Brust Peter, Zessin Jörg, Kuwabara Hiroto, Pawelke Beate, Kretzschmar Marion, Hinz Rainer, Bergman Jörgen, Eskola Olli, Solin Olof, Steinbach Jörg, Johannsen Bernd
Institut für Interdisziplinäre Isotopenforschung, 04318 Leipzig, Germany.
Synapse. 2003 Feb;47(2):143-51. doi: 10.1002/syn.10163.
S-([(18)F]fluoromethyl)-(+)-McN5652 ((18)F-FMe-McN5652) has recently been synthesized as a new potential radiotracer for positron emission tomography (PET) imaging of the 5-HT transporter. It is an analog of (11)CMcN5652, which has been used in clinical PET studies for 5-HT transporter imaging. This article describes the comparison of these two radiotracers in pigs with respect to their in vivo binding characteristics. PET images revealed that the highest accumulation of both radiotracers was found in the ventral midbrain, thalamus, olfactory lobe, and pons which is consistent with the known density of 5-HT transporters. The specific binding was determined by subtracting the values of the inactive (-) enantiomers or of the occipital cortex from those obtained with (11)CMcN5652 or (18)F-FMe-McN5652 in the time period between 75 and 115 min after radiotracer injection. The specific binding of the (18)F-labeled derivative was about 40% higher than that of the (11)C-labeled derivative. A strong inhibition of the specific binding was observed for both radiotracers after pretreatment with the selective 5-HT uptake inhibitor citalopram. (18)F-FMe-McN5652 showed faster kinetics than (11)CMcN5652. It reached the binding equilibrium during a study length of 120 min, which was not the case for (11)CMcN5652. It is concluded that (18)F-FMe-McN5652 is suitable for 5-HT transporter imaging with PET.
S-([(18)F]氟甲基)-(+)-McN5652（(18)F-FMe-McN5652）最近已被合成，作为一种用于5-羟色胺转运体正电子发射断层扫描（PET）成像的新型潜在放射性示踪剂。它是(11)CMcN5652的类似物，(11)CMcN5652已用于5-羟色胺转运体成像的临床PET研究。本文描述了这两种放射性示踪剂在猪体内结合特性方面的比较。PET图像显示，两种放射性示踪剂在腹侧中脑、丘脑、嗅叶和脑桥中积累最高，这与已知的5-羟色胺转运体密度一致。通过在注射放射性示踪剂后75至115分钟期间，用(11)CMcN5652或(18)F-FMe-McN5652获得的值减去无活性（-）对映体或枕叶皮质的值来确定特异性结合。(18)F标记衍生物的特异性结合比(11)C标记衍生物高约40%。在用选择性5-羟色胺摄取抑制剂西酞普兰预处理后，两种放射性示踪剂的特异性结合均受到强烈抑制。(18)F-FMe-McN5652的动力学比(11)CMcN5652更快。它在120分钟的研究时长内达到结合平衡，而(11)CMcN5652并非如此。结论是(18)F-FMe-McN5652适用于PET的5-羟色胺转运体成像。
