Person: Lorenzo González, Pedro Luis
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First Name
Pedro Luis
Last Name
Lorenzo González
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Fisiología
Area
Fisiología
Identifiers
13 results
Search Results
Now showing 1 - 10 of 13
Item Physiological effects on rabbit sperm and reproductive response to recombinant rabbit beta nerve growth factor administered by intravaginal route in rabbit does(Theriogenology, 2020) Sánchez Rodríguez, Ana; Arias Álvarez, María; Millán Pastor, María Pilar; Lorenzo González, Pedro Luis; García García, Rosa María; García Rebollar, PilarBeta nerve growth factor (β-NGF) is present in the seminal plasma of some species, including rabbits, acting as an ovulation-inducing factor in camelids. Traditionally, GnRH analogues are used to induce ovulation by intramuscular route when artificial insemination (AI) is performed in rabbit does. A specific rabbit recombinant β-NGF (rrβ-NGF) produced in our laboratory was tested as an alternative method to conventional treatment with GnRH analogues to induce ovulation. In the present work, different concentrations (0, 20, 100 ng/mL and 1, 20 and 100 μg/mL) of rrβ-NGF were added to diluted semen to assess its effect on sperm traits (viability and motility parameters). rrβ-NG was used also, incorporated to the AI dose, to evaluate ovulation response (LH and progesterone plasma concentrations, ovulation rate (OR) and embryo implantation at Day 7) after intravaginal administration. A negative control group stimulated with an empty catheter, and a positive control group inseminated and intramuscularly treated as usual with GnRH were also set up. Results showed that seminal quality was influenced by rrβ-NGF depending on the concentration added, being the highest concentrations tested deleterious for semen. Whereas the highest OR was found in the positive control group (100%), concentrations of 20 ng/mL, 1 μg/mL and 20 μg/mL of rrβ-NGF triggered intermediate OR (30, 60 and 42.9%, respectively), and 100 ng/mL and 100 μg/mL had the lowest OR (20 and 14.3%, respectively). Although LH peak was not observed in the first 2 h after AI in the ovulated females from rrβ-NGF groups, plasma progesterone significantly increased at Day 7, except in those females treated with 20 and 100 μg/mL. Also, 98.4% of ovulated females were pregnant on Day 7. In conclusion, rrβ-NGF added to diluted semen affects seminal quality and provokes ovulation, the development of functional CL and conception by intravaginal route in rabbit does, depending on the concentration added.Item Female reproduction and the microbiota in mammals: Where are we?(Theriogenology, 2022) García García, Rosa María; Arias Álvarez, María; Jordán Rodríguez, Daniela; Rebollar, Pilar G.; Lorenzo González, Pedro Luis; Herranz Sorribes, Carmen; Rodríguez, Juan MiguelWhile it is generally accepted that the mammalian vagina contains a site-specific microbiota that plays relevant roles in genital and reproductive health, the existence of an extra-vaginal microbiota in the female reproductive tract (i.e. follicular fluid, oviduct, endometrium, and placenta) is, at least, a matter of controversy. Many conclusions in this field have failed to consider the technical limitations, biases, and confounding factors inherent to next-generation sequencing (NGS) approaches. While this creates uncertainty in the field, there is no doubt this subject is set to be the focus of new research efforts because of its scientific and practical connotations in female reproductive health. The current art state, its limitations, and gaps in our knowledge about the female reproductive tract's microbiota and, particularly, about the microbes of the extra-vaginal environment are presented in this review. Also are discussed possible relationships between the gut and oral microbiota and reproductive events.Item Gestation Food Restriction and Refeeding Compensate Maternal Energy Status and Alleviate Metabolic Consequences in Juvenile Offspring in a Rabbit Model(Nutrients, 2021) García García, Rosa María; Arias Álvarez, María; Millán Pastor, María Pilar; Rodríguez, María; Sánchez Rodríguez, Ana; Lorenzo González, Pedro Luis; Rebollar, Pilar G.Nutritional status during gestation can influence mother and offspring metabolism. Undernutrition in pregnancy affects women in both western and developing countries, and it is associated with a high prevalence of chronic diseases in later life. The present work was conducted in the rabbit model, as a longitudinal study, to examine the effect of food restriction during early and mid-gestation, and re-feeding ad libitum until the end of pregnancy on metabolic status and body reserves of mother and, its association with development and metabolism of fetuses and female offspring to the juvenile stage. Little changes in live body weight (LBW), compensatory feed intake, similar body reserves, and metabolism