^(99)Tc^m-吡哆醛氨基酸类肝胆显像剂结构与生物体内分布行为的关系

THE RELATIONSHIP BETWEEN STRUCTURE AND BIODISTRIBUTION OF 99 Tc m PYRIDOXYLAMINO ACIDS FOR HEPATOBILIARY IMAGING AGENTS

采用３种分子结构不同的吡哆醛氨基酸（ＰＡ）即吡哆醛色氨酸（ＰＨＴ）、吡哆醛胱氨酸（ＰＨＣ）和吡哆醛酪氨酸（ＰＨＹ）进行９９Ｔｃｍ标记，ｐＨ＝７时标记率≥９５％。进行了３种９９Ｔｃｍ－ＰＡ在小白鼠体内生物分布的实验研究，并测定了３种９９Ｔｃｍ－ＰＡ在正辛醇与水相间的分配系数，结果表明：配体的分配系数愈高，亲脂性愈大，小鼠体内的血液清除愈快，肝胆浓集量愈高。

In order to investigate the relationship between structure and biodistribution of 99 Tc m pyridoxylamino acids(PA), pyridoxyl L tryptophan(PHT), pyridoxylamino L cystine(PHC) and pyridoxylamino tyrosine (PHY) are labelled with 99 Tc m using Sn(Ⅱ) as a reductant. The labelling yields of 99 Tc m PA is better than 95% at pH=7.0. The partition coefficients as lipophilic parameter in the octanol water system are determined. The biodistribution in male mice shows that 99 Tc m PA have fast blood clearance, but the difference is apparent in their hepatobiliary uptakes and intestinal accumulations. Particularly, there is a good correlation between the hepatobiliary uptake and the partition coefficient. The larger the partition coefficient, the higher the lipophilicity. This result may be valuable for developing new 99 Tc m PA of hepatobiliary imaging agent.