In this study, we synthesized ¹⁸F-ASu-BF₃, a close boramino acid analog of 5-[¹⁸F]fluoro-aminosuberic acid (¹⁸F-ASu), via ¹⁸F-¹⁹F isotope exchange reaction and evaluated its potential for imaging with positron emission tomography (PET). ¹⁸F-ASu-BF₃ was stable in mouse plasma and taken up into PC3 prostate cancer cells via the system x_C⁻ amino acid transporter. The continuous use of isoflurane for anesthesia during dynamic imaging acquisition slowed down the excretion of ¹⁸F-ASu-BF₃ and enabled visualization of PC3 tumor xenografts in mice. In contrast, no tumor visualization was observed from static images of ¹⁸F-BF₃-ASu due to its rapid renal excretion mediated in part by the organic anion transporter. Our data indicate that the pharmacokinetics of amino acids could be altered after being converted into their boramino acid analogs. Therefore, care should be taken when using the boramino acid strategy to design and prepare ¹⁸F-labeled tracers for imaging amino acid transporters/receptors with PET.

在这项研究中，我们通过¹⁸ F- ¹⁹ F同位素交换反应合成了¹⁸ F-ASu-BF ₃（5- [ ¹⁸ F]氟-氨基硫酸（¹⁸ F-ASu）的紧密硼酸类似物）并评估了其潜力用于正电子发射断层扫描（PET）成像。¹⁸ F-ASU-BF ₃是在小鼠血浆中稳定，并且经由系x吸收到PC3前列腺癌细胞_Ç ^-氨基酸转运。在动态成像采集过程中连续使用异氟烷进行麻醉会减慢¹⁸ F-ASu-BF ₃的排泄并实现了小鼠PC3肿瘤异种移植的可视化。相比之下，由于¹⁸ F-BF ₃ -ASu的静态肾脏部分由有机阴离子转运蛋白介导的快速肾脏排泄，因此从静态图像中未观察到肿瘤。我们的数据表明，氨基酸的药代动力学可以在转化成其硼氨基酸类似物后改变。因此，在使用硼氨基酸策略设计和制备¹⁸ F标记示踪剂以用PET对氨基酸转运蛋白/受体成像时，应格外小心。