RESUMO

In porcine placenta, abnormal development of the placental vasculature leads to placental insufficiency. The aim of this study was to determine the mRNA expression of angiogenic growth factors and to determine the vascular characteristics in placenta at day 40 of pig gestation. Samples were collected from maternal-chorioallantoic interface (n = 21) for the measurement of mRNA expression of VEGFA, ANGPT1, ANGPT2, FGF2 and its receptors KDR, TEK, FGFR1IIIc, FGFR2IIIb respectively, and for immunohistochemistry analysis of CD31 and VEGFA. Immunohistochemical analysis of CD31 and VEGFA, morphometric measurement of blood vessels, high-resolution light microscopy and transmission electron microscopy were performed. Capillary area density, number of blood vessels and capillary area were significantly higher on the maternal side than on the fetal side (p < .05). The ultrastructural finding of blood vessels demonstrates close contact with the trophoblastic epithelium. The relative mRNA expression of VEGFA and its receptor KDR was higher compared with the other angiogenic genes. In conclusion, a high mRNA expression of VEGFA and its receptor KDR added to the immunohistochemical results suggest a potential role of these genes in this pathway associated with an increase in the density of the capillary area on the maternal side and a reduction in the hemotrophic diffusion distance at the interface for nutrient exchange.

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RESUMO

Porcine embryo mortalities cause economic losses. Development of the placental vascular bed is required for successful gestation and postnatal survival. We studied the temporal and spatial distributions of vascular endothelial growth factor (VEGF), placenta growth factor (PlGF) and their receptors, Flt-1 and Flk-1. We used crossbred swine placental tissues from 30, 60, 80, 90 and 114 (term) days of gestation. Both VEGF and PlGF were present during gestation. At early pregnancy and at term, VEGF probably acts through Flt-1; during intermediate periods, its function is mediated by Flk-1. By day 90, factors other than members of VEGF family appear to be involved.

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RESUMO

The aim of this study was to evaluate the effect of feed restriction followed by a realimentation with monensin supplementation on morphological, ultrastructural, and apoptotic characteristics in the term placenta of Anglo-Nubian does. Treatments were a control group (C = 5), a group fed at 0.70 of that consumed by controls (R = 7), and the same as R with monensin (M = 7). After parturition, 27 placentas were gathered, C: 7, M: 10, and R: 10. No differences were detected between treatments in relation to morphological and ultrastructural analysis. The greatest values of binucleate cells were detected in placentas from R, and it could be due to the need to compensate and satisfy nutritional differences of restriction. We detected the highest apoptotic index in R as a consequence of nutritional treatment. We describe for the first time the structural and ultrastructural morphology and remodeling by apoptosis of Anglo-Nubian placenta at term of goats subjected to nutritional restriction during peripubertal period and the use of monensin as a growth promoter.

RESUMO

The molecules that constitute the extracellular matrix are important in several functions related to tissue support and cell-cell, cell-extracellular matrix interaction. Among the macromolecules that constitute the mentioned matrix we find osteopontin, fibrinogen and collagen. The present study was undertaken to analyze the rol of osteopontin, fibrinogen and collagen in uterine-placental interface during normal porcine gestation. Uterine and placental tissues from crossbred gilts of 30 (n=5), 60 (n=5), 70 (n=5) and 114 (at term, n=5) days of gestation were used. Macroscopic analysis of the embryos/fetuses allowed us to determine their gestational age by means of the crown-rump lenght. Haematoxylin-Eosin and Masson's Trichrome dyes along with light microscopy were used to structure analysis of every selected period of gestation. A spacial and temporal study of osteopontin and fibrinogen was performed through immunohistochemical technique. Determination of collagen fibers was carried out through Picrosirius red technique and polarizing microscopy. Results were expressed as semi-quantitative. Higher expression of osteopontin was observed at early periods of gestation, mainly in uterine and placental villi, endometrial gland epithelium and histotroph. Fibrinogen expressed abundantly in fetal mesenchyme in every period analyzed and in fetal and maternal vessels at Day 70. Negative expression of collagen fibers was observed in villi, however increasing expression of thick fibers throughout pregnancy was detected in uterine stroma and myometrium. These results confirm the importance of osteopontin, fibrinogen and collagen in the support of uterine and placental structures and in the suitable maintenance of pregnancy.

