Ohmomo Y, Hirata M, Murakami K, Magata Y, Tanaka C, Yokoyama A
Osaka University of Pharmaceutical Sciences, Matsubara, Japan.
Chem Pharm Bull (Tokyo). 1993 Nov;41(11):1994-7. doi: 10.1248/cpb.41.1994.
A new radioligand for monoamine oxidase type A (MAO-A), [11C]fluoroclorgyline, was synthesized from its desmethyl precursor by N-methylation reaction using [11C]methyl iodide with a radiochemical yield of 75-85%. The radiochemical purity of the product was more than 99% and the specific radioactivity was 7.4-18.5 GBq/micromol. The in vivo tissue distribution studies of [11C]fluoroclorgyline in mice demonstrated its high initial uptake and prolonged retention in the brain, comparable to those of [11C]clorgyline. A selective interaction with MAO-A in the accumulation of [11C]fluorclorgyline was confirmed by a competition experiment performed with the MAO-A specific inhibitor,clorgyline, and MAO-B specific inhibitor, l-deprenyl. These very desirable characteristics of [11C]fluoroclorgyline suggested that its 18F labeled counterpart, [18F]fluoroclorgyline, would have great potential as a longer-lived alternative to 11C labeled clorgyline for in vivo studies of MAO-A in the human brain with positron emission tomography (PET).
一种新型的单胺氧化酶A（MAO-A）放射性配体[11C]氟氯苯丙胺，由其去甲基前体通过用[11C]碘甲烷进行N-甲基化反应合成，放射化学产率为75 - 85%。产物的放射化学纯度大于99%，比活度为7.4 - 18.5 GBq/微摩尔。[11C]氟氯苯丙胺在小鼠体内的组织分布研究表明，其在脑中具有较高的初始摄取和较长时间的滞留，与[11C]氯苯丙胺相当。通过用MAO-A特异性抑制剂氯苯丙胺和MAO-B特异性抑制剂l-司来吉兰进行竞争实验，证实了[11C]氟氯苯丙胺在积累过程中与MAO-A的选择性相互作用。[11C]氟氯苯丙胺的这些非常理想的特性表明，其18F标记的类似物[18F]氟氯苯丙胺作为一种寿命更长的替代物，对于用正电子发射断层扫描（PET）在人脑中进行MAO-A的体内研究而言，相较于11C标记的氯苯丙胺具有巨大潜力。
