Trophoblast-decidual cell interactions and establishment of maternal blood circulation in the parietal yolk sac placenta of the rat

1987 ◽  
Vol 217 (2) ◽  
pp. 203-219 ◽  
Author(s):  
Alerick O. Welsh ◽  
Allen C. Enders
Keyword(s):  
Blood Circulation ◽  
Maternal Blood ◽  
Yolk Sac ◽  
Cell Interactions ◽  
Decidual Cell ◽  
Yolk Sac Placenta

Development of a placental blood circulation in rat embryos in vitro

Development ◽  
1977 ◽  
Vol 37 (1) ◽  
pp. 227-235
Author(s):  
D. A. T. New ◽  
P. T. Coppola
Keyword(s):  
Total Protein ◽  
Blood Circulation ◽  
Maternal Blood ◽  
Yolk Sac ◽  
Rat Embryos ◽  
Placental Blood ◽  
Foetal Blood

Rat embryos explanted with their membranes at head-fold stage (9½ days gestation) formed an allantoic placenta which enlarged in culture and developed a foetal blood circulation. Embryos explanted at early somite stages (10½ days) also formed a growing allantoic placenta but only after removal of most of the ectoplacental trophoblast. Assays of total protein in the embryo and placenta suggested that, in the absence of a maternal blood circulation to the placenta, embryo and placenta compete for the respiratory and nutritional resources obtained through the yolk-sac.

Enzymic differentiation of rat yolk-sac placenta as affected by a teratogenic agent

Development ◽  
1966 ◽  
Vol 16 (2) ◽  
pp. 271-288
Author(s):  
E. Marshall Johnson ◽  
Ralph Spinuzz
Keyword(s):  
Experimental Evidence ◽  
Central Zone ◽  
Maternal Blood ◽  
Yolk Sac ◽  
Waste Products ◽  
A Site ◽  
Obvious Source ◽  
Yolk Sac Placenta

In 1927, Brunschwig presented experimental evidence which indicated that the yolk-sac of the rat functioned as a site of transport between the mother and the developing embryo. Everett (1935) was able to demonstrate that the maternal blood within the central zone adjacent to the parietal wall of the yolk-sac was circulating and that this area was indeed serving as a locale for exchange. He further demonstrated that the allantoic lamellae and their circulation do not become established in the rat until the end of day 11 or early on day 12; and therefore, during days 10 and 11, circulating maternal blood in the central zone serves as the only obvious source available for supply of substances to the embryo as well as for removal of waste products from the embryo.

Visualization of Antibody Transport in Rat Visceral Yolk-Sac Placenta

1982 ◽  
Vol 40 ◽  
pp. 246-247
Author(s):  
William P. Jollie
Keyword(s):  
Phosphate Buffer ◽  
Yolk Sac ◽  
Female Rats ◽  
Thin Sections ◽  
Visceral Yolk Sac ◽  
Antibody Complex ◽  
Cytochemical Reaction ◽  
Hind Foot ◽  
Antigen Antibody ◽  
Yolk Sac Placenta

A technique has been developed for visualizing antibody against horseradish peroxidase (HRP) in rat visceral yolk sac, the placental membrane across which passive immunity previously has been shown to be transferred from mother to young just prior to birth. Female rats were immunized by injecting both hind foot pads with 1 mg HRP emulsified in complete Freund's adjuvant. They were given a booster of 0.5mg HRP in 0.1 ml normal saline i.v. after one week, then bred and autopsied at selected stages of pregnancy, viz., 12, 1 7 and 22 days post coitum, receiving a second booster, injected as above, five days before autopsy. Yolk sacs were removed surgically and fixed immediately in 2% paraformaldehye, 1% glutaraldehye in 0.1 M phosphate buffer with 0.01% CaCl2 at pH 7.4, room temperature, for 3 hr, rinsed 3X in 0.1 M phosphate buffer plus 5% sucrose, then exposed to 1 mg HRP in 1 ml 0.1 M phosphate buffer at pH 7.4 for 1 hr. They were refixed in aldehydes, as above, for 1 5 min (to assure binding of antigen-antibody complex). Following buffer washes, the tissues were incubated in 3 mg diaminobenzidine tetrahydrochloride and 0.01% H2O2 in 0.05 M Tris-HCl buffer for 30 min. After brief buffer washes, they were postfixed in 2% OsO4. in phosphate buffer at pH 7.4, 4°C for 2 hr, dehydrated through a graded series of ethanols, and embedded in Durcupan. Thin sections were observed and photographed without contrast-enhancement with heavy metals. Cytochemical reaction product marked the site of HRP (i.e., antigen) which, in turn, was present only where it was bound with anti-HRP antibody.

