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Sample records for hormone gnrh antagonist

  1. Effects of corticotropin-releasing hormone and its antagonist on the gene expression of gonadotrophin-releasing hormone (GnRH) and GnRH receptor in the hypothalamus and anterior pituitary gland of follicular phase ewes.

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    Ciechanowska, Magdalena; Łapot, Magdalena; Malewski, Tadeusz; Mateusiak, Krystyna; Misztal, Tomasz; Przekop, Franciszek

    2011-01-01

    There is no information in the literature regarding the effect of corticotropin-releasing hormone (CRH) on genes encoding gonadotrophin-releasing hormone (GnRH) and the GnRH receptor (GnRHR) in the hypothalamus or on GnRHR gene expression in the pituitary gland in vivo. Thus, the aim of the present study was to investigate, in follicular phase ewes, the effects of prolonged, intermittent infusion of small doses of CRH or its antagonist (α-helical CRH 9-41; CRH-A) into the third cerebral ventricle on GnRH mRNA and GnRHR mRNA levels in the hypothalamo-pituitary unit and on LH secretion. Stimulation or inhibition of CRH receptors significantly decreased or increased GnRH gene expression in the hypothalamus, respectively, and led to different responses in GnRHR gene expression in discrete hypothalamic areas. For example, CRH increased GnRHR gene expression in the preoptic area, but decreased it in the hypothalamus/stalk median eminence and in the anterior pituitary gland. In addition, CRH decreased LH secretion. Blockade of CRH receptors had the opposite effect on GnRHR gene expression. The results suggest that activation of CRH receptors in the hypothalamus of follicular phase ewes can modulate the biosynthesis and release of GnRH through complex changes in the expression of GnRH and GnRHR genes in the hypothalamo-anterior pituitary unit. © CSIRO 2011 Open Access

  2. Microdose Flare-up Gonadotropin-releasing Hormone (GnRH) Agonist Versus GnRH Antagonist Protocols in Poor Ovarian Responders Undergoing Intracytoplasmic Sperm Injection.

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    Boza, Aysen; Cakar, Erbil; Boza, Barıs; Api, Murat; Kayatas, Semra; Sofuoglu, Kenan

    2016-01-01

    Microdose flare-up GnRH agonist and GnRH antagonist have become more popular in the management of poor ovarian responders (POR) in recent years; however, the optimal protocol for POR patients undergoing in vitro fertilization has still been a challenge. In this observational study design, two hundred forty four poor ovarian responders were retrospectively evaluated for their response to GnRH agonist protocol (group-1, n=135) or GnRH antagonist protocol (group-2, n=109). Clinical pregnancy rate was the primary end point and was compared between the groups. Student t-test, Mann Whitney U test and χ (2)-test were used to compare the groups. The pmicrodose flare-up protocol has favorable outcomes with respect to the number of oocytes retrieved and implantation rate; nevertheless, the clinical pregnancy rate was found to be similar in comparison to GnRH antagonist protocol in poor ovarian responders. GnRH antagonist protocol appears to be promising with significantly lower gonadotropin requirement and lower treatment cost in poor ovarian responders.

  3. Suppression of the hypothalamic-pituitary-gonadal axis by TAK-385 (relugolix), a novel, investigational, orally active, small molecule gonadotropin-releasing hormone (GnRH) antagonist: studies in human GnRH receptor knock-in mice.

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    Nakata, Daisuke; Masaki, Tsuneo; Tanaka, Akira; Yoshimatsu, Mie; Akinaga, Yumiko; Asada, Mari; Sasada, Reiko; Takeyama, Michiyasu; Miwa, Kazuhiro; Watanabe, Tatsuya; Kusaka, Masami

