Müller R E, Wotiz H H
Endocrinology. 1977 Feb;100(2):513-9. doi: 10.1210/endo-100-2-513.
Estradiol, estradiol-16alpha, estriol and a series of positional isomers of estriol were tested for their post-coital contraceptive activity, and their ability to compete with estradiol for the cytosolic estrogen receptor protein of rat uteri. Estrogenicity was determined for each compound in immature rats with single injections and in mature castrated rats by injecting the lowest fully contraceptive dose for four consecutive days. All compounds were active anti-implantational agents, varying in required dosage from 4 mug to 2000 mug (total dosage over 4 days). The rank order or contraceptive activity was found to be: estradiol greater than estriol = epiestriol greater than 11beta - (OH) - estradiol greater than estradiol - 16alpha greater than 7alpha-(OH)-estradiol greater than 6beta-(OH)-estradiol, while the order of estrogenicity at levels of contraceptive activity in the ovariectomized mature rat was: epiestriol = estriol less than 7 alpha - (OH) - estradiol less than estradiol - 16alpha less than 6beta - (OH) - estradiol = 11beta - (OH)- estradiol less than estradiol-17beta. Reasonably good correlation between competition for estrogen receptor and anti-implantational activity was observed. The most active binding competitors were estradiol-16alpha, epiestriol, and estriol which showed an affinity from 50-20% that of estradiol, while the other compounds had 3% or less binding competition for estradiol.
对雌二醇、16α-雌二醇、雌三醇以及一系列雌三醇的位置异构体进行了它们的性交后避孕活性测试，以及它们与雌二醇竞争大鼠子宫胞质雌激素受体蛋白的能力测试。通过对未成熟大鼠单次注射以及对成熟去势大鼠连续四天注射最低完全避孕剂量，来测定每种化合物的雌激素活性。所有化合物均为有效的抗着床剂，所需剂量从4微克到2000微克不等（4天的总剂量）。发现避孕活性的排序为：雌二醇＞雌三醇=表雌三醇＞11β-(OH)-雌二醇＞16α-雌二醇＞7α-(OH)-雌二醇＞6β-(OH)-雌二醇，而在去卵巢成熟大鼠中，避孕活性水平下的雌激素活性顺序为：表雌三醇=雌三醇＜7α-(OH)-雌二醇＜16α-雌二醇＜6β-(OH)-雌二醇=11β-(OH)-雌二醇＜17β-雌二醇。观察到雌激素受体竞争与抗着床活性之间有较好的相关性。最具活性的结合竞争者是16α-雌二醇、表雌三醇和雌三醇，它们显示出的亲和力为雌二醇的50%-20%，而其他化合物对雌二醇的结合竞争为3%或更低。