were observed in dams. Placenta biometry and efficiency were slightly affected, but fetal BW and phenotype were not modified. However, hyperinsulinemia, insulin resistance, and hypertriglyceridemia were demonstrated in pre-term fetuses. In the juvenile period, these changes were not evidenced, and a similar pattern of growth and serum metabolic parameters in offspring of food-restricted mothers were found, except in serum aminotransferases levels, which increased. These were associated with higher liver fibrosis. Maternal food restriction in the early and mid-pregnancy followed by re-feeding in our rabbit model established a compensatory energy status in dams and alleviated potential long-term consequences in growth and metabolism in the offspring, even if fetal metabolism was altered.Item Managing sexual receptivity and ovulation induction in rabbit does: evidence from recent research(World Rabbit Science, 2023) García Rebollar, Pilar; Arias Álvarez, María; Lorenzo González, Pedro Luis; García García, Rosa MaríaThe sexual receptivity and ovulation induction of the reproductive rabbit are key points determining their success in productive life. Adequate synchronisation of the sexual receptivity methods of inseminated rabbit does unquestionably favours fertility and prolificacy outcomes. This review aims to bring together the different methods applied in synchronising primiparous rabbits and the consequences at metabolic, endocrine and ovarian levels, as well as in the embryonic, foetal and post-natal development that our research group has studied over the years. Likewise, the latest advances regarding ovulation induction in the rabbit are described, as well as the search for alternatives to the intramuscular injection of synthetic analogues of gonadotropins and seminal plasma components that could be involved in this process. Different experiments performed with a physiological basis confirm that nerve stimulation during artificial insemination or coitus is especially important in the ovulation induction reflex in rabbit females.Item Effects of feed restriction during pregnancy on maternal reproductive outcome, foetal hepatic IGF gene expression and offspring performance in the rabbit(Animal, 2021) García García, Rosa María; Arias Álvarez, María; Rodríguez, M.; Sánchez Rodríguez, Ana; Formoso Rafferty, N.; Lorenzo González, Pedro Luis; Rebollar, P.G.Primiparous female rabbits have high nutritional requirements and, while it is recommended that they are subjected to an extensive reproductive rhythm, this could lead to overweight, affecting reproductive outcomes. We hypothesised that restricting food intake during the less energetic period of gestation could improve reproductive outcome without impairing offspring viability. This study compares two groups of primiparous rabbit does in an extensive reproductive programme, one in which feed was restricted from Day 0 to Day 21 of gestation (R021), and another in which does were fed ad libitum (control) throughout pregnancy. The mother and offspring variables compared were (1) mother reproductive outcomes at the time points pre-implantation (Day 3 postartificial insemination [AI]), preterm (Day 28 post-AI) and birth; and (2) the prenatal offspring characteristic IGF system gene expression in foetal liver, liver fibrosis and foetus sex ratio, and postnatal factor viability and growth at birth, and survival and growth until weaning. Feed restriction did not affect the conception rate, embryo survival, or the number of morulae and blastocysts recovered at Day 3 post-AI. Preterm placenta size and efficiency were similar in the two groups. However, both implantation rate (P < 0.001) and the number of foetuses (P = 0.05) were higher in the R021 mothers than controls, while there was no difference in foetal viability. Foetal size and weight, the weights of most organs, organ weight/BW ratios and sex ratio were unaffected by feed restriction; these variables were only affected by uterine position (P < 0.05). Conversely, in the R021 does, foetal liver IGBP1 and IGF2 gene expression were dysregulated despite no liver fibrosis and a normal liver structure. No effects of restricted feed intake were produced on maternal fertility, prolificacy, or offspring birth weight, but control females weaned more kits. Litter weight and mortality rate during the lactation period were also unaffected. In conclusion, pre-implantation events and foetal development were unaffected by feed restriction. While some genes of the foetal hepatic IGF system were dysregulated during pregnancy, liver morphology appeared normal, and the growth of foetuses and kits until weaning was unmodified. This strategy of feed restriction in extensive reproductive rhythms seems to have no significant adverse effects on dam reproductive outcome or offspring growth and viability until weaning.Item Acquisition of fertilization competence in guinea pig spermatozoa