Gilna P, Martin F
Acta Endocrinol (Copenh). 1986 May;112(1):71-8. doi: 10.1530/acta.0.1120071.
In ovariectomized rats oestradiol and oestriol administered sc for 5 days increased basal plasma prolactin in a dose related manner to similar maximal values. The data fitted log dose-response curves. Oestradiol was about 12 times more potent than oestriol. These dose response relationships were retained on thyrotrophin releasing hormone (TRH) administration (50 ng iv, blood sampled 5 min post TRH). In addition, significantly higher maximal response values for both oestradiol and oestriol were now seen. The relative potency also increased in oestradiols favour. We subsequently examined the effect of co-administering oestriol with oestradiol on plasma secretory responses to a single dose of oestradiol in young male rats: Oestriol (30 micrograms) potentiated increases in basal plasma prolactin, TRH stimulated prolactin secretion and radioimmunoassayable pituitary prolactin in rats in response to a single sc injection of oestradiol (10 micrograms). Tamoxifen, administered once also potentiated these responses to a single sc injection of oestradiol. However, if the tamoxifen was administered sequentially i.e. 48 and 24 h before or 48 and 24 h before and simultaneous with the oestradiol the potentiation was completely reversed.
在去卵巢大鼠中，皮下注射雌二醇和雌三醇5天，基础血浆催乳素以剂量相关的方式增加至相似的最大值。数据符合对数剂量-反应曲线。雌二醇的效力约为雌三醇的12倍。给予促甲状腺激素释放激素（TRH）（静脉注射50 ng，TRH注射后5分钟采血）后，这些剂量反应关系依然存在。此外，现在观察到雌二醇和雌三醇的最大反应值均显著更高。雌二醇的相对效力也增加了。随后，我们研究了在年轻雄性大鼠中，将雌三醇与雌二醇共同给药对单次注射雌二醇后血浆分泌反应的影响：雌三醇（30微克）增强了基础血浆催乳素的升高、TRH刺激的催乳素分泌以及大鼠对单次皮下注射雌二醇（10微克）的放射免疫可测定垂体催乳素。单次给予他莫昔芬也增强了对单次皮下注射雌二醇的这些反应。然而，如果他莫昔芬在雌二醇之前48小时和24小时或之前48小时、24小时以及与雌二醇同时序贯给药，这种增强作用会完全逆转。
