放射性碘间接标记血管活性肠肽  

The indirect radioiodination of vasoactive intestinal peptide

作　　者：王丽华[1] 李俊玲[1] 尹端沚[1] 张蕾[1] 张秀利[1] 汪勇先[1] 

机构地区：[1]中国科学院上海原子核研究所,201800

出　　处：《中华核医学杂志》2002年第4期243-246,共4页Chinese Journal of Nuclear Medicine

基　　金：国际原子能机构(IAEA)基金资助项目 (9570 R0 )

摘　　要：目的　研究能有效降低体内脱碘的血管活性肠肽 (VIP)的标记方法。方法　①标记前体N 琥珀酰亚胺 3 (三正丁基锡 )苯甲酸酯 (ATE) ,得到中间体N 琥珀酰亚胺 3 I(1 2 5I)代苯甲酸酯(S1 2 5IB) :采用Iodogen方法进行放射性碘标记 ,并考察一系列条件对标记率的影响。通过Sep Pak硅胶柱分离得到产物S1 2 5IB ,于 4℃避光保存 2d。标记率和稳定性通过薄层层析 (TLC)方法测定。②S1 2 5IB与VIP的联接 :S1 2 5IB与VIP直接混合得到产物 3 I(1 2 5I)代苯甲酰化血管活性肠肽 (1 2 5IBA VIP)。以反相TLC测定其标记率。产物1 2 5IBA VIP经高效液相层析 (HPLC ,RPC18柱 )分离得到。三氯乙酸(TCA)沉淀法测定1 2 5IBA VIP的体外稳定性。体外生物活性分析通过与细胞株SGC790 1的细胞结合实验测定。结果　①前体标记结果。室温条件下 ,氧化剂用量约 10 μg ,n(ATE)∶n(Na1 2 5I)为 3～ 8∶1,反应 5min标记率 >96 %。S1 2 5IB在上述条件下较稳定 ,TLC结果显示无明显的放射性杂质产生。②S1 2 5IB与VIP的联接。TLC测定标记率 >75 % ,HPLC示1 2 5IBA VIP的保留时间 (tR)为 13.3min ,S1 2 5IB为 19 6min ,VIP为 8 32min。1 2 5IBA VIP的体外稳定性较好 ,4℃保存 7d后 ,无明显脱碘现象。细胞结合实验结果表明 ,1 2 5IBAObjective To seek for an effective way to acquire radiolabeled vasoactive intestinal peptide(VIP) with excellent in vivo stability N succinimidyl 3 iodo 125 benzoate (S 125 IB) came from radioiodination of N succinimidyl 3 (tri n butylstannyl) benzoate (ATE) precursor and then conjugated with VIP to form 125 IBA VIP The labeling procedure was optimized; the in vitro stability and biological activity were evaluated in this study Methods ①Radiolabeling of ATE precursor was achieved with iodogen oxidant and the influential factors were considered in this procedure The labeling efficiency was determined by thin layer chromatography(TLC) and the purification was carried out by Sep pak silica gel cartridge The stability was detected by TLC after 2 h storage in dark at 4 ℃ ②Conjugation of S 125 IB and VIP The labeling efficiency was determined with RP TLC and the purification was carried out with high performance liquid chromatography (HPLC, RP C18 column) Trichloroacetic acid (TCA) precipitation method was applied to evaluate the in vitro stability while the biological activity was determined by cell binding experiments with SGC7901 cell lines Results ①S 125 IB experiments The radioiodination of ATE was performed well for 5 min at 25 ℃ with 10 microgrammes of iodogen at suitable mole ratio (3～8∶1) of ATE/ Na 125 I, the labeling efficiency was about 96% The stability was kept well at 4 ℃ in dark, no significant decrease of S 125 IB was observed ② The conjugation efficiency of S 125 IB and VIP was above 75% with TLC HPLC showed the different retention time ( t R) as follows, 125 IBA VIP: 13 3 min,S 125 IB: 19 6 min,VIP: 8 32 min. The stability of 125 IBA VIP was better than 125 I VIP from direct radioiodination of VIP with iodogen oxidant, only 2 85% decrease was found after 7 d at 4 ℃ The biological activity of 125 IBA VIP was kept as well as 125 I VIP under the condition of 37 �

关 键 词：放射性碘 间接标记 血管活性肠肽 体外稳定性 生物活性 

分 类 号：R817[医药卫生—影像医学与核医学]