99mTc标记的大肠癌单克隆抗体在小鼠体内分布特点的研究

目的：研究^99m-Tc标记的大肠癌单克隆抗体(^99mTc—ACCmAb)在正常小鼠和荷瘤裸鼠体内的分布及在荷瘤裸鼠体内SPECT成像的研究。方法：将^99m-Tc和^99mTc—ACCmAb分别注射入正常小鼠、荷L010-16人结肠癌裸鼠，按不同时间点采取小鼠的脏器进行同位素放射性活度的测定；并在不同时间测定荷L010-16人结肠癌裸鼠注射^99mTc—ACCmAb的SPECT显像。结果：注射^99mTc后正常小鼠体内6h5min血液中的放射性活度与30min相比下降了76．6％，是30min的23．4％；肝脏中6h5min的放射性活度为30min的27．2％，下降了72．8％。尾静脉注射^99mTc-ACCmAb的正常小鼠，6h5min在血液中的放射性活度与30min血液中的放射性活度比较下降了68．4％，是30min的31．6％，24h为6h5min的6．1％，下降了93．9％；荷瘤裸鼠体内^99mTc-ACCmAb在24h血液中的放射性活度是6h5min的2．1％，下降了97．9％。SPECT显像结果表明，虽然在注射^99mTc-ACCmAb20h血液与肿瘤的比值为最高，但在24h的成像结果仍然好于其他的时间点。结论：^99m-Tc标记的大肠癌单克隆抗体可特异性浓聚于荷L010-16人结肠癌裸鼠模型中，可能成为大肠癌根除手术中使用的手术导向体内诊断用药，保证手术切除肿瘤的彻底性。

Biodistribution characteristics of 99mTc labeled anti-colon cancer monoclonal antibody in mice

AIM: To study the biodistribution of 99m Tc labeled Anti-colon cancer monoclonal antibody ( 99mTc-ACCmAb ) in normal and nude mice and the imaging of same antibody in nude mice, which were carried with human colon cancer. METHODS: Normal mice and Nude mice that are carried the L010-16 human colon cancer received, intravenously, 99m Tc labeled monoclonal antibodies, and then the radioactivity was detected in normal mice in different time points and the imaging was checked by using the SPECT in nude mice. RESULTS: The radioactivity of 99m Tc at 6 h 5 min decreased 76.6% in comparison with the 30 min in normal mice blood, and the radioactivity was the 23.4% of the 30 min in the blood. The radioactivity in 6 h 5 min was 27.2% of the 30 min in normal mice liver and decreased 76.8%. In the normal mice injected 99m Tc-ACCmAb, the radioactivity at 6 h 5 min decreased 68.4% compared with the 30 min in normal mice blood, the radioactivity was the 31.6% of the 30 min in the blood, the radioactivity at 24 h are 6.1% and it dropped 93.9% compare with the 6 h 5 min. In nude mice, the radioactivity of 99m Tc-ACCmAb at 24 h is 2.1% of the first half-life. It decreased 97.9% compared with the 6 h 5 min. Although the ratio of blood and tumor was the highest, the imaging results were still better than other time points. CONCLUSION: 99m Tc-ACCmAb may concentrate in nude mice, which are carried with human colon carcinoma. It may become the diagnostic reagent for radio-immunoguided and ensure to remove the tumor during operations.