Ovum pick-up technique in recently weaned ewe lambs subjected to ovarian stimulation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efficiency of superstimulatory protocol P-36 associated with the administration of eCG and LH in Nelore cows

Recent work with P-36 demonstrates that the replacement of the last two doses of Follicle-Stimulating Hormone (FSH) with equine chorionic gonadotropin (eCG) increases embryo yields. However, it is unclear if the positive effect of eCG is related to its FSH-like activity, LH-like activity, or both. This study aimed to verify the replacement of eCG with pLH on the last day of superstimulatory treatment. Twenty-five Nelore cows were allocated to four groups: P-36 (control), P-36/eCG, P-36/LH2, and P-36/LH4. All animals underwent four treatments in a crossover design. The control group cows were superstimulated with decreasing doses of porcine Follicle-Stimulating Hormone (pFSH, 133 mg, im). In the P-36/eCG, P-36/LH2, and P-36/LH4 groups, the last two doses of pFSH were replaced in the former group by two doses of eCG (200 IU each dose, im) and in the latter two groups by two doses of pLH (1 and 2 mg each dose, im), respectively. Donors received fixed-time artificial insemination 12 and 24 hours after pLH. Embryo flushing was performed on D16. Data were analyzed by ANOVA (Proc Mixed, SAS). There was a trend of decreasing ovulation rate when comparing groups LH2 and eCG (P = 0.06). However, there was no significant difference in the mean number of viable embryos among groups P-36 (3.3 ± 0.7), P-36/eCG (4.5 ± 0.5), P-36/LH2 (3.7 ± 0.8), and P-36/LH4 (4.2 ± 1.0). It is concluded that the replacement of eCG by pLH on the last day of superstimulatory treatment can be performed with no significant variation in the production of viable embryos.

Time course of the meiotic arrest in sheep cumulus-oocyte complexes treated with roscovitine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Maternal separation on the ethanol-preferring adult rat liver structure

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Activity of neurons in the preoptic area and their participation in reproductive senescence: preliminary findings

Alterations in the hypothalamic-pituitary-gonadal axis in females determine the transition from regular to irregular reproductive cycles, with loss of fertility. Stimulation of noradrenergic neurons of the anteroventral periventricular neurons (AVPV) is essential for regular reproductive cycles. Therefore, we examined the activity of neurons of the AVPV and measure the noradrenaline (NE) of acyclic rats, in constant estrus, and compared it with that of cyclic rats in estrus. Female cyclic (4-5months) and acyclic (17-18months) rats were euthanized at 10, 14, and 18h in estrus. Brains were processed for immunoreactivity to antigens related to Fos (FRA) in AVPV, and the NE was determined by HPLC-ED. Plasma concentrations of LH, FSH, E2 and P4 were determined. In the acyclic animals, plasma LH was higher but the FSH was lower. There was decreasing P4 at different times, while the E2 was constant and lower in acyclic rats. FRA-ir expression in AVPV neurons of acyclic rats as well as turnover of NE was higher when compared with cyclic group. The preliminary findings showed increased activity in AVPV neurons in aging contribute to changes in the temporal pattern of neuroendocrine signaling, compromising the accuracy of inhibitory and stimulatory effects, causing irregularity in the estrous cycle and determining reproductive senescence.

A substituição do meio TCM pelo meio BARC, suplementado com SFB, BSA ou PVA, para maturação de oócitos bovinos in vitro, não incrementa a subsequente produção de blastocistos

This study was carried out to assess the influence of bovine embryo culture medium Beltsville Agriculture Research Center (BARC), supplemented with FCS, BSA or PVA, on the in vitro oocyte maturation, evidenced by cleavage rate and blastocysts production at different developmental stages. Three experiments were performed, as follows: exp.1: addition of FCS to BARC medium at concentrations of 0, 5 and 10%; exp. 2: addition of BSA to BARC medium at concentrations of 0, 4 and 8 mg/ml; exp. 3: addition of PVA to BARC medium at concentrations of 0, 0.5 and 1.0 mg/ml. TCM 199 supplemented with bicarbonate, pyruvate, gentamicin sulfate, FSH, LH and FCS was used as control group. Oocytes obtained from cow ovaries at slaughterhouse were selected in PBS, and then matured in BARC medium supplemented with FSH, LH and gentamicin sulfate, according to the experimental design. Percoll gradient was used for sperm selection and TALP medium for IVF. In vitro embryo culture was in SOF-m medium; a humidified atmosphere with 5% CO2, in air, at 38.7oC was used for all steps. The number of oocytes reaching blastocyst, expanded blastocyst, and hatched blastocyt stages was recorded, respectively at 72 and 168 h post-insemination. ANOVA and Bonferroni t test were used to determine differences among groups. Differences of P<0.05 were taken as significant. Higher percentage (P<0.05) of cleaved oocytes was observed in group TCM + FCS than for the other groups matured in BARC supplemented with FCS or BSA, regardless the concentration used. However, the cleavage rate was similar between groups BARC plus PVA with 1 mg/ml (85.7%) and TCM + FCS (90.8%). Significant difference was found among groups for the production of blastocysts, with the control group yielding a higher number of blastocysts (results ranging from 47.4 to 51.4%, in comparison with groups using BARC + FCS (4.1 to 19.7%), BSA (1.4 to 5.6%) and PVA (5.7 to 10.6%). In conclusion, BARC medium supplemented with different macromolecules did not promote a beneficial effect on in vitro oocyte maturation, resulting in lower rate of cleavage and blastocyst production when compared with TCM + FCS medium.