    2014-01-15

    TAK-385 (relugolix) is a novel, non-peptide, orally active gonadotropin-releasing hormone (GnRH) antagonist, which builds on previous work with non-peptide GnRH antagonist TAK-013. TAK-385 possesses higher affinity and more potent antagonistic activity for human and monkey GnRH receptors compared with TAK-013. Both TAK-385 and TAK-013 have low affinity for the rat GnRH receptor, making them difficult to evaluate in rodent models. Here we report the human GnRH receptor knock-in mouse as a humanized model to investigate pharmacological properties of these compounds on gonadal function. Twice-daily oral administration of TAK-013 (10mg/kg) for 4 weeks decreased the weights of testes and ventral prostate in male knock-in mice but not in male wild-type mice, demonstrating the validity of this model to evaluate antagonists for the human GnRH receptor. The same dose of TAK-385 also reduced the prostate weight to castrate levels in male knock-in mice. In female knock-in mice, twice-daily oral administration of TAK-385 (100mg/kg) induced constant diestrous phases within the first week, decreased the uterus weight to ovariectomized levels and downregulated GnRH receptor mRNA in the pituitary after 4 weeks. Gonadal function of TAK-385-treated knock-in mice began to recover after 5 days and almost completely recovered within 14 days after drug withdrawal in both sexes. Our findings demonstrate that TAK-385 acts as an antagonist for human GnRH receptor in vivo and daily oral administration potently, continuously and reversibly suppresses the hypothalamic-pituitary-gonadal axis. TAK-385 may provide useful therapeutic interventions in hormone-dependent diseases including endometriosis, uterine fibroids and prostate cancer. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. GnRH agonist versus GnRH antagonist in in vitro fertilization and embryo transfer (IVF/ET

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    Depalo Raffaella

    2012-04-01

    Full Text Available Abstract Several protocols are actually available for in Vitro Fertilization and Embryo Transfer. The review summarizes the main differences and the clinic characteristics of the protocols in use with GnRH agonists and GnRH antagonists by emphasizing the major outcomes and hormonal changes associated with each protocol. The majority of randomized clinical trials clearly shows that in “in Vitro” Fertilization and Embryo Transfer, the combination of exogenous Gonadotropin plus a Gonadotropin Releasing Hormone (GnRH agonist, which is able to suppress pituitary FSH and LH secretion, is associated with increased pregnancy rate as compared with the use of gonadotropins without a GnRH agonist. Protocols with GnRH antagonists are effective in preventing a premature rise of LH and induce a shorter and more cost-effective ovarian stimulation compared to the long agonist protocol. However, a different synchronization of follicular recruitment and growth occurs with GnRH agonists than with GnRH antagonists. Future developments have to be focused on timing of the administration of GnRH antagonists, by giving a great attention to new strategies of stimulation in patients in which radio-chemotherapy cycles are needed.

  5. Nonsupplemented luteal phase characteristics after the administration of recombinant human chorionic gonadotropin, recombinant luteinizing hormone, or gonadotropin-releasing hormone (GnRH) agonist to induce final oocyte maturation in in vitro fertilization patients after ovarian stimulation with recombinant follicle-stimulating hormone and GnRH antagonist cotreatment

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    N.S. Macklon (Nick); M.J.C. Eijkemans (René); M. Ludwig (Michael); R.E. Felberbaum; K. Diedrich; S. Bustion; E. Loumaye; B.C.J.M. Fauser (Bart); N.G.M. Beckers (Nicole)

    2003-01-01

    textabstractReplacing GnRH agonist cotreatment for the prevention of a premature rise in LH during ovarian stimulation for in vitro fertilization (IVF) by the late follicular phase administration of GnRH antagonist may render supplementation of the luteal phase redundant, because

