Characteristics of the equine placenta at first trimester / Características de la placenta equina en el primer trimestre

The equine placenta is a simple apposition of fetal and maternal tissues, becoming more complex with the formation of microcotyledons around days 75 and 100 of gestation. The present study aimed to describe the gross and microscopic morphology of early equine placenta. Embryonic/fetal membranes from thirty-seven mares were submitted to macroscopic description, light, scanning and transmission microscopy. Overall the gross characteristics of membranes were similar with already described for older stages. However, transmission electron microscopy evidenced high metabolic rate in chorion and allantois, and high secretion profile in amnion and even higher in yolk sac. Gene ontologies enrichment, using published data, pointed several common ontologies in allantoic and amniotic fluids, related to oxygen and iron transport, extracellular space and high-density lipoprotein receptor binding. Overall, the morphological and ontology enrichment could indicate allantois and amnion crosstalk.

La placenta equina es una simple aposición de tejidos fetales y maternos, que se vuelve más compleja con la formación de microcotiledones alrededor de los días 75 y 100 de gestación. El presente estudio tuvo como objetivo describir la morfología macroscópica y microscópica de la placenta equina temprana. Las membranas embrionarias / fetales de treinta y siete yeguas fueron sometidas a descripción macroscópica, luz, escaneo y microscopía de transmisión. En general, las características generales de las membranas fueron similares a las ya descritas para las etapas más antiguas. Sin embargo, la microscopía electrónica de transmisión mostró una alta tasa metabólica en corion y alantoides, y un alto perfil de secreción en amnios e incluso mayor en el saco vitelino. El enriquecimiento de ontologías génicas, utilizando datos publicados, señaló varias ontologías comunes en fluidos alantoideos y amnióticos, relacionados con el transporte de oxígeno y hierro, espacio extracelular y unión a receptores de lipoproteínas de alta densidad. En general, el enriquecimiento morfológico y ontológico podría indicar alantoides y diafonía de amnios.

A hypomorphic Cbx3 allele causes prenatal growth restriction and perinatal energy homeostasis defects.

Mammals have three HP1 protein isotypes HP1β (CBX1), HP1γ (CBX3) and HP1α (CBX5) that are encoded by the corresponding genes Cbx1, Cbx3 and Cbx5. Recent work has shown that reduction of CBX3 protein in homozygotes for a hypomorphic allele (Cbx3hypo) causes a severe postnatal mortality with around 99% of the homozygotes dying before weaning. It is not known what the causes of the postnatal mortality are. Here we show that Cbx3hypo/hypo conceptuses are significantly reduced in size and the placentas exhibit a haplo-insufficiency. Late gestation Cbx3hypo/hypo placentas have reduced mRNA transcripts for genes involved in growth regulation, amino acid and glucose transport. Blood vessels within the Cbx3hypo/hypo placental labyrinth are narrower than wild-type. Newborn Cbx3hypo/hypo pups are hypoglycemic, the livers are depleted of glycogen reserves and there is almost complete loss of stored lipid in brown adipose tissue (BAT). There is a 10-fold reduction in expression of the BAT-specific Ucp1 gene, whose product is responsible for nonshivering themogenesis. We suggest that it is the small size of the Cbx3hypo/hypo neonates, a likely consequence of placental growth and transport defects, combined with a possible inability to thermoregulate that causes the severe postnatal mortality.

Efeito da enrofloxacina sobre a interação blastocisto endométrio e seu reflexo no desenvolvimento placentário e fetal em ratas / Effect of enrofloxacin on the blastocyst endometrial interactions and their impact on placental and fetal development in rats

Estudos têm mostrado efeitos tóxicos da enrofloxacina em diversos tecidos. Assim, testou-se a hipótese de que a enrofloxacina pode interferir no desenvolvimento placentário e gerar efeitos adversos ao feto. A enrofloxacina (Baytril(r)) foi administrada em ratas, na dose de 5mg/kg, diariamente, IM, durante toda a gestação. As placentas foram analisadas morfologicamente, morfometricamente e imuno-histoquimicamente aos sete, 14 e 21 dias de prenhez. Os resultados mostraram que a enrofloxacina reduziu o número de sítios de implantação, o peso e a área total do disco placentário aos 14 e 21 dias de desenvolvimento, além dos elementos constituintes da placenta. A análise histoquímica não revelou alterações significativas no teor de fibras colágenas, elásticas e reticulares. O teste de Tunel mostrou atividade apoptótica apenas nas placentas com 14 dias de desenvolvimento de ambos os grupos, sendo mais intensa no grupo tratado. Não foi observado nenhum indício de malformação na cabeça, no tronco e nos membros dos neonatos. No entanto, houve uma redução significativa no número e no peso dos neonatos no grupo tratado, porém sem afetar o seu comprimento. Assim, concluiu-se que a enrofloxacina administrada na dosagem de 5mg/kg durante prenhez em ratas interfere no número de embriões implantados e no desenvolvimento placentário. Isto sugere cautela na administração da enrofloxacina durante a gestação, pois a exposição contínua a esse antibiótico pode ter reflexos na redução do número e do peso da prole...

