Kilpatrick G J, Jenner P, Marsden C D
J Pharm Pharmacol. 1986 Dec;38(12):907-12. doi: 10.1111/j.2042-7158.1986.tb03381.x.
The specific in-vitro binding of [3H]SCH 23390 has been characterized and its use in the identification of D-1 sites in various brain regions examined. At a single ligand concentration (0.4 nM) the specific binding of [3H]SCH 23390 to striatal membranes was routinely 98% of total binding as defined using 10(-5) M cis-flupenthixol. Specific binding at 37 degrees C reached equilibrium at 15 min and was reversible with a t1/2 for dissociation of 14 min. Specific binding of [3H]SCH 23390 over a range of concentrations (0.01-3.5 nM) was saturable (Bmax 73 pmol g tissue-1) of high affinity (Kd 0.36 nM) and to a single population of binding sites. Specifically bound [3H]SCH 23390 (0.4 M) was stereo selectively displaced by the isomers of butaclamol and flupenthixol but not by the D-2 selective antagonist, sulpiride. 5-HT, noradrenaline and cinanserin caused little or no displacement. Specific binding of [3H]SCH 22390 (0.4 nM; as defined using 10(-5) M cis-flupenthixol) showed marked regional variation. Specific binding was highest in the striatum; high levels were also observed in the mesolimbic area and substantia nigra. Lower specific binding was found in the frontal cortex and superior colliculus with the lowest levels in cerebellar preparations. The inclusion of 3 X 10(-7) M cinanserin did not alter the extent of specific binding observed in any brain region. The properties of [3H]SCH 23390 suggest it to be an excellent ligand for identification of D-1 sites in a variety of brain regions.
已对[3H]SCH 23390的特异性体外结合进行了表征，并研究了其在鉴定不同脑区D-1位点中的应用。在单一配体浓度（0.4 nM）下，[3H]SCH 23390与纹状体膜的特异性结合通常占总结合量的98%，总结合量使用10^(-5) M顺式氟哌噻吨来定义。37℃下的特异性结合在15分钟时达到平衡，并且是可逆的，解离的t1/2为14分钟。[3H]SCH 23390在一系列浓度（0.01 - 3.5 nM）范围内的特异性结合是可饱和的（Bmax为73 pmol g组织^(-1)），具有高亲和力（Kd为0.36 nM），且针对单一结合位点群体。特异性结合的[3H]SCH 23390（0.4 M）可被布他拉莫和氟哌噻吨的异构体立体选择性取代，但不能被D-2选择性拮抗剂舒必利取代。5-羟色胺、去甲肾上腺素和西萘普明几乎没有或没有引起取代。[3H]SCH 22390（0.4 nM；使用10^(-5) M顺式氟哌噻吨定义）的特异性结合显示出明显的区域差异。特异性结合在纹状体中最高；在中脑边缘区和黑质中也观察到高水平。在额叶皮质和上丘中发现较低的特异性结合，在小脑制剂中水平最低。加入3×10^(-7) M西萘普明不会改变在任何脑区观察到的特异性结合程度。[3H]SCH 23390的特性表明它是用于鉴定多种脑区D-1位点的优秀配体。
