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Background: Leptin resistance is associated with lower reproductive efficiency, with deficiencies in embryo viability and growth leading to low prolificacy and high incidence of intrauterine growth restriction. Objective: We aimed to investigate the underlying mechanisms of the leptin-resistance, evaluating the antioxidant homeostasis of leptin-resistant and lean swine fetuses. Materials and Methods: The study included 70 plasma samples from fetuses at day 62 of gestation (mid-pregnancy), from breeds with (Iberian breed; n=35) and without leptin resistance (25% Large White x 25% Landrace x 50% Pietrain; n=35). The antioxidant status of the plasma samples was determined by photoinduced chemiluminescence whilst systemic oxidative stress was assessed determining plasma hydrogen peroxide concentration by enzimoimmunoassay. Results: Plasma total antioxidant capacity was significantly lower in leptin-resistant fetuses (p=0.003), whilst systemic oxidative stress was increased (p=0.02). Conclusion: Our results indicate key differences in the antioxidant status in pregnancies affected by leptin resistance

Hydroxytyrosol is a polyphenol with antioxidant, metabolism-regulatory, anti-inflammatory and immuno-modulatory properties. The present study aimed to determine whether supplementing the maternal diet with hydroxytyrosol during pregnancy can improve pre- and early post-natal developmental patterns and metabolic traits of the offspring. Experiment was performed in Iberian sows fed a restricted diet in order to increase the risk of IUGR. Ten sows were treated daily with 1.5 mg of hydroxytyrosol per kg of feed between Day 35 of pregnancy (30% of total gestational period) until delivery whilst 10 animals were left untreated as controls. Number and weight of offspring were assessed at birth, on post-natal Day 15 and at weaning (25 days-old). At weaning, body composition and plasma indexes of glucose and lipids were measured. Treatment with hydroxytyrosol was associated with higher mean birth weight, lower incidence of piglets with low birth weight. Afterwards, during the lactation period, piglets in the treated group showed a higher body-weight than control piglets; such effects were even stronger in the most prolific litters. These results suggest that maternal supplementation with hydroxytyrosol may improve pre- and early post-natal development of offspring in pregnancies at risk of IUGR.

The use of polyphenols is a promising strategy for preventing or alleviating intrauterine growth restriction (IUGR) because polyphenol supplementation increases plasma antioxidant capacity and improves oxidative stress at the feto-placental unit; which are recognized as main issues in IUGR. However, there is a scarcity of experimental data on both realistic benefits and potential hazards of polyphenol supplementation during gestation. Hence, we aimed to use a swine model of IUGR pregnancy to determine possible effects of maternal supplementation with polyphenols (hydroxytyrosol) on placental expression of genes involved in antioxidant homeostasis, vascularization and fetal growth and thus on antioxidant status, DNA-methylation and phenotypic traits (morphology and homeostasis) of the fetus. Hydroxytyrosol improves placental gene expression and fetal antioxidant status and glucose metabolism in a sex-dependent manner, in which males were favored in spite of developmental failures. Concomitantly, hydroxytyrosol prevented hypomethylation of DNA associated with oxidative stress. Finally, no major deleterious effects of hydroxytyrosol supplementation on constriction of the ductus arteriosus, a possible secondary effect of polyphenols during pregnancy, were found.

The Iberian pig is an autochthonous breed of the Mediterranean area, reared extensively in the central and southern areas of Spain and Portugal and that is known worldwide for the production of Iberian ham. The characteristics of the Iberian ham are related to its abundance of intramuscular fat, owing to the high capacity of the pig to accumulate fat under its skin and between the muscular fibres. This ability to store excess fat enables survival during periods of scarcity and it has been found in other antique animal breeds and even in humans, being named as the thrifty genotype. The reproductive management of the Iberian pig, in spite of a lack of accurate information unlike in other swine breeds, is based on the assumption of lower reproductive precocity and efficiency than the modern commercial breeds. The current study characterized and compared the onset of puberty in gilts of Iberian breed and meat commercial crosses (Large White × Landrace) reared in the same conditions by assessing weekly plasma progesterone profiles. At the end of the experimental period, when the gilts became 180 days old, the percentage of Iberian females that had reached puberty was 72.2%, with a mean age and weight of 160.5 ± 2.6 days and 92.9 ± 4.7 kg, respectively. The percentage of Large White × Landrace cross-breed females reaching puberty at 180 days was only 15% (p < 0.05). The mean age and weight were 165.0 ± 4.1 days and 107.8 ± 2.2 kg (p < 0.05), respectively. Thus, converse to the traditional assumption, onset of puberty was advanced in Iberian gilts. These results are important for the reproductive management of the Iberian pig but, at the same time, may set the basis for future studies on the metabolism-reproduction link and, specifically, on the possible relationship between earlier accumulation of fat and attainment of puberty. [ABSTRACT FROM AUTHOR]

The use of polyphenols is a promising strategy for preventing or alleviating intrauterine growth restriction (IUGR) because polyphenol supplementation increases plasma antioxidant capacity and improves oxidative stress at the feto-placental unit; which are recognized as main issues in IUGR. However, there is a scarcity of experimental data on both realistic benefits and potential hazards of polyphenol supplementation during gestation. Hence, we aimed to use a swine model of IUGR pregnancy to determine possible effects of maternal supplementation with polyphenols (hydroxytyrosol) on placental expression of genes involved in antioxidant homeostasis, vascularization and fetal growth and thus on antioxidant status, DNA-methylation and phenotypic traits (morphology and homeostasis) of the fetus. Hydroxytyrosol improves placental gene expression and fetal antioxidant status and glucose metabolism in a sex-dependent manner, in which males were favored in spite of developmental failures. Concomitantly, hydroxytyrosol prevented hypomethylation of DNA associated with oxidative stress. Finally, no major deleterious effects of hydroxytyrosol supplementation on constriction of the ductus arteriosus, a possible secondary effect of polyphenols during pregnancy, were found.

