Transport Functions of the Placenta

Hagerman, Dwain D.; Villee, Claude A.

doi:10.1152/physrev.1960.40.2.313

Cited by 99 publications

(15 citation statements)

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“…In guinea-pigs and humans the structure is haemomonochorial, while the rat placenta is haemotrichorial (Steven 1975) . There may, however, be important differences between guinea-pigs and humans in blood flow and surface area for exchange, as well as in mechanisms of transfer (Hagerman and Villee 1960, Faber 1973, Steven 1975) . In addition, the yolk sac of rodents has a placental function for most of gestation, complementary to that of the haemochorial placenta (Wislocki et al .…”

Section: Discussionmentioning

confidence: 99%

The Incorporation of Plutonium by the Embryo and Fetus of Rats and Guinea-pigs

Morgan¹,

Haines²,

Harrison³

1991

International Journal of Radiation Biology

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The transfer of 238Pu from the maternal circulation to the developing embryo and fetus was studied in rats and guinea-pigs to provide data for the development of dosimetric models for the human embryo and fetus. Following administration at different stages of gestation, measurements were made after 3 days in the rat and 7 days in guinea-pigs. The amount transferred was greater after administration at later stages of gestation, up to a maximum of about 0.8-0.9% of the injected activity per fetoplacental unit (FPU) and about 0.2% per fetus in both species. In advanced gestation the yolk sac, the initial site of haemopoietic stem cells, contained up to 80% of the total activity in the FPU in rats, compared with about 25% for the guinea-pig; retention in placental trophoblast was greater in the guinea-pig. The concentrations of 238Pu in the yolk sac were generally about two to three orders of magnitude greater than fetal concentrations and of the same order as in maternal liver and bone. In both species, concentrations in the embryo and fetus were greatest after injection early in gestation, reached their lowest around mid-organogenesis and increased again in later gestation. The fetus:mother whole-body concentration ratios in late gestation were about 0.1 and 0.05 in rats and guinea-pigs, respectively. Measurements were also made of the 238Pu retention in neonates at birth. In guinea-pigs the liver accounted for about 6-9% of retained activity; similar values for femora indicated skeletal retention of about 60-80%. For administration at each stage of gestation, and particularly at early stages, transfer of 238Pu to the fetus continued throughout gestation but concentrations decreased due to fetal growth.

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Section: Discussionmentioning

confidence: 99%

The Incorporation of Plutonium by the Embryo and Fetus of Rats and Guinea-pigs

Morgan¹,

Haines²,

Harrison³

1991

International Journal of Radiation Biology

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“…48 This estrogen is free to cross the placenta into the fetal circulation, 49 but, once transferred, its activity is suppressed by serum proteins including ␣-fetal protein 50,51 and sex-hormone binding globulin (SHBG). 52 After transition to the postnatal environment, ␣-fetal protein expression drops precipitously, 53 and estradiol binding to SHBG is diminished.…”

Section: Kleinman Et Al Stem Cell Mediators In Hemangioma 2667mentioning

confidence: 99%

Hypoxia-Induced Mediators of Stem/Progenitor Cell Trafficking Are Increased in Children With Hemangioma

Kleinman

Greives

Churgin

et al. 2007

ATVB

194

158

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Objective— The mechanism of neovascularization during the proliferative phase of infantile hemangioma is poorly understood. It is known that circulating bone marrow-derived endothelial progenitor cells (EPCs) form new blood vessels in ischemic tissues using mediators regulated by the transcription factor, HIF-1α. Mobilization of EPCs is enhanced by VEGF-A, matrix metalloproteinase (MMP)-9, and estrogen, whereas homing is secondary to localized expression of stromal cell-derived factor-1α (SDF-1α). We examined whether these mediators of EPC trafficking are upregulated during the proliferation of infantile hemangioma. Methods and Results— Surgical specimens and blood samples were obtained from children with proliferating hemangioma and age-matched controls (n=10, each group). VEGF-A and MMP-9 levels were measured in blood, and tissue sections were analyzed for SDF-1α, MMP-9, VEGF-A, and HIF-1α. The role of estrogen as a modulator of hemangioma endothelial cell growth was also investigated. We found that all these mediators of EPC trafficking are elevated in blood and specimens from children with proliferating infantile hemangioma. In vitro, the combination of hypoxia and estrogen demonstrated a synergistic effect on hemangioma endothelial cell proliferation. Conclusions— These findings demonstrate that proliferating hemangiomas express known mediators of vasculogenesis and suggest that this process may play a role in the initiation or progression of this disease.

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“…Indeed, it is known that corticoid secretion is increased by stress (Jost, 1966;Eguchi, 1969) and that these hormones easily cross the hemo-placental barrier (Dupouy, Coffigny, & Magre, 1975;Hagerman & Villee, 1960;Zarrow, Philpott, & Denenberg, 1970). When dams are subjected to a stressor early during pregnancy, it is conceivable that dams' hormonal alterations could have direct effects on fetal development (Milkovic, Paunovic, Kniewald, & Milkovic, 1973;Sandman & Kastin, 1981;Williams et al, 1999;Zarrow et al, 1970).…”

Section: Effects Of Prenatal Stress: An Animal Modelmentioning

confidence: 99%

Effects of pre‐ and postnatal stimulation on developmental, emotional, and cognitive aspects in rodents: A review

Chapillon

Patin

Roy

et al. 2002

Developmental Psychobiology

183

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Interactions between the organism and its environment, during pregnancy as well as during the postnatal period, can lead to important neurobehavioral changes. We briefly review the literature, and successively present the main results from our laboratory concerning the behavioral effects of prenatal stress, differential rearing conditions, and postnatal handling. We show that submitting primiparous DA/HAN rats to an acute emotional stress (exposure to a cat) at gestational day10, 14, or 19 leads to greatly increased mortality of pups and to decreased body weight of surviving animals. The effects of such a stressor on emotional reactivity are less obvious. Cognitive processes are impaired depending on the learning task. Enriched environments restore abnormal behaviors (emotional reactivity, motor skills, motor and spatial learning) due to brain trauma or genetic deficiencies. In any case, environmental enrichment does prevent or slow down aging effects. The effects of postnatal handling noted when using classical tests of emotional reactivity also are clear when defensive reaction paradigms are used. Furthermore, pregnant females that are early handled are less anxious than nonhandled females. We hypothesize that, when subjected to a stressor, the offspring of early-handled females would be protected from the deleterious effects of this stress compared to pups of nonhandled females.

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Transport Functions of the Placenta

Cited by 99 publications

References 0 publications

The Incorporation of Plutonium by the Embryo and Fetus of Rats and Guinea-pigs

The Incorporation of Plutonium by the Embryo and Fetus of Rats and Guinea-pigs

Hypoxia-Induced Mediators of Stem/Progenitor Cell Trafficking Are Increased in Children With Hemangioma

Effects of pre‐ and postnatal stimulation on developmental, emotional, and cognitive aspects in rodents: A review

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