Christensen T B, Marqversen J, Engbaek F, Berger P, Bacher T, von der Maase H
Department of Oncology, Aarhus University Hospital, Denmark.
Br J Cancer. 1999 Jul;80(10):1582-7. doi: 10.1038/sj.bjc.6690566.
We have recently introduced 125I-hCG as an elimination marker in patients with human chorionic gonadotrophin (hCG) producing testicular cancer. 125I-hCG is a well-known reagent in clinical biochemistry and is used extensively in hCG assays. Previous studies have shown that the iodination process leaves the hCG molecule mainly intact. The iodination, purification and stability of 125I-hCG tracer are described. The aim of the present study was to determine whether or not 125I is associated with hCG after the injection of 125I-hCG intravenously (i.v.) in humans. Three different methods were used. Following injection of 125I-hCG, the plasma disappearance of radioactivity and hCG were followed for a period of 28 days in 13 normal subjects. Serum from a normal healthy male following injection of 125I-hCG was analysed using a double antibody direct binding radioimmunoassay specific for holo-hCG and high performance liquid chromatography (HPLC). Following injection of 125I-hCG in eight normal healthy males and five normal healthy females, the disappearance of radioactivity and hCG showed identical paths in the 28 days follow-up period. The bindable radioactive fraction of immunologically active hCG in serum of a normal healthy male following injection of 125I-hCG was between 57.0% and 72.1%, and was constant over time. HPLC showed similar elution pattern of serum from a normal healthy male injected i.v. with 125I-hCG and 125I-hCG. Using three different methods, we were able concurrently to demonstrate the association of 125I with hCG in humans up to 28 days after injection of radiolabelled hCG i.v. Thus, information about the expected elimination of hCG can be obtained by following the elimination of activity in plasma after injection of 125I-hCG.
我们最近将125I - hCG作为一种消除标志物引入到患有产生人绒毛膜促性腺激素（hCG）的睾丸癌患者中。125I - hCG是临床生物化学中一种知名试剂，广泛用于hCG检测。先前的研究表明，碘化过程使hCG分子基本保持完整。本文描述了125I - hCG示踪剂的碘化、纯化及稳定性。本研究的目的是确定在人体静脉注射125I - hCG后，125I是否与hCG相关联。使用了三种不同方法。在13名正常受试者中静脉注射125I - hCG后，对放射性和hCG的血浆清除情况进行了为期28天的跟踪。使用针对全hCG的双抗体直接结合放射免疫测定法和高效液相色谱法（HPLC）对一名正常健康男性注射125I - hCG后的血清进行分析。在8名正常健康男性和5名正常健康女性中静脉注射125I - hCG后，在28天的随访期内，放射性和hCG的清除呈现相同路径。一名正常健康男性注射125I - hCG后血清中具有免疫活性的hCG的可结合放射性部分在57.0%至72.1%之间，且随时间保持恒定。HPLC显示，静脉注射125I - hCG的正常健康男性血清与125I - hCG具有相似的洗脱模式。通过三种不同方法，我们能够同时证明在静脉注射放射性标记的hCG后长达28天的时间里，人体中125I与hCG相关联。因此，通过跟踪注射125I - hCG后血浆中活性的清除情况，可以获得有关hCG预期清除的信息。