  6. Comparison of long GnRH agonist versus GnRH antagonist protocol in poor responders

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    Sadık Şahin

    2014-12-01

    Full Text Available Objective: To compare long GnRH agonist with GnRH antagonist protocol in poor responders. Materials and Methods: Medical charts of 531 poor responder women undergoing in-vitro fertilization (IVF cycle at Zeynep Kamil Maternity and Children’s Hospital, IVF Center were retrospectively analysed. Those who received at least 300 IU/daily gonadotropin and had ≤3 oocytes retrieved were enrolled in the study. Poor responders were categorized into two groups as those who received long GnRH agonist or GnRH antagonist regimen. Results: Treatment duration and total gonadotropin dosage were significantly higher in women undergoing the long GnRH agonist regimen compared with the GnRH antagonist regimen (p<0.001 for both. Although the number of total and mature oocytes retrieved was similar between the groups, good quality embryos were found to be higher in the GnRH antagonist regimen. The day of embryo transfer and number of transferred embryos were similar in the groups. No statistically significant differences were detected in pregnancy (10.5% vs 14.1%, clinical pregnancy (7.7% vs 10.6% and early pregnancy loss rates (27.2% vs 35% between the groups. Conclusion: GnRH antagonist regimen may be preferable to long GnRH regimen as it could decrease the cost and treatment duration in poor responders.

  7. Mental distress and personality in women undergoing GnRH agonist versus GnRH antagonist protocols for assisted reproductive technology

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    Stenbæk, D. S.; Toftager, M.; Hjordt, L. V.

    2015-01-01

    STUDY QUESTION: Do mental distress and mood fluctuations in women undergoing GnRH agonist and GnRH antagonist protocols for assisted reproductive technology (ART) differ depending on protocol and the personality trait, neuroticism? SUMMARY ANSWER: ART treatment did not induce elevated levels...... of mental distress in either GnRH antagonist or agonist protocols but neuroticism was positively associated with increased mental distress, independent of protocols. WHAT IS KNOWN ALREADY: ART treatment may increase mental distress by mechanisms linked to sex hormone fluctuations. General psychological...... characteristics, such as personality traits indexing negative emotionality, e.g. neuroticism, are likely to affect mental distress during ART treatment. STUDY DESIGN, SIZE, DURATION: A total of 83 women undergoing their first ART cycle were consecutively randomized 1:1 to GnRH antagonist (n = 42) or GnRH agonist...

  8. Antimüllerian hormone in gonadotropin releasing-hormone antagonist cycles

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    Arce, Joan-Carles; La Marca, Antonio; Mirner Klein, Bjarke

    2013-01-01

    To assess the relationships between serum antimüllerian hormone (AMH) and ovarian response and treatment outcomes in good-prognosis patients undergoing controlled ovarian stimulation using a gonadotropin-releasing hormone (GnRH) antagonist protocol....

  9. Effect of a low dose combined oral contraceptive pill on the hormonal profile and cycle outcome following COS with a GnRH antagonist protocol in women over 35 years old.

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    Bakas, Panagiotis; Hassiakos, Dimitrios; Grigoriadis, Charalampos; Vlahos, Nikolaos F; Liapis, Angelos; Creatsas, George

    2014-11-01

    This prospective study examines if pre-treatment with two different doses of an oral contraceptive pill (OCP) modifies significantly the hormonal profile and/or the IVF/ICSI outcome following COS with a GnRH antagonist protocol. Infertile patients were allocated to receive either OCP containing 0.03 mg of ethinylestradiol and 3 mg of drospirenone, or OCP containing 0.02 mg of ethinylestradiol and 3 mg of drospirenone prior to initiation of controlled ovarian stimulation (COS) with recombinant gonadotropins on a variable multi-dose antagonist protocol (Ganirelix), while the control group underwent COS without OCP pretreatment. Lower dose OCP was associated with recovery of FSH on day 3 instead of day 5, but the synchronization of the follicular cohort, the number of retrieved oocytes and the clinical pregnancy rate were similar to higher dose OCP.

  10. Cumulus cells gene expression profiling in terms of oocyte maturity in controlled ovarian hyperstimulation using GnRH agonist or GnRH antagonist.

