^99Tc^m-EC-guanine在小鼠体内分布的研究  

Bio-distribution of ^(99)Tc^m-EC-guanine in mice

作　　者：杨君[1] 唐军[1] 徐巧玲[1] 杨仪[1] 刘增礼[1] 

机构地区：[1]苏州大学附属第二医院核医学科,苏州215004

出　　处：《核技术》2008年第9期702-705,共4页Nuclear Techniques

摘　　要：本文研究99Tcm-EC-guanine在小鼠体内的生物分布规律,用薄层色谱仪和纸层析法测定其标记率及放化纯。正常健康昆明小鼠48只,随机分为8组,尾静脉注射99Tcm-EC-guanine3.7MBq,不同时间点放血处死,取血、心、肝、脾、肺、肾、胃、小肠、脑、骨骼、肌肉,测量其每克组织注射百分剂量率(%ID/g)。同时,正常小鼠及荷LOVO大肠癌小鼠各3只,注射99Tcm-EC-guanine,相同时间点进行平面显像,观察99Tcm-EC-guanine在小鼠体内各器官的分布。99Tcm-EC-guanine标记率98%,8h内放化纯大于95%,在30min内,正常小鼠除肾脏外的各组织、器官的%ID/g下降均明显。血液廓清速度快,主要通过肾排泄、肝代谢,5min时,在肾、肝的%ID/g分别为20.66和13.20,30min、4h时分别为15.43、7.03和11.37、7.31;脑的各时间点%ID/g均小于0.5;肌肉组织分布少,30min时为1.11,4h为0.65,在心、肺、脾、胃、肠及骨骼分布不多;显像结果与体内分布一致,荷瘤小鼠瘤体清晰显示。99Tcm-EC-guanine标记简便,标记率及放化纯高,小鼠体内生理分布表明其可能成为一种好的嘌呤代谢显像剂。In this paper, bio-distribution of ^99Tc^m-EC-guanine in mice was evaluated using TLC and paper chromatography to determine the labeling efficiency and radiochemical purity. Forty eight healthy Kunming mice were divided in random into 8 groups, which were given with 3.7 MBq ^99Tc^m-EC-guanine via i.v. injection. They were sacrificed by cutting the carotid at different minutes or hours after injection for radioactivity measurement of the tissues or organs. The bio-distribution of radioactivity in the samples was calculated as a percentage of the injection dose per gram of wet tissue weight （%ID/g）. Meanwhile, three normal Kunming mice and LOVO tumor-bearing mice were injected with 74 MBq ^99Tc^m-EC-guanine and imaged with clinical SPECT at the same time as the 8 groups after injection. The labeling efficiency of ^99Tc^m-EC-guanine was 98% and its radiochemical purity was over 95% in 8 h. The bio-distribution in all the samples but kidney decreased rapidly in 30 minutes after injection. The results demonstrated that ^99Tc^m-EC-guanine was metabolized through kidney and liver, in which the %ID/g were 20.66 and 13.22 at 5 rain, 15.43 and 7.03 at 30 rain, and 11.37 and 7.31 at 4h, respectively. The %ID/g of brain was less than 0.5 at any time. A little distribution appeared in muscle, the %ID/g were 1.11 at 30 rain and 0.65 at 4 h. In heart, lung, spleen, stomach, intestine and bones, there were little distributions. The SPECT images showed similar bio-distribution. The tumor was clearly visualized in LOVO tumor-bearing mice. ^99Tc^m-EC-guanine, which can be labeled easily with high efficiency and radiochemical purity, is probably a good imaging agent for guanine metabolism.

关 键 词：^99Tc^m标记鸟嘌呤 EC-Guanine 生物学分布 

分 类 号：R817.9[医药卫生—影像医学与核医学]