Sukjumlong S, Persson E, Kaeoket K, Dalin A-M
Department of Anatomy and Physiology, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences (SLU) Uppsala, Sweden.
Reprod Domest Anim. 2004 Oct;39(5):361-9. doi: 10.1111/j.1439-0531.2004.00529.x.
Oestrogen receptor alpha (ERalpha), the main subtype in the uterus, is involved in the regulation of uterine growth/proliferation. A relationship between ERalpha and proliferative activity has been shown in the cyclic sow uterus, but to our knowledge, no study has been carried out on early pregnant sows. Therefore, by means of immunohistochemistry and use of mouse monoclonal antibodies to ERalpha and a proliferative marker, Ki-67, the localization of these proteins was investigated in the sow uterus during early pregnancy. Eighteen crossbred multiparous sows were artificially inseminated once at 20-15 h before expected ovulation. After artificial insemination (AI), they were slaughtered at five different times: at oestrus, 5-6 h after AI (n = 4), 20-25 h after ovulation (n =4), 70 h after ovulation (n = 4), on day 11 (the first day of standing oestrus = day 1, n = 3) and on day 19 (n = 3). Immediately after slaughter, uterine samples were collected at the mesometrial side of the uteri, fixed in 10% formaldehyde and embedded in paraffin. Immunohistochemistry was performed by using mouse monoclonal antibodies to ERalpha (C-311) and Ki-67 (MM1). All sows slaughtered after ovulation were pregnant. In general, positive immunostaining for ERalpha and Ki-67 was found in the nuclei. Variations in staining intensity and proportion of positive nuclei were observed in different uterine compartments and stages of early pregnancy. The highest level of ERalpha presence in the surface epithelium and myometrium was found at oestrus (5-6 h after AI), and low levels of ERalpha in these compartments were observed as early as 20-25 h after ovulation. In the glandular epithelia, presence of ERalpha was highest at 70 h after ovulation. The largest number of ERalpha-positive cells in the stroma was observed at oestrus and early after ovulation. Low proliferation was observed, and with no significant difference in tissue compartments except in the glandular epithelium. High proliferative activity in the glandular epithelium at 70 h after ovulation indicated involvement in preparation for secretory activity and growth during pregnancy establishment. Significant positive correlation was found between the number of ERalpha-positive cells in the stroma and Ki-67-positive cells in the surface epithelium. In conclusion, the present study showed differences in immunolocalization of ERalpha and the proliferative marker Ki-67 in different tissue compartments of the sow uterus at oestrus and early pregnancy. In some uterine compartments, the patterns of ERalpha and Ki-67 immunostaining seemed to be influenced by insemination and the presence of embryos, in addition to the effects of steroid hormones.
雌激素受体α（ERα）是子宫中的主要亚型，参与子宫生长/增殖的调节。在发情周期的母猪子宫中已显示出ERα与增殖活性之间的关系，但据我们所知，尚未对早孕母猪进行研究。因此，通过免疫组织化学方法，使用针对ERα和增殖标记物Ki-67的小鼠单克隆抗体，研究了早孕期间母猪子宫中这些蛋白质的定位。18头经产杂交母猪在预期排卵前20 - 15小时人工授精一次。人工授精（AI）后，在五个不同时间屠宰母猪：发情期、AI后5 - 6小时（n = 4）、排卵后20 - 25小时（n = 4）、排卵后70小时（n = 4）、第11天（站立发情第一天 = 第1天，n = 3）和第19天（n = 3）。屠宰后立即从子宫的子宫系膜侧采集子宫样本，固定在10%甲醛中并石蜡包埋。使用针对ERα（C - 311）和Ki - 67（MM1）的小鼠单克隆抗体进行免疫组织化学检测。所有排卵后屠宰的母猪均已怀孕。总体而言，在细胞核中发现了ERα和Ki - 67的阳性免疫染色。在早孕的不同子宫区域和阶段观察到染色强度和阳性细胞核比例的变化。在发情期（AI后5 - 6小时），表面上皮和肌层中ERα的存在水平最高，早在排卵后20 - 25小时，这些区域的ERα水平就较低。在腺上皮中，排卵后70小时ERα的存在水平最高。在发情期和排卵后早期，基质中ERα阳性细胞数量最多。观察到增殖水平较低，除腺上皮外，各组织区域无显著差异。排卵后70小时腺上皮中的高增殖活性表明其参与了妊娠建立期间的分泌活动准备和生长过程。在基质中ERα阳性细胞数量与表面上皮中Ki - 67阳性细胞数量之间发现显著正相关。总之，本研究显示了发情期和早孕期间母猪子宫不同组织区域中ERα和增殖标记物Ki - 67免疫定位的差异。在一些子宫区域，除了类固醇激素的影响外，ERα和Ki - 67免疫染色模式似乎还受人工授精和胚胎存在的影响。