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    Devjak, Rok; Fon Tacer, Klementina; Juvan, Peter; Virant Klun, Irma; Rozman, Damjana; Vrtačnik Bokal, Eda

    2012-01-01

    In in vitro fertilization (IVF) cycles controlled ovarian hyperstimulation (COH) is established by gonadotropins in combination with gonadotropin-releasing hormone (GnRH) agonists or antagonists, to prevent premature luteinizing hormone (LH) surge. The aim of our study was to improve the understanding of gene expression profile of cumulus cells (CC) in terms of ovarian stimulation protocol and oocyte maturity. We applied Affymetrix gene expression profiling in CC of oocytes at different maturation stages using either GnRH agonists or GnRH antagonists. Two analyses were performed: the first involved CC of immature metaphase I (MI) and mature metaphase II (MII) oocytes where 359 genes were differentially expressed, and the second involved the two GnRH analogues where no differentially expressed genes were observed at the entire transcriptome level. A further analysis of 359 differentially genes was performed, focusing on anti-Müllerian hormone receptor 2 (AMHR2), follicle stimulating hormone receptor (FSHR), vascular endothelial growth factor C (VEGFC) and serine protease inhibitor E2 (SERPINE2). Among other differentially expressed genes we observed a marked number of new genes connected to cell adhesion and neurotransmitters such as dopamine, glycine and γ-Aminobutyric acid (GABA). No differential expression in CC between the two GnRH analogues supports the findings of clinical studies where no significant difference in live birth rates between both GnRH analogues has been proven.

  11. GnRH antagonist, cetrorelix, for pituitary suppression in modern, patient-friendly assisted reproductive technology.

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    Tur-Kaspa, Ilan; Ezcurra, Diego

    2009-10-01

    Gonadotropin-releasing hormone (GnRH) analogues are used routinely to prevent a premature luteinizing hormone (LH) surge in women undergoing assisted reproductive technology (ART) treatments. In contrast to GnRH agonists, antagonists produce rapid and reversible suppression of LH with no initial flare effect. To review the role of cetrorelix, the first GnRH antagonist approved for the prevention of premature LH surges during controlled ovarian stimulation in modern ART. A review of published literature on cetrorelix. Both multiple- and single-dose cetrorelix protocols were shown to be at least as effective as long GnRH agonist regimens for pituitary suppression in Phase II/III clinical trials. Furthermore, cetrorelix co-treatment resulted in similar live birth rates but a shorter duration of gonadotropin stimulation, a lower total gonadotropin dose requirement and lower incidence of ovarian hyperstimulation syndrome compared with long agonist regimens. A single-dose cetrorelix protocol further decreased the number of injections required. Preliminary studies have also produced promising data on the use of cetrorelix in modified ART protocols, such as frozen embryo transfer and donor oocyte recipient cycles. Cetrorelix offers a potential therapeutic alternative to GnRH agonists during controlled ovarian stimulation and has become an integral part of modern, patient-friendly reproductive medicine.

  12. Microdose flare-up vs. flexible-multidose GnRH antagonist protocols for poor responder patients who underwent ICSI.

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    Esinler, I

    2014-01-01

    To compare the performance of microdose flare-up (MF) and flexible-multidose gonadotropin-releasing hormone (GnRH) antagonist protocols in poor responder patients who underwent intracytoplasmic sperm injection (ICSI). One hundred and 12 consecutive patients (217 cycles) suspected to have poor ovarian response were enrolled. Group 1 (MF GnRH agonist group) constituted 64 patients (135 cycles) who underwent MF GnRH agonist protocol. Group 2 (flexible-multidose GnRH antagonist group) constituted 48 patients (82 cycles) who underwent flexible-multidose GnRH antagonist protocol. The duration of stimulation (d) (11.5 +/- 2.1 vs. 10.4 +/- 2.7, p or = seven blastomeres and < 10% fragmentation at day 3 (35.9% vs. 65.1%, p < 0.05) were significantly lower in Group 1 when compared to Group 2. The number of embryos transferred (2.2 +/- 1.3 vs. 2.4 +/- 0.9), the clinical pregnancy per embryo transfer (16.3% vs. 25.8%), and the implantation rate (8.6% vs. 12.2%) were comparable between groups. Although the flexible-multidose GnRH antagonist protocol produced better oocyte and embryo parameters, the clinical pregnancy rate and the implantation rates were comparable between the flexible-multidose GnRH antagonist and MF protocols in poor responder patients.

