In vitro binding properties and autoradiographic imaging of 3-iodobenzamide ([125I]-IBZM): a potential imaging ligand for D-2 dopamine receptors in SPECT.
In vitro binding properties and autoradiographic imaging of 3-iodobenzamide ([125I]-IBZM): a potential imaging ligand for D-2 dopamine receptors in SPECT.
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3-碘苯甲酰胺 ([125I]-IBZM) 的体外结合特性和放射自显影成像：SPECT 中 D-2 多巴胺受体的潜在成像配体。
DOI：
10.1016/0024-3205(88)90123-3
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发表时间：
1988
期刊：
影响因子：
6.1
通讯作者：
Chiueh,CC
中科院分区：
文献类型：
--
作者：
Brücke,T;Tsai,YF;McLellan,C;Singhanyom,W;Kung,HF;Cohen,RM;Chiueh,CC
[125] I标记的苯甲酰胺（S（-）-N-[（1-乙基-2-吡咯烷基）-甲基]-2-羟基-3-碘-6-甲氧基-苯甲酰胺，IBZM）的体外结合特性在牛和小鼠尾状核膜匀浆中和小鼠脑切片的放射自显影中测定。[125 I]-IBZM结合是可饱和的和可逆的，Bmax为373 ± 51 fmol/mg蛋白，Kd为3.1 ± 0.62 nM（平均值± SD，Scatchard分析）和0.56 nM，通过结合和解离时间常数计算。在竞争实验中，D-2拮抗剂YM-09151-2和螺哌隆的Ki值比D-1拮抗剂SCH-23390的Ki值低4个数量级，S（-）-IBZM的效力是R（+）-IBZM的10倍。[125 I]-IBZM对血清素S-2和α受体的亲和力较低。因此，它是多巴胺D-2受体的高选择性配体。用[125 I]-IBZM孵育的脑切片的放射自显影图像显示纹状体、丘脑核和嗅结节的多巴胺D-2受体具有高的特异性与非特异性结合比率。因此，S（-）-IBZM，当用[123 I]标记时，可用于通过单光子发射计算机断层扫描（SPECT）对多巴胺D-2受体进行体内显像。
Thein vitrobinding properties of the [125I] labeled benzamide (S(-)-N-[(1-ethyl- 2-pyrrolidinyl)-methyl]-2-hydroxy-3-iodo-6-methoxy-benzamide, IBZM) were determined in bovine and mouse caudate membrane homogenates and by autoradiography of mouse brain slices. [125I]-IBZM binding is saturable and reversible with a Bmaxof 373 ± 51 fmol/mg protein and a Kdof 3.1 ± 0.62 nM (mean ± SD, Scatchard analyses) and 0.56 nM as calculated by association and dissociation time constants. In competition experiments, Kivalues for the D-2 antagonists YM-09151-2 and spiperone are 4 orders of magnitude lower than the Kivalue for the D-1 antagonist SCH-23390 and S(-)-IBZM is ten-fold more potent than R(+)-IBZM. [125I]-IBZM has a low affinity for serotonin S-2 and for alpha receptors. Therefore, it is a highly selective ligand for dopamine D-2 receptors. Autoradiographic images of brain sections incubated with [125I]-IBZM show the dopamine D-2 receptors of the striatum, nucleus accumbens and olfactory tubercle with a high ratio of specific to nonspecific binding. Thus, S(-)-IBZM, when labeled with [123I], may be useful forin vivoimaging of dopamine D-2 receptors by single photon emission computerized tomography (SPECT).