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

Endoderm cells of the equine yolk sac from Day 7 until formation of the definitive yolk sac placenta

2010 ◽  
Vol 25 (S15) ◽  
pp. 3-9
Author(s):  
A. C. ENDERS ◽  
S. SCHLAFKE ◽  
K. C. LANTZ ◽  
I. K. M. LIU
Keyword(s):  
Yolk Sac ◽  
Yolk Sac Placenta
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