  13. A Flexible Multidose GnRH Antagonist versus a Microdose Flare-Up GnRH Agonist Combined with a Flexible Multidose GnRH Antagonist Protocol in Poor Responders to IVF

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    Gayem İnayet Turgay Çelik

    2015-01-01

    Full Text Available Objective. To compare the effectiveness of a flexible multidose gonadotropin-releasing hormone (GnRH antagonist against the effectiveness of a microdose flare-up GnRH agonist combined with a flexible multidose GnRH antagonist protocol in poor responders to in vitro fertilization (IVF. Study Design. A retrospective study in Akdeniz University, Faculty of Medicine, Department of Obstetrics and Gynecology, IVF Center, for 131 poor responders in the intracytoplasmic sperm injection-embryo transfer (ICSI-ET program between January 2006 and November 2012. The groups were compared to the patients’ characteristics, controlled ovarian stimulation (COH results, and laboratory results. Results. Combination protocol was applied to 46 patients (group 1, and a single protocol was applied to 85 patients (group 2. In group 1, the duration of the treatment was longer and the dose of FSH was higher. The cycle cancellation rate was significantly higher in group 2 (26.1% versus 38.8%. A significant difference was not observed with respect to the number and quality of oocytes and embryos or to the number of embryos transferred. There were no statistically significant differences in the hCG positivity (9.5% versus 9.4% or the clinical pregnancy rates (7.1% versus 10.6%. Conclusion. The combination protocol does not provide additional efficacy.

  14. A Flexible Multidose GnRH Antagonist versus a Microdose Flare-Up GnRH Agonist Combined with a Flexible Multidose GnRH Antagonist Protocol in Poor Responders to IVF.

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    Çelik, Gayem İnayet Turgay; Sütçü, Havva Kömür; Akpak, Yaşam Kemal; Akar, Münire Erman

    2015-01-01

    To compare the effectiveness of a flexible multidose gonadotropin-releasing hormone (GnRH) antagonist against the effectiveness of a microdose flare-up GnRH agonist combined with a flexible multidose GnRH antagonist protocol in poor responders to in vitro fertilization (IVF). A retrospective study in Akdeniz University, Faculty of Medicine, Department of Obstetrics and Gynecology, IVF Center, for 131 poor responders in the intracytoplasmic sperm injection-embryo transfer (ICSI-ET) program between January 2006 and November 2012. The groups were compared to the patients' characteristics, controlled ovarian stimulation (COH) results, and laboratory results. Combination protocol was applied to 46 patients (group 1), and a single protocol was applied to 85 patients (group 2). In group 1, the duration of the treatment was longer and the dose of FSH was higher. The cycle cancellation rate was significantly higher in group 2 (26.1% versus 38.8%). A significant difference was not observed with respect to the number and quality of oocytes and embryos or to the number of embryos transferred. There were no statistically significant differences in the hCG positivity (9.5% versus 9.4%) or the clinical pregnancy rates (7.1% versus 10.6%). The combination protocol does not provide additional efficacy.

  15. Pregnancy outcome of “delayed start” GnRH antagonist protocol versus GnRH antagonist protocol in poor responders: A clinical trial study

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    Abbas Aflatoonian

    2017-08-01

    Full Text Available Background: Management of poor-responding patients is still major challenge in assisted reproductive techniques (ART. Delayed-start GnRH antagonist protocol is recommended to these patients, but little is known in this regards. Objective: The goal of this study was assessment of delayed-start GnRH antagonist protocol in poor responders, and in vitro fertilization (IVF outcomes. Materials and Methods: This randomized clinical trial included sixty infertile women with Bologna criteria for ovarian poor responders who were candidate for IVF. In case group (n=30, delayed-start GnRH antagonist protocol administered estrogen priming followed by early follicular-phase GnRH antagonist treatment for 7 days before ovarian stimulation with gonadotropin. Control group (n=30 treated with estrogen priming antagonist protocol. Finally, endometrial thickness, the rates of oocytes maturation, , embryo formation, and pregnancy were compared between two groups. Results: Rates of implantation, chemical, clinical, and ongoing pregnancy in delayed-start cycles were higher although was not statistically significant. Endometrial thickness was significantly higher in case group. There were no statistically significant differences in the rates of oocyte maturation, embryo formation, and IVF outcomes between two groups. Conclusion: There is no significant difference between delayed-start GnRH antagonist protocol versus GnRH antagonist protocol.

