Objective To establish a highly specific and sensitive iadioimmunoassay(RIA) far human insulin-like growth-factor-II (IGF- II ) , and apply it to detect IGF- E in human serum and culture medium. Methods Rabbits were immunized with recombined IGF-II connected with thyroglobulin( TG) for several times to obtain IGF-E antibody with high tiler and specificity. Chlarozone-T method was used to prepare125I-IGF- E , and it was purified by Sephadex G-25. The reaction between antigen and antibody was proceeded by one-step balancing method. They were incubated at4℃ for 24h, and the binded or free labled antigen were separated by PR reagents. This assay was used to check the IGF- E level in ISO samples from normal blood donors and 180 samples from patients with liver cancer, and compare change of IGF- E level before and after interventionsl treatment in patients with liver cancer. Results The detective range of this assay was 0.1-24.3 ng/ml, the lowest detectable value was less than 0. 1ng/ml, while the inter-/intra-assay deviation were less than 6.3% and 10.0% respectively. Serum IGF-E of normal blood donors group (1.266 ±0.298)ng/ml was significantly lower than that in several liver cancer patients groups(P <0.05) ; while IGF- E level of liver cancer patients without treatment (4.916 ±1.24)ng/ml was significantly higher than that in group treated with intervention 3 days (4.263 ±1.411)ng/ml(P<0.05). However, no obviously disparity between group treated 3 days and group treated one month(4.796 ± 1.647 ng/ml). Conclusion This IGF- II radoimmunoassay is steady, convenient, specific and sensitive. Also, it can be used to detect IGF-E level in human serum.%目的 建立高特异性和高灵敏度的人胰岛素样生长因子Ⅱ(IGF-Ⅱ)放射免疫分析方法,用于测定人血清以及培养液中IGF-Ⅱ水平.方法 用人工合成的IGF-Ⅱ多肽连接甲状腺球蛋白,多次免疫兔子获取高效价、高特异的人IGF-Ⅱ抗体.用氯氨T法制备125I标记的IGF-Ⅱ,经交联葡聚糖凝胶(Sephadex G-25)纯化.抗原抗体反应采用平衡一步法,4℃温浴24h后经PR试剂分离结合和游离的标记抗原.用该法测定正常献血员150例和肝癌患者180例,并比较了肝癌患者介入治疗前后IGF-Ⅱ水平的变化.结果 该法测定范围为(0.1～24.3)ng/ml,最低检出值<0.1ng/ml,批内和批间误差<6.3%和10.0%.正常献血员血清IGF-Ⅱ水平(1.266±0.298)ng/ml明显低于肝癌各组患者(P<0.05);肝癌患者进行介入治疗3d后IGF-Ⅱ水平(4.263±1.411)ng/ml明显低于治疗前(4.916±1.24 )ng/ml(P<0.05);介入治疗后3d与治疗后1个月(4.796±1.647)ng/ml水平相比无明显差异.结论 该法稳定、简便、特异、灵敏,适于检出人血清中的IGF-Ⅱ水平.
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