Cyp17a1 and cyp19a1 in the zebrafish testis are differentially affected by oestradiol

Oestrogens can affect expression of genes encoding steroidogenic enzymes in fish gonads. However, little information is available on their effects at the protein level. In this context, we first analysed the expression of key steroidogenic enzyme genes and proteins in zebrafish testis, paying attention also to other cell types than Leydig cells. Gene expression was analysed by quantitative PCR on fluorescence-activated cell-sorting fractions coupled or not to differential plating, while protein synthesis was studied by immunohistochemistry using specific antibodies against zebrafish Cyp17a1, Cyp19a1a and Cyp19a1b. Furthermore, we have evaluated the effect of oestrogen treatment (17β-oestradiol (E2), 10 nM) on the localization of these enzymes after 7 and 14 days of in vivo exposure in order to study how oestrogen-mediated modulation of their expression is linked to oestrogen effects on spermatogenesis. The major outcomes of this study are that Leydig cells express Cyp17a1 and Cyp19a1a, while testicular germ cells express Cyp17a1 and both, Cyp19a1a and Cyp19a1b. As regards Cyp17a1, both protein and mRNA seem to be quantitatively dominating in Leydig cells. Moreover, E2 exposure specifically affects only Leydig cell Cyp17a1 synthesis, preceding the disruption of spermatogenesis. The oestrogen-induced suppression of the androgen production capacity in Leydig cells is a major event in altering spermatogenesis, while germ cell steroidogenesis may have to be fuelled by precursors from Leydig cells. Further studies are needed to elucidate the functionality of steroidogenic enzymes in germ cells and their potential role in testicular physiology. © 2013 Society for Endocrinology.

Values of 13,14-Dihydro-15-Keto-PGF(2 alpha), Progesterone and Oestradiol After Injection of Prostaglandin at Different Periods of Buffalo Puerperium

Knowledge of the effectiveness of prostaglandins in uterine involution process led to the development of protocols with its analogues in postpartum period. However, this hormone mechanism of action is not yet fully elucidated. Thus, the objective of this study was to verify if chloprostenol administration, at early or intermediary puerperium, can induce changes on progesterone, PGFM and oestradiol plasma concentrations. 30 Murrah postpartum buffaloes were randomly divided into three groups: CONT (saline, n = 10); CLO2 (chloprostenol at days 2 and 5 postpartum, n = 10) and; CLO15 (chloprostenol at days 15 and 20 postpartum, n = 10). Blood samples were collected from jugular vein to measure progesterone, PGFM and oestradiol plasma concentrations at days 2, 7, 14, 21 and 28 postpartum. CLO2 group presented lower progesterone and PGFM plasma concentrations in relation to CONT and CLO15 groups (0.23 +/- 0.00 and 0.32 +/- 0.11, 0.19 +/- 0.00 and 0.23 +/- 0.11, 0.23 +/- 0.00 and 0.30 +/- 0.19, for groups CONT, CLO2 and CLO15, respectively; P < 0.05). There was no significant difference in oestradiol plasma concentration between experimental groups (P > 0.05). Prostaglandin synthetic analogue administration induced hormonal changes in postpartum buffaloes, which can partially explain its positive effect under reproductive function of this specie.

Actions of oestradiol and progesterone on the prostate in female gerbils: reversal of the histological effects of castration

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

Effects of Hormonal Supplementation on Nuclear Maturation and Cortical Granules Distribution of Canine Oocytes During Various Reproductive Stages

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

Seasonal variability in the fertilization rate of women undergoing assisted reproduction treatments

