摘要
目的 :99Tcm 直接法标记血管抑素 (angiostatin ,AS) ,观察其在荷瘤小鼠体内的生物分布并进行显像 ,以探讨其在监测肿瘤对抗血管生成治疗的应答中的价值 .方法 :氯化亚锡还原法进行AS的99Tcm 标记 ,纸层析法测标记率 ;用人脐静脉内皮细胞系 (ECV30 4 )观察其生物活性 ;为了明确99Tcm AS与肿瘤的结合 ,是否存在受体特异性 ,我们进行了封闭实验 .在给药前 2h用未标记AS预处理荷乳腺癌EMT6瘤株的BALB/c小鼠 ,尾静脉注射99Tcm AS ,观察其体内分布并进行显像 .结果 :氯化亚锡还原法标记AS可获得较高的标记率 (>95 % ) ,其抑制内皮细胞生长的生物活性与AS相似 .在荷瘤小鼠体内分布结果显示 :肿瘤的摄取率随着时间延长而增加 ,在注射99Tcm AS后 2～ 1 2h ,肿瘤可清晰显像 ,同时 ,用未标记AS预先封闭肿瘤可使肿瘤对99Tcm AS摄取率下降 .结论 :99Tcm AS在荷瘤小鼠体内可浓聚于肿瘤 ,肿瘤对显像剂的摄取存在一定的特异性 ;99Tcm
AIM: To observe the distribution of direct labelled angiostatin (AS) by 99 Tc m in tumor bearing mice and to evaluate the value of 99 Tc m AS in positive imaging of tumor. METHODS: Angiostatin was labeled by stannous reduced approach and the labeling efficiency was examined by TLC. The bioactivity of 99 Tc m AS was observed using human umbilical vein epithelial cell line (CEV304). Blocking experiment was conducted to make sure that the combination of tumor and 99 Tc m AS was related to angiostatin receptors. The EMT6 tumor bearing BALB/c mice were pretreated with non labeled angiostatin 2 h before administration of 99 Tc m AS. 99 Tc m AS was injected via tail vein, the distribution of 99 Tc m AS in vivo was observed and imaging was made. RESULTS: The labeling efficiency (>95%) of 99 Tc m AS was high and its bioactivity was the same as that of non labeled AS. Its distribution in tumor bearing mice indicated that the uptake of 99 Tc m AS increased gradually 2-12 h after 99 Tc m AS injection and the positive image of tumor was displayed clearly. The blocking with non labeled AS decreased the uptake of 99 Tc m AS. CONCLUSION: 99 Tc m AS can gather in tumors in mice and this specific binding may be related to the receptors of AS. 99 Tc m AS probably can be used in predicting the effects of anti angiogenesis therapy in tumor treatment.
出处
《第四军医大学学报》
北大核心
2004年第17期1625-1627,共3页
Journal of the Fourth Military Medical University
关键词
血管抑素
锝
同位素标记
体内分布
显像
Angiostatin
99 Tc m
Isotope labeling
distribution in vivo
imaging
