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，这为寻找理想的肝胆显像药物提供了一定的理论依据 Three kinds of pyridoxal amino acids (PA) with different molecular structures, namely, pyridoxal-tyrosine (PHT), pyridoxal cystine (PHC) and pyridoxal tyrosine 7 mark rate of ≥ 95%. Three biodistribution studies of 99Tcm-PA in mice were carried out. The partition coefficients of three kinds of 99Tcm-PA in n-octanol and aqueous phase were determined. The results showed that the higher partition coefficient of ligand and the more lipophilic Large, the faster blood clearance in mice, the higher the concentration of liver and gallbladder, which provides a theoretical basis for the search for the ideal hepatobiliary imaging drugs