Haslam S Z
Anatomy Department, Michigan State University, East Lansing 48824.
J Steroid Biochem. 1988 Jul;31(1):9-13. doi: 10.1016/0022-4731(88)90199-9.
Progesterone is known to stimulate cell proliferation of normal and neoplastic rodent mammary tissues. Recently we have observed that while progesterone is highly effective in sexually mature mice, no significant effect of progesterone can be demonstrated in immature, pubertal mammary gland. In the case of the adult gland, the mitogenic effects of progesterone appear to be related to the presence of E-dependent progesterone receptors (PgR). By contrast, immature mammary glands lack E-dependent PgR. The purpose of the present studies was to study the ontogeny of E-dependent PgR and the factors that lead to the acquisition of responsiveness to progesterone. The results obtained demonstrate that E-dependent PgR are first detectable at 7 weeks of age. Analysis of changes occurring in the mammary gland around this time indicate that E-dependent PgR are not acquired until the pubertal mammary epithelial growth phase has occurred. Furthermore both the growth phase and acquisition of PgR are dependent upon the presence of the ovaries. Analysis of concentration and subcellular distribution of both PgR and estrogen receptors indicate that there are no differences between pubertal and adult mice that could account for the absence of this estrogenic response and lack of E-dependent PgR in immature mammary gland.
已知孕酮可刺激正常和肿瘤性啮齿动物乳腺组织的细胞增殖。最近我们观察到，虽然孕酮在性成熟小鼠中非常有效，但在未成熟的青春期乳腺中，孕酮没有明显作用。对于成年腺体，孕酮的促有丝分裂作用似乎与雌激素依赖性孕酮受体（PgR）的存在有关。相比之下，未成熟的乳腺缺乏雌激素依赖性PgR。本研究的目的是研究雌激素依赖性PgR的个体发生以及导致获得对孕酮反应性的因素。获得的结果表明，雌激素依赖性PgR在7周龄时首次可检测到。对此时乳腺中发生的变化进行分析表明，直到青春期乳腺上皮生长阶段出现，才获得雌激素依赖性PgR。此外，生长阶段和PgR的获得均依赖于卵巢的存在。对PgR和雌激素受体的浓度及亚细胞分布进行分析表明，青春期小鼠和成年小鼠之间没有差异可以解释未成熟乳腺中这种雌激素反应的缺失和雌激素依赖性PgR的缺乏。
