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https://www.readbyqxmd.com/read/28810213/the-effect-of-circulating-progesterone-on-magnitude-of-the-gnrh-induced-lh-surge-are-there-any-differences-between-bos-indicus-and-bos-taurus-heifers
#1
E O S Batista, T A Del Valle, M D D V Ortolan, F P Rennó, G P Nogueira, A H Souza, P S Baruselli
This study evaluated the effects of differing circulating progesterone (P4) levels on the luteinizing hormone (LH) surge profile following treatment with gonadotropin releasing hormone (GnRH) in B. indicus (Nelore, n = 13) and B. taurus (Holstein, n = 16) heifers. All heifers were synchronized with a hormonal protocol to induce either a Low or High circulating P4 environment at the time of GnRH treatment. Heifers were randomly assigned to a 2 × 2 factorial design composed by two genetic groups (B. indicus and B...
August 5, 2017: Theriogenology
https://www.readbyqxmd.com/read/28808448/relevance-of-the-nr4a-sub-family-of-nuclear-orphan-receptors-in-trophoblastic-bewo-cell-differentiation
#2
Sudha Saryu Malhotra, Satish Kumar Gupta
Nur-77, a member of the NR4A sub-family of nuclear orphan receptors, is downregulated in the placentae of pre-eclamptic women. Here, we investigate the relevance of Nor-1, Nurr-1 and Nur-77 in trophoblastic cell differentiation. Their transcript levels were found to be significantly upregulated in BeWo cells treated with forskolin. The maximum increase was observed after 2 h, with a second peak in the expression levels after 48 h. The expression of NR4A sub-family members was also found to be upregulated in BeWo cells after treatment with hCG and GnRH...
2017: Cellular & Molecular Biology Letters
https://www.readbyqxmd.com/read/28808344/hypothalamic-effects-of-progesterone-on-regulation-of-the-pulsatile-and-surge-release-of-luteinising-hormone-in-female-rats
#3
Wen He, Xiaofeng Li, Daniel Adekunbi, Yali Liu, Hui Long, Li Wang, Qifeng Lyu, Yanping Kuang, Kevin T O'Byrne
Progesterone can block the oestradiol-induced GnRH/LH surge and inhibit LH pulse frequency. Recent studies reported that progesterone prevented premature LH surges during ovarian hyperstimulation in women. As the most potent stimulator of GnRH/LH release, kisspeptin is believed to mediate the positive and negative feedback effects of oestradiol in the hypothalamic anteroventral periventricular (AVPV) and arcuate (ARC) nuclei, while the region-specific role of progesterone receptors in these nuclei remains unknown...
August 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28805911/effects-of-post-weaning-growth-rate-and-puberty-induction-protocol-on-reproductive-performance-of-bos-indicus-influenced-beef-heifers
#4
P Moriel, P Lancaster, G C Lamb, J M B Vendramini, J D Arthington
A 3-yr study evaluated the effectiveness of puberty induction using exogenous reproductive hormones in beef heifers undergoing different post-weaning growth rates. On d 0 of each year, grazing Angus × Brahman heifers (60 heifers/yr) were stratified by initial BW and age (BW = 253 ± 30 kg; age = 310 ± 18 d), and randomly assigned, in a 3 × 2 factorial design, to achieve a low (LOW; 0.45 kg/d), medium (MED; 0.73 kg/d), or high (HIGH; 1.00 kg/d) growth rate from d 0 to 168 (5 heifers/pasture; 4 pastures/growth rate/yr)...
August 2017: Journal of Animal Science
https://www.readbyqxmd.com/read/28804932/kisspeptin-regulates-ovarian-steroidogenesis-during-delayed-embryonic-development-in-the-fruit-bat-cynopterus-sphinx
#5
Anuradha, Amitabh Krishna
Cynopterus sphinx, a fruit bat, undergoes delayed embryonic development during the winter months, a period that corresponds to low levels of progesterone and estradiol synthesis by the ovary. Kisspeptins (KPs) are a group of neuropeptide hormones that act via G-protein coupled receptor 54 (GPR54) to stimulate hypothalamic secretion of Gonadotropin-releasing hormone, thereby regulating ovarian steroidogenesis, folliculogenesis, and ovulation. GPR54 is also expressed in the ovary, suggesting a direct role for KPs in ovarian steroidogenesis...
