红景天苷的碘标记及其在小鼠体内的分布

通过131碘标记红景天苷以探索红景天苷在神经母细胞(SH-SY5Y)中的摄取及在小鼠体内的代谢分布.采用氯胺-T法对红景天苷进行131碘标记;以聚酰胺薄膜为支持介质、V三氯甲烷:V甲醇:V丙酮:V水=6:3:1:1的下层液为展开剂,测定标记率及标记物放化纯;分析神经母细胞SH-SY5Y及肿瘤细胞MCF-7对131I-红景天苷的摄取;KM小鼠尾静脉注射131I-红景天苷(1.85 MBq/只,n=5),于5、10、30、60、120、240 min分别取心、肝、肺、肾、脾、肌、骨、脑、肠、血,称重、计数,计算每克组织百分注射剂量率(%ID/g).结果表明,131I-红景天苷标记率达98%,其放化纯在1、4、20 d分别为98.5%、97.3%、97.1%;SH-SY5Y对131I-红景天苷基本无摄取,在0.5-4 h内摄取维持在0.035%左右,而MCF-7则为0.1%;131I-红景天苷在体内主要通过肝代谢、肾排泄,其中肝和肾5 min%ID/g组织分别为7.71%和11.32%,4 h则分别下降为0.36%和0.3%;血液中清除也较快,5 min时为6.41%,4 h为0.35%;在脑中虽分布较少,但清除较慢,5 min时为0.27%,4 h为0.11%;在心、肺、脾、肌、骨及肠中分布不多.结论是,碘标红景天苷标记率高,标记物稳定;神经母细胞对131I-红景天苷基本无摄取.

Radioiodine-labeling of salidroside and its biodistribution in mice

To investigate the preparation of radioiodinated salidroside and its cell uptake in SH-SY5Y and its biodis-tribution in mice, salidroside was labeled with 131I using the chloramine-T method and the radiolabeled compound was characterized by polyamide TLC, in which the substratum of Vtrichoromethane: Vmethanol: Vacetone: Vwater=6:3:1:1 was used as the developing agent. The uptake of 131I-salidroside in human neuroblast cells(SH-SY5Y) and mammary can-cer cells(MCF-7) was then measured and the biodistribution studies were carried out in KM mice. At different time(5, 10, 30, 60, 120, and 240 min) after radiopharmaceutical i.v. administration (1.85MBq 131I-salidroside /mouse), the animals were sacrificed (n=5 animals for each time). Blood and the interested tissues samples were collected, washed, weighted and counted. The percent injected dose per gram (%ID/g) was calculated for each sample. The labeling yield of 131I-salidroside was 98% and its RCPs were 98.5%, 97.3%, and 97.1% after 1, 4 and 20 days, respectively. In SH-SY5Y, 131I-salidroside uptake kept at a low level of around 0.035% from 0.5 to 4h, while in MCF-7 a slightly higher uptake of 0.1% was reached. Biodistribution in mice demonstrated that 131I-salidroside was metabolized mainly in liver and rapid elimination through kidney, in which the % ID/g were 7.71% and 11.31% at 5 min, 0.36% and 0.3% at 4h, respectively. Rapid clearance was also found in blood, 6.43% at 5 min and decreased to 0.35% at 4h. A little distribution appeared in brain with slower clearance, the %ID/g were 0.27% at 5 min and 0.11% at 4h. In heart, lung, spleen, muscle, bone, and intestines, there were little distributions. It is concluded that labeling yield of 131I-salidroside was high and the radioiodinated salidroside was stable, but its uptake in neuroblast was little.