  16. GnRH antagonist versus long agonist protocols in IVF

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    Lambalk, C B; Banga, F R; Huirne, J A

    2017-01-01

    BACKGROUND: Most reviews of IVF ovarian stimulation protocols have insufficiently accounted for various patient populations, such as ovulatory women, women with polycystic ovary syndrome (PCOS) or women with poor ovarian response, and have included studies in which the agonist or antagonist...... was not the only variable between the compared study arms. OBJECTIVE AND RATIONALE: The aim of the current study was to compare GnRH antagonist protocols versus standard long agonist protocols in couples undergoing IVF or ICSI, while accounting for various patient populations and treatment schedules. SEARCH...... in couples undergoing IVF or ICSI. The primary outcome was ongoing pregnancy rate. Secondary outcomes were: live birth rate, clinical pregnancy rate, number of oocytes retrieved and safety with regard to ovarian hyperstimulation syndrome (OHSS). Separate comparisons were performed for the general IVF...

  17. THE USE OF GnRH ANTAGONISTS IN OVARIAN STIMULATION FOR INTRAUTERINE INSEMINATION

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    Mete Işıkoğlu

    2013-12-01

    Full Text Available The first paper entitled intrauterine insemination (IUI was published in 1962. By time, several methods involving the technique and the ovulation induction schedules have evolved in order to improve the success rates. Although gonadotrophin releasing hormone antagonists (GnRHa is a crucial part of assisted reproductive treatments now, concerns also arouse regarding the need for the use of it in IUI cycles. These drugs may be considered in IUI programs basically in order to prevent premature LH surges and related cycle cancellations. Although administration of a GnRH antagonist almost completely abolishes premature luteinization, it does not substantially improve the pregnancy rate. The decision of using GnRH antagonists in IUI cycles should be based primarily on the local cost/benefit analysis of individual centers. It will be prudent to limit the involvement of the antagonists in ovulation induction protocols to: patients who frequently exhibit premature LH discharges and therefore either fail to complete treatment or result in unsuccessful outcome; initiated cycles intented for IUI but converted to ART; if it is not possible for logistic reasons (weekend to perform the insemination or for medical centers in which a gynecologist on call is not available and in order to decrease clinical task burden resulting from strict cycle monitoring such as serial transvaginal sonography and/or frequent urine tests.

  18. Gonadotropin-releasing hormone agonist versus HCG for oocyte triggering in antagonist assisted reproductive technology cycles

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    Youssef, Mohamed A. F. M.; van der Veen, Fulco; Al-Inany, Hesham G.; Griesinger, Georg; Mochtar, Monique H.; Aboulfoutouh, Ismail; Khattab, Sherif M.; van Wely, Madelon

    2011-01-01

    Background Gonadotropin-releasing hormone (GnRH) antagonist protocols for pituitary down regulation in in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) allow the use of GnRH agonists for triggering final oocyte maturation. Currently, human chorionic gonadotropin (HCG) is