The objective of this study was to evaluate whether seasonality affects human-assisted reproduction treatment outcomes. For this, 1932 patients undergoing intracytoplasmic sperm injection (ICSI) were assigned to a season group according to the day of oocyte retrieval: winter (n = 435), spring (n = 444), summer (n = 469) or autumn (n = 584). Analysis of variance was used to compare the ICSI outcomes. The fertilization rate was increased during the spring (winter: 67.9%, spring: 73.5%, summer: 68.7% and autumn: 69.0%; p < 0.01). In fact, a nearly 50% increase in the fertilization rate during the spring was observed (odds ratio 1.45, confidence interval 1.20-1.75; p < 0.01). The oestradiol concentration per number of oocytes was significantly higher during the spring (winter: 235.8 pg/mL, spring: 282.1 pg/mL, summer: 226.1 pg/mL and autumn: 228.7 pg/mL; p = 0.030). This study demonstrates a seasonal variability in fertilization after ICSI, where fertilization is higher during the spring than at any other time.

Evaluation of mammographic density and Tc-99m-sestamibi scintimammographic uptake in postmenopausal women on hormone replacement therapy

Objective: To evaluate changes in mammographic density and Tc-99m-sestamibi scintimammographic uptake in postmenopausal women on hormone replacement therapy (HRT).Methods: Seventy-five postmenopausal women were prospectively studied and allocated into three groups: 50 women were randomized to either Group 1 (G1, n = 25), which received 2 mg of 17 beta-oestradiol continuously combined with 1 mg of norethisterone acetate (E-2/NETA, Kliogest (R), Medley) or Group 2 (G2), which received 2.5 mg/day of tibolone (Livial (R), Organon). The remaining 25 women, who were asymptomatic and had no desire to undergo HRT, constituted the control group (G3). Each patient was submitted to both mammography and scintimammography at baseline and after six months. Mammographic density was evaluated by using the BI-RADS classification system. The classification system of Barros et al. was used in the interpretation of scintimammography. For statistical analysis, the Chi-square test, ANOVA and Pearson's correlation were used.Results: At six months, increased mammographic density was observed in 48% of G1, 12% of G2 and 16% of G3 patients (p < 0.001). The increase in sestamibi uptake was 56% in G1, 28% in G2 and 24% in G3 (p < 0.001). Increases in both density and uptake were significantly higher in the group on E-2/NETA than among tibolone users and the controls.Conclusion: In postmenopausal women, HRT with E-2/NETA was associated with increased mammographic density and increased Tc-99m-sestamibi scintimammographic uptakes, suggesting greater mithochondrial activity in the cells of the mammary duct. This was not observed in users of 2.5 mg of tibolone, demonstrating that the effects on the breast were reduced. The same was observed in the control group. (c) 2005 Elsevier B.V.. All rights reserved.

Effect of combined hormonal and insulin therapy on the steroid hormone receptors and growth factors signalling in diabetic mice prostate

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

Oestrogen supplementation following castration promotes stromal remodelling and histopathological alterations in the Mongolian gerbil ventral prostate

The effect of oestradiol on the intact and castrated adult gerbil prostate was evaluated by focussing on stromal and epithelial disorders, and hormonal receptor immunoreactivity. The experimental animals were studied by histological, histochemical and immunohistochemical techniques, morphometric-stereological analysis and transmission electron microscopy. Epithelial alterations in the oestradiol-treated animals were frequent, with an increase in epithelial cell height, areas of intense dysplasia and hyperplasia and formation of prostatic intraepithelial neoplasia (PIN). Another aspect that did not depend on the presence of testosterone was the arrangement of the fibrillar and non-fibrillar elements of the extracellular matrix among smooth muscle cells (SMC), suggesting a possible role of these cells in rearrangement and synthesis of these components, after oestrogenic treatment. In the castrated animals, an accumulation of extracellular matrix elements under the epithelium was evident, while in the intact animals the same compounds were dispersed and scarce. In the groups of intact and castrated animals, SMC and fibroblasts exhibited a secretory phenotype, which was accentuated after oestradiol administration. There was an increase of the immunoreactivity to alpha-oestrogen and androgen receptors in hyperplastic areas compared to normal epithelium, revealing the involvement of these steroid receptors in the hyperplasia and PIN development.

