Haslam S Z
Physiology Department, Michigan State University, East Lansing 48824.
Endocrinology. 1989 Nov;125(5):2766-72. doi: 10.1210/endo-125-5-2766.
An investigation was carried out to define the ontogeny of normal mouse mammary gland responsiveness to the proliferative effects of estrogen (E) and/or progesterone (P). Since hormone receptors for both estrogen (ER) and progesterone (PgR) are present in both epithelial and stromal cells, we have investigated how the effects of E and P are related to the presence of receptor activity in the epithelium and stroma. Intact or ovariectomized mice, between 3 days and 10 weeks of age, were used to study the effects of E and/or P on DNA synthesis, as determined by DNA histoautoradiography; the cellular distribution of ER and PgR was investigated by steroid autoradiography. The results indicate that the mammary gland sequentially acquires the ability to respond to the stimulatory effects of E and/or P. In the early postnatal period (3-14 days) neither hormone was effective. Both epithelial and stromal cells first became responsive to E at 3-4 weeks of age. Estrogen receptors were first detected in stromal cells at 5 days of age and in epithelial cells at 2 weeks of age. Thus, the acquisition of estrogen responsiveness did not appear to be tightly coupled to the presence of ER in either epithelial or stromal cells. In contrast, responsiveness to P was acquired significantly later, at 7 weeks of age, and was closely linked to the presence of E-inducible PgR in epithelial cells. P caused a highly synergistic effect on epithelial cell DNA synthesis when combined with E, providing further support for the concept that the major proliferative effect of P is mediated via E-inducible PgR. PgR were also present in stromal cells, but the proliferative effect of P in that cell type was not correlated with the presence of PgR.
开展了一项研究以确定正常小鼠乳腺对雌激素（E）和/或孕激素（P）增殖作用的个体发育情况。由于雌激素（ER）和孕激素（PgR）的激素受体存在于上皮细胞和基质细胞中，我们研究了E和P的作用如何与上皮和基质中受体活性的存在相关。使用3天至10周龄的完整或去卵巢小鼠来研究E和/或P对DNA合成的影响（通过DNA组织放射自显影术测定）；通过类固醇放射自显影术研究ER和PgR的细胞分布。结果表明，乳腺依次获得对E和/或P刺激作用的反应能力。在出生后早期（3 - 14天），两种激素均无效。上皮细胞和基质细胞在3 - 4周龄时首次对E产生反应。雌激素受体在5日龄时首次在基质细胞中检测到，在2周龄时在上皮细胞中检测到。因此，雌激素反应性的获得似乎与上皮或基质细胞中ER的存在没有紧密联系。相比之下，对P的反应性在7周龄时显著延迟获得，并且与上皮细胞中E诱导的PgR的存在密切相关。当与E联合使用时，P对上皮细胞DNA合成产生高度协同作用，进一步支持了P的主要增殖作用是通过E诱导的PgR介导的这一概念。PgR也存在于基质细胞中，但P在该细胞类型中的增殖作用与PgR的存在无关。