August 14, 2017: Molecular Reproduction and Development
https://www.readbyqxmd.com/read/28803576/age-at-castration-surgical-or-immunological-impacts-carcass-characteristics-and-meat-quality-of-male-pigs
#6
L Huber, E J Squires, I B Mandell, C F M de Lange
In order to accurately estimate body composition at slaughter and to meet specific market targets, the influence of age at time of castration (surgical or immunological) on body composition and boar taint indicators must be determined for male pigs. In all, 48 males were randomly assigned to one of four management regimens: (1) entire male pigs (EM), (2) EM surgically castrated at ~40 kg BW and 10 weeks of age (late castrates; LC), (3) conventional, early surgical castrates (within 4 days of birth; EC) and (4) EM immunized with a gonadotropin-releasing hormone (GnRH) analog (primary dose at 30 kg BW and 8 weeks of age; booster dose at 70 kg and 14 weeks of age; IM)...
August 14, 2017: Animal: An International Journal of Animal Bioscience
https://www.readbyqxmd.com/read/28802241/the-9-d-cidr-pg-protocol-ii-characterization-of-endocrine-parameters-ovarian-dynamics-and-pregnancy-rates-to-fixed-time-ai-following-use-of-long-term-cidr-based-estrus-synchronization-among-mature-beef-cows
#7
J M Thomas, J W C Locke, B E Bishop, J M Abel, M R Ellersieck, S E Poock, M F Smith, D J Patterson
An experiment was designed to evaluate endocrine parameters, ovarian dynamics, and pregnancy rates to fixed-time artificial insemination (FTAI) following the 9-d CIDR-PG protocol in comparison to the 14-d CIDR-PG protocol. While both are long-term protocols using CIDR treatment for presynchronization, the 9-d CIDR-PG protocol differs from the 14-d CIDR-PG protocol in that prostaglandin F2α (PG) is administered at CIDR insertion and removal to facilitate a decreased length of progestin treatment and potentially enhance response to the presynchronization treatment...
August 3, 2017: Theriogenology
https://www.readbyqxmd.com/read/28802064/neurokinin-3-receptor-antagonism-decreases-gonadotropin-and-testosterone-secretion-in-healthy-men
#8
Karolina Skorupskaite, Jyothis T George, Johannes D Veldhuis, Robert P Millar, Richard A Anderson
OBJECTIVE: Patients with mutations of NKB and its receptor show hypogonadotrophic hypogonadism, but there is little evidence for the importance of this pathway in reproductive function in normal men, or its functional hierarchy with kisspeptin. DESIGN: An open label study wherein men (n=6) were administered the NK3R antagonist MLE4901 40mg orally twice a day for 7 days. Kisspeptin-10 (0.3 μg/kg iv bolus) was given before and on day 7 of NK3R antagonist treatment...
August 12, 2017: Clinical Endocrinology
https://www.readbyqxmd.com/read/28802044/the-neuropeptide-corazonin-controls-social-behavior-and-caste-identity-in-ants
#9
Janko Gospocic, Emily J Shields, Karl M Glastad, Yanping Lin, Clint A Penick, Hua Yan, Alexander S Mikheyev, Timothy A Linksvayer, Benjamin A Garcia, Shelley L Berger, Jürgen Liebig, Danny Reinberg, Roberto Bonasio
Social insects are emerging models to study how gene regulation affects behavior because their colonies comprise individuals with the same genomes but greatly different behavioral repertoires. To investigate the molecular mechanisms that activate distinct behaviors in different castes, we exploit a natural behavioral plasticity in Harpegnathos saltator, where adult workers can transition to a reproductive, queen-like state called gamergate. Analysis of brain transcriptomes during the transition reveals that corazonin, a neuropeptide homologous to the vertebrate gonadotropin-releasing hormone, is downregulated as workers become gamergates...
August 10, 2017: Cell
https://www.readbyqxmd.com/read/28800500/sb223412-a-neurokinin-3-receptor-selective-antagonist-suppresses-testosterone-secretion-in-male-guinea-pigs
#10
Sho Nakamura, Yoshiko Ito, Koki Yamamoto, Chudai Takahashi, Mingdao Dai, Miyu Tanahashi, Yoshihisa Uenoyama, Hiroko Tsukamura, Shinya Oishi, Kei-Ichiro Maeda, Fuko Matsuda
Guinea pigs are important zoo animals and have been recommended for animal-assisted activities or therapy, however there are problems concerning testosterone inducing aggressive or sexual behaviors in male guinea pigs. Testicular testosterone secretion is regulated by pulsatile gonadotropin releasing hormone (GnRH)/luteinizing hormone (LH) release in mammals. The mechanism generating GnRH/LH pulses is thought to be governed by kisspeptin neurons, which coexpress neurokinin B (NKB) and dynorphin A (Dyn), in the arcuate nucleus (ARC)...
