Krzymowski T, Stefańczyk-Krzymowska S
Department of Local Physiological Regulations, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland.
Reprod Domest Anim. 2008 Feb;43(1):80-91. doi: 10.1111/j.1439-0531.2007.00859.x.
A critical analysis of the results of research in the function of the endometrium was carried out and a view point presented. The role of the endometrium in endocrine regulation of the oestrus cycle can be summarized as follows: 1. The transfer of prostaglandin F(2alpha) (PGF(2alpha)) from the uterus to an ovary, which causes luteolysis, occurs mainly via the lymphatic pathways. 2. The system of retrograde transfer of PGs enables PGF(2alpha) and PGE(2) to reach the myometrium and endometrium with arterial blood at high concentration. In the luteal phase, PGF(2alpha), together with the increasing concentration of progesterone, constricts the arterial vessels of the uterus; in the follicular phase and in early pregnancy, PGE(2) together with oestrogen and embryonic signals, relaxes the arterial vessels. In addition, this system protects the corpus luteum from premature luteolysis during the cycle and luteolysis during early pregnancy. 3. In days 10-12 of the cycle, the blood flow in the uterus decreases by 60-70% in pigs and around 90% in sheep. This causes ischaemia and local hypoxia confirmed by the presence of hypoxia inducible factor and thus remodelling of the endometrium commences. 4. The pulsatile elevations in PGF(2alpha) concentration occurring in the blood flowing out of the uterus during the period of luteolysis and the next few days, do not result from increased PGF(2alpha) synthesis as suggested in numerous studies. They are the effect of excretion of PGF(2alpha) and its metabolites together with lymph and venous blood and tissue fluids in which prostaglandin accumulates.
对子宫内膜功能的研究结果进行了批判性分析并提出了一种观点。子宫内膜在发情周期内分泌调节中的作用可总结如下：1. 前列腺素F(2α)（PGF(2α)）从子宫向卵巢的转移导致黄体溶解，主要通过淋巴途径发生。2. 前列腺素逆行转运系统使PGF(2α)和PGE(2)能够以高浓度随动脉血到达子宫肌层和子宫内膜。在黄体期，PGF(2α)与孕酮浓度的增加一起，使子宫动脉血管收缩；在卵泡期和妊娠早期，PGE(2)与雌激素和胚胎信号一起，使动脉血管舒张。此外，该系统在周期中保护黄体免于过早黄体溶解，并在妊娠早期防止黄体溶解。3. 在周期的第10 - 12天，猪子宫的血流量减少60 - 70%，绵羊减少约90%。这导致缺血和局部缺氧，缺氧诱导因子的存在证实了这一点，从而开始子宫内膜重塑。4. 在黄体溶解期及随后几天，从子宫流出的血液中PGF(2α)浓度的脉动性升高，并非如众多研究所表明的那样是由于PGF(2α)合成增加所致。它们是PGF(2α)及其代谢产物与淋巴、静脉血和组织液一起排泄的结果，前列腺素在这些液体中积累。
