^(131)Ⅰ标记热休克蛋白90抑制剂17-丙烯胺基-17-去甲氧基格尔德霉素的方法学研究

Labeling method of 17-allylamino,17-demethoxygeldanamycin with ^(131)I and its biodistribution in normal mice

目的:建立131I标记热休克蛋白90抑制剂17-丙烯胺基-17-去甲氧基格尔德霉素(17-AAG)的方法,探讨其标记条件。方法:采用放射性碘标记氯胺-T法标记17-AAG,并研究其在ICR正常小鼠体内的生物分布。结果:131I氯胺-T法标记17-AAG的最佳条件为:17-AAG乙醇溶液40μl(含17-AAG 5μg),0.5 mol.L-1磷酸盐缓冲液50μl(pH7.5),Na131I溶液20μl,氯胺-T30μg.(15μl)-1(用pH7.5的0.05 mo.lL-1PB溶解),25℃反应50 s,偏重亚硫酸钠40μg.(20μl)-1(用pH7.5的0.05 mo.lL-1PB溶解)中止反应。标记率约为53.1%,经乙酸乙酯纯化后所得标记物的放射化学纯度>90%;其生理盐水溶液4℃放置5 d,放射化学纯度大于90%。小鼠尾静脉注射131I-17-AAG后0.5 h131I-17-AAG在胆囊达到高峰(369.44±147.81)%ID.g-1,肝脏中仅有(2.23±0.50)%ID.g-1,说明对肝脏毒性小。结论:热休克蛋白90抑制剂17-AAG的标记方法操作简便,反应时间短。

Objective To study the method for ^131I and its biodistribution in normal mice. Methods in the presence of chloramines-T. The conditions of labeling 17-allylamino, 17-demethoxygeldanamycin （17-AAG） with ^131I-17-AAG was prepared by the reaction of 17-AAG with Na ^131I labeling, the stability of ^131I -17-AAG and the biodistribution in normal mice were investigated. Results To search for the optimal conditions,5 μg 17AAG dissolved by 40 μl alcohol, 50 μl 0.5 mol·L^-1 phosphate buffer saline （pH 7.5） ,20 μl Na ^131I （185 MBq·ml^-1 ）, ehloramines-T（2 g·L^-1 ） dissolved by 0.05 mol·L^-1 phosphate buffer （ pH 7.5 ） were mixed at 25℃ for 50 seconds. After the labeling reaction, an excess of sodium metabisulfite dissolved by 0.05 mol·L^-1 phosphate buffer （ pH 7.5 ） was added to terminate the reaction. The average labeling efficiency was around 53. 1%. The radioehemieal purity of ^131 I-17-AAG was over 90% after purification. ^131 I-17-AAG showed the stability above 90% in saline up to 5 d at 4 ℃. The biodistribution study in normal mice showed that there was high uptake in eholeeyst, stomach and intestine. Conclusion Our preliminary results demonstrate that the labeling of ^131I-17-AAG is simple and successful. Further study is going on.