外周苯二氮受体示踪剂的合成和评价

Synthesis and Evaluation of a Trace for Peripheral Benzodiazepine Receptors

合成了用作外周苯二氮革受体潜在的选择性配体的N，N-二乙基-2-（4-碘苯基）-6-三氟甲基-咪唑并[1，2-a]吡啶-3-乙酰胺（ITFZOL）．其放射性标记物[^125I]ITFZOL通过碘脱锡化反应制备，放化得率75％～85％，比活度大于76GBq／μmol．小鼠尾静脉注射[^125I]ITFZIOL后，放射性集中分布于肾上腺、肺、肾、心、嗅球和小脑等外周苯二氮革受体高密度区域．预先给与外周苯二氮革受体选择性配体PK11195明显减少外周苯二氮革受体高密度区域放射性分布，提示[^125I]ITFZOL对外周苯二氮革受体具有较高的特异亲和性．生物活性数据表明，[^125I]ITFZO是一种潜在的选择性外周苯二氮革受体单光子放射性配体．

The 2-iodophenyl-imidazo [ 1,2-a ] -pyridines tirfluoromethyl derivative （ITFZOL） was prepared to study the PBR. The [^125I] analogue was prepared via iododestannylation reaction in radiochemical yields of 75%-85% and a specific activity 〉 76 GBq/μmol. After injection of [^125I] ITFZOL into mice through the tail vein, high accumulations of radioactivity were found in PBR-rich tissues such as adrenal, lung, kidney, heart, olfactory bulb and cerebellum. Per-administration of PBR-selective PK11195 displayed a significant reduction of radioactivity, suggesting a high specific binding of [ ^125I ] ITFZOL to PBR. The biological data reveal that [ ^125I] ITFZOL is a potential and selective single photo emitting radioligand for PBR.