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.

Effect of yolk-sac antibody on rat embryos grown in culture

Development ◽  
1972 ◽  
Vol 27 (3) ◽  
pp. 543-553
Author(s):  
D. A. T. New ◽  
R. L. Brent
Keyword(s):  
Direct Contact ◽  
Culture Medium ◽  
Gamma Globulin ◽  
Yolk Sac ◽  
Amniotic Cavity ◽  
Pregnant Rats ◽  
Rat Embryos ◽  
Visceral Yolk Sac ◽  
Primary Action

Rat embryos, explanted with their embryonic membranes during the early stages of organogenesis ( days gestation), were grown in culture in roller tubes. Yolk-sac antibody (sheep anti rat yolk-sac gamma globulin), known to be teratogenic when injected into pregnant rats, was added to the culture medium. At concentrations of 0·1 mg/ml or more the antibody caused gross retardation of growth and differentiation. Injection of antibody into the amniotic cavity so that it had direct contact with the embryo, or between the amnion and yolk sac so that it was in contact with the mesodermal surface of the yolk sac, had little or no effect on development of the embryo or its membranes. These in vitro experiments indicate that yolk-sac antibody has an effect on development independent of any immunological reaction of the mother, and the primary action is probably on the visceral yolk-sac endoderm.

scholarly journals The route of antibodies passing from the maternal to the foetal circulation in rabbits

1949 ◽  
Vol 136 (882) ◽  
pp. 131-144 ◽  
Keyword(s):  
Maternal Blood ◽  
Yolk Sac ◽  
Rabbit Serum ◽  
Maternal Circulation ◽  
Uterine Lumen ◽  
Foetal Circulation ◽  
Circulating Antibodies ◽  
Immune Rabbit ◽  
Foetal Blood

It has long been known that maternal circulating antibodies pass into the foetal blood in rabbits during the latter half of pregnancy. The allanto-chorionic placenta has been assumed to be the site of this transference, the number of tissues separating the two blood streams being reduced to a minimum in rabbits at these stages. It was shown in a recent paper that, at a stage before the establishment of the embryonic circulation, maternal circulating antibodies pass the bilaminar omphalopleur into the yolk-sac cavity. It is shown in this paper that in 24-day embryos antibodies pass from the maternal circulation by way of the uterine lumen and the yolk-sac splanchnopleur into the foetal vitelline circulation, and do not pass by way of the allanto-chorionic placenta. The method employed involved injection of immune rabbit serum either into the uterine lumen or the maternal blood and interruption of the foetal vitelline circulation of some of the embryos by ligaturing the yolk-sac stalk.

An in vitro study of functions of embryonic membranes in the rat

Development ◽  
1972 ◽  
Vol 27 (3) ◽  
pp. 533-542
Author(s):  
G. S. Payne ◽  
E. M. Deuchar
Keyword(s):  
Total Protein ◽  
In Vitro Study ◽  
Axial Rotation ◽  
Yolk Sac ◽  
Amniotic Cavity ◽  
Outer Membranes ◽  
Leucine Uptake ◽  
Visceral Yolk Sac ◽  
Extraembryonic Membranes

Ten-day rat embryos have been cultivated in vitro, with different layers of the extraembryonic membranes removed. The effects of presence or absence of each membrane on the morphology of the embryos, their histodifferentiation and their uptake of leucine into protein have been followed. Explants with all membranes left intact failed to expand fully and to undergo axial rotation of the embryo, but nevertheless showed highest total protein and highest leucine uptake in biochemical estimations and in autoradiographs. Explants with outer membranes removed and the visceral yolk sac left intact showed the most normal morphology and expansion of the extraembryonic cavities when compared with embryos removed from the uterus at 11·5 days” gestation, but they showed less protein and less leucine uptake than the first series. Explants in which the visceral yolk sac was removed underwent little growth or development and had low total protein values and radioactivity counts. The amnion collapsed and the amniotic cavity disappeared. When the amnion was removed there was a greater incidence of death, as well as little or no development, and lower radioactivity counts than in the first two series. It is concluded that the outer membranes and the visceral yolk sac play an important role in the transfer of small metabolites to the embryo, as well as in regulating the volume of the extraembryonic fluids.

Quantitation and immunohistochemical localization of DNA adducts in rat embryos and associated yolk sac membranes exposed in vitro to N-acetoxy-2-acetylaminofluorene (N-Ac-AAF)

1991 ◽  
Vol 11 (2) ◽  
pp. 93-102 ◽  
Author(s):  
Philip E. Mirkes ◽  
Sally A. Little ◽  
Frederick A. Beland ◽  
Henrik S. Huitfeldt ◽  
Miriam C. Poirier
Keyword(s):  
Dna Adducts ◽  
Immunohistochemical Localization ◽  
Yolk Sac ◽  
Rat Embryos

Ethanol-induced inhibition of pinocytosis and proteolysis in rat yolk sac in vitro

Development ◽  
1987 ◽  
Vol 99 (2) ◽  
pp. 247-253
Author(s):  
G.B. Steventon ◽  
K.E. Williams
Keyword(s):  
Maternal Blood ◽  
Yolk Sac ◽  
Late Gestation ◽  
Acute Administration ◽  
Pregnant Rat ◽  
Low Concentrations ◽  
Uterine Fluid ◽  
Chorioallantoic Placenta ◽  
Proteolytic Capacity

Pinocytic capture of 125I-labelled polyvinylpyrrolidone and of formaldehyde-denatured 125I-labelled bovine serum albumin by 17.5-day rat visceral yolk sacs incubated in vitro was rapidly and strongly inhibited by low concentrations (0.01 and 0.05%, v/v) of ethanol. The induced inhibition of pinocytosis was readily reversible, but a marked lag was observed before ethanol-exposed tissue regained its full proteolytic capacity towards the exogenous protein. These observations suggest that the acute administration of ethanol to a pregnant rat may give rise to concentrations of ethanol in the maternal blood and/or uterine fluid that induce dysfunction of the yolk sac. In late gestation such inhibition of yolk-sac function may interfere with the transfer of passive immunity across the yolk sac. If similar dysfunction is induced earlier in gestation, in the period before the chorioallantoic placenta is functional, this could cause a transient period of inhibition of histiotrophic nutrition that may be important to the pathogenic mechanism of action of ethanol as a teratogen.

Changes in visceral yolk sac ultrastructure after exposure of rat embryos to selected teratogens in vitro

1990 ◽  
Vol 4 (4-5) ◽  
pp. 593-597 ◽  
Author(s):  
G.P. Daston ◽  
J.L. Burns ◽  
M.H. Chestnut
Keyword(s):  
Yolk Sac ◽  
Rat Embryos ◽  
Visceral Yolk Sac

Growth of opossum embryos in vitro during organogenesis

Development ◽  
1977 ◽  
Vol 41 (1) ◽  
pp. 111-123
Author(s):  
D. A. T. New ◽  
M. Mizell ◽  
D. L. Cockroft
Keyword(s):  
Neural Tube ◽  
Blood Circulation ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Body Movements

Opossum embryos, explanted between primitive streak and late fetal stages, were grown in culture for periods of 20–30 h. Many of the explants had a good heartbeat and blood circulation in embryo and yolk sac after 12 h, and a few after 24 h. Growth of the embryos included formation of the neural tube and body flexures, increase in the number of somites, differentiation of the limbs and digits, and development of the amnion and allantois. Embryos explanted during the last day of gestation showed persistent and vigorous body movements in culture, particularly of the forelimbs, head and tongue.

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