~(125)I标记重组融合蛋白dTMP-GH在小鼠体内分布的实验研究

目的研究重组融合蛋白dTMP-GH在小鼠体内的分布情况,明确其是否具有靶向分布特点。方法实验室制备dTMP-GH重组融合蛋白;用放射性125I标记融合蛋白dTMP-GH后,按100μg/kg的标准小鼠尾静脉注射125I-dTMP-GH,分别于给药后5 min、15 min、30 min、1 h、2 h、4 h、8 h、12 h、24 h取心、肝、脾、肾、股骨、甲状腺等进行放射性计数。结果制备得到纯度大于98%的重组融合蛋白dTMP-GH;125I标记率为71.53%,放化纯度为96.53%,比活度为0.22 MBq/μl;尾静脉注射125I标记的dTMPGH后30 min股骨的放射性计数占到注射总量的10%,并随时间推移经肝脏和肾脏代谢。结论融合蛋白dTMP-GH经尾静脉注射后在小鼠体内主要分布于骨髓,具有骨髓组织偏向分布特点。

Experimental research on distribution of 125I labeled recombinant fusion protein dTMP-GH in mice

Objective To assess the distribution of recombinant fusion protein dTMP-GH in mice and to determine whether it is of tar- geted distribution characteristics. Methods A laboratory scale preparation of dTMP-GH recombinant fusion protein was obtained. Protein dT- MP-GH was labeled with radioactive 125I,then mice were sacrificed at 5 min,15 min,30 min,1 h,2 h,4 h,8 h,12 h,24 h after tail vein injec- tion of 125 I-dTMP-GH at a dose of 100 μg/kg, and the organs and tissues （heart, liver, spleen, kidney, bone and thyroid） were collected for radioactive counting. Results Preparation of purified （ 〉 98% ） dTMP-G was obtained. 125I labeling rate was 71.53%, radiochemical purity was 96.53% ,and specific activity was 0.22 MBq/μl. 30 min after tail vein injection of 125I labeled dTMP-GH, radioactivity accounted for 10% of the total injected in femoral, and metabolism was carried via liver and kidney over time. Conclusion Fusion protein mainly distribu- ted in bone marrow via tail vein injection in mice, which expressed that dTMP-GH has the characteristics of selective distribution in bone mar- row tissue.