Clerico A, Del Chicca M G, Zucchelli G C, Biver P, Mariani G, Bertelli A, Bertelli A A
CNR Institute of Clinical Physiology, University of Pisa, Italy.
Int J Tissue React. 1994;16(2):79-87.
Endothelin(s) is (are) generally measured by highly-sensitive RIA (radioimmunoassay) or sandwich-EIA (enzyme immunoassay) methods after preliminary extraction and chromatographic purification using Sep-Pak C18 cartridges; however, there is no general consensus about the range of endothelin circulating levels in healthy subjects and patients. We have evaluated the analytical performance of two commercial RIAs for plasma endothelin-1 assay (supplied by Peninsula Laboratories, Belmont, California, and by Biomedica Gruppe, Biomedica Gesellschaft mbH, Vienna, Austria) in order to verify whether differences in extraction procedures, antibody affinities or standard preparations can explain the different results obtained by these two RIAs. The RIA kits tested in the present study showed some differences in the analytical performance; in particular, different antibody specificities have been observed. The concentration range of endothelin(s) assayed with an imprecision better than 15%, which can be considered the working range, was wider for the Peninsula than for the Biomedica kit (i.e. from 1.6 to 50 fmol/tube vs 0.7 to 10 fmol/tube), whereas the two RIA kits showed similar sensitivity (i.e. about 0.2 fmol/tube). Taking into account the working range and sensitivity of the two RIAs to measure with an acceptable error the samples of normal subjects and the most part of patients, > or = 3-ml volumes of plasma must be extracted by Sep-Pak C18 cartridges and then measured by RIA. Owing to the central role played by the endothelin superfamily in several pathophysiological conditions, it is important to have a reliable assay for the measurement of these peptides in biological fluids and tissues.(ABSTRACT TRUNCATED AT 250 WORDS)
内皮素通常在使用Sep - Pak C18柱进行初步提取和色谱纯化后，通过高灵敏度放射免疫分析（RIA）或夹心酶免疫分析（EIA）方法进行测定；然而，对于健康受试者和患者体内内皮素循环水平的范围尚无普遍共识。我们评估了两种用于血浆内皮素 - 1测定的商业RIA试剂盒（由加利福尼亚州贝尔蒙特的半岛实验室和奥地利维也纳的生物医学集团生物医学有限公司提供）的分析性能，以验证提取程序、抗体亲和力或标准制剂的差异是否能解释这两种RIA试剂盒获得的不同结果。本研究中测试的RIA试剂盒在分析性能上存在一些差异；特别是观察到了不同的抗体特异性。对于半岛试剂盒，测定内皮素时不精密度优于15%的浓度范围（可视为工作范围）比生物医学试剂盒更宽（即分别为1.6至50 fmol/管和0.7至10 fmol/管），而两种RIA试剂盒显示出相似的灵敏度（即约0.2 fmol/管）。考虑到两种RIA试剂盒在以可接受误差测量正常受试者和大多数患者样本时的工作范围和灵敏度，必须用Sep - Pak C18柱提取≥3 ml体积的血浆，然后通过RIA进行测定。由于内皮素超家族在几种病理生理状况中发挥的核心作用，拥有一种可靠的测定生物体液和组织中这些肽的方法很重要。（摘要截短于250字）