Las moléculas que constituyen la matriz extracelular son importantes en varias funciones relacionadas con el soporte del tejido y la interacción célula-célula, célula-matriz extracelular. Entre las macromoléculas que constituyen la matriz mencionada se encuentra la osteopontina, el fibrinógeno y el colágeno. Este estudio se realizó para analizar el rol de la osteopontina, el fibrinógeno y el colágeno en la interface útero-placentaria durante la gestación porcina normal. Tejidos uterinos y la placentarios de hembras porcinas cruzadas de 30 (n=5), 60 (n=5), 70 (n=5) y 114 (a término, n=5) días de gestación fueron utilizados. El análisis macroscópico de los embriones/fetos nos permitió determinar la edad gestacional por medio de la longitud cráneo-rabadilla. Tinciones de Hematoxilina-Eosina y Tricrómico de Masson con microscopía de luz se utilizó para estructurar el análisis de cada periodo de tiempo seleccionado de la gestación. Un estudio espacial y temporal de la osteopontina y el fibrinógeno se realizó mediante técnicas de inmunohistoquímica. La determinación de fibras colágenas se llevó a cabo a través de la técnica Picrosirius rojo por microscopia de polarización. Los resultados se expresaron como semi-cuantitativos. La expresión de osteopontina se observó en los primeros períodos de gestación, principalmente en las vellosidades del útero y la placenta, epitelio de las glándulas endometriales e histotrofos. El fibrinógeno se expresa abundantemente en mesénquima fetal en todos los períodos analizados y en los vasos fetales y maternos el día 70. Una expresión negativa de fibras colágenas se observó en las vellosidades, sin embargo, un aumento de expresión de las fibras gruesas durante la gestación se detectó en el estroma uterino y el miometrio. Estos resultados confirman la importancia de la osteopontina, fibrinógeno y colágeno en el soporte de las estructuras del útero y placenta, así como el mantenimiento adecuado durante la gestación.

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RESUMO

Aflatoxins (AF) are a major problem in broiler production and are significant economic and public health burdens worldwide. A commercial sodium bentonite (Na-B) adsorbent was used to prevent the effect of AF [50 µg of aflatoxin B1 (AFB1)/kg of feed] in broiler productivity, biochemical parameters, macroscopic and microscopic liver changes, and AFB1 liver residues. The influence of Na-B (0.3%) and monensin (MON, 100 mg/kg), alone or in combination, was investigated in depth. The dietary treatments were as follows: treatment (T) 1: basal diet (B); T2: B + MON; T3: B + Na-B; T4: B + Na-B + MON; T5: B + AFB1; T6: B + AFB1 + Na-B + MON; T7: B + AFB1 + MON; T8: B + AFB1 + Na-B. Birds were fed dietary treatments for 28 d (d 18 to 46). No significant differences (P < 0.05) were observed among treatments with respect to broiler performance, biochemical parameters, or relative liver weights. With the exception of T8, all livers showed histopathological alterations, with accumulation of fat vacuoles. The normal appearance of livers from T8 showed the protective effect of Na-B against aflatoxicosis. The residual AFB1 levels in livers from T5 to T8 ranged from 0.2 to 1.0 ng/g and were higher in livers from T6 (P < 0.05). Results of this study indicate a competition between AFB1 and MON for adsorption sites on Na-B when feed contains low levels of the toxin, indicating a nonselective adsorption capacity of this particular Na-B. In addition, significant levels of AFB1 in livers indicate that this determination is an important technique not only for diagnosis of aflatoxicosis in broilers, but also for quality control of avian products.

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