<i>In Vivo</i> Metabolic Trapping Radiotracers for Imaging Monoamine Oxidase-A and -B Enzymatic Activity
作者:Allen F. Brooks、Xia Shao、Carole A. Quesada、Phillip Sherman、Peter J. H. Scott、Michael R. Kilbourn
DOI:10.1021/acschemneuro.5b00223
日期:2015.12.16
is trapped within brain tissues. Radiotracers with phenyl, biphenyl, and 7-coumarinyl ethers were evaluated using microPET imaging in rat and primate brains. No isozyme selectivity for radiotracer trapping was observed in the rat brain for any compound, but in the monkey brain, the phenyl ether demonstrated MAO-A selectivity and the coumarinyl ether showed MAO-B selectivity. These are lead compounds
单胺氧化酶(MAO-A和MAO-B)的同工酶是参与许多生物胺代谢的重要酶,包括神经递质5-羟色胺,多巴胺和去甲肾上腺素。近来,已经提出MAO-B浓度的变化是与阿尔茨海默氏病有关的神经炎症的体内标志物。用于对MAO酶表达或活性变化进行成像的体内放射性示踪剂的先前开发已经利用了不可逆的基于炔丙基胺的自杀抑制剂或高亲和力可逆结合抑制剂。作为替代方法,我们研究了1- [ 11C]甲基-4-芳氧基-1,2,3,6-四氢吡啶类作为单胺氧化酶的代谢捕获剂。MAO介导的氧化和自发水解产生1- [ 11 C]甲基-2,3-二氢-4-吡啶酮作为一种亲水性代谢产物,被捕集在脑组织中。使用microPET成像在大鼠和灵长类动物大脑中评估了具有苯基,联苯和7-香豆素醚的放射性示踪剂。在大鼠脑中没有观察到任何化合物对放射性示踪剂捕获的同工酶选择性,但是在猴脑中,苯醚显示出MAO-A选择性,香豆素醚显示出MAO-B选择