Ong H, De Léan A, Gagnon C
Clinical Research Institute, Montreal, Quebec, Canada.
Clin Chem. 1988 Nov;34(11):2275-9.
This highly sensitive radioreceptor assay (RRA) for the active circulating form of atrial natriuretic factor (ANF), fragment 99-126, in human plasma requires 125I-labeled ANF, bovine zona-glomerulosa membrane receptors, and amiloride HCl. The amiloride elicits an increase in the binding affinity of ANF to its receptors. ANF is extracted from human plasma with "Sep-Pak" cyano cartridges. After a 90-min incubation at 25 degrees C, bound and free fractions are separated by filtration. The ANF concentration that inhibits receptor binding of the radioligand by 50% is 12.4 fmol of unlabeled ANF per tube. The minimum detectable concentration is 0.2 fmol per tube. Using ANF-supplemented plasma samples, there was a good correlation (r = 0.99) between ANF concentrations found and those expected. Only the active circulating form of ANF fully cross-reacts in this assay, which confirms its high selectivity. Results correlated strongly (r = 0.93) for clinical samples tested by RRA and RIA.
这种用于检测人血浆中活性循环形式心房利钠因子（ANF）片段99 - 126的高灵敏度放射受体测定法（RRA），需要125I标记的ANF、牛肾小球带膜受体和盐酸阿米洛利。阿米洛利可提高ANF与其受体的结合亲和力。用“Sep - Pak”氰基柱从人血浆中提取ANF。在25℃孵育90分钟后，通过过滤分离结合和游离部分。使放射性配体的受体结合被抑制50%的ANF浓度为每管12.4飞摩尔未标记的ANF。最低检测浓度为每管0.2飞摩尔。使用添加了ANF的血浆样本，所测ANF浓度与预期浓度之间具有良好的相关性（r = 0.99）。在此测定法中，只有活性循环形式的ANF能完全交叉反应，这证实了其高选择性。通过RRA和RIA检测的临床样本结果相关性很强（r = 0.93）。