  19. Random-start GnRH antagonist for emergency fertility preservation: a self-controlled trial

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    Checa MA

    2015-02-01

    Full Text Available Miguel A Checa,1,2 Mario Brassesco,2 Margalida Sastre,1 Manuel Gómez,2 Julio Herrero,3 Laura Marque,3 Arturo Brassesco,2 Juan José Espinós3 1Department of Obstetrics and Gynecology, Parc de Salut Mar, Universitat Autònoma de Barcelona, 2Centro de Infertilidad y Reproducción Humana (CIRH, 3Centro de Reproducción Asistida Sagrada Familia, Clínica Sagrada Familia, Barcelona, Spain Abstract: The aim of this study is to evaluate the feasibility and safety of random-start controlled ovarian hyperstimulation (COH for emergency fertility preservation, regardless of the phase of the menstrual cycle. A self-controlled pilot clinical trial (NCT01385332 was performed in an acute-care teaching hospital and in two private reproductive centers in Barcelona, Spain. Eleven egg donors participated in the study. Two random-start gonadotropin-releasing hormone (GnRH antagonist protocols were assessed in which ganirelix was initiated on either day 10 (protocol B or on day 20 (protocol C of the menstrual cycle and was continued until estradiol levels were below 60 pg/dL. These protocols were compared with a standard protocol (protocol A. The main outcome of interest was the number of metaphase 2 oocytes retrieved. Results from this study show that the number of mature oocytes retrieved was comparable across the different protocols (14.3±4.6 in the standard protocol versus 13.0±9.1 and 13.2±5.2 in protocols B and C, respectively; values expressed as mean ± standard deviation. The mean number of days needed for a GnRH antagonist to lower estradiol levels, as well as the ongoing pregnancy rates, were also similar when protocols B (stimulation in follicular phase and C (stimulation on luteal phase were compared with protocol A (standard stimulation. GnRH antagonists can be effectively used for random-start controlled ovarian hyperstimulation with an ovarian response similar to that of standard protocols, and the antagonists appear suitable for emergency

  20. Microdose GnRH Agonist Flare-Up versus Ultrashort GnRH Agonist Combined with Fixed GnRH Antagonist in Poor Responders of Assisted Reproductive Techniques Cycles.

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    Eftekhar, Maryam; Mohammadian, Farnaz; Yousefnejad, Fariba; Khani, Parisa

    2013-01-01

    This study compares the microdose flare-up protocol to the ultrashort gonadotropinreleasing hormone (GnRH) agonist flare combined with the fixed multidose GnRH antagonist protocol in poor responders undergoing ovarian stimulation. In this randomized clinical trial, 120 women who were candidates for assisted reproductive techniques (ART) and had histories of one or more failed in vitro fertilization (IVF) cycles with three or fewer retrieved oocytes were prospectively randomized into two groups. Group I (60 patients) received the microdose flare-up regimen and group II (60 patients) received the ultrashort GnRH agonist combined with fixed GnRH antagonist. There were no significant differences between the groups in the number of used gonadotropin ampoules (p=0.591), duration of stimulation (p=0.610), number of retrieved oocytes (p=0.802), fertilization rate (p=0.456), and the number of transferred embryos (p=0.954). The clinical pregnancy rates were statistically similar in group I (10%) compared with group II (13.3%, p=0.389). According to our results, there is no significant difference between these protocols for improving the ART outcome in poor responders. Additional prospective, randomized studies with more patients is necessary to determine the best protocol (Registration Number: IRCT201105096420N1).

  1. Fanconi anemia A is a nucleocytoplasmic shuttling molecule required for gonadotropin-releasing hormone (GnRH) transduction of the GnRH receptor.

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    Larder, Rachel; Karali, Dimitra; Nelson, Nancy; Brown, Pamela