Respostas endócrinas e ovarianas associadas com o folículo dominante da primeira onda folicular em ovelhas sincronizadas com CIDR ou PGF2alfa

Os efeitos de prostaglandina (PGF2a) vs CIDR e eCG (gonadotrofina coriônica eqüina) na dinâmica folicular da primeira onda e sua relação com as concentrações plasmáticas de P4 e E2 foram investigadas em ovelhas cíclicas. Foram utilizadas 14 fêmeas ovinas da raça Bergamascia; o Grupo 1 (G1) foi submetido a duas aplicações de PGF2alfa e o Grupo 2 (G2), tratado com CIDR durante 14 dias, sendo que, no momento de sua retirada, administraram-se 500 UI de eCG. A dinâmica folicular ovariana foi monitorada por meio de ultra-som. Monitoraram-se todos os folículos > 2mm e mapeou-se sua posição diariamente, observando-se o desenvolvimento individual de cada folículo. Desde o dia anterior à aplicação da segunda dose de PGF2alfa (G1) e desde a administração de eCG (G2) até o décimo dia do ciclo estral, foram coletadas amostras de sangue para análise de P4 e E2. Houve diferença significativa nas concentrações plasmáticas de P4 e E2 entre os tratamentos. A sincronização de estro e ovulação, utilizando CIDR + 500 UI de eCG, incrementou a quantidade de folículos recrutados, além de aumentar o diâmetro máximo e a taxa de crescimento dos folículos grandes na primeira onda folicular.

Níveis séricos de cortisol e 17-& estradiol durante o ciclo estral em marrãs (Sus domestica - Linnaeus 1758)

In the present study 21 young swine females, sexually mature, reared and kept under an industrial management system were assessed for cortisol and oestradiol-17 beta serum prolifes during the oestrus cycle. Blood sampling was performed always at the same interval, from 8:00 to 10:00 a.m. Each animal was submitted to 14 venal punctions at days 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 21, 22 and 23 of the oestrous cycle. The first day of the oestrous phase was assumed to be day 0 and the 23(rd) as the first of the next cycle. Hormone determinations were performed using a solid phase radioimmunoassay (RIA). Regarding to cortisol concentrations, there was a variation from 3.5 to 8.0 mu g/dl and for oestradiol-17 beta the mean values detected varied from 3.5 to 14.9pg/ml.

13,14-Dihydro-15-Keto Prostaglandin F-2 alpha Release in Response to Oxytocin Challenge Early Post-Partum in Anoestrous Nelore Cows Submitted to Temporary Calf Removal and Progesterone Priming

The study evaluated, in early post-partum anoestrous Nelore cows, if the increase in plasma oestradiol (E2) concentrations in the pre-ovulatory period and/or progesterone priming (P4 priming) preceding ovulation, induced by hormonal treatment, reduces the endogenous release of prostaglandin PGF(2)alpha and prevents premature lysis of the corpus luteum (CL). Nelore cows were subjected to temporary calf removal for 48 h and divided into two groups: GPE/eCG group (n = 10) and GPG/eCG group (n = 10). Animals of the GPE/eCG group were treated with a GnRH agonist. Seven days later, they received 400 ID of eCG, immediately after PGF(2)alpha treatment, and on day 0, 1.0 mg of oestradiol benzoate (EB). Cows of the GPG/eCG group were similarly treated as those of the GPE/eCG group, except that EB was replaced with a second dose of GnRH. All animals were challenged with oxytocin (OT) 9, 12, 15 and 18 days after EB or GnRH administration and blood samples were collected before and 30 min after OT. Irrespective of the treatments, a decline in P4 concentration on day 18 was observed for cows without P4 priming. However, animals exposed to P4 priming, treated with EB maintained high P4 concentrations (8.8 +/- 1.2 ng/ml), whereas there was a decline in P4 on day 18 (2.1 +/- 1.0 ng/ml) for cows that received GnRH to induce ovulation (p < 0.01). Production of 13,14-dihydro-15-keto prostaglandin F-2 alpha (PGFM) in response to OT increased between days 9 and 18 (p < 0.01), and this increase tended to be more evident in animals not exposed to P4 priming (p < 0.06). In conclusion, the increase in E2 during the pre-ovulatory period was not effective in inhibiting PGFM release, which was lower in P4-primed than in non-primed animals. Treatment with EB promoted the maintenance of elevated P4 concentrations 18 days after ovulation in P4-primed animals, indicating a possible beneficial effect of hormone protocols containing EB in animals with P4 priming.

