Ford M M, Young I R, Caddy D J, Thorburn G D
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Biol Reprod. 1998 Apr;58(4):1065-70. doi: 10.1095/biolreprod58.4.1065.
We investigated the temporal relationship of fetal cortisol secretion to circulating concentrations of fetal ACTH1-39 and its high-molecular weight precursors in goats. We also measured the concentrations of progesterone, estradiol-17beta estrone sulfate, prostaglandin (PG) E, PGF2alpha, and PGF2alpha metabolite (PGFM) in maternal arterial plasma over the last month of gestation. Prostaglandin concentrations were also measured in utero-ovarian venous plasma. There was a positive association between ACTH1-39 in fetal plasma and the prepartum surge in fetal cortisol that commenced 8 days before labor. The fetal cortisol surge was followed by a simultaneous decrease in maternal progesterone and an increase in plasma estrogens commencing 3-4 days before labor. No change in basal prostaglandin concentration occurred before this time. There was a positive veno-arterial difference of PGE and PGF2alpha across the uterine vascular bed, confirming the uteroplacental unit as a major source of these eicosanoids in the plasma of the pregnant doe. We conclude that the fetal signal for parturition precedes luteolysis by some 5 days and find no evidence of changes in the basal concentrations of PGE and PGF2alpha in maternal plasma at the time of luteolysis.
我们研究了山羊胎儿皮质醇分泌与胎儿促肾上腺皮质激素1 - 39（ACTH1 - 39）及其高分子量前体的循环浓度之间的时间关系。我们还测量了妊娠最后一个月母羊动脉血浆中孕酮、雌二醇 - 17β、硫酸雌酮、前列腺素（PG）E、前列腺素F2α和前列腺素F2α代谢物（PGFM）的浓度。同时也测量了子宫 - 卵巢静脉血浆中的前列腺素浓度。胎儿血浆中的ACTH1 - 39与临产前8天开始的胎儿皮质醇产前激增之间存在正相关。胎儿皮质醇激增之后，母羊孕酮同时下降，血浆雌激素在临产前3 - 4天开始增加。在此之前，基础前列腺素浓度没有变化。子宫血管床中PGE和前列腺素F2α存在正的静脉 - 动脉差异，证实子宫胎盘单位是妊娠母羊血浆中这些类二十烷酸的主要来源。我们得出结论，分娩的胎儿信号比黄体溶解提前约5天，并且在黄体溶解时未发现母羊血浆中PGE和前列腺素F2α基础浓度变化的证据。
