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.

scholarly journals 279VASCULAR MORPHOMETRY OF BOVINE PLACENTOMES IN LATE GESTATION FROM EMBRYOS PRODUCED IN VIVO OR IN VITRO

2004 ◽  
Vol 16 (2) ◽  
pp. 259
Author(s):  
J.R. Miles ◽  
C.E. Farin ◽  
K.F. Rodriguez ◽  
J.E. Alexander ◽  
P.W. Farin
Keyword(s):  
Blood Vessels ◽  
Maternal Blood ◽  
Volume Density ◽  
Late Gestation ◽  
Embryo Production ◽  
Vascular Volume ◽  
Treatment Groups ◽  
In Vitro Embryo Production

The role of the vascular supply in the development of placentas from embryos produced in vitro is poorly understood. The objective of this study was to determine the effects of in vitro embryo production on morphometry of blood vessels within fetal (cotyledonary) and maternal (caruncular) components of the placentome during late gestation. In vivo-produced embryos were recovered from superovulated Holstein cows on Day 7 after estrus. For in vitro embryo production, oocytes were aspirated from the ovaries of Holstein cows, matured in vitro, and then fertilized. Presumptive zygotes with their cumulus cells were transferred into M-199 with 10% estrus cow serum and cultured for 168h post-insemination. Semen from the same Holstein sire was used for the production of in vivo and in vitro embryos. Single blastocysts from each production system were transferred into the uteri of heifers. On Day 222 of gestation, fetuses and placentas were recovered in utero (in vivo, n=12; in vitro, n=12). Placentomes were collected, fixed and sectioned. Fetal and maternal blood vessels were identified within placentome sections using immunocytochemistry for vascular endothelial growth factor (VEGF) protein. A total of 4.8×105μm2 of tissue were examined from each placentome. Stereological methods were used to determine the volume densities of fetal and maternal blood vessels. Data were analyzed by GLM procedures. Fetuses were heavier (P=0.03) in the in vitro group (20.7±1.0kg, LS mean±SEM) compared to the in vivo group (17.3±1.0kg). Placentas were also heavier (P=0.06) for the in vitro group (2.5±0.2kg) compared to the in vivo group (2.0±0.2kg). Placental efficiency, calculated as fetal weight/placental weight, was similar between the two treatment groups (9.0±0.5 and 8.9±0.5 for in vivo and in vitro, respectively). Fetal vascular volume density in placentomes was not different between the two treatment groups (5.4±0.3% and 5.4±0.3% for in vivo and in vitro, respectively). In contrast, maternal vascular volume density was greater (P=0.02) for placentomes in the in vitro group (5.9±0.3%) compared to in vivo controls (4.9±0.3%). In summary, compared to placentomes from embryos produced in vivo, placentomes from embryos produced in vitro had similar volume density of fetal vessels, but had significantly increased volume density of maternal vessels. Supported by the State of North Carolina.

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.

The role of the visceral yolk sac in mediating protein utilization by rat embryos cultured in vitro

Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 223-234
Author(s):  
Stuart J. Freeman ◽  
Felix Beck ◽  
John B. Lloyd
Keyword(s):  
Serum Proteins ◽  
Yolk Sac ◽  
Rat Serum ◽  
Pregnant Rats ◽  
Digestion Product ◽  
Background Levels ◽  
Visceral Yolk Sac ◽  
Chorioallantoic Placenta

Conceptuses from 9·5-day pregnant rats have been cultured for 48 h in heat-inactivated homologous serum. Embryonic development was normal. The protein contents of embryos and visceral yolk sacs after different periods of culture were recorded. When 125-labelled polyvinylpyrrolidone or [3H]dextran were added to the culture serum, radioactivity was accumulated by the yolk sac, but only background levels were detected in the embryo itself. The amount of radioactivity found in the yolk sac varied with the length of the interval before harvesting during which 125 I-labelled PVP or [3H]dextran was present. When formaldehyde-denatured 125 I-labelled bovine serum albumin was added to the culture serum, little radioactivity accumulated in the yolk sac and only background levels were found in the embryo. Trichloroacetic acid-soluble radioactivity steadily appeared in the culture serum, however. When conceptuses were cultured in glucose- and vitamin-supplemented dialysed serum from rats injected 2 h previously with [3H]leucine, radioactivity was found in both embryos and yolk sacs. The amount of radioactivity in these tissues increased with duration of exposure to 3H-labelled serum proteins. After short exposures little of the yolk sac and embryonic radioactivity was acid-insoluble, but this proportion increased with duration of exposure. These results are interpreted as follows. Intact macromolecules cannot enter the cells of the embryo itself, but are captured by pinocytosis into the cells of the visceral yolk-sac endoderm. Indigestible macromolecules such as 125 I-labelled polyvinylpyrrolidone and [3H]- dextran accumulate within the yolk-sac lysosomes, but proteins are digested there by the lysosomal enzymes. The radiolabelled digestion product of 125 I-labelled bovine albumin is [125 I]iodotyrosine, which cells cannot utilize and so is excreted into the culture serum. The labelled digestion product of the 3H-labelled rat serum proteins is [3H]leucine, which is used for protein synthesis in both embryo and yolk sac. The experiments provide direct evidence for the long-suspected role of the yolk sac in mediating embryonic nutrition in the period of development prior to the establishment of a functional chorioallantoic placenta.

