^125Ⅰ标记的血管内皮生长因子受体3多抗在大鼠体内的分布研究

Study on ^125Ⅰ-vascular endothelial growth factor receptor-3 polyclonal antibody biod- istribution in rat

目的研究血管内皮生长因子受体3多抗（Flt4 PcAb）在大鼠体内的分布,为进一步应用Flt4 PcAb进行前哨淋巴结（SLN）的特异性定位奠定基础。方法应用氯胺T法对Flt4 PcAb行125I标记;将125I-Flt4 PcAb经大鼠足背皮下注射后不同时间分批处死大鼠,取血液、腋窝淋巴结及主要脏器测量其放射性计数,经衰变校正后计算每克组织的百分注射剂量率（%ID/g）,观察标记物的生物学分布。结果125I-Flt4 PcAb的标记率达46.5%,放射性比活度为1.72×10^12Bq/g,放射性化学纯度达96.7%;大鼠体内分布实验显示：125I-Flt4 PcAb主要分布于腋窝淋巴结及血液中,其余脏器较低;注射后16h内腋窝淋巴结与血液单位质量的放射性比值均大于2.5。结论①应用氯胺T法可以成功标记Flt4 PcAb;②皮下注射后Flt4 PcAb的体内分布表现为淋巴结浓集;③本实验为进一步应用Flt4 PcAb进行SLN的特异性定位奠定了基础。

Objective To study the biodistribution of ^125Ⅰ-Flt4 PcAb in rat and to establish the foundation of sentinel lymph node （SLN） exceptional orientation. Methods Flt4 PcAb was labeled with ^125Ⅰ via chloramine T method. ^125Ⅰ-Flt4 PcAb was subcutaneous injected in dorsum of foot in rats. The rats were killed at different stages after injection and the popliteal lymph nodes and major organs were taken out, then the radioactivity count of those organs and lymph nodes were measured. Results The labeling efficiency was 46.5%. The specific activity and the radiochemical purity of ^125Ⅰ-Flt4 PcAb were 1.72 × 10^12Bq/g and 96.7% respectively. It showed higher distribution in popliteal lymph nodes and blood than the other organs. The radioactivity ratio of popliteal lymph node to blood was more than 2.5 in 16 hours after injection. Conclusions： （1）It was successful to label Flt4 PcAb with ^125Ⅰ via chloramine T method.（2）Flt4 PcAb would concentrate in lymph node after subcutaneous injection. （3）This study provided experimental basis for SLN exceptional orientation with Flt4 PcAb.