新型肺癌小分子多肽的^(131)I标记及其在小鼠体内的生物分布  

Radioiodine-Labeling of New Small Polypeptide Targeted to Lung Cancer and Its Biodistribution in Mice

作　　者：李贵平[1] 黄宝丹[1] 杜丽[1] 韩彦江[1] 张辉[1] 黄凯[1] 郑文莉[1] 

机构地区：[1]南方医科大学南方医院核医学科,广东广州510515

出　　处：《同位素》2014年第2期104-108,共5页Journal of Isotopes

基　　金：广东省自然科学基金项目(S2013010014420);广东省科技计划项目(2012B031800391);南方医院院长基金项目(2012Z008)

摘　　要：建立肺癌特异性靶向小分子多肽cNGQGEQc的^(131)I标记方法,研究^(131)I-cNGQGEQc在正常小鼠体内的生物学分布特性。采用氯胺-T法对N端连接有酪氨酸的cNGQGEQc进行^(131)I标记,测定^(131)IcNGQGEQc的标记率、放化纯度、脂水分配系数及在生理盐水(NS)和正常人血清中的体外稳定性,并对标记物在正常小鼠体内的分布进行了初步研究。结果表明,^(131)I-cNGQGEQc的标记率大于90%,比活度为0.4TBq/g;^(131)I-cNGQGEQc在正常人血清和NS中较稳定;^(131)I-cNGQGEQc的脂水分配系数lgP为—1.68,体内生物分布结果表明,肾脏的放射性摄取率在1 h和12 h分别为(10.59±4.66)%ID/g和(1.79±0.89)%ID/g,肾脏的放射性摄取明显高于其他脏器,表明^(131)I-cNGQGEQc主要经肾脏代谢。以上结果表明,^(131)IcNGQGEQc的标记率较高,在体外具有良好的稳定性。^(131)I-cNGQGEQc为水溶性,可用于进一步的靶向诊断与治疗的研究。The radiolabeling method of polypeptide （cNGQGEQc） for specific targeting lung cancer with lalI was established, and the biodistribution of 131I-cNGQGEQc in normal mice was carried out. Radiolabeling of polypeptide with 131I was performed by chloramine-T method by tyrosine linked its N-terminal. The labeling ratio and radiochemical purity were determined using paper chromatography. The octanol-water partition coefficient and stabili-ty in vitro in saline and normal human serum of labeling polypeptide were also determined. The biodistribution of 131I-cNGQGEQc in normal mice were measured through caudal vein injection of the labeled peptide. The results showed that the labeling yield of 131I- cNGQGEQc was more than 90% with specific activity of 0.4 TBq/g. The 131I-cNGQGEQc had good stability in saline and normal human serum. The octanol-water partition coefficient lgP=-1. 68, which indicate that radiolabeled polypeptide was water soluble. The biodistribution in mice demonstrated that the radioactivity in kidney was obviously higher than that of other organs, and it was metabolized mainly in kidney, as indicated by their uptake of （10.59±4.66）%ID/g at 1 h and （1.79±0. 89）%ID/g at 12 h, respectively. In conclusion, 131I-cNGQGEQc can be easily labeled with a high labeling ratio and was stable in vitro. It has good distribution characteristics, and can be used in further study on targeting diagnosis and treatment.

关 键 词：小分子多肽 放射性碘标记 生物分布 肺癌 

分 类 号：R815[医药卫生—放射医学]