Bovine oviductal and uterine fluid support in vitro embryo development

2018 ◽  
Vol 30 (7) ◽  
pp. 935 ◽  
Author(s):  
Meriem Hamdi ◽  
Ricaurte Lopera-Vasquez ◽  
Veronica Maillo ◽  
Maria Jesus Sanchez-Calabuig ◽  
Carolina Núnez ◽  
...  
Keyword(s):  
Embryo Development ◽  
Dna Methyltransferase ◽  
Calf Serum ◽  
Stress Genes ◽  
Low Concentrations ◽  
Uterine Fluid ◽  
Oviduct Fluid ◽  
Oviductal Fluid ◽  
Intracellular Channel

In order to mimic the maternal oviductal environment, we evaluated the effect of oviductal fluid (OF) and/or uterine fluid (UF) supplementation on in vitro embryo development and quality. In vitro-produced zygotes were cultured with 1.25% OF from Day 1 to Day 4 after insemination (OF group), 1.25% OF from Day 1 to Day 4 followed by 1.25% UF from Day 4 to Day 9 (OF+UF group) or 1.25% UF only from Day 4 to Day 9 (UF group). Control groups were cultured in the presence of synthetic oviduct fluid (SOF) supplemented with 3 mg mL−1 bovine serum albumin (BSA) or 5% fetal calf serum (FCS). Supplementation of the culture medium with OF and/or UF (both at 1.25%) supported embryo development (Day 9 blastocyst rate 28.2–30.6%). At 72 h after vitrification–warming, the survival of blastocysts from the OF and OF+UF groups was similar to that of blastocysts in the SOF+BSA group (61.0 ± 5.7% and 62.8 ± 6.4% vs 64.8 ± 6.4% respectively), but significantly higher than that of blastocysts from the SOF+FCS group (31.6 ± 4.9%; P < 0.001). Blastocysts from the OF group exhibited upregulation of epigenetic genes (i.e. DNA methyltransferase 3α (DNMT3A) and insulin-like growth factor 2 receptor (IGF2R)), compared with expression in the SOF+FCS group (P < 0.05). Whereas those from OF+UF and UF groups exhibited downregulation of oxidative stress genes compared to SOF+BSA and OF groups for glutathione peroxidase (GPX1) and to SOF+FCS, SOF+BSA and OF groups for chloride intracellular channel 1 (CLIC1) (P < 0.05). In addition, accumulation of reactive oxygen species was lower in blastocysts from the OF, OF+UF and UF groups. In conclusion, the use of low concentrations of OF and UF in in vitro serum-free culture supports embryo development, with OF providing a better control of embryo methylation, whereas UF may have antioxidant activity.

Free blastocyst and implantation stages in the European brown hare: correlation between ultrasound and histological data

2013 ◽  
Vol 25 (6) ◽  
pp. 866 ◽  
Author(s):  
Barbara Drews ◽  
Jennifer Ringleb ◽  
Romy Waurich ◽  
Thomas Bernd Hildebrandt ◽  
Katharina Schröder ◽  
...  
Keyword(s):  
Reproductive Tract ◽  
Developmental Stages ◽  
Maternal Blood ◽  
Yolk Sac ◽  
Lepus Europaeus ◽  
Brown Hare ◽  
European Brown Hare ◽  
Histological Data ◽  
Peristaltic Movement ◽  
Chorioallantoic Placenta