July 31, 2017: Theriogenology
https://www.readbyqxmd.com/read/28797743/importance-of-a-5-versus-7-day-pill-free-interval-in-a-gnrh-antagonist-protocol-using-corifollitropin-alfa-a-prospective-cohort-study-in-oocyte-donors
#11
Alicia Pérez-Calvo, Francisca Martínez, Christophe Blockeel, Elisabeth Clúa, Ignacio Rodríguez, Pere N Barri, Buenaventura Coroleu
In this prospective cohort study, oocyte donors were recruited prospectively and assigned to receive corifollitropin alfa: 5 days after pill discontinuation (group D5; 42 donors), or 7 days after pill discontinuation (group D7; 50 donors) in a gonadotrophin-releasing hormone antagonist protocol. Fixed additional daily doses of 200 IU recombinent FSH (rFSH) were started after 7 days of corifollitropinalfa, until triggering. No significant differences in basal characteristics were observed between both groups...
July 14, 2017: Reproductive Biomedicine Online
https://www.readbyqxmd.com/read/28796038/clomiphene-citrate-is-associated-with-favorable-cycle-characteristics-but-impaired-outcomes-of-obese-women-with-polycystic-ovarian-syndrome-undergoing-ovarian-stimulation-for-in-vitro-fertilization
#12
Shutian Jiang, Yanping Kuang
The aim of this study was to explore the effect of clomiphene citrate (CC) on the cycle characteristics and outcomes of obese women with polycystic ovarian syndrome (PCOS) undergoing ovarian stimulation for in vitro fertilization (IVF).This is a retrospective cohort study, and it was conducted at the tertiary-care academic medical center.This study included 174 obese PCOS patients undergoing IVF.In the study group (n = 90), CC and human menopausal gonadotropin (HMG) were administered simultaneously beginning on cycle day 3, while in control group (n = 84) HMG was used only...
August 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28795043/the-use-of-gonadotropin-releasing-hormone-antagonist-post-ovulation-trigger-in-ovarian-hyperstimulation-syndrome
#13
REVIEW
Neil Chappell, William E Gibbons
The purpose of this paper is to assimilate all data pertaining to the use of gonadotropin-releasing hormone (GnRH) antagonists in in vitro fertilization cycles after ovulation trigger to reduce the symptoms of ovarian hyperstimulation syndrome (OHSS). A systematic review of the literature was performed to identify all studies performed on the use of a GnRH antagonist in IVF cycle post-ovulation trigger with patients at high risk for OHSS. Ten studies were identified and reviewed. Descriptions of the studies and their individual results are presented in the following manuscript...
June 2017: Clinical and Experimental Reproductive Medicine
https://www.readbyqxmd.com/read/28790978/progress-and-challenges-in-the-search-for-the-mechanisms-of-pulsatile-gonadotropin-releasing-hormone-secretion
#14
REVIEW
Stephanie Constantin
Fertility relies on the proper functioning of the hypothalamic-pituitary-gonadal axis. The hormonal cascade begins with hypothalamic neurons secreting gonadotropin-releasing hormone (GnRH) into the hypophyseal portal system. In turn, the GnRH-activated gonadotrophs in the anterior pituitary release gonadotropins, which then act on the gonads to regulate gametogenesis and sex steroidogenesis. Finally, sex steroids close this axis by feeding back to the hypothalamus. Despite this seeming straightforwardness, the axis is orchestrated by a complex neuronal network in the central nervous system...
2017: Frontiers in Endocrinology
https://www.readbyqxmd.com/read/28790326/intestinal-toxicity-of-the-type-b-trichothecene-mycotoxin-fusarenon-x-whole-transcriptome-profiling-reveals-new-signaling-pathways
#15
Imourana Alassane-Kpembi, Juliana Rubira Gerez, Anne-Marie Cossalter, Manon Neves, Joëlle Laffitte, Claire Naylies, Yannick Lippi, Martine Kolf-Clauw, Ana Paula L Bracarense, Philippe Pinton, Isabelle P Oswald
The few data available on fusarenon-X (FX) do not support the derivation of health-based guidance values, although preliminary results suggest higher toxicity than other regulated trichothecenes. Using histo-morphological analysis and whole transcriptome profiling, this study was designed to obtain a global view of the intestinal alterations induced by FX. Deoxynivalenol (DON) served as a benchmark. FX induced more severe histological alterations than DON. Inflammation was the hallmark of the molecular toxicity of both mycotoxins...
