Okada Akinobu, Ohta Yasuhiko, Buchanan David, Sato Tomomi, Iguchi Taisen
Safety Research Laboratories, Yamanouchi Pharmaceutical Co Ltd, Tokyo, Japan.
Mol Cell Endocrinol. 2002 Sep 30;195(1-2):55-64. doi: 10.1016/s0303-7207(02)00211-3.
Ontogenetic expression of progesterone receptor (PR) and effect of estrogens on PR expression in the fetal female rat reproductive tract were investigated. To evaluate ontogenetic PR expression, female reproductive tract from untreated fetuses was examined on gestational days (GD) 15.5, 17.5, 19.5 and 21.5. To evaluate estrogen effects, pregnant rats were injected once per day with oil, 17beta-estradiol (E(2)) or diethylstilbestrol (DES) from GD 15 through 21. Female fetuses were prepared for real-time reverse-transcription polymerase chain reaction (RT-PCR) or immunohistochemistry for PR. Increase in PR mRNA expression was detected in the Müllerian duct on GD 21.5 compared to that on GDs 15.5 and 17.5 in untreated fetuses (P<0.05). Prenatal administration of E(2) or DES increased Müllerian PR mRNA levels by GD 21.5 compared with oil controls (P<0.01). To identify cell and region in which PR was expressed and up-regulated by E(2) and DES, localization was evaluated within three regions along the Müllerian duct axis which differentiate into oviduct, uterus and upper vagina in immunohistochemistry. In untreated fetuses, Müllerian epithelial PR immunoreactivity was weak on GDs 15.5 and 17.5, but then became moderate on GDs 19.5 and 21.5 in all three regions. These fetuses exhibited faint signals in Müllerian mesenchymal PR immunoreactivity during gestational monitoring. Critically, Müllerian mesenchymal PR staining became intense after E(2) exposure in all three regions by GD 21.5, but no change was observed in Müllerian epithelial PR. Similarly, DES dramatically induced Müllerian mesenchymal PR in all regions by GD 21.5, and also enhanced proximal epithelial PR. On the other hand, middle and caudal epithelial PRs were reduced by DES. These affected mesenchymal and epithelial cells by DES were ER alpha immunopositive in the Müllerian duct, except for middle Müllerian epithelium. These findings clearly demonstrate cell-specific PR localization and region-specific effect of DES on PR in the developing rat Müllerian duct, and provide fundamental information critical for investigating the tissue-specific mechanisms underlying the prenatal response to estrogen receptor agonists.
研究了孕激素受体（PR）的个体发育表达以及雌激素对胎鼠雌性生殖道PR表达的影响。为评估PR的个体发育表达，在妊娠第15.5、17.5、19.5和21.5天检查未处理胎儿的雌性生殖道。为评估雌激素的作用，从妊娠第15天至21天，每天给孕鼠注射一次油、17β-雌二醇（E₂）或己烯雌酚（DES）。对雌性胎儿进行实时逆转录聚合酶链反应（RT-PCR）或PR免疫组织化学检测。与未处理胎儿妊娠第15.5天和17.5天相比，妊娠第21.5天苗勒管中PR mRNA表达增加（P<0.05）。与油剂对照相比，产前给予E₂或DES可使妊娠第21.5天苗勒管PR mRNA水平升高（P<0.01）。为确定PR表达及被E₂和DES上调的细胞和区域，在免疫组织化学中沿苗勒管轴的三个区域评估定位，这三个区域分别分化为输卵管、子宫和上阴道。在未处理胎儿中，苗勒管上皮PR免疫反应性在妊娠第15.5天和17.5天较弱，但在所有三个区域的妊娠第19.5天和21.5天变为中等强度。在妊娠监测期间，这些胎儿的苗勒管间充质PR免疫反应性呈微弱信号。至关重要的是，到妊娠第21.5天，E₂暴露后所有三个区域的苗勒管间充质PR染色均变强，但苗勒管上皮PR未观察到变化。同样，到妊娠第21.5天，DES显著诱导所有区域的苗勒管间充质PR，并且还增强了近端上皮PR。另一方面，DES使中部和尾部上皮PR降低。DES影响的间充质和上皮细胞在苗勒管中ERα免疫阳性，但中部苗勒管上皮除外。这些发现清楚地证明了发育中大鼠苗勒管中PR的细胞特异性定位以及DES对PR的区域特异性作用，并为研究产前对雌激素受体激动剂反应的组织特异性机制提供了关键的基础信息。
