Ward W K, Paquette T L, Frank B H, Porte D
Clin Chem. 1986 May;32(5):728-33.
In this assay for immunoreactive human proinsulin (IRPI), it first is separated from plasma by use of an antiserum to human C-peptide. An immunoprecipitate is then formed by using a precipitating antiserum and polyethylene glycol, after which IRPI is dissociated from the antiserum by incubation in warm HCl, pH 2.0. The resulting mixture is assayed for insulin immunoreactivity by a double-antibody tracer-competition method involving incubation for four days with a high-affinity anti-insulin antiserum. Human proinsulin of recombinant-DNA origin is used as the standard. Added C-peptide at supraphysiological concentrations did not interfere with or react in the assay. Human insulin cross reacted by 1.5%. The detection limit for IRPI (2 SD from zero-dose binding) is 3 pmol/L. Proinsulin conversion intermediates are measured nearly as well as intact proinsulin. IRPI concentrations in 10 nondiabetic human subjects averaged 12.0 (SEM 1.6) pmol/L. The ratio of proinsulin to immunoreactive insulin averaged 14.3 (SEM 2.2)%. After intravenous arginine, the increase in proinsulin was less than that of insulin, and it declined more slowly.
在这项免疫反应性人胰岛素原（IRPI）检测中，首先使用抗人C肽抗血清将其从血浆中分离出来。然后用沉淀抗血清和聚乙二醇形成免疫沉淀物，之后通过在pH 2.0的温热盐酸中孵育使IRPI与抗血清解离。通过双抗体示踪竞争法对所得混合物进行胰岛素免疫反应性检测，该方法包括与高亲和力抗胰岛素抗血清孵育四天。以重组DNA来源的人胰岛素原作为标准品。超生理浓度添加的C肽在检测中不产生干扰或反应。人胰岛素的交叉反应率为1.5%。IRPI的检测限（零剂量结合的2个标准差）为3 pmol/L。胰岛素原转化中间体的测量效果与完整胰岛素原几乎相同。10名非糖尿病受试者的IRPI浓度平均为12.0（标准误1.6）pmol/L。胰岛素原与免疫反应性胰岛素的比例平均为14.3（标准误2.2）%。静脉注射精氨酸后，胰岛素原的增加幅度小于胰岛素，且下降更缓慢。
