Embryonic steroids and the establishment of pregnancy in pigs.
Embryonic steroids and the establishment of pregnancy in pigs.
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DOI：
10.1530/biosciprocs.13.0021
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发表时间：
2020-10
期刊：
影响因子：
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通讯作者：
R. Geisert;M. T. Zavy;R. Moffatt;R. Blair;T. Yellin
中科院分区：
文献类型：
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作者：
R. Geisert;M. T. Zavy;R. Moffatt;R. Blair;T. Yellin
在猪中，在发情开始后约11-12天开始妊娠。在此期间，猪孕体合成和释放雌激素的能力，以及在发情周期第11-15天给予外源性雌激素诱导假妊娠的能力，为雌激素参与母猪妊娠的母体识别提供了证据。第11-12天，来自孕体或来自周期性后备母猪给药的雌激素刺激子宫分泌钙和特定多肽。子宫对雌激素的分泌反应在维持妊娠中的具体作用尚不清楚。然而，已经提出雌激素通过子宫内膜前列腺素释放的重新定向，即进入子宫腔而不是进入子宫脉管系统来防止母猪的黄体溶解。雌激素可能与催乳素和/或孕体分泌蛋白相互作用，改变前列腺素运动的方向。虽然孕体雌激素合成在第11天触发了许多子宫分泌事件，但从第14天至第18天的第二个持续阶段的雌激素刺激似乎是第25天以后维持黄体所必需的。猪的孕体在妊娠的第14天至第18天之间合成并释放大量雌激素。孕体雌激素显然与妊娠的建立有关。然而，孕体也分泌许多生物活性物质，如儿茶酚雌激素、甘草素和多肽，它们可以与雌激素相互作用以防止黄体溶解。这些因素在控制血管通透性、血流、胎盘附着和免疫保护中的作用无疑表明，除了雌激素外，其他因素也参与了猪妊娠的建立。
In the pig, establishment of pregnancy begins about 11-12 days after the start of oestrus. The ability of pig conceptuses to synthesize and release oestrogens during this period, as well as the ability of exogenous oestrogens to induce pseudo-pregnancy when administered from Day 11-15 of the oestrous cycle, provide evidence for an involvement of oestrogen in the maternal recognition of pregnancy in the sow. Oestrogen derived from the conceptus or from administration to cyclic gilts stimulates uterine secretion of calcium and specific polypeptides on Day 11-12. The specific roles for the uterine secretory response to oestrogen in the maintenance of pregnancy are unknown. However, it has been proposed that oestrogen prevents luteolysis in the sow through reorientation of endometrial prostaglandin release, i.e. into the uterine lumen rather than into the uterine vasculature. Oestrogen may interact with prolactin and/or conceptus secretory proteins to shift the direction of prostaglandin movement. Although conceptus oestrogen synthesis triggers a number of uterine secretory events on Day 11, a second sustained phase of oestrogen stimulation from Day 14 to 18 appears to be necessary for luteal maintenance beyond Day 25. Pig conceptuses synthesize and release large amounts of oestrogens between Days 14 and 18 of pregnancy. Conceptus oestrogens are clearly involved with the establishment of pregnancy. However, the conceptus also secretes a number of biologically active substances such as catechol oestrogens, prostaglandins and polypeptides which could interact with oestrogen to prevent luteolysis. The roles of these factors in control of vascular permeability, blood flow, placental attachment and immunological protection certainly indicate that, in addition to oestrogens, other factors are involved in the establishment of pregnancy in pigs.