scholarly journals Fetomaternal interactions and influences during equine pregnancy

Reproduction ◽  
2001 ◽  
pp. 513-527 ◽  
Author(s):  
WR Allen

The equine embryo takes 6 days to traverse the oviduct and, when it finally enters the uterus, it remains spherical in shape and moves continually throughout the uterine lumen until day 17 after ovulation to deliver its maternal recognition of pregnancy signal to the entire endometrium. Between day 25 and day 35 after ovulation, the trophoblast cells of a discrete annulate portion of the chorion multiply rapidly and acquire an invasive phenotype and, between day 36 and day 38, migrate deeply into the maternal endometrium to form the equine-unique endometrial protuberances known as endometrial cups. These cups secrete large quantities of a gonadotrophic hormone (eCG) into the maternal circulation which, in conjunction with pituitary FSH, stimulates the development of accessory luteal structures in the maternal ovaries to supplement the supply of progesterone to maintain the pregnancy until the placenta can assume this role at about day 100. The non-invasive allantochorion extends slowly to fill the uterus by days 80-85 and its microcotyledonary architecture, which provides both haemotrophic and histotrophic nutrition for the growing fetus, is not fully established until days 120-140. The fetoplacental unit synthesizes large quantities of steroid hormones during the second half of pregnancy, using fetal C-19 precursors secreted by the enlarged fetal gonads for the production of oestrogens and maternal C-21 precursors for the synthesis of progesterone and large quantities of 5alpha-reduced progestagens. Near term, additional pregnenelone is secreted by the fetal adrenal glands so that the mare exhibits the unusual phenomenon of foaling while maternal serum progestagen concentrations are increasing and oestrogen concentrations are decreasing.

2017 ◽  
Author(s):  
Sankat Mochan ◽  
Manoj Kumar Dhingra ◽  
Betsy Varghese ◽  
Sunil Kumar Gupta ◽  
Shobhit saxena ◽  
...  

AbstractBackgroundThe concentration of sFlt-1, a major anti-angiogenic protein in maternal circulation has been seen to be raised in preeclamptic pregnancies. Endoplasmic reticulum (ER) stress represents one of the three (immunological, oxidative and ER stress) major stresses which placenta undergoes during pregnancies. The present study is designed to investigate the role of sFlt-1 in induction of ER stress in trophoblast cells.Materials and MethodsMaternal serum levels of anti-angiogenic protein sFlt-1 and central regulator of unfolded protein response GRP78 was measured using sandwich ELISA. The expression of various ER stress markers (GRP78, eIF2α, XBP1, ATF6 and apoptotic protein CHOP) were analyzed depending on various treatments given to the trophoblast cells using Immunofluorescence, western blot and q-RT PCR.ResultsIncreased expression of ER stress markers (GRP78, eIF2α, XBP1 ATF6 and apoptotic protein CHOP) was detected in the placental trophoblast cells treated with raised concentration of sFlt-1.ConclusionSignificant upregulated expression of ER stress markers in trophoblast cells exposed with increased concentration of sFlt-1 suggested that it may be one of the anti-angiogenic factors present in maternal sera which not only contributes to oxidative stress but also may cause endoplasmic reticulum stress.


Active immunity to Brucella abortus was induced in adult female rabbits. They were mated a week after the last injection of antigen and were killed and the yolk-sac contents of the embryos tested for agglutinins 8½ days after copulation. Specific agglutinins were found to be present in the yolk-sac contents in all cases. The titre varied significantly from embryo to embryo in the same litter, and was in some as high as that in the maternal serum at the time of killing. Passive immunity to Br. abortus was imparted to female rabbits 7 to 9 days pregnant by intravenous injection of immune serum of high titre. The rabbits were killed and the yolk-sac fluid of the embryos tested for agglutinins 10 to 17 hr. after injection. Specific agglutinins were present in most of the embryos from five of the six rabbits injected before 8 days post-coitum. All the embryos in the sixth rabbit were regressing. Specific agglutinins were not found in any of the embryos from two rabbits injected after 9 days post-coitum, by which time the yolk-sac fluid has ceased to increase in volume. Positive results were obtained both when rabbit and bovine immune sera were used. Active immunity to Br. abortus was induced in pregnant rabbits by injections beginning after the 15th day post-coitum. The serum of the newborn young, removed from their immune mothers before they had suckled, was tested and specific agglutinins were found to be present with a titre corresponding to that of the maternal serum. It was concluded that agglutinins, whether actively or passively acquired, pass freely from the maternal circulation into the yolk-sacs of 7- and 8-day rabbit embryos. This constitutes a delicate test of the passage of protein without alteration through the yolk-sac wall. The yolk-sac wall does not appear to be selective, since it is at least as permeable to foreign proteins as it is to those of maternal origin. Agglutinins pass from the maternal circulation into the embryo after the disappearance of the bilaminar wall of the yolk-sac also, either by way of the yolk-sac splanchnopleur or the allantochorionic placenta or both. The bearing of these results on current theories of placental permeability are discussed.


