Timing of prostaglandin F2α treatment in an estrogen-based protocol for timed artificial insemination or timed embryo transfer in lactating dairy cows

Objectives were to investigate progesterone concentrations and fertility comparing 2 different intervals from PGF2α treatment and induced ovulation in an estrogen-based ovulation synchronization protocol for timed artificial insemination (TAI) or timed embryo transfer (TET) in lactating dairy cows. A total of 1,058 lactating Holstein cows [primiparous (n=371) and multiparous (n=687)], yielding 34.1±0.33 kg of milk/d at various days in milk were randomly assigned to receive treatment with PGF2α on either d 7 or 8 of the following protocol: d 0: 2mg of estradiol benzoate + controlled internal drug release device; d 8: controlled internal drug release device removal + 1.0mg of estradiol cypionate; d 10: TAI or d 17: TET. Only cows with a corpus luteum at d 17 received an embryo and all cows received GnRH at TET. Pregnancy diagnoses were performed by detection (transrectal ultrasonography) of an embryo on d 28 or a fetus on d 60. Fertility [pregnancy per artificial insemination (P/AI) or pregnancy per embryo transfer (P/ET)] was affected by breeding technique (AI vs. ET) and time of PGF2α treatment (d 7 vs. 8) at the 28-d pregnancy diagnosis for TAI [32.9% (238) vs. 20.6% (168)] and TET cows [47% (243) vs. 40.7% (244)] and at the 60-d pregnancy diagnosis for TAI [30% (238) vs. 19.2% (168)] and TET cows [37.9% (243) vs. 33.5% (244)]. The progesterone (P4) concentration at d 10 altered fertility in TAI cows, with higher P/AI in cows with P4 concentration <0.1 ng/mL compared with cows with P4 concentration ≥0.1 ng/mL, and in ET cows, with higher P/ET in cows with P4 concentration <0.22 ng/mL compared with cows with P4 concentration ≥0.22 ng/mL. Prostaglandin F2α treatment at d 7 increased the percentage of cows with P4 <0.1 ng/mL on d 10 [39.4 (85) vs. 23.2 (54)]. Reducing the period between PGF2α and TAI from 72 to 48h in dairy cows resulted in a clear reduction in fertility in cows bred by TAI and a subtle negative effect in cows that received TET. The earlier PGF2α treatment benefits are most likely mediated through gamete transport, fertilization, or early embryo development and a more subtle effect of earlier PGF2α treatment that may be mediated through changes in the uterine or hormonal environment that manifests itself after ET on d 7. © 2013 American Dairy Science Association.

Progesterone restores the female prostate activity in ovariectomized gerbil and may act as competitor of testosterone in intraprostatic environment

Aims Little is known about the effect of progesterone on gerbil female prostate. It is known that normal oscillation in the progesterone and estradiol levels during the estrous cycle phases influence the morphophysiology of this gland. The present study aims to evaluate the isolated effect of prolonged administration of progesterone combined or not with testosterone on the prostate of ovariectomized female gerbil. Main methods To observe the morphological changes caused by castration in the prostate of different groups stereologic analyses of all prostate compartments, analysis of nuclear area and perimeter, and morphometric measurements of epithelial and smooth muscle cells layers were used. In addition, immunocytochemistry was performed to investigate the distribution of the androgen, estrogen alfa and beta and progesterone receptors in different prostatic compartments. Key findings This study demonstrated that both treatments partially recovered the structure of the gland. In the group treated with progesterone plus testosterone a higher incidence of epithelial and stromal disorders occurred, besides the absence of secretory activity. Thus, treatment only with progesterone showed better results in the restoration of glandular homeostasis mainly seen by the regulation of the secretory activity. Significance Collectively, the findings of this study indicate that progesterone may have a significant role on the maintenance of prostate morphophysiology, and showed an interesting evidence of hormonal competition between progesterone and testosterone. © 2013 Elsevier Inc.

Excess androgen during perinatal life alters steroid receptor expression, apoptosis, and cell proliferation in the uteri of the offspring

Exposure to environmental chemicals may contribute to reproductive disorders, especially when it occurs in critical periods of development. The female reproductive system can be a target for androgens derived from environmental contaminants or pathological conditions. The purpose of this study was to assess the long-term effects of androgens on uterine tissue after maternal exposure limited to the time of gestation and lactation. Pregnant Wistar rats were treated with testosterone propionate (TP) at 0.05. mg/kg, 0.1. mg/kg, 0.2. mg/kg or corn oil (vehicle), s.c., from gestational day 12 until the end of lactation. The results show changes in the pattern of expression of receptors for estrogen, progesterone, and androgen at all doses tested, and decreases in both apoptosis and cell proliferation indices at 0.1 and 0.2. mg/kg. We conclude that early TP exposure, under these experimental conditions, causes changes in cellular and molecular parameters that are essential for normal uterine function in the adult. © 2013 Elsevier Inc.

Exposição ao cádmio e/ou à cafeína na puberdade: expressão de marcadores de alterações pré-neoplásicas na próstata de rato

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Programaçao fetal por restrição proteica in utero: avaliação do imprinting estrogênico nas próstatas ventral e dorsolateral do rato Wistar

Pós-graduação em Biologia Geral e Aplicada - IBB

Estrogen-Responsive Genes Overlap with Triiodothyronine-Responsive Genes in a Breast Carcinoma Cell Line

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

Maternal obesity disturbs the postnatal development of gonocytes in the rat without impairment of testis structure at prepubertal age

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Progesterone as a morphological regulatory factor of the male and female gerbil prostate

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

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)

Efeitos da exposição prolongada ao bisfenol-A sobre a próstata de gerbilos adultos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Impact of gestational diabetes and lactational insulin replacement on structure and secretory function of offspring rat ventral prostate

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

Gestational protein restriction delays prostate morphogenesis in male rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Key participants of the tumor microenvironment of the prostate: An approach of the structural dynamic of cellular elements and extracellular matrix components during epithelial-stromal transition

Cancer is a multistep process that begins with the transformation of normal epithelial cells and continues with tumor growth, stromal invasion and metastasis. The remodeling of the peritumoral environment is decisive for the onset of tumor invasiveness. This event is dependent on epithelial–stromal interactions, degradation of extracellular matrix components and reorganization of fibrillar components. Our research group has studied in a new proposed rodent model the participation of cellular and molecular components in the prostate microenvironment that contributes to cancer progression. Our group adopted the gerbil Meriones unguiculatus as an alternative experimental model for prostate cancer study. This model has presented significant responses to hormonal treatments and to development of spontaneous and induced neoplasias. The data obtained indicate reorganization of type I collagen fibers and reticular fibers, synthesis of new components such as tenascin and proteoglycans, degradation of basement membrane components and elastic fibers and increased expression of metalloproteinases. Fibroblasts that border the region, apparently participate in the stromal reaction. The roles of each of these events, as well as some signaling molecules, participants of neoplastic progression and factors that promote genetic reprogramming during epithelial–stromal transition are also discussed.

Identificação das proteínas que compõem a glândula prostática do Gerbilo da Mongólia por espectrometria de massas pelo método Shotgun

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)