Maternal nutritional restriction modulates placental VEGF immunolocalization and fetoplacental development in the rabbit

Maternal nutritional disorders during pregnancy can modify placental vascularization and therefore, fetal development. The aim of this work was to assess the effect of a feed restriction of 60% of the nutritional requirements during pregnancy on fetoplacental development, placental efficiency (fetal/placental weight) and expression of vascular endothelial growth factor (VEGF) in the rabbit. Multiparous pregnant rabbits were fed ad libitum (C; n = 17) or food restricted (R021, n = 25) from day (D) 0 to D21. On D28, 11 dams were euthanized to study fetoplacental features and the rest (n = 31) were used to assess perinatal survival and birth weight. Immunohistochemical studies of paraffined placentae (ABC method) was performed for VEGF. No differences were found in the number of viable fetuses between C and R021 groups (11.6 ± 2.9 vs. 12.0 ± 2.0). However, fetuses of C group showed higher size (thoracic diameter: 20.5 ± 2.8 vs. 19.1 ± 1.8 mm, occipital-nasal length: 29.0 ± 1.4 vs. 27.9 ± 1.4 mm); total weight (39.2 ± 7.3 vs. 34.7 ± 5–9 g), and separated head and body weights (9.1 ± 1.5 vs. 8.1 ± 1.1 and 29.3 ± 6.0 vs. 25.6 ± 4.8 g, respectively) than R021 (p < 0.05). Placental efficiency was lower in R021 than in C group (p < 0.05). VEGF was mainly immunolocalized in endothelial cells in labyrinth zone in both groups being slightly intensive in C group. Mean number of born alive per doe (10.4 ± 3.0 vs. 12.3 ± 3.1) and their weight (59.1 ± 9.8 vs. 56.4 ± 6.8 g) were similar between groups. In conclusion, maternal feed restriction seems to modulate VEGF expression, placental efficiency and fetal development in the rabbit. These effects were not reflected in a low body weight at parturition. (Funds by AGL2015-65572-C2.

Maternal nutritional restriction modulates placental VEGF immunolocalization and fetoplacental development in the rabbit

Maternal nutritional disorders during pregnancy can modify placental vascularization and therefore, fetal development. The aim of this work was to assess the effect of a feed restriction of 60% of the nutritional requirements during pregnancy on fetoplacental development, placental efficiency (fetal/placental weight) and expression of vascular endothelial growth factor (VEGF) in the rabbit. Multiparous pregnant rabbits were fed ad libitum (C; n = 17) or food restricted (R021, n = 25) from day (D) 0 to D21. On D28, 11 dams were euthanized to study fetoplacental features and the rest (n = 31) were used to assess perinatal survival and birth weight. Immunohistochemical studies of paraffined placentae (ABC method) was performed for VEGF. No differences were found in the number of viable fetuses between C and R021 groups (11.6 ± 2.9 vs. 12.0 ± 2.0). However, fetuses of C group showed higher size (thoracic diameter: 20.5 ± 2.8 vs. 19.1 ± 1.8 mm, occipital-nasal length: 29.0 ± 1.4 vs. 27.9 ± 1.4 mm); total weight (39.2 ± 7.3 vs. 34.7 ± 5–9 g), and separated head and body weights (9.1 ± 1.5 vs. 8.1 ± 1.1 and 29.3 ± 6.0 vs. 25.6 ± 4.8 g, respectively) than R021 (p < 0.05). Placental efficiency was lower in R021 than in C group (p < 0.05). VEGF was mainly immunolocalized in endothelial cells in labyrinth zone in both groups being slightly intensive in C group. Mean number of born alive per doe (10.4 ± 3.0 vs. 12.3 ± 3.1) and their weight (59.1 ± 9.8 vs. 56.4 ± 6.8 g) were similar between groups. In conclusion, maternal feed restriction seems to modulate VEGF expression, placental efficiency and fetal development in the rabbit. These effects were not reflected in a low body weight at parturition. (Funds by AGL2015-65572-C2.