1978 ◽  
Vol 79 (3) ◽  
pp. 393-394 ◽  
Author(s):  
R. GUNASEGARAM ◽  
K. L. PEH ◽  
P. C. T. CHEW ◽  
S. M. M. KARIM ◽  
S. S. RATNAM

Department of Obstetrics and Gynaecology, University of Singapore, Kandang Kerbau Hospitalfor Women, Singapore 8, Republic of Singapore (Received 3 May 1978) From the previous studies of Bloch & Benirschke (1959, 1962) and Plotz, Kabara, Davis, LeRoy & Gould (1968) it appears that at mid-term, human foetal adrenal glands are capable of synthesizing C21- and C19-steroids de novo from acetate and cholesterol. Villee, Engel, Loring & Villee (1961), however, incubated slices and homogenates of foetal adrenal gland with [2-14C]acetate or [4-14C]cholesterol and could not demonstrate the incorporation of radioactivity into these steroids. Moreover, perfusion studies by three groups of investigators indicated only minute conversions of the same radioactive substrates into neutral steroids in the foetal adrenal glands (Solomon, Bird, Ling, Iwamiya & Young, 1967; Telegdy, Weeks, Archer, Wiqvist & Diczfalusy, 1970a; Telegdy, Weeks, Lerner, Stakemann & Diczfalusy, 1970b). It is widely believed that steroid hormones are normally synthesized from acetate via


Reproduction ◽  
2016 ◽  
pp. 171-184 ◽  
Author(s):  
Denis Aleksic ◽  
Lisa Blaschke ◽  
Sophie Mißbach ◽  
Jana Hänske ◽  
Wiebke Weiß ◽  
...  

Pregnancy-specific glycoproteins (PSGs) are members of the carcinoembryonic antigen cell adhesion molecule (CEACAM) family that are secreted by trophoblast cells. PSGs may modulate immune, angiogenic and platelet responses during pregnancy. Until now, PSGs are only found in species that have a highly invasive (hemochorial) placentation including humans, mice and rats. Surprisingly, analyzing the CEACAM gene family of the horse, which has a non-invasive epitheliochorial placenta, with the exception of the transient endometrial cups, we identified equine CEACAM family members that seem to be related to PSGs of rodents and primates. We identified seven genes that encode secreted PSG-like CEACAMs. Phylogenetic analyses indicate that they evolved independently from an equine CEACAM1-like ancestor rather than from a common PSG-like ancestor with rodents and primates. Significantly, expression of PSG-like genes (CEACAM44, CEACAM48, CEACAM49 and CEACAM55) was found in non-invasive as well as invasive trophoblast cells such as purified chorionic girdle cells and endometrial cup cells. Chorionic girdle cells are highly invasive trophoblast cells that invade the endometrium of the mare where they form endometrial cups and are in close contact with maternal immune cells. Therefore, the microenvironment of invasive equine trophoblast cells has striking similarities to the microenvironment of trophoblast cells in hemochorial placentas, suggesting that equine PSG-like CEACAMs and rodent and primate PSGs have undergone convergent evolution. This is supported by our finding that equine PSG-like CEACAM49 exhibits similar activity to certain rodent and human PSGs in a functional assay of platelet–fibrinogen binding. Our results have implications for understanding the evolution of PSGs and their functions in maternal–fetal interactions.


2018 ◽  
Vol 45 (3) ◽  
pp. 168-175 ◽  
Author(s):  
Raigam Jafet Martinez-Portilla ◽  
Ameth Hawkins-Villarreal ◽  
Pamela Alvarez-Ponce ◽  
Zarela Lizbeth Chinolla-Arellano ◽  
Ana Lisbeth Moreno-Espinosa ◽  
...  