under different capacitation protocols(Theriogenology, 2023) Cañón Beltrán, Karina Esperanza; Cajas Suárez, Yulia Nathaly; González Martínez, María Encina; Fernández-González, Raul; Fierro, Natacha; Lorenzo González, Pedro Luis; Arias Álvarez, María; García García, Rosa María; Gutiérrez Adán, Alfonso; Rizos, DimitriGuinea pig in vitro fertilization (IVF) are poorly developed due to the limited accessibility to oocytes and the lack of an efficient method of sperm capacitation. Thus, we aimed to evaluate different capacitation protocols that we validated through sperm analysis and using heterologous (He) IVF with zona-intact bovine oocytes. Spermatozoa of guinea pigs were collected and processed separately by 4 different protocols: A) Spermatozoa were obtained by flushing the lumen of one cauda epididymis and incubated in a minimal culture medium (MCM); B) One epididymis was placed in a prewarmed of M2 medium and gently minced with fine scissors. Spermatozoa were incubated in a modified human tubal fluid medium (HTF). In both protocols, the spermatozoa were capacitated at 37 °C under an atmosphere of 5% CO2 for 2 h. In the protocols C and D, the spermatozoa were collected by flushing the lumen of the cauda epididymis and selected by commercial density gradient Bovipure® (Nidacon Laboratories AB, Göthenborg, Sweden), according to the manufacturer's instructions. Then for Protocol C) spermatozoa were incubated in MCM medium supplemented with 10 mg/mL heparin (MCM-Hep); while for Protocol D) spermatozoa were incubated in FERT medium supplemented 10 mg/mL heparin (FERT-Hep). Incubation of C and D protocols were performed at 38.5 °C under an atmosphere of 5% CO2 for 2 h. Capacitation protocols C and D showed a higher percentage of viability, total and hyperactive-like motility, and acrosome reaction compared to protocols A and B. For this reason, protocols C and D were used for further He-IVF analysis. Guinea pig sperm and matured zona-intact bovine oocytes were co-incubated at 5% CO2 and 38.5 °C. Sperm-oocyte interaction was assessed at 2.5 h post-insemination (hpi) and pronuclear formation (PrF) were evaluated at 18, 20, 22, 24 and 26 hpi, while the cleavage rate was evaluated at 48 hpi. In protocol D, PrF was significantly higher than in protocol C (P ≤ 0.05) at every time point evaluated. Also, the cleavage rate at 48 hpi was higher (P ≤ 0.05) in He-IVF protocol D (69.8 ± 1.7%) compared to He-IVF protocol C (49.1 ± 1.1%). In conclusion, we determined the most adequate sperm capacitation conditions for guinea pig that allow zona-intact bovine oocyte penetration and lead to hybrid embryo formation, suggesting that these conditions could be optimal to develop IVF in guinea pigs.Item Influence of Different Regimes of Moderate Maternal Feed Restriction during Pregnancy of Primiparous Rabbit Does on Long-Term Metabolic Energy Homeostasis, Productive Performance and Welfare(Animals, 2021) Fernández Pacheco, Carlota; Millán Pastor, María Pilar; Rodríguez, María; Formoso Rafferty, Nora; Sánchez Rodríguez, Ana; Lorenzo González, Pedro Luis; Arias Álvarez, María; García García, Rosa María; Rebollar, Pilar G.In this study, a maternal feed restriction (MFR; 105 g/d) in primiparous rabbit does was applied from day 0 to 7 post artificial insemination (AI) (R07, n = 96), from day 7 to 21 post AI (R721, n = 92), from day 0 to 21 post AI (R021, n = 94) or fed ad libitum during whole pregnancy (Control, n= 92). Feed intake (FI) was measured after MFR was over. On day 28 of gestation, fetoplacental development was evaluated (n = 11/group) and the productive parameters of the remaining dams were analyzed. Plasma free tri-iodothyronine (T3) and thyroxine, glucose, insulin, non-esterified fatty acids (NEFA), and corticosterone were analyzed during gestation and lactation (n = 5/group). After MFR, all groups significantly increased their voluntary FI. The longer MFR was, the lower the weight and length of the fetuses, but no long-term effects over litter performance were observed. R021 groups had the lowest T3 and the highest NEFA concentrations during pregnancy and showed insulin resistance at the end of gestation, but during lactation, energy homeostasis was balanced in all groups. MFR did not affect corticosterone concentrations. In conclusion, the ration setting applied slightly involved the energy homeostasis and metabolism of the animals, but their overall metabolic condition, productive performance and welfare were not compromised.Item Improvement of oocyte competence and in vitro oocyte maturation with EGF and IGF-I in Guinea pig model(Theriogenology, 2023) Cañón Beltrán, Karina Esperanza; García García, Rosa María; Cajas Suárez, Yulia Nathaly; Fierro, Natacha; Lorenzo González, Pedro Luis; Arias Álvarez, MaríaIn vitro maturation (IVM) system is an alternative method to superovulation protocols to obtain mature oocytes. Epidermal Growth Factor (EGF) and Insulin-like