MacNab M W, Tallarida R J, Joseph R
Eur J Pharmacol. 1984 Aug 17;103(3-4):321-6. doi: 10.1016/0014-2999(84)90493-x.
Tamoxifen is known to have both agonist and antagonist properties. Classical receptor theory predicts that given the relative concentrations of a partial agonist and full agonist acting on the same receptor, the partial agonist may reduce the effect of the full agonist. The immature rat uterine model is an excellent system to evaluate the interactions of estradiol and tamoxifen by application of receptor theory. Using this model, tamoxifen demonstrates both additive and antagonistic effects to estradiol in the fashion predicted by theory. The effects of tamoxifen are additive at low doses of estradiol and antagonistic over higher estradiol doses. It is possible that the dualism of agonism and antagonism seen in other target organs and species is a function of these basic characteristics of a partial agonist.
已知他莫昔芬具有激动剂和拮抗剂的双重特性。经典受体理论预测，在作用于同一受体的部分激动剂和完全激动剂相对浓度一定的情况下，部分激动剂可能会降低完全激动剂的效应。未成熟大鼠子宫模型是通过应用受体理论来评估雌二醇与他莫昔芬相互作用的极佳系统。利用该模型，他莫昔芬对雌二醇表现出理论所预测的相加和拮抗作用。他莫昔芬在低剂量雌二醇时表现为相加效应，而在高剂量雌二醇时则表现为拮抗效应。在其他靶器官和物种中观察到的激动和拮抗双重作用可能是部分激动剂这些基本特性的一种表现。
