碘标记毒死蜱及其在小鼠体内的生物分布

为探讨¹³¹I标记毒死蜱（Chlorpyrifos, CPF）在小鼠体内的分布特点，采用Iodogen法对CPF进行¹³¹I标记，KM小鼠尾静脉注射¹³¹I-CPF（185 kBq/只，n=5），分别于注射后5、10、30、60、120、240、1440 min取各脏器，计算每克组织摄取注射剂量的百分率（%ID/g）。结果显示，¹³¹I-CPF标记率达93.5%，放化纯度为96.9%，¹³¹I-CPF在小鼠体内广泛分布，主要经肺、胃、小肠、大肠、肌肉和颌下腺吸收，其放射性摄取率在注药后 10 min 时达高峰，分别为37.12%ID/g、6.18%ID/g、8.12%ID/g、8.15%ID/g、7.04%ID/g和7.02%ID/g；经肝和肾进行代谢，其放射性摄取率在5 min时分别为4.34%ID/g和8.50%ID/g, 4 h为0.22%ID/g和 0.69%ID/g。血液中放射性清除较快，放射性摄取率在注入后5 min时为37.27%ID/g，4 h为1.35%ID/g。碘标记CPF体外稳定，体内主要经肺和消化道吸收，肝、肾代谢，可用于进一步的微量示踪研究。

Radioiodine-Labeling of Chlorpyrifos and Its Biodistribution in Mice

To investigate the preparation of radioiodinated Chlorpyrifos and its biodistribution in mice, Chlorpyrifos was labeled with¹³¹I using the Iodogen method. Biodistribution studies were carried out in KM mice. At different times after radiopharmaceutical i.v. administration (185 kBq¹³¹I-Chlorpyrifos/mouse, n=5), the animals were sacrificed. Blood samples and the tissues of interested were collected, weighted and counted. The percentage of injected does per gram (%ID/g) was calculated for each sample. The labeling yield of ¹³¹I-Chlorpyrifos was 93.5%, The radiochemical purity (RCP) was 96.9%. Biodistribution in mice demonstrated that¹³¹I-Chlorpyrifos was extensive, and the uptakes mainly occur in lung, stomach, small-intestine, colon, musle, and submaxillay gland, as indicated by their amount of 37.12%ID/g, 6.18%ID/g, 8.12%ID/g, 8.15%ID/g, 7.04%ID/g, and 7.02%ID/g at 10 min, respectively. And it was metabolized in liver and kidney, as indicated by their uptake of 4.34%ID/g and 8.50%ID/g at 5 min, and 0.22%ID/g and 0.69%ID/g at 4 h, respectively. In addition,¹³¹I-Chlorpyrifos was cleared out from blood quickly, and the uptake of¹³¹I-Chlorpyrifos in blood was 37.27%ID/g at 5 min, and decreased to 1.35%ID/g at 4 h post injection. In conclusion, ¹³¹I-Chlorpyrifos was stable in vitro and it was absorbed in lung and digestive tract, and it was metabolized mainly in liver and kidney, worthy of further investigation to trace the compound in vivo and in vitro.