Baumann G, Rappaport G, Lemarchand-Béraud T, Felber J P
J Clin Endocrinol Metab. 1975 Mar;40(3):462-9. doi: 10.1210/jcem-40-3-462.
A rapid and simple method for the estimation of free (nonprotein-bound) cortisol in human plasma is described. Total plasma cortisol (F) was determined by a competitive protein binding assay. An estimate of the saturation of Corticosteroid Binding Globulin was obtained by the use of "charcoal cortisol uptake" (CFU). "Charcoal cortisol uptake ratio" (CFUR) was defined as the ratio of the CFU of the unknown plasma to that of a reference serum pool. Free cortisol index (FFI) was calculated as (total plasma F) times (CFUR). Percent free cortisol and free cortisol concentration (FF) was determined by equilibrium dialysis at 37 C. 169 plasma samples with an F range of 0.8-61.2 mug/100 ml from 18 normal, 10 ACTH-stimulated, 17 estrogen-treated and 12 pregnant subjects were analyzed. A highly significant correlation between FFI and FF was found (r = 0.952). Inter-assay coefficients of variation were 7% for total plasma F and 3.5% for CFU. The method allows the rapid processing of large numbers of samples and can be performed on 0.2 ml of plasma.
本文描述了一种快速简便的估算人血浆中游离（非蛋白结合）皮质醇的方法。采用竞争性蛋白结合分析法测定血浆总皮质醇（F）。通过“活性炭皮质醇摄取量”（CFU）来估算皮质类固醇结合球蛋白的饱和度。“活性炭皮质醇摄取率”（CFUR）定义为未知血浆的CFU与参考血清库的CFU之比。游离皮质醇指数（FFI）计算为（血浆总F）乘以（CFUR）。通过在37℃下进行平衡透析来测定游离皮质醇百分比和游离皮质醇浓度（FF）。分析了来自18名正常受试者、10名促肾上腺皮质激素刺激受试者、17名雌激素治疗受试者和12名孕妇的169份血浆样本，其F范围为0.8 - 61.2μg/100ml。发现FFI与FF之间存在高度显著的相关性（r = 0.952）。血浆总F的批间变异系数为7%，CFU的批间变异系数为3.5%。该方法能够快速处理大量样本，且仅需0.2ml血浆即可进行检测。
