Sigma receptors are expressed in high density in various types of cancer cells including brain tumours and are also involved in various diseases of central nervous system. This makes ligands that bind to these receptors, attractive molecular vectors for targeting radiation to the specific sites with the purpose of imaging and therapy of neurological disorders. We report synthesis of three derivatives of 4-amino-N-benzylpiperidine namely, 4-dithiocarbamato-N-benzylpiperidine, 4-iminodiacetato-N-benzylpiperidine and 4-(N-benzylpiperidine)-pyridin-2-ylmethyl-amino)-acetic acid and their radiolabeling with technetium-99m. The in vivo evaluation of these radiolabeled compounds has been carried out in mice, for assessment of their binding affinity with sigma receptors. Of the three complexes, [99mTcN]-4-dithiocarbamato-N-benzylpiperidine, [99mTcN]Pip-DTC exhibited the most promising characteristics with brain uptake of 0.6% ID/g at 5 min.p.i. that reduced to 0.3% ID/g after 2 h.p.i. Competition experiment carried out with [99mTcN]Pip-DTC complex, using (+)-pentazocine showed its specificity towards sigma receptors, as was found to be evident from reduction in the brain uptake of this complex. Introduction of iminodiacetate and pyridine moieties and subsequent radiolabeling did not result in complexes with significant potential of targeting and binding with sigma receptors. Copyright © 2010 John Wiley & Sons, Ltd.
西格玛受体在包括脑肿瘤在内的各种类型的癌细胞中高密度表达,也与中枢神经系统的各种疾病有关。因此,能与这些受体结合的
配体成为具有吸引力的分子载体,可将辐射靶向特定部位,从而达到成像和治疗神经系统疾病的目的。我们报告了 4-
氨基-N-
苄基哌啶的三种衍
生物,即 4-二
硫代
氨基甲酸-N-
苄基哌啶、4-
亚氨基二乙酸-N-
苄基哌啶和 4-(N-
苄基哌啶)-
吡啶-2-基
甲基氨基)-
乙酸的合成及其
锝-99m 放射性标记。在小鼠体内对这些放射性标记化合物进行了体内评估,以评估它们与 sigma 受体的结合亲和力。在这三种复合物中,[99mTcN]-4-二
硫代
氨基甲酸-N-
苄基哌啶、[99mTcN]Pip-DTC 表现出最有希望的特性。用 (+)-pentazocine 与[99mTcN]Pip-DTC 复合物进行的 p.i. 竞争实验表明,[99mTcN]Pip-DTC 复合物对 sigma 受体具有特异性,这一点从该复合物大脑摄取量的减少可以明显看出。
亚氨基二乙酸盐和
吡啶分子的引入以及随后的放射性标记并没有产生具有明显靶向性和与 sigma 受体结合潜力的复合物。Copyright © 2010 John Wiley & Sons, Ltd. All Rights Reserved.