2019 ◽  
Vol 3 (1) ◽  
pp. e000443 ◽  
Author(s):  
Ramin Iranpour ◽  
Amir-Mohammad Armanian ◽  
Ahmad-Reza Abedi ◽  
Ziba Farajzadegan

BackgroundCurrently, various forms of non-invasive respiratory support have been used in the management of respiratory distress syndrome (RDS) in preterm neonates. However, nasal high-frequency oscillatory ventilation (nHFOV) has not yet been applied commonly as an initial treatment.ObjectivesThis study was designed to investigate the efficacy and safety of nHFOV compared with nasal continuous positive airway pressure (NCPAP) in preterm and near-term infants with RDS.MethodsIn a randomised clinical trial, a total of 68 neonates (gestational age (GA) between 30 and 36 weeks and 6 days) with a clinical diagnosis of RDS were randomly assigned to either the NCPAP (n=34) or the nHFOV (n=34) group. The primary outcome was the duration of non-invasive respiratory support (duration of using NCPAP or nHFOV).ResultThe median (IQR) duration of non-invasive respiratory support, was significantly shorter in the nHFOV group than that in the NCPAP group (20 (15–25.3) versus 26.5 (15–37.4) hours, respectively; p=0.02). The need for a ventilator occurred in 4 out of 34 (11.8%) neonates in the NCPAP group and in none of the neonates in the nHFOV group (p=0.03). In addition, intraventricular haemorrhage (IVH) occurred in nine cases (6.9%) in the NCPAP group and two cases (3.3%) in the nHFOV group, which showed a significant difference (p=0.04). The incidence of pneumothorax, chronic lung disease, pulmonary haemorrhage and necrotising enterocolitis was similar between the two groups.ConclusionThis study showed that nHFOV significantly reduced the duration of non-invasive respiratory support and decreased the need for intubation compared with NCPAP in infants with RDS. Furthermore, nHFOV seems to reduce the incidence of IVH without increasing other complications.Trial registration numberIRCT2017062734782N1.


2010 ◽  
Vol 22 (9) ◽  
pp. 69
Author(s):  
G. Nie ◽  
Y. Li ◽  
M. Puryer ◽  
L. Salamonsen

The pathogenic origin of preeclampsia is defective placental development (placentation) and function. Preeclampsia is not diagnosed until later in pregnancy and reliable early detection is highly desirable. HtrA3 is a recently cloned gene with high expression during placentation in the mouse, rhesus monkey and human. In human 1st trimester placenta, HtrA3 is highly expressed in maternal decidual cells and in certain trophoblast cell types. Placental HtrA3 is secreted into the maternal circulation and clearly detectable in serum of pregnant women in the 1st trimester. The present study examined placental production and serum profile of HtrA3 across gestation in women, the potential molecular mechanisms regulating HtrA3 production, and association between maternal HtrA3 serum levels and preeclampsia. Immunohistochemistry determined HtrA3 expression pattern and cellular localization in 1st, 2nd and 3rd trimester placenta. Maternal serum HtrA3 levels were analysed by Western blotting. Regulation of placental HtrA3 production and secretion by oxygen tension was investigated in 1st trimester placental explants and trophoblast cells. Placental HtrA3 protein was maximally produced in the 1st trimester, then dramatically down-regulated, especially in the syncytiotrophoblast. HtrA3 was secreted into the maternal circulation with a serum profile reflecting placental production. Oxygen tension regulated HtrA3; low oxygen enhanced, while transition from low-to-high oxygen decreased, HtrA3 protein production in syncytiotrophoblast. Maternal serum HtrA3 levels at ~13-14 weeks of gestation were significantly higher in women who subsequently developed preeclampsia. It appeared that HtrA3 down-regulation was delayed in preeclamptic pregnancies. In conclusion, HtrA3 protein production is closely associated with oxygen tension in the placenta. The decline in HtrA3 at the end of 1st trimester may reflect the placental low-to-high oxygen switch. Abnormally high levels of serum HtrA3 at the end of 1st trimester is associated with preeclampsia.


2011 ◽  
Vol 85 (Suppl_1) ◽  
pp. 148-148
Author(s):  
Kaye L. Stenvers ◽  
Maree Bilandzic ◽  
Yao Wang ◽  
Jock K. Findlay

Sign in / Sign up

Export Citation Format

Share Document