Sprangers S A, Fahrenbach W H, Bethea C L
Division of Reproductive Biology, Oregon Regional Primate Research Center, Beaverton 97006.
Endocrinology. 1991 Apr;128(4):1907-17. doi: 10.1210/endo-128-4-1907.
Estradiol (E) treatment of spayed macaques induces progestin receptors (PR) in pituitary gonadotropes, but not lactotropes. In contrast, levels of pituitary estrogen receptors (ER) remain constant in spayed or E-treated monkeys. In monkey pituitary cultures, the number of PR-positive cells varies depending on the donor status, whereas the percentage of ER-positive cells in similar. We sought to determine whether E can directly induce PR in monkey pituitary gonadotropes in culture and to provide further evidence that monkey pituitary ER are constitutively expressed. Dispersed pituitary cells from intact or gonadectomized male and female macaques were cultured on extracellular matrix with and without E, phenol red, high or low insulin, insulin-like growth factor-I, or 5% ovariectomized monkey serum, ER- and PR-positive parenchymal cells were immunohistochemically detected with monoclonal antibodies H222 and D75 (against human ER) and B39 (against human PR). ER levels were also measured with a gradient shift assay incorporating H222. Neither the percentage of ER-positive cells nor the levels of nuclear ER were altered by donor status or by 8 days of culture in phenol red or E. In contrast, cultures from gonad-intact donors exhibited the highest average percentage of PR-positive cells. The lower number of PR-positive cells in cultures from spayed donors did not vary for 8 days on extracellular matrix without phenol red, E, insulin, or serum. E directly increased the percentage of PR-expressing cells in serum-free cultures. Addition of serum also increased the percentage of PR-positive cells. Addition of E to serum-containing cultures further increased the percentage of PR-positive cells. Neither insulin nor insulin-like growth factor-I directly affected the number of PR-positive cells, but a high level of insulin blunted the action of E on PR induction in serum-free culture. We conclude that E treatment has no obvious effect on ER expression in macaque pituitary. However, the induction of pituitary PR by E treatment of spayed monkeys can be accounted for by a direct action of E on PR gene expression in gonadotropes.
对切除卵巢的猕猴进行雌二醇（E）治疗可诱导垂体促性腺细胞中的孕激素受体（PR）生成，但不会诱导催乳细胞生成。相比之下，在切除卵巢或接受E治疗的猴子中，垂体雌激素受体（ER）水平保持恒定。在猴垂体培养物中，PR阳性细胞的数量因供体状态而异，而ER阳性细胞的百分比相似。我们试图确定E是否能在培养的猴垂体促性腺细胞中直接诱导PR生成，并提供进一步证据证明猴垂体ER是组成性表达的。将来自完整或去势的雄性和雌性猕猴的分散垂体细胞在含有或不含有E、酚红、高或低胰岛素、胰岛素样生长因子-I或5%去卵巢猴血清的细胞外基质上培养，用单克隆抗体H222和D75（针对人ER）以及B39（针对人PR）免疫组织化学检测ER和PR阳性实质细胞。还使用结合H222的梯度迁移试验测量ER水平。ER阳性细胞的百分比和核ER水平均未因供体状态或在酚红或E中培养8天而改变。相比之下，来自性腺完整供体的培养物中PR阳性细胞的平均百分比最高。在不含酚红、E、胰岛素或血清的细胞外基质上培养8天，来自切除卵巢供体的培养物中PR阳性细胞数量较少的情况没有变化。E直接增加了无血清培养物中表达PR的细胞百分比。添加血清也增加了PR阳性细胞的百分比。向含血清的培养物中添加E进一步增加了PR阳性细胞的百分比。胰岛素和胰岛素样生长因子-I均未直接影响PR阳性细胞的数量，但高浓度胰岛素减弱了E在无血清培养中对PR诱导的作用。我们得出结论，E治疗对猕猴垂体中的ER表达没有明显影响。然而，对切除卵巢的猴子进行E治疗诱导垂体PR生成可归因于E对促性腺细胞中PR基因表达的直接作用。
