STEREOSELECTIVE BINDING OF 11C-RACLOPRIDE IN LIVING HUMAN-BRAIN - A SEARCH FOR EXTRASTRIATAL CENTRAL D2-DOPAMINE RECEPTORS BY PET
STEREOSELECTIVE BINDING OF 11C-RACLOPRIDE IN LIVING HUMAN-BRAIN - A SEARCH FOR EXTRASTRIATAL CENTRAL D2-DOPAMINE RECEPTORS BY PET
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DOI：
10.1007/bf00212840
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发表时间：
1988-01-01
影响因子：
3.4
通讯作者：
STONEELANDER, S
中科院分区：
文献类型：
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作者：
FARDE, L;PAULI, S;STONEELANDER, S
选择性d2 -多巴胺受体拮抗剂raclopride及其药理活性(R)-对映体FLB472被标记为11C，并在正电子发射断层扫描中用于研究11C-raclopride结合中枢d2 -多巴胺受体的立体选择性。注射11c -氯氯pride后，在富含多巴胺的基底节区有较高的放射性积累，而注射11C-FLB472后则没有这种放射性积累。因此，11C-raclopride的结合具有立体选择性。计算了两种对映体的分布比[脑区的放射性/血浆中的“自由”（非蛋白质结合）放射性]，以研究放射性积累的区域差异。两种对映体在白质中的分布比例相似。在壳核中，11C-raclopride的分布比11C-FLB472高3 - 4倍，这反映了11C-raclopride与基底神经节d2 -多巴胺受体的特异性结合。然而，在颞叶和额叶皮层中，11C-raclopride的分布比例仅比11C-FLB472高几个百分点，这表明如果d2 -多巴胺受体存在于人类的新皮层中，那么它们的密度确实很低。
The selective D2-dopamine receptor antagonist raclopride and its pharmacologically inactive (R)-enatiomer FLB472 were labelled with 11C and used in a study with positron emission tomography to examine the stereoselectivity of 11C-raclopride binding to central D2-dopamine receptors in three healthy men. After the injection of 11C-raclopride, there was a high accumulation of radioactivity in the dopamine-rich basal ganglia, whereas after the injection of 11C-FLB472 there was no such accumulation of radioactivity. Thus, the binding of 11C-raclopride is stereoselective. Distribution ratios [radioactivity in a brain region/"free" (not protein-bound) radioactivity in plasma] were calculated for the two enantiomers to study regional differences in the accumulation of radioactivity. The distribution ratios in white matter were similar for the two enantiomers. In the putamen, a three to four-fold higher distribution ratio was found for 11C-raclopride than for 11C-FLB472, reflecting the presence of specific binding of 11C-raclopride binding to D2-dopamine receptors in the basal ganglia. In the temporal and frontal cortices the distribution ratios were, however, only a few per cent higher for 11C-raclopride than for 11C-FLB472, indicating that if D2-dopamine receptors are present in the human neocortex, then their density is indeed very low.