Growth Factor I (IGF-I) have been widely used in IVM medium in different species. Although the guinea pig is a valuable animal model for reproductive studies, IVM is rarely used. We aimed to establish a suitable in vitro production system using EGF and/or IGF-I during IVM to improve oocyte competence. Firstly, immunolocalization of EGF and IGF-I receptors in the ovary was assessed. An IVM dose-response experiment was performed with cumulus-oocyte complexes (COCs) supplemented with: 1) EGF [0, 10, 50, 100 ng/mL or 10% fetal calf serum (FCS)]; 2) IGF-I [0, 50, 100, 200 ng/mL or 10% FCS]; or 3) the concentrations of EGF and IGF-I which showed the best IVM index in the previous experiments, with or without Fetal Calf Serum (FCS). Cortical granule and mitochondria distribution patterns were determined in in vivo and in vitro-matured oocytes for the first time in this species. Apoptotic rate after IVM and oocyte competence by in vitro embryo development were evaluated. Immunohistochemistry results showed positive immunostaining of EGF and IGF receptors in corpus luteum, oocytes, granulosa and theca cells in follicles in all stages of development. Supplementation of IVM medium with 50 ng/mL EGF or 100 ng/mL IGF-I or their combination with FCS successfully led to oocyte nuclear and cytoplasmic maturation and reduced the apoptotic rate. Both growth factors improved oocyte competence during IVM in this species since early embryos were in vitro developed, showing better results when FCS was used in the IVM medium.Item Role of nerve growth factor in the reproductive physiology of female rabbits: A review(Theriogenology, 2020) Rebollar, P.G.; García García, Rosa María; Arias Álvarez, María; Sánchez Rodríguez, Ana; Lorenzo González, Pedro LuisRabbit does are reflex ovulators such that coitus is needed to release GnRH and elicit the LH surge that triggers the ovulation of mature oocytes. However, the mechanisms eliciting ovulation in this species remain unclear. One of the most promising recently discovered candidates with a role in female reproductive physiology is nerve growth factor beta (b-NGF). This neurotrophin and its high-affinity receptor TrkA and low affinity receptor p75, is present in all compartments of the ovary, oviduct and uterus suggesting a physiologic role in ovarian folliculogenesis, steroidogenesis, ovulation, luteogenesis and embryo development. Besides, evidence exists that b-NGF found in seminal plasma could exert a modulatory role in the female hypothalamus-pituitary-ovarian axis contributing to the adrenergic and cholinergic neuronal stimulus of GnRH neurons in an endocrine manner during natural mating. Probably, the paracrine and local roles of the neurotrophin in steroidogenesis and ovulation reinforce the neuroendocrine pathway that leads to ovulation. This review updates knowledge of the role of b-NGF in rabbit reproduction, including its possible contribution to the mechanisms of action that induce ovulation, and discusses perspectives for the future applications of this neurotrophin on rabbit farms.Item Strategies to Reduce the Use of Antibiotics in Fresh and Chilled Equine Semen(Animals, 2024) Zabala Argüelles, Sonsoles Mercedes; Serres Dalmau, María Consolacion; Montero Serra, Natalia; Crespo Castejón, Francisco; Lorenzo González, Pedro Luis; Pérez-Aguilera, Verónica; Galán López, Carmen; Domínguez Gimbernat, Mónica; Oliet Palá, Agustín; Moreno, Santiago; González Zorn, Bruno; Gutiérrez Cepeda, LunaThe study assessed the impact of four equine semen processing techniques on sperm quality and microbial load immediately post-processing and after 48 h of refrigeration. The aim was to explore the potential reduction of prophylactic antibiotic usage in semen extenders. Semen from ten adult stallions was collected and processed under a strict hygiene protocol and divided into four aliquots: Simple Centrifugation with antibiotics (SC+), Simple Centrifugation (SC−), Single-Layer Colloidal Centrifugation (CC−), and Filtration (with SpermFilter®) (F−), all in extenders without antibiotics. Sperm motility, viability, and microbial load on three culture media were assessed. No significant differences were observed in the main in the sperm quality parameters among the four protocols post-processing and at 48 h (p < 0.05 or p < 0.1). Microbial loads in Columbia 5% Sheep Blood Agar and Schaedler vitamin K1 5% Sheep Blood Agar mediums were significantly higher (p < 0.10) for raw semen than for CS+, CC−, and F− post-processing. For Sabouraud Dextrose Agar medium, the microbial load was significantly higher (p < 0.10) in raw semen compared to CS+ and F−. No significant differences (p < 0.10) were found in 48 h chilled samples. Regardless of antibiotic presence, the evaluated processing methods, when combined with rigorous hygiene measures, maintained semen quality and reduced microbial load to the same extent as a traditional protocol using antibiotics.