摘要
设计合成了新的生长抑素类似物99Tcm-EDDA/HYNIC-Lys0-TOCA,并研究了其在正常小鼠及荷瘤裸鼠体内的分布和显像,以探讨99Tcm-EDDA/HYNIC-Lys0-TOCA作为生长抑素受体阳性肿瘤显像药物的可行性。在优化的标记条件下,99Tcm-EDDA/HYNIC-Lys0-TOCA的标记率约为96%,经Sep-Pak柱纯化后,放化纯度>99%。标记物具有很好的体内外稳定性9。9Tcm-EDDA/HYNIC-Lys0-TOCA在正常小鼠体内清除快,血液半衰期约为20 min,主要通过肾脏代谢,同时在胃、肺和肾上腺也有相对较高的放射性摄取。荷瘤裸鼠体内分布实验显示,该药物在肿瘤组织有较高的放射性摄取,给药1 h后,肿瘤与血、肌肉、心脏均有较高的放射性摄取比(T/NT)。γ显像表明,在给药后1~2 h,肿瘤组织有明显的放射性摄取,显像清晰。初步研究结果显示,该药物有望成为生长抑素受体阳性肿瘤的显像剂。
The new somatostatin analogue ^99Tc^m-EDDA/HYNIC-Lys^0-TOCA was designed and synthesized. The biological studies were carried out in normal and tumor-bearing nude mice in order to evaluate its potential application as an imaging agent for somatostatin recep- tor positive tumors. The labelling yield of ^99Tc^m-EDDA/HYNIC-Lys^0-TOCA was approxi- mately 96% under the optimized conditions, and the radiochemical purity was more than 99% after Sep-pak column purification. The labelled complex showed satisfactory stability in vitro. ^99Tc^m-EDDA/HYNIC-Lys^0-TOCA displayed a rapid blood clearance （a half-life of about 20 rain ） and the predominant excretion via the kidney and urinary system in normal mice. Meanwhile, the substantial uptakes of radioactivity in stomach, lung and adrenal were observed. The biodistribution in tumor-bearing nude mice of ^99Tc^m-EDDA/HYNIC-Lys^0-TOCA suggested that there was high radioactivity uptake in tumor and rapid blood clearance, and thus high ratios of tumor to blood and muscle were obtained at 1 h post injection. The labelled complex remained almost stable in urine as assayed by HPLC. Planar gamma imaging allowed contrasting visualisation of tumours at 1 h and 2 h post injection. All these results indicate that ^99Te^m-EDDA/HYNIC-Lys^0-TOCA is a novel promising candidate for somatostatin receptor positive tumor imaging.
出处
《同位素》
CAS
北大核心
2008年第1期6-14,共9页
Journal of Isotopes
