目的探讨188Re标记VEGF189外显子6编码的多肽(QKRKRKKSRYKS)的方法、标记物在荷瘤裸鼠体内的分布及显像。方法以S-acetyl-MAG3为双功能螯合剂,正交设计法寻找188Re标记多肽QKRKRKKSRYKS的最佳条件;研究标记物在荷卵巢癌SKOV3裸鼠的体内分布,并在不同时间行SPECT平面显像。结果采用SPSS13.0进行分析。结果188Re标记QKRKRKKSRYKS在最佳标记条件下的标记率为(73.1±5.5)%,HPLC纯化后放射化学纯度>95%,且受体结合活性良好;标记物室温下放置24h,其放射化学纯度为(91.76±1.36)%;尾静脉注射标记物后,0.5h荷瘤裸鼠肿瘤部位开始出现放射性浓聚,1h浓聚更为明显,肿瘤放射性摄取为(1.846±0.511)%ID/g,肿瘤/对侧肌肉组织比值达(2.43±0.30)。此外,肝脏、小肠、肾脏及膀胱等部位也可见明显的放射性浓聚,但3h后肿瘤部位的放射性浓聚影基本消退。结论188Re-MAG3-QKRKRKKSRYKS能明显聚集于肿瘤组织。 OBJECTIVE: To investigate the method of labeling 188R-labeled VEGF189 exon 6 (QKRKRKKSRYKS) and the distribution and imaging of the marker in tumor-bearing nude mice. Methods The optimal conditions of 188Re-labeled polypeptide QKRKRKKSRYKS were determined by S-acetyl-MAG3 as a bifunctional chelator. The distribution of the marker in nude mice bearing ovarian cancer SKOV3 was studied and SPECT images were taken at different time points . The results were analyzed by SPSS13.0. Results The labeled rate of 188Re-labeled QKRKRKKSRYKS was (73.1 ± 5.5)% under optimal labeling conditions. The purity of radiochemical purity was> 95% after HPLC purification and the binding activity of the receptor was good. The radiochemical purity of 188Re- (91.76 ± 1.36)%. After the tail vein injection of the marker, radioactive concentration started to appear in the tumor site of the 0.5h tumor-bearing nude mice and the concentration was more obvious at 1h. The tumor radioactivity uptake was (1.846 ± 0.511)% ID / g, / Contralateral muscle tissue ratio (2.43 ± 0.30). In addition, the liver, small intestine, kidneys and other parts of the bladder can also be seen significant radioactive concentration, but 3h after the tumor part of the radioactive concentration shadow subsided. Conclusion 188Re-MAG3-QKRKRKKSRYKS can obviously accumulate in tumor tissue.