John C S, Kinuya S, Minear G, Keast R K, Paik C H
Radiopharmaceutical Chemistry Section, George Washington University Medical Center, Washington, DC 20037.
Nucl Med Biol. 1993 Feb;20(2):217-23. doi: 10.1016/0969-8051(93)90118-e.
Two polyaminothiol ligands, one hexadentate, N,N',N"-tris[2-methyl(2-propanethiol)]-1,4,7-triazacyclononane (TACN), and another potentially heptadentate, tris[2-methyl(2-propanethiol)]aminoethylamine (TMAE), were synthesized and characterized using spectroscopic and analytical methods. Both ligands were labeled with gallium-67 at pH 3.0-3.5 in high yields. The resulting gallium chelates were lipophilic. The biodistribution studies for both the chelates showed hepatic uptake and biliary clearance. The total % ID activity for [67Ga]TACN in liver and intestine at 5 min was 33.86 increasing gradually to 61.4% at 30 min. The chelates were in vivo stable to plasma-transferrin transchelation as confirmed by scintigraphic images obtained by [67Ga]TACN in rats and by plasma incubation of the chelates. These results indicate that Ga-TACN is a potentially useful tracer for hepatobiliary imaging using PET. No brain uptake was found.
合成了两种多氨基硫醇配体，一种是六齿配体N,N',N"-三[2-甲基(2-丙硫醇)]-1,4,7-三氮杂环壬烷(TACN)，另一种是潜在的七齿配体三[2-甲基(2-丙硫醇)]氨基乙胺(TMAE)，并采用光谱和分析方法对其进行了表征。两种配体在pH 3.0 - 3.5条件下均以高产率用镓-67进行了标记。所得的镓螯合物具有亲脂性。两种螯合物的生物分布研究均显示有肝脏摄取和胆汁清除。[67Ga]TACN在肝脏和肠道中的5分钟总ID活性百分比为33.86%，在30分钟时逐渐增加到61.4%。通过大鼠体内[67Ga]TACN获得的闪烁图像以及螯合物的血浆孵育证实，螯合物在体内对血浆转铁蛋白的转螯合作用稳定。这些结果表明，Ga-TACN是一种潜在的用于PET肝胆成像的有用示踪剂。未发现脑摄取。
