Morphological study of the chorio-allantoic fetal membranes

Minh, Hoang-Ngoc; Smadja, A; Orcel, L

doi:10.1016/0028-2243(84)90108-4

Cited by 2 publications

(2 citation statements)

References 6 publications

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“…Bovine amnion presents cells with polygonal shapes, coated with short microvilli, distributed all over the superficial part of the membrane and delimited by condensed microvillous lines. Using scanning electron microscopy, the bovine amnion was shown to be similar to that of the rabbit, sheep, swine, cat and human (Kühnel, 1965; Tiedemann, 1979a,b; Steven et al., 1982; Minh et al., 1984).…”

Section: Discussionmentioning

confidence: 99%

Initial Development of Bovine Placentation (Bos indicus) from the Point of View of the Allantois and Amnion

Neto¹,

Santos

Pereira

et al. 2009

Anat Histol Embryol

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The aim of this study was to perform a morphological characterization of the initial bovine placental development, between 20 and 70 days post-insemination (p.i.), with emphasis on the differentiation of the allantois and amnion. After collection, the conceptuses were dissected, macroscopically measured and photographically documented. The extraembryonic membranes were cut into fragments measuring 5 cm 2 , and then fixed in 4% paraformaldehyde for analysis using light microscopy, and in 2.5% glutaraldehyde for use in scanning and transmission electron microscopy. The extraembryonic and fetal membranes presented variable degrees of development throughout the periods analysed. The macroscopic appearance of vascularization of the allantois, its attempt to merge with the chorium and the effective appearance of the first cotyledons in development were the events observed from 30 to 40 days of pregnancy. The measurements of the amnion increased gradually as gestation developed. The allantoic epithelia presented cellular dimorphism from 20 to 25 days of pregnancy, but was shown to be immature from 60 to 70 days of pregnancy.

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Section: Discussionmentioning

confidence: 99%

Initial Development of Bovine Placentation (Bos indicus) from the Point of View of the Allantois and Amnion

Neto¹,

Santos

Pereira

et al. 2009

Anat Histol Embryol

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“…Early studies described the amniotic membrane as epithelial with transport characteristics. [1][2][3] Subsequently, a role for the placental amnion in the regulation of amniotic fluid volume (AFV) has been proposed. 4 In humans, the amnion is partitioned into 3 regions with distinct morphology and gene expression patterns 5 : placental amnion, reflected amnion juxtaposed to the membranous chorion, and amnion overlaying the umbilical cord.…”

Section: Introductionmentioning

confidence: 99%

Retinoic Acid Pathway Regulation of Vascular Endothelial Growth Factor in Ovine Amnion

et al. 2019

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Vascular endothelial growth factor (VEGF) has been proposed as an important regulator of amniotic fluid absorption across the amnion into the fetal vasculature on the surface of the placenta. However, the activators of VEGF expression and action in the amnion have not been identified. Using the pregnant sheep model, we aimed to investigate the presence of the retinoic acid (RA) pathway in ovine amnion and to determine its effect on VEGF expression. Further, we explored relationships between RA receptors and VEGF and tested the hypothesis that RA modulates intramembranous absorption (IMA) through induction of amnion VEGF in sheep fetuses subjected to altered IMA rates. Our study showed that RA receptor isoforms were expressed in sheep amnion, and RA response elements (RAREs) were identified in ovine RARβ and VEGF gene promoters. In ovine amnion cells, RA treatment upregulated RARβ messenger RNA (mRNA) and increased VEGF transcript levels. In sheep fetuses, increases in IMA rate was associated with elevated VEGF mRNA levels in the amnion but not in the chorion. Further, RARβ mRNA was positively correlated with VEGF mRNA levels in the amnion and not chorion. We conclude that an RA pathway is present in ovine fetal membranes and that RA is capable of inducing VEGF. The finding of a positive relationship between amnion VEGF and RARβ during altered IMA rate suggests that the retinoid pathway may play a role through VEGF in regulating intramembranous transport across the amnion.

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Morphological study of the chorio-allantoic fetal membranes

Cited by 2 publications

References 6 publications

Initial Development of Bovine Placentation (Bos indicus) from the Point of View of the Allantois and Amnion

Initial Development of Bovine Placentation (Bos indicus) from the Point of View of the Allantois and Amnion

Retinoic Acid Pathway Regulation of Vascular Endothelial Growth Factor in Ovine Amnion

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