North W G, LaRochelle F T, Haldar J, Sawyer W H, Valtin H
Endocrinology. 1978 Dec;103(6):1976-84. doi: 10.1210/endo-103-6-1976.
The region of the arginine-vasopressin (AVP) molecule critical for binding to the effective antibodies in a RIA has been localized to the vicinity of the Phe3 position by using the cross-reaction in the assay between AVP and a number of its structural analogs. Binding seems to be almost independent of any direct contributions from components of the tripeptide tail of AVP. Using this RIA it was found that disequilibrium conditions of incubation produce a 5-fold increase in assay sensitivity over equilibrium conditions. Amino acid analysis revealed that three synthetic peptide preparations used as reference standards comprised only 70-80% of their weight as peptide and this finding points up the need to correct such reference standards for their peptide content. The ratio of rat vasopressor activity to RIA activity of these three preparations as well as of a natural AVP preparation, however, approximated unity. Results obtained comparing measurements of AVP in rat neural lobes by RIA and rat vasopressor assay show a correlation between RIA and bioassay of 0.9406, a slope of 1.086, and an intercept of 20 mU, suggesting good agreement for AVP determined by these two assay systems.
通过利用精氨酸加压素（AVP）与其多种结构类似物在放射免疫分析（RIA）中的交叉反应，已将AVP分子中对于与RIA中有效抗体结合至关重要的区域定位到苯丙氨酸3位置附近。结合似乎几乎与AVP三肽尾部成分的任何直接贡献无关。使用这种RIA发现，孵育的非平衡条件比平衡条件下的分析灵敏度提高了5倍。氨基酸分析表明，用作参考标准品的三种合成肽制剂中，肽的重量仅占其总重量的70 - 80%，这一发现凸显了需要对这些参考标准品的肽含量进行校正。然而，这三种制剂以及天然AVP制剂的大鼠升压活性与RIA活性之比接近1。通过RIA和大鼠升压测定法比较大鼠神经叶中AVP测量结果所获得的结果显示，RIA与生物测定法之间的相关性为0.9406，斜率为1.086，截距为20 mU，表明这两种测定系统所测定的AVP结果具有良好的一致性。
