Title: Experimental studies of colon carcinoma imaging with ~(99)Tc~m labeled neurotension peptide
Abstract: Objective To prepare neurotension (NT) peptide labeled with 99 Tc m for the early diagnosis of colon carcinoma and to evaluate the advantages of the tracer. Methods Biodistribution studies were performed at 3 and 12 h,respectively after injection of 99 Tc m-NT,and tissue distribution analysis after receptor-blocking was performed at 3 h in nude mice bearing colon carcinoma. Imaging with 99 Tc m-NT was performed at different time points in nude mice bearing colon carcinoma,and imaging after receptor-blocking was also performed at 3 h. The affinity of 99 Tc m-NT binding to the cell of colon carcinoma was studied in vitro. Results The affinity constant of 99 Tc m-NT binding to the cells of colon carcinoma was obtained ( K _d=0.91 nmol/L). The labeling yield of 99 Tc m-NT was more than 94% and the complex was stable in vitro and in vivo. Biodistribution analysis in nude mice bearing colon carcinoma showed that 99 Tc m-NT was excreted chiefly from the kidney,the ratios of tumor to muscle at 3 and 12 h were 3.25±1.02 and 4.15±1.46,respectively. In mice pretreated with unlabeled NT,the uptake of 99 Tc m-NT decreased in the tumor,the ratio of tumor to muscle at 3 h (1.21±0.62) was significantly different from that of the mice without unlabeled NT treatment. Tumor lesion was detected with 99 Tc m-NT earlier (the lesion image showed up at 0.5 h postinjection),the ratio of tumor to contralateral limb at 3 h postinjection was 2.68±0.44 obtained by technique of region of interest (ROI). The ratio at 3 h was 1.14±0.36 and that was significantly different from the ratio at 3 h postinjection in mice pretreated with unlabeled NT. Conclusion The results of all studies in vitro and in vivo indicate that this labeling procedure of 99 Tc m-NT is simple and its specific binding to the cells of colon carcinoma is high,and it is a promising method for diagnosis of colon carcinoma.
Publication Year: 2004
Publication Date: 2004-01-01
Language: en
Type: article
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot