Placental Secretion of Unconjugated Estrone, Estradiol and Estriol into the Maternal and the Fetal Circulation

Tulchinsky, Dan

doi:10.1210/jcem-36-6-1079

Cited by 73 publications

(25 citation statements)

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“…If the umbilical vein or mixed cord blood are sampled, the levels will indicate high concentrations due to placental synthesis of sex steroids, whereas umbilical artery values reflect systemic levels within the fetus. Several studies have found that the umbilical artery estradiol or conjugated estrogen levels are significantly lower than the umbilical vein values (589,617,696). Such findings confirm that placental production of sex steroids confounds the cord blood measurements and that the umbilical artery values alone should be used to indicate systemic fetal concentrations.…”

Section: Sex Steroidsmentioning

confidence: 85%

“…It is generally considered that in fetal humans estradiol and testosterone are present at low levels in cord blood near term compared with normal adult values (133,676). Indeed, in most studies the fetal levels of estradiol and testosterone were much lower than simultaneous maternal concentrations at term (15,179,216,458,465,509,681,682,696). However, in a few studies either or both of testosterone and estradiol have been approximately equal to (250,545) or significantly greater than (14,357,739) the maternal concentrations.…”

Section: Sex Steroidsmentioning

confidence: 97%

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Bone Development and Mineral Homeostasis in the Fetus and Neonate: Roles of the Calciotropic and Phosphotropic Hormones

Kovacs

2014

Physiological Reviews

197

188

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Mineral and bone metabolism are regulated differently in utero compared with the adult. The fetal kidneys, intestines, and skeleton are not dominant sources of mineral supply for the fetus. Instead, the placenta meets the fetal need for mineral by actively transporting calcium, phosphorus, and magnesium from the maternal circulation. These minerals are maintained in the fetal circulation at higher concentrations than in the mother and normal adult, and such high levels appear necessary for the developing skeleton to accrete a normal amount of mineral by term. Parathyroid hormone (PTH) and calcitriol circulate at low concentrations in the fetal circulation. Fetal bone development and the regulation of serum minerals are critically dependent on PTH and PTH-related protein, but not vitamin D/calcitriol, fibroblast growth factor-23, calcitonin, or the sex steroids. After birth, the serum calcium falls and phosphorus rises before gradually reaching adult values over the subsequent 24 -48 h. The intestines are the main source of mineral for the neonate, while the kidneys reabsorb mineral, and bone turnover contributes mineral to the circulation. This switch in the regulation of mineral homeostasis is triggered by loss of the placenta and a postnatal fall in serum calcium, and is followed in sequence by a rise in PTH and then an increase in calcitriol. Intestinal calcium absorption is initially a passive process facilitated by lactose, but later becomes active and calcitriol-dependent. However, calcitriol's role can be bypassed by increasing the calcium content of the diet, or by parenteral administration of calcium.

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Section: Sex Steroidsmentioning

confidence: 85%

Section: Sex Steroidsmentioning

confidence: 97%

Bone Development and Mineral Homeostasis in the Fetus and Neonate: Roles of the Calciotropic and Phosphotropic Hormones

Kovacs

2014

Physiological Reviews

197

188

View full text Add to dashboard Cite

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“…The level of oestrogens is known to rise throughout pregnancy (Roy and Mackay, 1962;Loriaux et al, 1972). Large amounts of oestrogens which are present in the amniotic fluid may enter the fetus and may reach the fetal circulation through the umbilical vein as well (Tulchinsky, 1973). The role of oestrogens in the porcine fetus is unclear, but they seem to be important in the maturation of fetal tissues, as the fetus is exposed to large amounts of oestrogens.…”

mentioning

confidence: 99%

Immunolocalisation of oestrogen receptors alpha (ERα) and beta (ERβ) in porcine embryos and fetuses at different stages of gestation

Knapczyk

Duda

Szafrańska

et al. 2008

Acta Veterinaria Hungarica

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The sites of oestrogen action can be shown by the localisation of their receptors in the target tissues. The aim of the present study was to show the localisation of oestrogen receptors in porcine embryos and fetuses obtained on days 18, 22, 32, 40, 50, 60, 71 and 90 post coitum (p.c.). The visualisation of proteins was conducted in embryos and various fetal organs such as gonads, uterus, lung, kidney, intestine and adrenal gland. Both ERs were observed in the blastocysts on day 18 p.c. In the male, ERβ was detected in the testis and epididymis, whereas ERα was present in the efferent ductules. In the female, ERβ was detected in the ovarian stromal cells investing the oocyte nests, while ERα protein was detected in the surface epithelium. In the uterus, ERs were present in the stromal cells, while ERβ was present in the luminal epithelium. In the non-reproductive fetal porcine tissues ERβ was localised in the lungs, kidneys, adrenal glands and in the umbilical cords. Both ERs were observed in the intestine. It is possible that ERβ may play important roles in the development of the adrenal gland, testis, kidney and lungs, while both ERs are involved in the development of the ovary, uterus, epididymis and intestine of the porcine fetus.

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“…These findings indicate a transient reversion to the fetal liver by E3 and, furthermore, a possible physiological influence of E3-secreted into the fetal circulation from the placenta (TULCHINSKY, 1973;RYAN, 1980), on the development of the fetal liver. The present study presented several lines of evidence suggesting an effect of E3 on liver development during fetal life.…”

Section: Discussionmentioning

confidence: 76%

“…It is generally agreed that placental estrogens reaching the fetus are extensively metabolized and conjugated. On the other hand, it is known that the fetus is exposed to high plasma concentrations of unbound unconjugated estrogens (TULCHINSKY, 1973;RYAN, 1980). The influence of these biologically active estrogen fractions on the development of fetal organs is little understood.…”

mentioning

confidence: 99%

Promotion by Estriol of the Development of Grafted Fetal Livers in Mice.

Terao

Kotani

1995

Archives of Histology and Cytology

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Summary. Mouse fetal livers of 12 days gestation were transplanted beneath the kidney capsule of syngeneic castrated male hosts. Recipients received a single intraperitoneal injection of 5 mg estriol (E3) immediately after transplantation and were sacrificed 4, 7 and 14 days later. Control mice received injections of solvent only. The fetal liver grafts of the E3 groups showed remarkable growth compared with the control grafts at each corresponding time. In the grafted fetal livers of the E3 groups, many more basophilic hepatocytes appeared for much longer periods, and the early formation of wide sinusoids was noted. Although hemopoietic activity had almost ceased a short time after transplantation in the control grafts, many prominent extra. sinusoidal erythroid, granulocytic and megakaryocytic hemopoietic foci developed and persisted to the end of the experiments in the grafted fetal livers of the E3 groups. In the next experiment, the recipients received three injections of 0.5-5 mg E3 at 5-day intervals, and were sacrificed 21 days after transplantation. Control animals received solvent only in the same manner. The fetal liver grafts of the E3 groups also showed remarkable, dose dependent growth. The growth was particularly striking at doses of 3-5 mg E3. In the grafts of these groups, basophilic hepatocytes were predominant, and hepatic cords and sinusoids were well formed. Moreover, sinusoidal erythropoiesis was intense. These results provide evidence for the possible role of E3, secreted from the placenta into the fetal circulation, in the development of the fetal liver.

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Placental Secretion of Unconjugated Estrone, Estradiol and Estriol into the Maternal and the Fetal Circulation

Cited by 73 publications

References 0 publications

Bone Development and Mineral Homeostasis in the Fetus and Neonate: Roles of the Calciotropic and Phosphotropic Hormones

Bone Development and Mineral Homeostasis in the Fetus and Neonate: Roles of the Calciotropic and Phosphotropic Hormones

Immunolocalisation of oestrogen receptors alpha (ERα) and beta (ERβ) in porcine embryos and fetuses at different stages of gestation

Promotion by Estriol of the Development of Grafted Fetal Livers in Mice.

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