Zou K, Ing N H
Department of Animal Science, Institute of Biosciences and Technology, Texas A&M University, College Station 77843-2471, USA.
J Steroid Biochem Mol Biol. 1998 Mar;64(5-6):231-7. doi: 10.1016/s0960-0760(97)00194-5.
Oestradiol regulates reproductive physiology and cardiovascular health in women. In the endometrium of ovariectomized ewes, previous work demonstrated that a single dose of oestradiol (50 microg) up-regulates oestrogen receptor-alpha (ER) and progesterone receptor (PR) gene expression within 24 h. Here we compared responses to different doses of oestradiol and different dosing regimens in two diverse tissues: endometrium and liver. ER, c-fos, cyclophilin and glyceraldehyde phosphate dehydrogenase (GAPDH) mRNA concentrations were analyzed on replicate RNA slot blots in both tissues, while PR and apolipoprotein AI (apo AI) mRNA concentrations were only analyzed in endometrium or liver, respectively. Along with ER mRNA, oestradiol strongly up-regulated GAPDH and cyclophilin mRNA concentrations in endometrium. In liver, however, oestradiol down-regulated them, along with apo AI mRNA. Responses to different doses and dose regimens, including repeated 50 microg doses, were similar to those evoked by a single 50 microg dose of oestradiol. Thus, oestradiol appears to have all-or-none effects which include up-regulation of ER, cyclophilin and GAPDH gene expression in endometrium and down-regulation of ER, apo AI, cyclophilin and GAPDH gene expression in liver. These results illustrate the sharp contrast between two mammalian tissues in their responses to physiological levels of oestradiol.
雌二醇调节女性的生殖生理和心血管健康。在去卵巢母羊的子宫内膜中，先前的研究表明，单剂量的雌二醇（50微克）在24小时内上调雌激素受体α（ER）和孕激素受体（PR）基因表达。在此，我们比较了两种不同组织（子宫内膜和肝脏）对不同剂量雌二醇和不同给药方案的反应。在两个组织的重复RNA斑点印迹上分析了ER、c-fos、亲环蛋白和甘油醛-3-磷酸脱氢酶（GAPDH）的mRNA浓度，而PR和载脂蛋白AI（apo AI）的mRNA浓度分别仅在子宫内膜或肝脏中进行分析。与ER mRNA一起，雌二醇强烈上调子宫内膜中GAPDH和亲环蛋白的mRNA浓度。然而，在肝脏中，雌二醇使其下调，同时apo AI mRNA也下调。对不同剂量和给药方案（包括重复50微克剂量）的反应与单次50微克剂量雌二醇所引起的反应相似。因此，雌二醇似乎具有全或无效应，包括上调子宫内膜中ER、亲环蛋白和GAPDH基因表达以及下调肝脏中ER、apo AI、亲环蛋白和GAPDH基因表达。这些结果说明了两种哺乳动物组织对生理水平雌二醇反应的鲜明对比。
