Manifestation of estrous behavior and subsequent progesterone concentration at timed-embryo transfer in cattle are positively associated with pregnancy success of recipients

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Plasma concentrations of progesterone, 17 beta-estradiol and androstenedione and superovulatory response of nelore cows (Bos indicus) treated with FSH

Progesterone (P-4), 17 beta- estradiol (E2) and androstenedione (A4) plasma concentrations were correlated with palpated corpora lutea (CL), recovered embryos and viable embryos in 13 Nelore cows induced to superovulate with FSH, starting on Day 10 of the estrous cycle. Administration of FSH increased the number of ovulations and recovered embryos. Plasma P4, E2 and A4 levels on Day O and of P4 on Days 10 and 11 of the cycle were not correlated with the superovulatory response. Determination of CL by palpation per rectum was used to estimate the number of recovered embryos. Plasma P4 levels higher than 1 ng/ml on the induced estrus day (Day 14) had an adverse effect on the embryo viability rate. Plasma E2 concentrations on Day 14 were positively correlated with the number of viable embryos collected, a correlation that has not been previously reported. The present data indicate that plasma P4 and E2 concentrations in FSH-PGF2 alpha-treated Nelore cows are useful for the identification of 2 different populations of Nelore donors and are correlated with superovulatory response and, particularly, with the number of viable embryos.

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.

Supressão temporária do crescimento folicular ovariano em ovelha pela administraçao continuada de deslorelina na forma injetável ou implante de liberação controlada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The manipulation of progesterone profiles during progesterone + estradiol timed ai protocols in dairy cattle: effects on fertility

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

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

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise hormonal, imunolocalização e quantificação dos receptores de andrógenos (AR) e estrógenos (ER-α E ER-β) em ovário e útero de ratas submetidas a diferentes doses de decanoato de nandrolona: avaliação nos períodos pós-tratamento e pós-recuperação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fatores que afetam a expressão de estro detectado por monitores de atividade e riscos de concepção em vacas leiteiras lactantes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morfologia do útero e ovários de Artibeus planirostris (Phyllostomidae: Chiroptera) durante as fases do ciclo reprodutivo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reproductive physiology, and physical and sexual development of female offspring born to diabetic dams

Objectives: The objective of this study was to evaluate physical and sexual development and reproductive physiology in female rat offspring that developed in hyperglycemia conditions in utero and during lactation. Materials and methods: Maternal diabetes was induced in female rats by a single IV injection of streptozotocin before mating. Female offspring development was evaluated by means of the following parameters: physical development; age of vaginal opening and first estrus; weight and histological evaluation of uterus and ovaries; duration of the estrous cycle, sexual behavior, and fertility after natural mating. Results: In the female offspring, maternal diabetes caused delays in initial physical development; diminution in ovary weight and number of follicles; and inferior reproductive performance compared with the control group. Conclusions: The exposure to hyperglycemia in uterus and during lactation caused delays in physical and sexual development, and affected the reproductive physiology of female rats negatively.

Detecção imunoistoquímica de receptores de estrógeno e progesterona no endométrio de vacas Nelore (Bos taurus indicus) durante o anestro pós-parto

Twenty-four postpartum anestrous Nelore purebred cows were used in the study. Anestrous was determined based on the reproductive history which was confirmed in each cow based on plasma progesterone concentration and by transrectal ultrasonography. Endometrial biopsies were collected. The animals were separated into two groups according to maximum follicular diameter- Group 1: follicles <6mm (n=12) and Group 2: follicles >-6mm follicles (n=12). The immunohistochemistry technique was employed to evaluate the presence of estrogen and progesterone receptors in the uterine glandular epithelium and stroma. High counts of positive nuclei and high intensity of immunostain for estrogen and progesterone receptors in the glandular epithelium and stroma were observed in the two groups. However, the immunostain intensity of progesterone receptors in the glandular epithelium was higher in Group 2 compared to Group 1. When glandular epithelium and stroma were compared within each group, the relative number of estrogen receptors in the Group 1 was higher in the glandular epithelium compared to stroma and the immunostain intensity for the progesterone receptor in Group 2 was higher in the glandular epithelium compared to stroma. The results suggest that the mechanisms that control the expression of endomerial receptors in the anestrus are similar to the ones observed during the estrus cycle.

Influência de gênero e do ciclo estral no reflexo auditivo de sobressalto em ratos Wistar

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

Dinâmica de corpos lúteos em protocolos com redução da dose de FSH na superovulação em ovelhas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo de associação genômica e perfil de expressão gênica de folículos antrais em novilhas das raças nelore e angus, associadas ao fenótipo de alta e baixa população folicular

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

Análise multivariada de características reprodutivas e produtivas de vacas da raça Holandesa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)