本文制备了一类新的99mTc标记的潜在5-HT1A受体显像剂。以2-甲氧基苯基哌嗪(MPP，与5-羟色胺1A受体结合的活性基团)、6-氯-尼古丁酸等为起始物，通过7步反应得到配体HYNIC-MPP2，并对该配体进行了红外、质谱、核磁等表征。通过与HYNIC偶联可以实现99mTc的标记。本次实验选择了两种不同的共配体，并选择其中一种共配体—Tricine对标记条件进行了探索。实验结果表明，在室温条件下，pH=6～7,标记时间为30min为最佳标记条件，可获得最高标记率。体外稳定性实验表明两种共配体形成的两种放射性配合物都有较好的稳定性。脂水分配系数和电泳实验实验表明两种配合物都是水溶性的电中性的配合物。 从正常小鼠生物性能实验中可以看出，两种配合物在生物体内的血清除比较快，并且都有一定的脑摄取。99mTc-Tricine/HYNIC-MPP2在脑中清除较快，1 h后有84.7﹪从脑中清除,而99mTc-Bicine/HYNIC-MPP2在脑中滞留率比较高，1 h后滞留率为79%。在脑区域分布抑制实验中, 99mTc-Tricine/HYNIC-MPP2在5-HT1A受体富集的区域海马组织具有较高的脑摄取（2 min时为1.00%ID/g），在注入抑制剂（8-OH-DPTA）后，其摄取量显著降低（2 min时为0.42%ID/g）。表明该标记配合物与5-HT1A受体具有特异性结合，是一种潜在的5-HT1A受体显像剂。

The goal of this study is to develop a new 99mTc-complex as potential 5-HT1A receptor imaging agent. A ligand, HYNIC-MPP2, containing the MPP ((2-methoxyphenyl)piperazine) motif of WAY-100635 which is known to have high affinity to the 5-HT1A receptor, was synthesized and conformed by 1H-NMR. The labeling conditions were optimized and the 99mTc-Tricine/HYNIC-MPP2 complex was prepared in high yield (>90% by TLC) under pH 6-7 at room temperature (RT). The labeled complex remained stable over 3 h at RT. Both of 99mTc-Tricine/HYNIC-MPP2 and 99mTc-Bicine/HYNIC-MPP2 complexes are neutral and hydrophilic, which were conformed by paper electrophoresis and octanol/water partition coefficient, respectively. In vivo biodistribution of 99mTc-Tricine/HYNIC-MPP2 was investigated in normal mice showed that this complex had moderate brain uptake (0.59%ID/g at 2 min and 0.09%ID/g at 120 min) with rapid clearance (<50% of the activity was retained in the brain at 120 min post-injection). In vivo biodistribution of 99mTc-Bicine/HYNIC-MPP2 was investigated in normal mice showed that this complex had lower brain uptake (0.31%ID/g at 2 min and 0.24%ID/g at 120 min) than that of 99mTc-Tricine/HYNIC-MPP2 complex while it had pretty good retention (>50% of the activity was retained in the brain at 120 min post-injection). Although the blood uptake was high at the beginning, about 80% radioactivity was cleared after 1 h post-injection time. The specific binding affinity of 99mTc-Tricine/HYNIC-MPP2 to 5-HT1A receptor was tested by block experiment. After blocking the uptake of Hippocampus was decreased significantly from 1.00%ID/g to 0.42%ID/g. This result showed that 99mTc-Tricine/HYNIC-MPP2 complex would be developed as a potential 5-HT1A receptor imaging agent in the near future.