Some studies have shown the toxic effects of enrofloxacin in various tissues. Thus, the hypothesis that enrofloxacin could interfere with placental development and generate adverse effects to the fetus was tested in this study. Enrofloxacin (Baytril(r)) was administered in the dose of 5mg/kg daily, i.m., throughout gestation in rats. The placentas were analyzed morphologically, morphometrically, and immunohistochemically on the 7, 14, and 20th days of pregnancy. The results showed that enrofloxacin reduced the number of implantation sites, weight, and placental disk total area at 14 and 20 days of development, in addition to the element components of the placenta. The histochemical analysis did not reveal significant changes in the content of collagen, reticular, and elastic fibers. The TUNEL test showed apoptosis only in placenta development at 14 days in both groups and more intense in the treated group. Head, trunk, and limb malformations were not observed in the neonates. A significant reduction in the number and weight of neonates were observed in the treated group, however, without affecting their length. Thus, it was concluded that the administration of enrofloxacin, at the dosage of 5 mg/kg during pregnancy in rats, interferes in the number of implanted embryos and placental development. This suggests caution in the administration of enrofloxacin during pregnancy because continuous exposure to this antibiotic may have adverse effects, reducing the number and weight of the offspring...

Desarrollo placentario temprano: aspectos fisiopatológicos

El éxito de la gestación humana es el resultado de una sucesión de procesos que se dan en forma coordinada en tiempo y espacio en la interfase materno, placentario, embrionario-fetal. El fallo de esta sucesión de procesos determina una inadecuada placentación, preeclampsia y restricción del crecimiento intrauterino. En este artículo se revisa aspectos fisiopatológicos del desarrollo placentario temprano.

Successful human pregnancy is the result of a series of processes that occur in a coordinated manner in time and space in the embryonic, placental, fetal-maternal interface. Failure of these series of processes determines inadequate placentation, preeclampsia and intrauterine growth restriction. Pathophysiological aspects of early placental development are reviewed in this article.

Desórdenes hipertensivos asociados a desprendimiento prematuro grave de placenta normoinserta / Hypertensive disorders associated with severe abruption placentae

Para evaluar el desarrollo de la vellosidad de anclaje, en desórdenes hipertensivos del embarazo, asociados con desprendimiento prematuro grave de placenta normoinserta (DPGPN), en el laboratorio de microscopía electrónica de la Facultad de Ciencias de la Salud. Universidad de Carabobo se examinaron 20 placentas, 17 con desórdenes hipertensivos y tres de embarazos normales, en el tercer trimestre, aplicándose protocolo con las variables que determinan tipos de vellosidades según su desarrollo y cambios degenerativos encontrados con microscopía de luz. Se encontró 91% de vellosidad troncal, 92% de intermedia madura, 28% de intermedia inmadura, 47% de terminales, 92% con membrana vásculosincitial periférica y 44% de membrana vásculosincitial central y notables cambios degenerativos como cambios fibrinoides en el 100%, igual la necrosis del trofoblasto, 96% de fibrosis estromal, 88% de edema y 74% de hemorragia; además 92% de trombosis, congestión vascular y cambios de la pared del vaso y más de seis vasos en las vellosidades en 52%. El espacio íntervelloso tiene importantes cambios como los depósitos de fibrina en 84%, la trombosis íntervellosa en 76% y los infartos en 56%, estos cambios degenerativos son estadísticamente significativos. Conclusión: un acelerado crecimiento de la vellosidad empotrada en la placa basal o cercana a ella se evidencia en los resultados con simultáneos procesos indicativos de degeneración y desarrollo anormal en un ambiente de daño velloso hipóxico extenso.

To evaluate the development of placental anchoring villi of the basal plate in hypertensive disorders of pregnancy associated with abruption placentae severe. Twenty placentas were examined. Seventeen patients with hypertensive disorders and three of normal pregnancy during the third trimester of gestation applying a protocol in order to determine types of villi according to their development and degenerative changes found with light microscopy. We found 91% of stem villi, 92% of intermediate mature villi, 28% of intermediate immature villi, 47% of terminal villi, 92% with peripheral and 44% vascular sincitial membrane and 44% central vascular sincitial membrane also remarkable degenerative changes, as fibrinoide deposits and trophoblastic necrosis in 100%, fibrous stroma 96%, edema 88% and hemorrhage 74%; moreover 92% off thrombosis, vascular congestion and changes vessel wall and mayor six vessel in 52%. Intervellous space have important changes as fibrin deposits in 84%, intervellous thrombosis 76% and intervellous attach 56%. All degenerative changes are statistically significant. Conclusion: An accelerated development of placental anchor villi or of other villous types near to basal plate were seen with simultaneous processes indicative of degeneration as extensive hypoxic villous damage and abnormal development.