Geisert R D, Pratt T N, Bazer F W, Mayes J S, Watson G H
Department of Animal Science, Oklahoma State University, Stillwater 74078, USA.
Reprod Fertil Dev. 1994;6(6):749-60. doi: 10.1071/rd9940749.
Changes of progesterone receptor (PR) protein and cellular localization in the endometrium were evaluated during the oestrous cycle and early pregnancy of the gilt. During the oestrous cycle, the concentration of total PR protein within the endometrium was highest on Days 0-5 and decreased on Day 10. The endometrial concentration of PR reached a nadir on Day 12 and this level was maintained throughout the remainder of the oestrous cycle (Day 18). In pregnant gilts, the concentration of endometrial PR protein from Day 10 to Day 18 was similar to that in cyclic gilts. Western blot analysis with antiserum specific for the A and B isoforms of PR indicated that porcine endometrium expresses both isoforms of PR. Immunostaining was detectable for both the A and B isoforms of PR from Day 0 to Day 12 of the oestrous cycle. However, no staining was observed on Day 15 and Day 18 of the oestrous cycle or pregnancy Immunocytochemical localization of PR in the endometrium of cyclic gilts and pregnant gilts indicated that there was intense staining for PR in surface epithelium and glandular epithelium during oestrus (Day 0) and on Day 5. However, the staining was less intense on Day 7 and Day 10 of the oestrous cycle and no epithelial staining was observed after Day 12. PRs were present in the stroma and myometrium throughout the oestrous cycle and early pregnancy. The presence of conceptuses during pregnancy did not affect the loss of PR from the uterine epithelium after Day 10 of gestation. Down-regulation of epithelial PR might be one factor involved in the timing of luteolysis during the oestrous cycle as well as conceptus growth and placentation during early pregnancy.
在后备母猪的发情周期和妊娠早期，对子宫内膜中孕酮受体（PR）蛋白及细胞定位的变化进行了评估。在发情周期中，子宫内膜内总PR蛋白浓度在第0至5天最高，在第10天下降。PR的子宫内膜浓度在第12天降至最低点，并在发情周期的其余时间（第18天）维持该水平。在妊娠后备母猪中，从第10天到第18天，子宫内膜PR蛋白浓度与发情周期的后备母猪相似。用针对PR A和B亚型的抗血清进行的蛋白质印迹分析表明，猪子宫内膜表达PR的两种亚型。在发情周期的第0天到第12天，PR的A和B亚型均能检测到免疫染色。然而，在发情周期的第15天和第18天或妊娠期未观察到染色。对发情周期和妊娠后备母猪子宫内膜中PR的免疫细胞化学定位表明，在发情期（第0天）和第5天，表面上皮和腺上皮中PR有强烈染色。然而，在发情周期的第7天和第10天染色较弱，在第12天后未观察到上皮染色。在整个发情周期和妊娠早期，PR存在于基质和子宫肌层中。妊娠期着床的存在并不影响妊娠第10天后子宫上皮中PR的丢失。发情周期中黄体溶解的时间以及妊娠早期着床的生长和胎盘形成，上皮PR的下调可能是其中一个因素。