Structure of the paraplacenta and the yolk sac placenta of the viviparous Australian sharpnose shark, Rhizoprionodon taylori

Placenta ◽  
2021 ◽  
Vol 108 ◽  
pp. 11-22
Author(s):  
Alice L. Buddle ◽  
James U. Van Dyke ◽  
Michael B. Thompson ◽  
Colin A. Simpfendorfer ◽  
Christopher R. Murphy ◽  
...  
Keyword(s):  
Yolk Sac ◽  
Yolk Sac Placenta

Uptake and transfer of amino acids in the artificially perfused guinea-pig yolk sac placenta

Placenta ◽  
1989 ◽  
Vol 10 (5) ◽  
pp. 474
Author(s):  
C. Schoch ◽  
H. Schröder ◽  
H.-P. Leichtweil
Keyword(s):  
Amino Acids ◽  
Guinea Pig ◽  
Yolk Sac ◽  
Yolk Sac Placenta

100 BOVINE PREGNANCY-ASSOCIATED GLYCOPROTEINS ARE ALLOCATED TO COTYLEDONARY OR INTERCOTYLEDONARY TROPHOBLAST ACCORDING TO THEIR PHYLOGENETIC ORIGIN

2013 ◽  
Vol 25 (1) ◽  
pp. 197 ◽  
Author(s):  
E. Touzard ◽  
P. Reinaud ◽  
O. Dubois ◽  
C. Joly-Guyader ◽  
P. Humblot ◽  
...  
Keyword(s):  
Blood Circulation ◽  
Bos Taurus ◽  
Pcr Primers ◽  
Maternal Blood ◽  
Phylogenetic Groups ◽  
Binucleate Cells ◽  
Trophoblastic Cells ◽  
Reverse Transcription Pcr ◽  
Phylogenetic Origin ◽  
Aspartic Peptidases

The pregnancy-associated glycoproteins (PAG) form a multigenic family of aspartic peptidases specifically expressed within the trophoblast of the ruminant placenta. In Bos taurus, this family is composed of 21 members segregated into 2 phylogenetic groups. The PAG are mainly produced by the cotyledons, which are discrete areas of massive interdigitations between the maternal endometrium and the foetal trophoblast. Cotyledons are separated by the flat cell layer of intercotyledonary trophoblast areas. According to former studies, modern PAG (PAG I) are produced by binucleate trophoblastic cells of the cotyledons, whereas ancient PAG (PAG II) are reported to be synthesized by both mononucleate and binucleate trophoblastic cells. Binucleate cells migrate into the maternal endometrium and to pour their intracellular content, allowing modern PAG as PAG1 to reach maternal blood circulation where they can be assayed as gestation diagnosis. Investigations about the PAG family are often restricted to a few molecules used for the diagnosis of gestation in blood circulation or in cotyledonary extracts. The aim of this study was to inform PAG I and PAG II expression during gestation in cotyledonary and intercotyledonary tissues. To build strong and innovative results in spite of the high identity sequence between PAG, we designed very specific tools such as RT-PCR primers for the transcripts analysis and antibodies for the proteins studies. Using real-time reverse-transcription PCR, we described the transcript expression of 16 of the 21 bovine PAG. Overall, they showed an increasing expression during gestation. However, we demonstrated a segregation of modern PAG in cotyledon and ancient PAG in the intercotyledonary trophoblast. Belonging to the ancient group, PAG2 was expressed in the cotyledon as a modern PAG. We raised specific antibodies against PAG1 (I), PAG11 (II), and PAG2 (II) that allowed to us confirm transcript data at the protein level using Western blot analysis. Three glycosylation variants of PAG11 were detected along with the gestation: a 45-kDa PAG11 is synthesized from 50 to 220 days of gestation, whereas a 78-kDa and a 70-kDa PAG11 were synthesized from 100 days of gestation. Immunolocalization described specific populations of binucleate cells producing PAG1 or PAG11 or PAG2. The PAG1 is mainly detected in binucleate cells of the whole cotyledon and in a lesser extent in the intercotyledonary trophoblast. The PAG11 was mainly localized in binucleate cells of the intercotyledonary trophoblast but also in a restricted population of binucleate cells of the cotyledon. The PAG2 was only synthesized in the villi of the cotyledon. To conclude, we demonstrated modern and ancient PAG have specific anatomical localization according to their phylogenetic origin. Ancient PAG are specific of nonvillous tissues, whereas modern PAG are mainly synthesized within the villous part of the cotyledon. The PAG2 seem to be an exception, belonging to the ancient group but expressed as a modern PAG and synthesized only in the cotyledon.

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