Dupont H, Cayrol C, Deparis P
Centre de Biologie du Développement (CNRS UA 675), Université Paul Sabatier, Toulouse, France.
Gen Comp Endocrinol. 1989 Feb;73(2):217-22. doi: 10.1016/0016-6480(89)90094-4.
The effects of hormonal changes on the male-specific, middle-affinity, estrogen-binding component (MEBC) were investigated in the Pleurodele. Induction of MEBC was shown to be under androgen control, similar to that observed for the cytoplasmic middle-affinity estrogen-binding sites in rat liver and human hepatoma cells. But, in contrast to the male-specific middle-affinity estrogen-binding sites identified in the rat, the administration of estrogen to male Pleurodeles did not lead to the disappearance of MEBC but raised levels significantly. The MEBC displays the properties of type II middle-affinity estrogen-binding sites, which are characterized by an oestrogen-dependent rise, a sensitivity to reducing agents, a specificity for diethylstilbestrol, and a binding capacity enhanced by increasing dilutions of cytosol. In female Pleurodeles, MEBC can be induced by treatment with androgens. This induction appears to be modulated by the estrogen/androgen ratio. The induction of MEBC and the estrogen-dependent increase in the male were not found to be correlated with hepatocyte proliferation.
在肋突螈中研究了激素变化对雄性特异性、中等亲和力雌激素结合成分（MEBC）的影响。结果表明，MEBC的诱导受雄激素控制，这与在大鼠肝脏和人肝癌细胞中观察到的细胞质中等亲和力雌激素结合位点的情况相似。但是，与在大鼠中鉴定出的雄性特异性中等亲和力雌激素结合位点不同，给雄性肋突螈施用雌激素并不会导致MEBC消失，反而会使其水平显著升高。MEBC具有II型中等亲和力雌激素结合位点的特性，其特征为雌激素依赖性升高、对还原剂敏感、对己烯雌酚具有特异性以及通过增加细胞质稀释度而增强结合能力。在雌性肋突螈中，用雄激素处理可诱导MEBC。这种诱导似乎受雌激素/雄激素比例调节。未发现雄性中MEBC的诱导和雌激素依赖性增加与肝细胞增殖相关。