Background: Leptin resistance is associated with lower reproductive efficiency, with deficiencies in embryo viability and growth leading to low prolificacy and high incidence of intrauterine growth restriction., Objective: We aimed to investigate the underlying mechanisms of the leptin-resistance, evaluating the antioxidant homeostasis of leptin-resistant and lean swine fetuses., Materials and Methods: The study included 70 plasma samples from fetuses at day 62 of gestation (mid-pregnancy), from breeds with (Iberian breed; n=35) and without leptin resistance (25% Large White x 25% Landrace x 50% Pietrain; n=35). The antioxidant status of the plasma samples was determined by photoinduced chemiluminescence whilst systemic oxidative stress was assessed determining plasma hydrogen peroxide concentration by enzimoimmunoassay., Results: Plasma total antioxidant capacity was significantly lower in leptin-resistant fetuses (p=0.003), whilst systemic oxidative stress was increased (p=0.02)., Conclusion: Our results indicate key differences in the antioxidant status in pregnancies affected by leptin resistance., Competing Interests: The authors declare that they had no competing or conflict of interests.

Hydroxytyrosol is a polyphenol with antioxidant, metabolism-regulatory, anti-inflammatory and immuno-modulatory properties. The present study aimed to determine whether supplementing the maternal diet with hydroxytyrosol during pregnancy can improve pre- and early post-natal developmental patterns and metabolic traits of the offspring. Experiment was performed in Iberian sows fed a restricted diet in order to increase the risk of IUGR. Ten sows were treated daily with 1.5 mg of hydroxytyrosol per kg of feed between Day 35 of pregnancy (30% of total gestational period) until delivery whilst 10 animals were left untreated as controls. Number and weight of offspring were assessed at birth, on post-natal Day 15 and at weaning (25 days-old). At weaning, body composition and plasma indexes of glucose and lipids were measured. Treatment with hydroxytyrosol was associated with higher mean birth weight, lower incidence of piglets with low birth weight. Afterwards, during the lactation period, piglets in the treated group showed a higher body-weight than control piglets; such effects were even stronger in the most prolific litters. These results suggest that maternal supplementation with hydroxytyrosol may improve pre- and early post-natal development of offspring in pregnancies at risk of IUGR.

The current study indicates that life-long intake, from early-life, of an obesogenic diet with high saturated-fat (HSF) content induces dyslipidemia (high plasma concentrations of triglycerides in concurrence with low concentrations of HDL-cholesterol) in obese swine with leptin resistance (Iberian sows). In case of pregnancy, ovarian features (ovulatory efficiency and luteal steroidogenesis) of sows fed with HSF are not affected but embryo features are affected at so early stages like 28 days of pregnancy (first quarter), although embryo viability was still not affected. In this way, offspring from HSF sows showed a higher incidence of alterations in their developmental trajectory, mainly due to a higher incidence of growth retardation, in their steroidogenic activity and in their availability of triglycerides and cholesterol. In conclusion, the results obtained in the present study illustrate the deleterious effects of maternal dyslipidemia, induced by the intake of HSF diets, on the oestradiol secretion of the conceptuses at early-pregnancy stages and, thus, on their developmental and metabolic features. This article is part of a Special Issue entitled 'Pregnancy and steroids'., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Patterns of leptin secretion during the estrous cycle and the possible relationship of changes in circulating leptin during the periovulatory period with ovarian function in sows of obese (Iberian breed) and lean genotype (Large White x Landrace) were evaluated in two consecutive experiments. Plasma leptin concentrations throughout the estrous cycle in lean sows remain unchanged, but Iberian females showed a periovulatory increase in circulating leptin levels without associated changes in body condition and fatness. In these sows, plasma leptin concentrations at Days -1 and 0 of the cycle were found to be positively correlated with the ovulation rate (r=0.943 and r=0.987, respectively; P<0.05 for both), but the levels of leptin at Day 0 were negatively correlated with the progesterone release from Day 3 (r=-0.557; P<0.05) and, became more evident at Day 5 of the estrous cycle (r=-0.924; P<0.005). Such relationships were not observed in the females of the lean genotype. In conclusion, the present study indicates the existence of a distinctive pattern in the periovulatory leptin secretion in swine with obesity and leptin resistance, which is associated with the number and functionality of the corpora lutea present in the subsequent cycle., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Our objective was to determine the effects of the administration of growth hormone (GH) alone or plus teverelix, a gonadotrophin releasing hormone antagonist (GnRHa), on follicle development in sheep. Ewes were treated daily for 6 days by the intramuscular route with 15 mg of GH alone (GH group; n = 6) or combined with two subcutaneous doses of GnRHa (1.5 mg) on days 0 and 3 of GH treatment (GH/GnRHa group; n = 6); the control group (n = 6) received similar treatment with saline solution. Plasma follicle stimulating hormone levels were significantly lower in the GH/GnRHa group than in the control (P < 0.001) and GH groups (P < 0.05). The number of follicles > or =2 mm increased to reach significant differences with control (18.7 +/- 0.6) on day 4 in GH/GnRHa group (22.7 +/- 0.5, P < 0.001) and on day 5 in GH group (20.3 +/- 0.4 vs. 17.0 +/- 0.6, P < 0.05). These results indicate that GH and GnRHa may be useful for increasing the number of gonadotrophin-responsive follicles in the ovary. However, follicle function could be affected as both GH and GH/GnRHa groups showed lower plasma inhibin A concentrations than control sheep (90-110 pg/mL vs. 170-185 pg/mL, P < 0.005).