碘标记血清淀粉样P成分在动物模型中的体内分布及显像研究  

The biodistribution and imaging of a novel amyloid probe ^131I-serum amyloid P-component in mice model of amyloidosis

作　　者：魏海亮[1] 张春丽[1] 王荣福[1] 张建华[1] 闫平[1] 康磊[1] 郭凤琴[1] 

机构地区：[1]北京大学第一医院核医学科,100034

出　　处：《中华核医学杂志》2011年第6期410-413,共4页Chinese Journal of Nuclear Medicine

基　　金：国家重点基础研究发展计划（973计划）（2006CB705705）;国家自然科学基金（30870729,30900374）北京大学“985工程”二期建设项目（985-2-056）

摘　　要：目的探讨^131I标记的人血清淀粉样P成分（SAP）诊断淀粉样变性的价值。方法用Iodogen法对SAP标准品进行^131I标记，测定标记率与放化纯，观察标记物的稳定性；对实验组小鼠用质量分数10％酪蛋白（Casein）0．5ml每日皮下注射，连续21d，制作继发性淀粉样变性小鼠动物模型，对照组连续注射21d0．5ml生理盐水；2组小鼠各4只，经尾静脉注射200μl（7．4MBq）^131I—SAP，分别于1，3，6，24，48和72h进行显像。实验组、对照组小鼠各30只，经尾静脉注射100μl（555kBq）^131I-SAP后，分别于1，3，6，24，48和72h处死小鼠（每个时相实验组与对照组各5只），取心、肺、肝、脾、肾、肌肉、主动脉、血液等组织，测定放射性计数。两组间比较采用单因素独立样本t检验。结果^131I-SAP的标记率为70．6％，经分离纯化后，放化纯为（95．5±3．4）％，且稳定性好；^131I—SAP在淀粉样变性小鼠肝、脾与肾中的放射性摄取明显高于对照组，实验组24h单位质量放射性计数肝／血、脾／血、肾／血比值分别为2．201±0．301，2．139±0．223，4．797±0．615，对照组分别为0．657±0．126，1．014±0．063，0．607±0．028，t值分别为10．747，11．626和15．135，P均〈0．01。48h二者差异仍具有统计学意义（t值分别为15．128，4．558，16．960，P均〈0．01）；72h2组除脾／血比值外，其余2个比值差异有统计学意义，对应t值为3．022（P〉0．05），7．8011，6．442（P均〈0．01）。显像结果示，注药后24h实验组小鼠腹部放射性摄取增加，而对照组无明显摄取。结论SAP易于进行^131I标记，且标记物稳定性好；^131I-SAP可以特异性结合于淀粉样变性脏器，生物分布与显像结果一致，提示^131I—SAP可以作为特异性的显像剂无创诊断淀粉样变性。Objective To validate ^131I-serum amyloid P-component （SAP） as a novel amyloid probe in mice bearing amyloidosis and evaluate its diagnostic value. Methods Standard SAP was labeled with ^131I using Iodogen method. Amyloidotic mice model was established by subcutaneous injection of 0.5 ml 10% Casein daily for 21 d, and the control group was injected with 0.5 ml saline. Both groups were injected with 7.4 MBq ^131I-SAP through the tail veins and imaging was performed at 1, 3, 6, 24, 48 and 72 h post injection. In biodistribution study, 30 amyloidotic mice model and 30 controls were injected with 555 kBq ^131 I- SAP and were killed evenly at 1,3, 6, 24, 48 and 72 h post injection. T test was used to analysis the data. Results The labeling efficiency of ^131I-SAP was 70.6%, and the radiochemical purity was （95.5 ± 3.4） %. There was significant tracer uptake by liver, spleen and kidney at 24 h in the test group and mild uptake by these organs in the control group. The uptake ratios of liver, spleen and kidney over blood in the test group were 2. 201 ± 0. 301, 2. 139 ± 0. 223, 4. 797 ± 0. 615, vs 0. 657 ± 0. 126, 1. 014 ± 0. 063, 0. 607 ±0.028 in the control group, respectively （t = 10. 747, 11. 626 and 15. 135, all P 〈0.01 ）. The uptake differences between the two groups were still statistically significant at 48 h （ t = 15. 128, 4. 558, 16. 960, all P 〈 0, 01 ）. The uptake ratios of spleen over blood between the two groups were not significantly different at 72 h （ t = 3. 022, P 〉 0.05）, but the other two uptake ratios were both sigificantly different （ t = 7. 801, 6. 442, both P 〈 0.01 ）. Conclusions SAP can be reliably labeled with ^131I. The labeled product ^131 I-SAP can accumulate in amyloid laden tissues, thus rendering it a potential agent in the detection of amyloidosis.

关 键 词：淀粉样蛋白P成分 碘放射性同位素 同位素标记 淀粉样变 放射性核素显像 小鼠 

分 类 号：R-332[医药卫生] R817