大肠癌荷瘤鼠放免显像SA-gal促清除作用的实验研究  

Utilization of SA-gal as clearing agent in pretargeting RII of colon carcinoma xenograft bearing models

作　　者：吴湖炳[1] 黄祖汉[1] 彭武和[1] 高晓[1] 

机构地区：[1]第一军医大学附属南方医院核医学科,广州510515

出　　处：《中华核医学杂志》2001年第2期97-98,I002,共3页Chinese Journal of Nuclear Medicine

摘　　要：目的　研究半乳糖化链霉亲和素 (SA gal)在大肠癌预定位放免显像中对血中13 1I标记生物素化单抗 (13 1I Bt McAb)的“促清除”作用。方法　从荷瘤鼠的尾静脉内注射13 1I Bt McAb ,预定位于肿瘤靶位 ,2 4h后给予SA gal促清除 ,0 5h和 6h后分别进行体内分布测定和显像 ;对照组未给予SA gal。结果　给予SA gal促清除后 ,血液本底水平明显降低 ,促清除前、促清除 0 5h和 6h的肿瘤 /血比值分别为 0 32、1 44、5 2 3,促清除 6h的肿瘤 /血比值明显高于单纯给予13 1I Bt McAb后 30h值(对照 2组肿瘤 /血比值为 0 41) ,且肿瘤显像清晰。SA gal促清除 0 5h ,在血中放射性水平明显降低的同时 ,肝内放射性水平明显增高。结论　SA gal是一种良好的促清除剂 ,用于大肠癌预定位放免显像能使肿瘤 /非肿瘤比值明显增高。Objective To conjugate galactosylated streptavidin (SA-gal) and use it as a clearing agent in pretargeting radioimmunoimaging(RII) of colon carcinoma xenograft models Methods SA-gal was obtained by incubating galactose moiety with streptavidin at a molar ratio of 45∶1 For imaging in vivo, biotinylated antibody radiolabeled with 131I was injected into the nude mice bearing the colon carcinoma xenograft via the tail vein 24 h later, SA-gal were intraperitoneally injected at a ratio of 10-fold (molar) excess to antibody At 05 h and 6 h after SA-gal administration, the animals of different test groups were killed for biodistribution study or imaging No clearing agent was administrated to the animals of two control groups and they were also killed for biodistribution study or imaging at 24 h or 30 h after injection of 131I labeled antibody Results ①Galactose moiety was bound to SA at a molar ratio of 20∶1②In pretargeting RII, SA-gal undertook the chase effect very fast At 05 h after injection, the blood level of radioactivity decreased very fast and tumor-to-blood(T/B) ratio increased from 032 to 144 At 6 h after SA-gal administration, T/B ratio reached 523, significantly higher than 041 of the control group(P<0001), and the tumor was imaged clearly At 05 h after SA-gal administration, a large increment in liver radioactivity was seen accompaning with a rapid decrease of blood radioactivity Conclusion SA-gal can considerably improve T/NT ratio and offer better early tumor images and it is a favorable clearing agent in 131I-biotinylated antitumor antibody RII.

关 键 词：大肠癌 荷瘤鼠 放射免疫显像 SA-gal 实验研究 

分 类 号：R735.3[医药卫生—肿瘤] R730.44[医药卫生—临床医学]