Characterization of beta-Nerve Growth Factor-TrkA system in male reproductive tract of rabbit and the relationship between beta-NGF and testosterone levels with seminal quality during sexual maturation

b-Nerve Growth Factor (b-NGF) is a neurotrophin which acts through its receptors TrkA and p75, performing important actions in male reproductive physiology and its presence in seminal plasma (SP) has been related to male fertility. The aim of the present study was to evaluate the gene expression profile and the immunolocalization ofb-NGF and its high-affinity receptor TrkA in sex organs in rabbits during sexual maturation period.b-NGF concentration for both SP and blood plasma (BP) and BP testosterone levels were determined as well as the seminal parameters during such period. Ten New Zealand White x California young rabbits were trained to semen collection since 20 weeks of age and routinely done once a week with two ejaculations per session. At 22 and 37 weeks of age, semen collection was carried out three times a week and seminal parameters were evaluated. Four males were randomly assigned and slaughtered in each age (n¼8); sex organs (prostate, bulbourethral glands and epididymis) were dissected and collected to determineb-NGF and TrkA gene expression and immunolocalization. SP and BP were also taken at each semen collection session to evaluateb-NGF concentration, and testosterone levels were also assessed in BP. The highestb-NGF mRNA expression was observed in prostate compared to bulbourethral glands and epididymis. These two last tissues showed residualb-NGF mRNA expression and limited localization of the neurotrophin. The prostate epithelial cells and lumen were strongly stained with regard to the other sex organs indicating that immunolocalization ofb-NGF rely mainly in the prostate. TrkA gene expression was lower but constant and differentially immunolocalized in the sex organ tissues. Finally,b-NGF concentration in SP and BP remained unchanged in accordance to age, while some seminal characteristics such as sperm concentration, percentage of live sperm and mass and progressive motility were enhanced as endowed by BP testosterone variation.b-NGF and its cognate TrkA receptor are expressed and immunolocalized in the male reproductive tract in the two ages studied, independently of the circulating levels of testosterone andb-NGF

Indicadores metabólicos y de estrés tras el ajuste de consumo en conejas primíparas = Metabolic and stress indicators after intake adjustment in primiparous pregnant rabbit does

El objetivo principal de este trabajo fue determinar si aplicando un ajuste en el consumo de alimento durante la gestación en conejas primíparas, se ven afectados indicadores metabólicos y de estrés. Para ello, se utilizaron conejas primíparas, inseminadas después del destete que se dividieron en 4 grupos: Control (consumo od Iibitum toda la gestación, n=30), y restringidas al 60% de su consumo voluntario (1 OSg/d) la primera semana (RO?; n=31), la segunda y la tercera semana (R721; n=31) y las 3 primeras semanas (R021; n=30) de la gestación. En la cuarta y última semana de gestación todas disponían de pienso od libitum. Se tomaron muestras de sangre el día de la inseminación y tras el diagnóstico de gestación, se muestrearon animales gestantes de los 4 grupos en 3 puntos de la gestación el día 14 (n=20), 21 (n= 20) y 28 (n=20). Tras el parto, las hembras se re-inseminaron el día 14 post-parto y se tomaron muestras en otros 3 puntos de la lactación: día? (n=13), día 14 (n=13) y día 30 (n=41). En estas muestras se analizaron mediante enzimoinmunoanálisis: tri-iodotironina y tiroxina libres, y corticosterona. El ajuste del consumo de alimento durante la gestación aplicado en conejas primíparas afectó levemente a la homeostasis energética de los animales pero su estado de bienestar no se vio comprometido

Indicadores metabólicos y de estrés tras el ajuste de consumo en conejas primíparas = Metabolic and stress indicators after intake adjustment in primiparous pregnant rabbit does

El objetivo principal de este trabajo fue determinar si aplicando un ajuste en el consumo de alimento durante la gestación en conejas primíparas, se ven afectados indicadores metabólicos y de estrés. Para ello, se utilizaron conejas primíparas, inseminadas después del destete que se dividieron en 4 grupos: Control (consumo od Iibitum toda la gestación, n=30), y restringidas al 60% de su consumo voluntario (1 OSg/d) la primera semana (RO?; n=31), la segunda y la tercera semana (R721; n=31) y las 3 primeras semanas (R021; n=30) de la gestación. En la cuarta y última semana de gestación todas disponían de pienso od libitum. Se tomaron muestras de sangre el día de la inseminación y tras el diagnóstico de gestación, se muestrearon animales gestantes de los 4 grupos en 3 puntos de la gestación el día 14 (n=20), 21 (n= 20) y 28 (n=20). Tras el parto, las hembras se re-inseminaron el día 14 post-parto y se tomaron muestras en otros 3 puntos de la lactación: día? (n=13), día 14 (n=13) y día 30 (n=41). En estas muestras se analizaron mediante enzimoinmunoanálisis: tri-iodotironina y tiroxina libres, y corticosterona. El ajuste del consumo de alimento durante la gestación aplicado en conejas primíparas afectó levemente a la homeostasis energética de los animales pero su estado de bienestar no se vio comprometido

