orsay, France.
J Cereb Blood Flow Metab. 1988 Jun;8(3):304-13. doi: 10.1038/jcbfm.1988.65.
The central type benzodiazepine receptors were studied in 17 healthy human subjects with 11C-RO 15 1788 and positron emission tomography (PET). The brain regional distribution of the tracer in eight control studies performed after injection of trace doses of 11C-RO 15 1788 was consistent with that of benzodiazepine receptors. Saturation studies with co-injected cold RO 15 1788 in the remaining subjects showed a dose-dependent decrease of brain radiotracer until full inhibition of specific binding was achieved with doses above 0.1 mg/kg (four studies). Based on the results, a simple method to estimate the specifically bound 11C-RO 15 1788 regionally in a single PET study is proposed, using the data from the full-saturation studies as a stable estimate of the nondisplaceable radioligand concentration. Using this method, it was found that quasiequilibrium between the estimated specifically bound and nondisplaceable components was achieved at times equal to or longer than 20 min after tracer administration. The validity of this method was partly supported by further results, showing a good agreement between the regional specific binding so calculated and postmortem data of receptor density.
利用11C-RO 15 1788和正电子发射断层扫描（PET）技术，对17名健康人体受试者的中枢型苯二氮䓬受体进行了研究。在注射微量11C-RO 15 1788后进行的八项对照研究中，示踪剂在脑区的分布与苯二氮䓬受体的分布一致。在其余受试者中，用共注射的冷RO 15 1788进行的饱和研究显示，脑放射性示踪剂呈剂量依赖性减少，直到剂量高于0.1mg/kg时特异性结合被完全抑制（四项研究）。基于这些结果，提出了一种在单次PET研究中局部估计特异性结合的11C-RO 15 1788的简单方法，即使用完全饱和研究的数据作为不可置换放射性配体浓度的稳定估计值。使用该方法发现，在给予示踪剂后20分钟及以上的时间，估计的特异性结合成分与不可置换成分之间达到了准平衡。该方法的有效性得到了进一步结果的部分支持，结果表明，如此计算出的局部特异性结合与受体密度的尸检数据之间具有良好的一致性。
