Here, we describe the characterization of a radioligand selective for GluN2B‐containing NMDA receptors, 3‐[3H] 1‐(azetidin‐1‐yl)‐2‐(6‐(4‐fluoro‐3‐methyl‐phenyl)pyrrolo[3,2‐b]pyridin‐1‐yl)ethanone ([3H]‐JNJ‐ GluN2B‐5). In rat cortical membranes, the compound bound to a single site, and the following kinetic parameters were measured; association rate constant Kon = 0.0066 ± 0.0006 min−1 nM−1, dissociation rate constant Koff = 0.0210 ± 0.0001 min−1 indicating calculated KD = Koff/Kon = 3.3 ± 0.4 nM, (mean ± SEM, n = 3). The equilibrium dissociation constant determined from saturation binding experiments in rat cortex was KD of 2.6 ± 0.3 nM (mean ± SEM, n = 3). In contrast to the widely used GluN2B radioligand [3H]‐Ro 25‐6981, whose affinity Ki for sigma 1 and sigma 2 receptors are 2 and 189 nM, respectively, [3H]‐JNJ‐GluN2B‐5 exhibits no measurable affinity for sigma 1 and sigma 2 receptors (Ki > 10 μM for both) providing distinct selectivity advantages. Anatomical distribution of [3H]‐JNJ‐GluN2B‐5 binding sites in rat, mouse, dog, monkey, and human brain tissue was studied using in vitro autoradiography, which showed high specific binding in the hippocampus and cortex and negligible binding in the cerebellum. Enhanced selectivity for GluN2B‐containing receptors translated to a good signal‐to‐noise ratio in both in vitro radioligand binding and in vitro autoradiography assays. In conclusion, [3H]‐JNJ‐GluN2B‐5 is a high‐affinity GluN2B radioligand with excellent signal‐to‐noise ratio and unprecedented selectivity. image

中文翻译：

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氚化 JNJ-GluN2B-5 (3-[3H] 1-(氮杂环丁烷-1-基)-2-(6-(4-氟-3-甲基-苯基)吡咯并[3,2-b]吡啶-的表征1-基)乙酮)，一种高亲和力 GluN2B 放射性配体，对 Sigma 受体具有选择性


在这里，我们描述了对含有 GluN2B 的 NMDA 受体具有选择性的放射性配体的表征，3-[ 3 H] 1-(氮杂环丁烷-1-基)-2-(6-(4-氟-3-甲基-苯基)吡咯并[3,2-乙]吡啶-1-基）乙酮（[ 3 H]-JNJ-GluN2B-5)。在大鼠皮质膜中，化合物与单个位点结合，并测量了以下动力学参数；关联率常数K在= 0.0066 ± 0.0006 分钟−1纳米−1 ，解离速率常数K离开= 0.0210 ± 0.0001 分钟−1表示已计算K D = K离开/ K在= 3.3 ± 0.4 nM，（平均值 ± SEM， n = 3）。由大鼠皮层饱和结合实验确定的平衡解离常数为K D 2.6 ± 0.3 nM（平均值 ± SEM， n = 3）。与广泛使用的 GluN2B 放射性配体相比 [ 3 H]-Ro 25-6981，其亲和力K我对于 sigma 1 和 sigma 2 受体，分别为 2 和 189 nM，[ 3 H]-JNJ-GluN2B-5 对 sigma 1 和 sigma 2 受体没有可测量的亲和力（ K我> 10 μM 两者）提供独特的选择性优势。 [的解剖分布3使用体外放射自显影技术研究了大鼠、小鼠、狗、猴子和人脑组织中的 H]-JNJ-GluN2B-5 结合位点，结果显示在海马和皮质中具有高特异性结合，而在小脑中的结合可忽略不计。 在体外放射性配体结合和体外放射自显影测定中，对含 GluN2B 受体的选择性增强转化为良好的信噪比。综上所述， [ 3 H]-JNJ-GluN2B-5 是一种高亲和力 GluN2B 放射性配体，具有出色的信噪比和前所未有的选择性。图像