Improvements in the conception rate, milk composition and embryo quality of rabbit does after dietary enrichment with n-3 polyunsaturated fatty acids

This work attempts to confirm the effect of an enriched diet with n-3 polyunsaturated fatty acids (PUFA) trying to mitigate the reproductive performances issues such as low conception rate of primiparous rabbits. A total of 127 does were fed ad libitum throughout their two first cycles with two diets with different fat sources: mixed fat in the control and salmon oil in the enriched one, with 3.19 g/100 g (n=63 does) and 28.77 g/100 g (n=64 does) of n-3 of the total fatty acid, respectively. Feed intake was similar between groups ( P>0.05). Plasma progesterone concentration was higher in the enriched females than in control ones at 7 (30.9 ± 2.18 v. 23.9 ± 2.30 ng/ml, respectively; P= 0.029) and 14 (38.7 ± 2.18 v. 28.2 ± 2.30 ng/ml, respectively; P=0.001) days of first gestation. Considering both cycles, reproductive parameters of mothers (fertility, duration of gestation and prolificacy) and litter parameters (weight at parturition and weaning, mortality and average daily gain (ADG) of kits during lactation) were similar in both groups. However, individual measurements of neonates of enriched group improved 5.87%, 7.10% and 18.01% ( P 0.05), but embryo apoptosis rate was higher in control group than in enriched one (31.1 ± 4.56% v. 17.1 ± 3.87%, respectively; P < 0.05). In conclusion, dietary PUFA enrichment from the rearing and throughout two productive cycles improved plasma progesterone during pregnancy, fertility, milk fatty acid profile and neonates development of primiparous supporting the beneficial effect of n-3 PUFA supplementation in rabbit does

Efecto del factor de crecimiento nervioso recombinante de conejo (rrβNGF) en la dosis seminal sobre la respuesta hipofisaria y reproductiva en conejas nultíparas

El conejo es una especie de ovulación inducida, en la que los estímulos sensoriales y neuroendocrinos parecen actuar en conjunto para inducir una oleada preovulatoria de (LH) (Barbe et al., 1973). En el caso de conejas inseminadas artificialmente (IA), la ovulación se suele inducir con una inyección intramuscular de análogos de (GnRH) (Rebollar et al., 1997). La tendencia, en la actualidad, es reducir todo lo posible la manipulación de la hembra y el gasto de consumibles (agujas y jeringuillas) en el momento de la IA. Una alternativa para esto podría ser la utilización de la neurotrofina β-NGF, que actúa como factor inductor de ovulación en camélidos (Ratto et al., 2013), incluida en la dosis seminal. Dado que recientemente hemos sintetizado la proteína recombinante de conejo (rrβNGF) (Sánchez-Rodríguez, 2018), el objetivo del presente trabajo ha sido evaluar el efecto de este factor incluido en la dosis seminal, sobre la liberación de LH hipofisaria y la fertilidad en conejas nulíparas

Efecto del factor de crecimiento nervioso recombinante de conejo (rrβNGF) en la dosis seminal sobre la respuesta hipofisaria y reproductiva en conejas nultíparas

El conejo es una especie de ovulación inducida, en la que los estímulos sensoriales y neuroendocrinos parecen actuar en conjunto para inducir una oleada preovulatoria de (LH) (Barbe et al., 1973). En el caso de conejas inseminadas artificialmente (IA), la ovulación se suele inducir con una inyección intramuscular de análogos de (GnRH) (Rebollar et al., 1997). La tendencia, en la actualidad, es reducir todo lo posible la manipulación de la hembra y el gasto de consumibles (agujas y jeringuillas) en el momento de la IA. Una alternativa para esto podría ser la utilización de la neurotrofina β-NGF, que actúa como factor inductor de ovulación en camélidos (Ratto et al., 2013), incluida en la dosis seminal. Dado que recientemente hemos sintetizado la proteína recombinante de conejo (rrβNGF) (Sánchez-Rodríguez, 2018), el objetivo del presente trabajo ha sido evaluar el efecto de este factor incluido en la dosis seminal, sobre la liberación de LH hipofisaria y la fertilidad en conejas nulíparas