Critical Variables in the Radioimmunoassay of Serum Insulin Using the Double Antibody Technic
Critical Variables in the Radioimmunoassay of Serum Insulin Using the Double Antibody Technic
复制标题
双抗体技术放射免疫测定血清胰岛素的关键变量
作者：
Soeldner Js;D. Slone
描述了摩根和拉扎罗最初提出的胰岛素双抗体放射免疫测定法的改进。这些研究证实血清和血浆中存在一种抑制剂（肝素），它可以延迟含有豚鼠球蛋白抗体的兔血清使胰岛素-胰岛素抗体复合物变得不溶的速率。血清稀释会降低抑制剂的作用，但会增加稀释误差。肝素同样会降低抑制剂的作用，但过量的肝素会产生错误的低免疫反应性胰岛素 (IRI) 值。提供的血清数据表明，如果在添加沉淀抗体（兔、抗豚鼠球蛋白、血清）后经过足够的时间（72小时），则沉淀系统达到平衡。采用这种修改，提供了额外的数据，显示添加到血清中的人胰岛素的良好恢复，重复测定中各自血清IRI值的良好重复，以及重复采样中任何一个个体的空腹血清IRI的稳定性。正常成人的空腹血清 IRI 值为 1 至 20 μU./ml。平均为 8.4 μU./ml.，快速静脉注射葡萄糖后，血清 IRI 通常在一到两分钟内达到最高水平。
An adaptation of the double antibody radioimmunoassay for insulin originally presented by Morgan and Lazarow is described. These studies have confirmed the presence of an inhibitor in serum and plasma (heparin) which delays the rate at which the insulin-insulin antibody complex is rendered insoluble by rabbit serum containing antibodies to guinea pig globulin. Serum dilution reduces the effect of the inhibitor but increases dilutional error. Heparin similarly reduces the effect of the inhibitor, but excess heparin produces falsely low values for immunoreactive insulin (IRI). Data are presented for serum which show that if sufficient time (72 hrs.) is allowed to elapse after the addition of the precipitating antibody (rabbit, anti-guinea pig globulin, serum), the precipitating system reaches equilibrium. Employing this modification, additional data are presented, showing excellent recovery of human insulin added to serum, good duplication of respective serum IRI values in repeat assays, and constancy of fasting serum IRI in any one individual on repeated sampling. Normal adults exhibit fasting values of serum IRI from 1 to 20 μU./ml. with a mean of 8.4 μU./ml., and after rapid intravenous glucose, serum IRI usually reaches maximum levels in one to two minutes.