August 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28783712/machine-learning-for-predicting-lifespan-extending-chemical-compounds
#16
Diogo G Barardo, Danielle Newby, Daniel Thornton, Taravat Ghafourian, João Pedro de Magalhães, Alex A Freitas
Increasing age is a risk factor for many diseases; therefore developing pharmacological interventions that slow down ageing and consequently postpone the onset of many age-related diseases is highly desirable. In this work we analyse data from the DrugAge database, which contains chemical compounds and their effect on the lifespan of model organisms. Predictive models were built using the machine learning method random forests to predict whether or not a chemical compound will increase Caenorhabditis elegans' lifespan, using as features Gene Ontology (GO) terms annotated for proteins targeted by the compounds and chemical descriptors calculated from each compound's chemical structure...
July 18, 2017: Aging
https://www.readbyqxmd.com/read/28782536/immunolesion-of-melanopsin-neurons-causes-gonadal-regression-in-pekin-drakes-anas-platyrhynchos-domesticus
#17
H Potter, E Alenciks, K Frazier, A Porter, G S Fraley
Several light sensitive receptors have been described in the avian brain that are thought to regulate the reproductive axis independently from the eyes and pineal gland.Recently, our lab has described the presence of three of these photoneuroendocrine systems in the Pekin duck: opsin, opsin 5, & melanopsin. We set out to test the hypothesis that melanopsin receptive neurons are necessary to maintain seasonal reproductive status along with growth and development in the Pekin drake. To accomplish these goals we first investigated 50-week-old Pekin drakes that were housed in the aviary at Hope College under long day length (18 hrs lights on) conditions in floor pens...
August 4, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28782533/co-localization-of-three-gonadotropin-releasing-hormone-transcripts-in-larval-parasitic-and-adult-sea-lamprey-brains
#18
Emily R Van Gulick, Timothy J Marquis, Stacia A Sower
RNA expression of lamprey gonadotropin-releasing hormone (lGnRH)-I, -II, and -III was demonstrated in the brains of larval, parasitic phase and adult sea lampreys, Petromyzon marinus, using a highly sensitive triple-label in situ hybridization technique. In female larval lampreys, lGnRH-I and-II were co-expressed in the same neurons throughout the olfactory bulbs, preoptic area (POA), and rhombencephalon (hindbrain); lGnRH-I, -II and -III were triple co-expressed in the hypothalamus and in the paranuclear region of neuronal somas in the rhombencephalon...
August 3, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28780570/sex-steroids-differentially-regulate-fshb-lhb-and-gnrhr-expression-in-atlantic-cod-gadus-morhua
#19
Kristine von Krogh, Gunnveig Toft Bjørndal, Rasoul Nourizadeh-Lillabadi, Kjetil Hodne, Erik Ropstad, Trude Marie Haug, Finn-Arne Weltzien
Depending on the stage of gonad maturation, as well as other factors, gonadal steroids can exert either a positive or negative feedback at the brain and pituitary level. While this has been demonstrated in many teleost species, little is known about the nature of steroid feedback in Gadiform fish. Using an optimized in vitro model system of the Atlantic cod pituitary, the present study investigated potential effects of two physiologically relevant doses of estradiol, testosterone or dihydrotestosterone (DHT) on cell viability and gene expression of gonadotropin subunits (fshb/lhb) and two suggested reproduction relevant gonadotropin-releasing hormone receptors (gnrhr1b/gnrhr2a) during three stages of sexual maturity...
August 5, 2017: Reproduction: the Official Journal of the Society for the Study of Fertility
https://www.readbyqxmd.com/read/28780109/comparison-of-2-protocols-to-increase-circulating-progesterone-concentration-before-timed-artificial-insemination-in-lactating-dairy-cows-with-or-without-elevated-body-temperature
#20
M H C Pereira, M C Wiltbank, T G Guida, F R Lopes, J L M Vasconcelos
Two treatments designed to increase circulating progesterone concentration (P4) during preovulatory follicle development were compared. One treatment used 2 intravaginal P4 implants (controlled internal drug-releasing inserts; CIDR) and the other used a GnRH treatment at beginning of the protocol. Lactating Holstein cows that had been diagnosed as nonpregnant were randomly assigned to receive timed artificial insemination (TAI) following 1 of 2 treatments (n = 1,638 breedings): (1) GnRH: CIDR+ 2 mg of estradiol (E2) benzoate + 100 µg of GnRH on d -11, PGF2α on d -4, CIDR withdrawal + 1...
August 2, 2017: Journal of Dairy Science
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