The European brown hare (Lepus europaeus) is the only species with superconception, whereby the maternal reproductive tract hosts two sets of conceptuses at different developmental stages. The embryonic development of the hare has not yet been described. To understand the mechanism of superconception, we studied oviduct transport and implantation stages by embryo flushing and live high-resolution ultrasound. Ultrasound data of implantation stages is correlated with histology. In the oviduct, a mucin coat is deposited on the zona pellucida. The blastocysts enter the uterine horns on Day 5, 1 day later than in the rabbit, and directly expand approximately threefold. Spacing is accompanied by peristaltic movement of the endometrium. The mucin coat disappears and the conceptuses attach. The yolk-sac expands in the blastocoel and syncytial knobs invade the antimesometrial endometrium. Maternal blood lacunae appear in the mesometrial endometrial folds, which are subsequently invaded by the syncytiotrophoblast. The haemochorial chorioallantoic placenta forms. The yolk-sac cavity is gradually replaced by the allantois and finally by the exocoel. The different reproductive strategies of the precocial hare and the altricial rabbit are discussed. We assume that the lagomorph-specific mucin coat and the hare-specific delay of the oviduct–uterine transition are prerequisites for superconception.

THE IMPORTANCE OF INSULIN, CORTISOL, PROGESTERONE AND PROLACTIN FOR THE MAMMOTROPHIC EFFECT OF PREGNANT RAT SERUM

1977 ◽  
Vol 85 (3) ◽  
pp. 548-558
Author(s):  
J. M. Peters
Keyword(s):  
Culture Medium ◽  
Indirect Evidence ◽  
High Concentration ◽  
Promoting Effect ◽  
Rat Serum ◽  
Pregnant Rat ◽  
Low Concentrations ◽  
Prolactin Content ◽  
Growth Promoting

ABSTRACT In order to explain the increased mammotrophic activity of pregnant rat serum, some hormones known to have an in vitro effect on the mammary gland were added to non-pregnant rat serum and their effect compared with that of pregnant rat serum. The addition of insulin to the culture medium increased the mammotrophic effect of pregnant rat serum, but a difference between non-pregnant and pregnant rat serum could be demonstrated either in the presence or absence of a high concentration of insulin. While pregnant rat serum had a mammogenic (i. e. growth-promoting) effect, cortisol had no such effect and antagonized the mitotic activity induced by the pregnant serum. Pregnant rat serum was active at such low concentrations, that the progesterone content of pregnant rat serum could not explain the mammogenic activity of the latter. Moreover, the combination of progesterone with non-pregnant rat serum did not produce other changes produced by pregnant rat serum alone such as cytoplasmic opalescence and the localized development of vacuolization and secretion. Prolactin with non-pregnant rat serum produced a mammotrophic effect which was in all respects similar to that of pregnant rat serum. An effect could be demonstrated at 0.08 μg prolactin/ml medium. However, again pregnant rat serum was active at such low concentrations that the prolactin content of pregnant rat serum could not explain the mammotrophic effect of pregnant rat serum. Moreover, the effect of pregnant rat serum could not be blocked with rabbit anti-rat prolactin serum, but the anti-serum blocked the effect of rat prolactin added to non-pregnant rat serum. The results exclude the possibility that insulin, cortisol, progesterone or prolactin can account for the mammotrophic activity in pregnant rat serum. They provide indirect evidence for the importance of rat chorionic mammotrophin.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Aggregation of Cat Platelets in Vitro

1970 ◽  
Vol 23 (03) ◽  
pp. 601-620 ◽  
Author(s):  
Th. B Tschopp
Keyword(s):  
Adenosine Monophosphate ◽  
Blood Collection ◽  
Base Line ◽  
Reversible Aggregation ◽  
Low Concentrations ◽  
Irreversible Aggregation ◽  
High Concentrations ◽  
Two Phases ◽  
Improved Technique

SummaryAggregation of cat platelets in the citrated plasma is examined by means of Born’s absorptiometer. A marked tendency of the platelets of this species to spontaneous aggregation necessitated first of all the development of an improved technique of blood collection.A hypothesis according to which 5-HT is released from the platelets, explains the absence of oscillations on the base line of the absorptiometer, the absence of platelet swelling, when ADP is added, and the effect of stirring on the aggregation curves in cat PRP. The average volume of cat platelets amounts to 10.46 μ3 when directly fixed in the blood, when fixed from PRP to 12.17 μ3, when fixed from stirred PRP to 13.51 μ3.In low concentrations (0.3-2 μM) ADP produce reversible aggregation; in narrowly restricted, individually dissimilar mean concentrations irreversible aggregation in two phases and in high concentrations, irreversible aggregation in one phase. Like ADP serotonin produces 2 phase irreversible aggregation in concentrations of 3-10 μM, but unlike ADP, the aggregation velocity decreases again with high 5-HT concentrations (>100 μM). Adrenaline does not produce aggregation and it is likely that adenosine and adenosine monophosphate inhibit the aggregation by serotonin but not by ADP. Species differences in the aggregation of human, rabbit and cat platelets are discussed.

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