Jefferson W N, Padilla-Banks E, Newbold R R
Developmental Endocrinology Section, Laboratory of Toxicology, Environmental Toxicology Program, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, NC 27709, USA.
Reprod Toxicol. 2000 Mar-Apr;14(2):103-10. doi: 10.1016/s0890-6238(00)00061-7.
To identify lactoferrin (LF) and determine its estrogen-responsiveness in the rat uterus, immature Sprague-Dawley rats were untreated or subcutaneously injected with 17beta-estradiol (500 microg/kg) for 3 days and uterine tissues collected. Outbred immature CD-1 mice, treated with 17beta-estradiol, provided the positive control. By using a polyclonal antibody raised against mouse LF, minimal detectable protein was immunolocalized in uterine epithelial cells of untreated immature rats and mice. After estrogen treatment, LF was localized in all uterine epithelial cells of both species, although staining was more intense in mice than rats. In mice, LF was evenly distributed throughout the cytoplasm with intense staining in some cells, while in rats, it was seen mainly in the apical cytoplasm. For comparison to another well-known estrogen responsive protein in rats, complement C3 was immunolocalized within epithelial cells and it showed a different staining pattern than LF. Uterine tissue homogenates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blots showed cross-reactivity with the mouse LF antibody. These findings indicate that LF is present in the rat uterus, and is induced by estrogens as reported in other species. Thus, LF is an important marker of estrogenic activity across species and will, therefore, have utility in screening for effects of environmental estrogenic compounds.
为了鉴定乳铁蛋白（LF）并确定其在大鼠子宫中的雌激素反应性，对未成熟的斯普拉格-道利大鼠不进行处理或皮下注射17β-雌二醇（500微克/千克），持续3天，然后收集子宫组织。用17β-雌二醇处理的远交系未成熟CD-1小鼠作为阳性对照。通过使用针对小鼠LF产生的多克隆抗体，在未处理的未成熟大鼠和小鼠的子宫上皮细胞中免疫定位到了最低可检测蛋白。雌激素处理后，LF定位在两种动物的所有子宫上皮细胞中，不过小鼠中的染色比大鼠中的更强烈。在小鼠中，LF均匀分布于整个细胞质中，一些细胞染色强烈，而在大鼠中，它主要见于顶端细胞质中。为了与大鼠中另一种著名的雌激素反应蛋白进行比较，补体C3在子宫上皮细胞内进行了免疫定位，其染色模式与LF不同。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳对子宫组织匀浆进行分析，蛋白质印迹显示与小鼠LF抗体有交叉反应。这些发现表明LF存在于大鼠子宫中，并且如在其他物种中所报道的那样由雌激素诱导产生。因此，LF是跨物种雌激素活性的重要标志物，因此将可用于筛选环境雌激素化合物的作用。
