Peck E J, Clark J H
Endocrinology. 1977 Oct;101(4):1034-43. doi: 10.1210/endo-101-4-1034.
The effect of increasing ionic strength on the efficacy of the charcoal adsorption assay for estrogen receptors has been examined. Cytosol prepared from immature rat uteri was exposed to variable concentrations of KCl and the saturable or "specific" binding of [3H]estradiol was measured by charcoal and hydroxylapatite adsorption, gel filtration, and/or density gradient centrifugation using excess diethylstilbestrol to correct for non-saturable or "non-specific" binding. As the concentration of KCl was increased, the number of estradiol binding sites as measured via charcoal adsorption decreased in proportion to the conversion of receptor from a low salt (8S) to a high salt (4S) complex. This "stripping" of [3H]estradiol from the 4S receptor species was both time- and charcoal concentration-dependent. It is concluded that the charcoal adsorption procedure quantitatively assesses the binding of [3H]estradiol to low salt, 8S receptor species but is not the assay of choice for salt-extracted or salt-treated receptors in view of the potential for artifactually low estimates of receptor number. Low values for receptor number under high salt conditions may result from exposure of the binding site of the estrogen receptor to charcoal.
研究了增加离子强度对雌激素受体活性炭吸附测定法效能的影响。从未成熟大鼠子宫制备的胞质溶胶暴露于不同浓度的氯化钾，使用过量己烯雌酚校正非饱和或“非特异性”结合，通过活性炭和羟基磷灰石吸附、凝胶过滤和/或密度梯度离心法测量[3H]雌二醇的饱和或“特异性”结合。随着氯化钾浓度的增加，通过活性炭吸附测量的雌二醇结合位点数量与受体从低盐（8S）复合物向高盐（4S）复合物的转化成比例减少。从4S受体种类中“剥离”[3H]雌二醇既依赖时间也依赖活性炭浓度。得出的结论是，活性炭吸附程序可定量评估[3H]雌二醇与低盐8S受体种类的结合，但鉴于可能会人为低估受体数量，它不是盐提取或盐处理受体的首选测定方法。高盐条件下受体数量的低值可能是由于雌激素受体的结合位点暴露于活性炭所致。
