IGF-IA~（99）Tc~m标记及其在正常裸鼠体内放射性分布

目的：建立99Tcm标记胰岛素样生长因子I类似物（IGF-IA）的方法,观察其在正常裸鼠体内的生物学分布。方法：SnCl2.2H2O浓度0.75g～4g/L,IGF-IA的用量（20～100）μg,Tween80的用量从（0～10）μl,淋洗液的体积从（20～200）μl,在0.25h～6h不同时间点测定标记率及其在体外的稳定性。将标记物经正常裸鼠尾静脉注射,于5min、30min、1h、2h、4h取血液及主要脏器测量其放射性计数率值。结果：99Tcm标记IGF-IA的最佳标记方法为：浓盐酸溶解SnCl2.2H2O后用葡萄糖酸钠溶液配成3g/L,吸取100μl后加入40μlIGF-IA（2g/L）;300μlNa3PO4和2μl0.1%Tween80混匀后加入50μl99TcmO4-新鲜淋洗液;在IGF-IA体系中加入淋洗液体系,混匀,室温下反应0.5h;加入500μlNaH2PO4将pH值调节到7左右,99Tcm-IGF-IA最高标记率为（94.43±0.75）%,室温下放置6h标记率为（85.57±2.81）%。99Tcm-IGF-IA在正常裸鼠体内主要分布于肾脏和肝脏。结论：预锡化法进行99Tcm标记IGF-IA方法简捷且具有较高标记率和良好稳定性。99Tcm-IGF-IA在正常裸鼠体内主要被肾脏和肝脏摄取,血液清除快。

Labeling Insulin-like Growth Factor I Analogue with 99Tcm and Study on the Biodistribution in Normal Nude Mice

Objective To establish an original method for labeling insulin-like growth factor I analogue （IGF-IA） with 99Tcm and study its biodistribution in normal nude mice. Methods Several labeling conditions were tested：concentration of SnCl2·2H2O,from 0.75g/L to 4g/L,the amount of IGF-IA,from 20 to 100 μg,the volume of Tween80 from 0 to 10 μl,the volume of 99Tcm perrhenate from 20 to 200 μl,and the labeling efficiency was determined from 0.25h to 6 h after labeling and the in vitro stability of 99Tcm -IGF-IA were analyzed. SPECT scanning was carried out before the nude mice were sacrificed. The blood and major organs were taken out from those mice at 5min,30min,1h,2h,4h after 99Tcm -IGF-IA injection through the tail vein,and the radioactivity count of those organs were measured. Results The optimal labeling method for 99Tcm -IGF-IA was 100μl SnCl2·2H2O （3g/L） dissolved in sodium gluconate,40μl IGF-IA （2g/L）,300μl Na3PO4,2μl 0.1% Tween 80,50μl 99Tcm perrhenate,incubated for 0.5h at room temperature,then added 500μl NaH2PO4. The labeling efficiency of 99Tcm -IGF-IA could reach （94.43±0.75）%,which would decrease to （85.57±2.81）% after 6h incubation at room temperature. 99Tcm -IGF-IA was mainly distributed in kidney and liver. Conclusion This method of labeling IGF-IA with 99Tcm using SnCl2·2H2O and sodium gluconate was stable with high labeling efficiency. The clearance of 99Tcm -IGF-IA from blood was fast. 99Tcm -IGF-IA was up taken highly by kidney and liver.