Recombinant LH supplementation to recombinant FSH during induced ovarian stimulation in the GnRH-antagonist protocol: A meta-analysis

This study aims to compare the efficacy of recombinant LH (rLH) supplementation for ovarian stimulation in gonadotrophin-releasing hormone-antagonist protocol for IVF/intracytoplasmic sperm injection cycles. Search strategies included online surveys of databases. The fixed effects model was used for odds ratio (OR) and effect size (weighted mean difference, WMD). Five trials fulfilled the inclusion criteria. When the meta-analysis was carried out, advantages were observed for the LH supplementation protocol with respect to higher serum oestradiol concentrations on the day of human chorionic gonadotrophin administration (P < 0.0001; WMD: 514, 95% CI 368, 660) and higher number of mature oocytes (P = 0.0098; WMD: 0.88, 95% CI 0.21, 1.54). However, these differences were not observed in the total amount of recombinant FSH (rFSH) administered, days of stimulation, number of oocytes retrieved, the clinical pregnancy rate per oocyte retrieval, the implantation rate and miscarriage rate. This result demonstrates that the association of rLH with rFSH may prevent any decrease in oestradiol after antagonist administration and that a significantly higher number of mature oocytes was available for laboratory work. Nevertheless, it failed to show any statistically significant difference in clinically significant end-points in IVF (implantation and pregnancy rates). Additional randomized controlled trials are needed to confirm these results further. © 2007 Published by Reproductive Healthcare Ltd.

Corpus Luteum Development and Function after Supplementation of Long-Acting Progesterone During the Early Luteal Phase in Beef Cattle

Contents: Strategic supplementation of P4 may be used to increase conception rates in cattle, but timing of supplementation in relation to ovulation, mass of supplementary P4 and formulation of the P4-containing supplement has not been determined for beef cattle. Effects of supplementation of long-acting progesterone (P4) on Days 2 or 3 post-ovulation on development, function and regression of corpus luteum (CL) were studied in beef cattle. Cows were synchronized with an oestradiol/P4-based protocol and treated with 150 or 300 mg of long-acting P4 on Day 2 or 3 post-ovulation (6-7 cows/group). Colour-doppler ultrasound scanning and blood sample collection were performed from Day 2-21.5. Plasma P4 concentrations were greater (p < 0.05) from Day 2.5-5.5 in the Day 2-treated groups and from Day 3.5-5.5 in the Day 3-treated cows than in the control group. CL area and blood flow during Day 2-8.5 did not differ (p > 0.05) among groups, suggesting no effect of P4 treatment on luteal development. The frequency of cows that began luteolysis before Day 15 was greater (p < 0.04) in cows treated with 300 mg than in the controls, but there were no differences between non-treated and 150 mg-treated cows. The interval from pre-treatment ovulation to functional and structural luteolysis was shorter (p < 0.01) in the combined P4-treated groups than in the control cows. In conclusion, was showed for the first time that long-acting P4 supplementation on Day 2 or 3 post-ovulation increases P4 concentrations for ≥3 day, has no effect on luteal development, but anticipates the beginning of luteolysis in beef cattle. © 2013 Blackwell Verlag GmbH.