What regulates placental steroidogenesis in 90-day pregnant ewes?

Weems, Y.S.; Kim, Laurie; Tsuda, V.; Yin, Chaoquan; Weems, C.W.

doi:10.1016/j.prostaglandins.2007.04.002

Cited by 11 publications

(8 citation statements)

References 69 publications

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“…An increase in conjugated E 2 in the maternal circulation, supportive of increased aromatization, has been reported in prenatal testosterone-treated monkeys [25]. The progressive increase with advancing pregnancy in maternal E 2 in both control and prenatal testosterone-treated groups is consistent with placental contribution of E 2 [22,23]; in sheep, more than 85% of the E 2 found in maternal circulation at D90 of gestation is of placental origin [43]. In this species, aromatase is expressed throughout gestation, but peaks once around midgestation, and again close to term [23], in contrast to humans and primates, where aromatase is highly expressed throughout gestation [44,45].…”

Section: Maternal Endocrine Milieumentioning

confidence: 57%

Developmental Programming: Impact of Excess Prenatal Testosterone on Intrauterine Fetal Endocrine Milieu and Growth in Sheep1

Veiga-López

Steckler

Abbott

et al. 2011

Biology of Reproduction

106

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Prenatal testosterone excess in sheep leads to reproductive and metabolic disruptions that mimic those seen in women with polycystic ovary syndrome. Comparison of prenatal testosterone-treated sheep with prenatal dihydrotestosterone-treated sheep suggests facilitation of defects by androgenic as well as androgen-independent effects of testosterone. We hypothesized that the disruptive impact of prenatal testosterone on adult pathology may partially depend on its conversion to estrogen and consequent changes in maternal and fetal endocrine environments. Pregnant Suffolk sheep were administered either cottonseed oil (control) or testosterone propionate in cottonseed oil (100 mg, i.m. twice weekly), from Day 30 to Day 90 of gestation (term is ~147 d). Maternal (uterine) and fetal (umbilical) arterial samples were collected at Days 64-66, 87-90, and 139-140 (range; referred to as D65, D90, and D140, respectively) of gestation. Concentrations of gonadal and metabolic hormones, as well as differentiation factors, were measured using liquid chromatography/mass spectrometer, radioimmunoassay, or ELISA. Findings indicate that testosterone treatment produced maternal and fetal testosterone levels comparable to adult males and D65 control male fetuses, respectively. Testosterone treatment increased fetal estradiol and estrone levels during the treatment period in both sexes, supportive of placental aromatization of testosterone. These steroidal changes were followed by a reduction in maternal estradiol levels at term, a reduction in activin A availability, and induction of intrauterine growth restriction in D140 female fetuses. Overall, our findings provide the first direct evidence in support of the potential for both androgenic as well as estrogenic contribution in the development of adult reproductive and metabolic pathology in prenatal testosterone-treated sheep.

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Section: Maternal Endocrine Milieumentioning

confidence: 57%

Developmental Programming: Impact of Excess Prenatal Testosterone on Intrauterine Fetal Endocrine Milieu and Growth in Sheep1

Veiga-López

Steckler

Abbott

et al. 2011

Biology of Reproduction

106

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“…Although factors and mechanisms governing estradiol and progesterone secretion and release are complex during pregnancy, concentrations of these hormones in maternal and fetal blood may partially reflect placental functions, since previous studies have demonstrated that the placenta produces these hormones [15, 16]. Here, both estradiol and progesterone levels were altered by dark deprivation.…”

Section: Discussionmentioning

confidence: 79%

“…In both pregnant women and sheep, plasma estradiol concentrations increase significantly, peaking during late pregnancy [15, 16, 29]. In late pregnancy, estradiol may promote uterine blood flow, stimulate cervical softening at term, and be essential for initiation of labor [19,20,21].…”

Section: Discussionmentioning

confidence: 99%

“…Plasma concentrations of progesterone increase abruptly in the early weeks of pregnancy and remain at high levels throughout pregnancy [15, 16, 29]. Recent studies have suggested that a reduction in progesterone is critical for the initiation of labor [21, 22].…”

Section: Discussionmentioning

confidence: 99%

“…In the absence of pregnancy, estradiol and progesterone are produced in high amounts in mammalian ovaries. In pregnant women and sheep, estradiol and progesterone are increased because of placental secretion [15, 16]. The concentration of estradiol and progesterone in the peripheral plasma of maternal and fetal sheep gradually increases during pregnancy progression [17, 18].…”

mentioning

confidence: 99%

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Disrupting the circadian photo-period alters the release of follicle-stimulating hormone, luteinizing hormone, progesterone, and estradiol in maternal and fetal sheep

Gao

et al. 2016

Journal of Reproduction and Development

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Although a large number of studies show that photo-period disruption potentially affects hormone secretion in mammals, information about the effects of circadian photo-period disruption during pregnancy on fetal blood reproductive hormone levels is scarce. This study used ewes and their fetuses to determine the effects of circadian photo-period disruption (deprivation of darkness) on follicle-stimulating hormone, luteinizing hormone, estradiol, and progesterone in maternal and fetal circulation at late gestation. Pregnant ewes (gestational age: 135 ± 3 days) were randomly placed into control and dark deprivation groups. The control (N = 5) and dark deprivation (N = 5) groups were exposed to a fixed 12 h light/12 h dark cycle and a 24 h constant light cycle, respectively, for 2 days. Dark deprivation up-regulated follicle-stimulating hormone and estradiol levels and down-regulated progesterone levels in both maternal and fetal circulation, and up-regulated luteinizing hormone levels in fetal but not maternal circulation. These results provide new information about how circadian photo-period disruption during pregnancy could alter the release of certain reproductive hormones into fetal blood, which may influence the development of fetal organs in utero, as well as long-term health.

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