Katsumata M, Gupta C, Goldman A S
Arch Biochem Biophys. 1985 Dec;243(2):385-95. doi: 10.1016/0003-9861(85)90515-6.
We studied the glucocorticoid receptor complexes of pulmonary and thymic cytosols of female A/J and CD-1 mice and of hepatoma G2 cells by two column-chromatographic systems, using both [3H]dexamethasone (DEX) and [3H]phenytoin (DPH) as ligands. Three DNA-cellulose adsorbable [3H]DEX-receptor complexes were separated in each system. Molecular sieving gave a 7-, a 5.4-, and a 3.5-nm complex (Stokes radii), and DEAE-Sephadex A-50 chromatography gave a complex eluting in the wash, one at 0.14 M KCl, and one at 0.20 M KCl by a KCl gradient. DPH blocked the binding of the 7- and 3.5-nm, wash, and 0.14 M KCl [3H]DEX complexes. Only two DNA-cellulose adsorbable [3H]DPH complexes, each blocked by DEX, were obtained in each system: a 7- and a 3.5-nm, a wash, and a 0.14 M KCl complex. Thus, there is a common receptor for both DPH and DEX. This receptor has two properties which distinguish it from the 5.4-nm DEX-specific receptor: (i) it binds with a variety of steroids other than glucocorticoids and DPH, and (ii) it rebinds new [3H]DEX or [3H]DPH after loss of ligand during chromatographic separation. These results indicate that DPH binds to receptor IB and not to receptor II of Litwack. [G. Litwack, 1976, in Glutathion: Metabolism and Function (Arias, I.M., and Jakoby, W.B., eds.), pp. 285-299, Raven Press, New York]. We have also found that hepatoma G2 cells have only receptor II. DPH affects neither the induction of tyrosine aminotransferase by DEX nor the basal level of this enzyme in these cells. Moreover, neither DEX nor DPH inhibits the release of [3H]arachidonic acid prelabeled in these cells, as they do in thymocytes which have the common receptor. Thus, it appears that glucocorticoid receptor IB binds DEX and DPH as glucocorticoid agonists mediating the anti-inflammatory and teratogenic action of these drugs, while receptor II apparently is responsible for the induction of tyrosine aminotransferase by DEX.
我们使用[3H]地塞米松（DEX）和[3H]苯妥英（DPH）作为配体，通过两种柱色谱系统研究了雌性A/J和CD-1小鼠以及肝癌G2细胞的肺和胸腺胞质溶胶中的糖皮质激素受体复合物。在每个系统中分离出三种可被DNA纤维素吸附的[3H]DEX受体复合物。分子筛分离出了7纳米、5.4纳米和3.5纳米的复合物（斯托克斯半径），DEAE-葡聚糖A-50柱色谱通过KCl梯度洗脱，得到一种在洗脱液中洗脱的复合物、一种在0.14M KCl时洗脱的复合物和一种在0.20M KCl时洗脱的复合物。DPH可阻断7纳米、3.5纳米、洗脱液中和0.14M KCl的[3H]DEX复合物的结合。在每个系统中仅获得两种可被DNA纤维素吸附的[3H]DPH复合物，每种均被DEX阻断：一种7纳米和一种3.5纳米的复合物、一种洗脱液中的复合物和一种0.14M KCl的复合物。因此，DPH和DEX有共同的受体。该受体有两个特性使其与5.4纳米的DEX特异性受体不同：（i）它能与除糖皮质激素和DPH之外的多种类固醇结合，（ii）在色谱分离过程中配体丢失后，它能重新结合新的[3H]DEX或[3H]DPH。这些结果表明DPH与Litwack的受体IB结合，而不与受体II结合。[G. Litwack，1976，《谷胱甘肽：代谢与功能》（Arias，I.M.和Jakoby，W.B.编），第285 - 299页，Raven出版社，纽约]。我们还发现肝癌G2细胞只有受体II。DPH既不影响DEX对酪氨酸转氨酶的诱导作用，也不影响这些细胞中该酶的基础水平。此外，DEX和DPH均不抑制这些细胞中预先标记的[3H]花生四烯酸的释放，而它们在具有共同受体的胸腺细胞中则有此作用。因此，糖皮质激素受体IB似乎作为糖皮质激素激动剂结合DEX和DPH，介导这些药物的抗炎和致畸作用，而受体II显然负责DEX诱导酪氨酸转氨酶的作用。
