99TcmN-CHDTC的制备，生物分布及与99Tcm-CHDTC的对比

摘要

99TcmN-CHDTC(CHDTC：N-cyclohexyl dithiocarbamate dihydrate) isprepared through a two-step ligand-exchange reaction by using SnCl2.2H2O as reduction agent and SDH(succinic dihydrazide) as a donor of nitride nitrogen atom (N3-) at room temperature. The radiochemical purity (RCP) of the product is over 90% by TLC. The biodistribution results in mice indicate that 99TcmN-CHDTC has good brain uptake and retention, suggesting that it will be a new potential brain perfusion imaging agent. 99TcmN-CHDTC also exhibits high myocardial uptake, but the R(heart/liver) is low thereby restricting the use of the complex as a good myocardial perfusion imaging agent. The ligand CHDTC is also labelled with 99TcmO4- directly by using FSA (formamidine sulfinic acid) as reduction agent. The biodistribution results in mice suggest 99Tcm-CHDTC is mostly accumulated in liver, whereas the heart and brain uptake is very low. This fact proves that the introduction of the[99Tcm≡N]2+ core into the molecular structure of a radiopharmaceutical may obviously alter its biological behavior.%以SnCl2.2H2O为还原剂，丁二酰二酰肼(SDH)为N3-离子提供体，在室温下制备[99TcmN]2+int中间体，然后与二水.N-环己基-二硫代氨基甲酸钠(CHDTC)发生配位体交换反应得到放化纯大于90％的99TcmN-CHDTC配合物。小鼠体内的生物分布实验表明，99TcmN-CHDTC有较高的脑摄取和较好的脑滞留。注射后5，30，60min时，脑摄取量(％/g)分别为2.91，5.88，5.91，R(脑/血)比值分别为0.14，1.46，2.10。99TcmN-CHDTC在心肌中也有较高的摄取，但R(心/肝)比值低。采用甲脒亚磺酸(FSA)作还原剂对配位体CHDTC进行99Tcm直接标记，其在小鼠体内的生物分布结果表明，99Tcm-CHDTC主要蓄积在肝脏，脑、心肌摄取很少。这表明放射性药物分子中引入[99TcmN]2+核会引起生物分布性质的明显改变。