Estetrol (hydrate)

种雌激素类类固醇激素，主要由胎儿肝脏在怀孕期间从雌二醇和雌三醇中合成；与雌激素受体α（ERα）的亲和力是雌激素受体β（ERβ）的四倍；在骨骼、大脑、阴道和子宫内膜中表现出雌激素效应；在雌二醇存在时作为雌激素拮抗剂，防止乳腺肿瘤生长。An estrogen steroid hormone exclusively produced by fetal liver from estradiol and estriol during pregnancy; binds ERα with 4-fold higher affinity for over ERβ; exhibits estrogenic effects in bone, brain, vagina, and endometrium; acts as an estrogen antagonist in the presence of estradiol, preventing breast tumor growth.