Controle do crescimento e da seleção folicular por fatores locais e sistêmicos na espécie bovina

The regulation of ovarian activity is an integrated process involving extraovarian signals and intrafollicular factors. In such process, gonadotropins have an important role, but not always crucial. The initiation of primordial follicle growth and the early stages of folliculogenesis can occur without gonadotropins, however FSH may affect the rate of preantral follicle growth. On the other hand, the antral follicle development from 1 to 4 mm in diameter is completely gonadotropin-dependent in bovine, and the alternation of dependency from FSH to LH may be part of the mechanism involved in follicular selection. Locally produced growth factors, such as the IGF system, work in association with gonadotropins throughout the follicular growth and can influence follicular selection. Thus, the integration of these extraovarian signals and intrafollicular factors seems to determine whether a follicle will continue to develop or go atretic. This review focuses on the interaction between gonadotropins and intrafollicular factors in follicular development and selection in cattle.

Atividade dos neurônios do núcleo anterovental periventricular e sua participação no envelhecimento reprodutivo de ratas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspiração folicular por videolaparoscopia e maturação oocitária in vitro em pacas (Cuniculus paca – linnaeus, 1766) mantidas em cativeiro e submetidas a protocolos de superestimulação ovariana

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Potential endocrinedisruptor activity of drinking water samples

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prostaglandin receptors (EP2 and EP4) and angiotensin receptor (AGTR2) mRNA expression increases in the oviducts of Nelore cows submitted to ovarian superstimulation

Many peptides are responsible for the coordination of muscle contraction, secretion and ciliary beating of the oviduct epithelium to allow the transport of gametes and embryos, including vascular endothelial growth factors (VEGF), prostaglandins (PGs), endotelin-1 (ET-1) andangiotensinII(Ang II). The effect of reproductive biotechnologiesusedto improve embryo yield on oviduct gene expression is poorly understood. Thus, the aim of the present study was to evaluate the effect of ovarian superstimulation on the mRNA expression of the genes encoding the major peptides involved in oviduct contraction in bovine. Therefore, Nelore cows were submitted to P-36 (n = 5) or P-36/eCG (n = 5) ovarian superstimulatory protocols and a control group of cows was not submitted to any superstimulatory protocol (n = 5). The relative expression of VEGF (VEGF, Flk1, Flt1), Ang II (AGTR2, ACE1), ET1 (ET1, ECE1) and PG pathway members (PGES, EP2, EP4, COX1, COX2) was analyzed using real time RT-PCR in each of oviduct segment (infundibulum, ampulla and isthmus). All target genes were expressed in the three segments of the bovine oviduct; however, specific genes were regulated by ovarian superstimulation: EP2 and EP4 receptors mRNA was affected by P- 36/eCG protocol, in the ampulla and infundibulum, respectively; and AGTR2 mRNA was up-regulated by both the P-36/eCG and P-36 protocols in the isthmus. The upregulation of EP2, EP4 and AGTR2 expression in the superstimulated cows suggests a suitable effect of FSH and eCG on bovine oviduct physiology, coordinating the contraction in Nelore cows

Efeitos do acetato de deslorelina sobre a produção in vivo e in vitro de embriões de gatas domésticas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Insuficiência de vitamina D em pacientes infectados pelo HIV tratados com terapia antirretroviral contendo tenofovir

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Responsividade das variáveis da composição corporal e metabólicas de mulheres pós-menopausa submetidas a 16 semanas de treinamento combinado

Pós-graduação em Ciências da Motricidade - IBRC

Efeitos do acetato de deslorelina sobre a produção in vivo e in vitro de embriões de gatas domésticas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)