    2006-12-01

    GnRH binds its cognate G protein-coupled GnRH receptor (GnRHR) located on pituitary gonadotropes and drives expression of gonadotropin hormones. There are two gonadotropin hormones, comprised of a common alpha- and hormone-specific beta-subunit, which are required for gonadal function. Recently we identified that Fanconi anemia a (Fanca), a DNA damage repair gene, is differentially expressed within the LbetaT2 gonadotrope cell line in response to stimulation with GnRH. FANCA is mutated in more than 60% of cases of Fanconi anemia (FA), a rare genetically heterogeneous autosomal recessive disorder characterized by bone marrow failure, endocrine tissue cancer susceptibility, and infertility. Here we show that induction of FANCA protein is mediated by the GnRHR and that the protein constitutively adopts a nucleocytoplasmic intracellular distribution pattern. Using inhibitors to block nuclear import and export and a GnRHR antagonist, we demonstrated that GnRH induces nuclear accumulation of FANCA and green fluorescent protein (GFP)-FANCA before exporting back to the cytoplasm using the nuclear export receptor CRM1. Using FANCA point mutations that locate GFP-FANCA to the cytoplasm (H1110P) or functionally uncouple GFP-FANCA (Q1128E) from the wild-type nucleocytoplasmic distribution pattern, we demonstrated that wild-type FANCA was required for GnRH-induced activation of gonadotrope cell markers. Cotransfection of H1110P and Q1128E blocked GnRH activation of the alphaGsu and GnRHR but not the beta-subunit gene promoters. We conclude that nucleocytoplasmic shuttling of FANCA is required for GnRH transduction of the alphaGSU and GnRHR gene promoters and propose that FANCA functions as a GnRH-induced signal transducer.

  2. Risk of severe ovarian hyperstimulation syndrome in GnRH antagonist versus GnRH agonist protocol

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    Toftager, M.; Bogstad, J; Bryndorf, T

    2016-01-01

    interval (CI): 0.33-0.57) compared with the traditional GnRH agonist protocol. Previous trials comparing the two protocols mainly included selected patient populations, a limited number of patients and the applied OHSS criteria differed, making direct comparisons difficult. In two recent large meta...... IV, dual-centre, open-label, RCT including 1050 women allocated to either short GnRH antagonist or long GnRH agonist protocol in a 1:1 ratio and enrolled over a 5-year period using a web-based concealed randomization code. This is a superiority study designed to detect a difference in severe OHSS...... between the two arms. None of the women had undergone previous ART treatment. PARTICIPANTS/MATERIALS, SETTING, METHODS: All infertile women referred for their first IVF/ICSI at two public fertility clinics, less than 40 years of age and with no uterine malformations were asked to participate. A total...

  3. Pharmacokinetic/Pharmacodynamic Modelling of GnRH Antagonist Degarelix: A Comparison of the Non-linear Mixed-Effects Programs NONMEM and NLME

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    Tornøe, Christoffer Wenzel; Agersø, Henrik; Nielsen, Henrik Aalborg

    2004-01-01

    proposed by Lindstrom and Bates. The two programs were tested using clinical PK/PD data of a new gonadotropin-releasing hormone (GnRH) antagonist degarelix currently being developed for prostate cancer treatment. The pharmacokinetics of intravenous administered degarelix was analysed using a three...

  4. Gonadotrophin releasing hormone antagonist in IVF/ICSI

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    M S Kamath

    2008-01-01

    Full Text Available Objective : To study the efficacy of gonadotrophin releasing hormone (GnRH antagonist in In-vitro-fertilization/Intracytoplasmic sperm injection (IVF/ICSI cycles. Type of Study : Observational study. Setting: Reproductive Medicine Unit, Christian Medical College Hospital, Vellore, Tamil Nadu. Materials and Methods: GnRH antagonists were introduced into our practice in November 2005. Fifty-two women undergoing the antagonist protocol were studied and information gathered regarding patient profile, treatment parameters (total gonadotrophin dosage, duration of treatment, and oocyte yield, and outcomes in terms of embryological parameters (cleavage rates, implantation rates and clinical pregnancy. These parameters were compared with 121 women undergoing the standard long protocol. The costs between the two groups were also compared. Main Outcome : Clinical pregnancy rate. Results : The clinical pregnancy rate per embryo transfer in the antagonist group was 31.7% which was comparable to the clinical pregnancy rate in women undergoing the standard long protocol (30.63%. The costs between the two groups were comparable. Conclusions : GnRH antagonist protocol was found to be effective and comparable to the standard long protocol regimen. In addition it was simple, convenient, and patient friendly.

  5. Letrozole+ GnRH antagonist stimulation protocol in poor ovarian responders undergoing intracytoplasmic sperm injection cycles: An RCT

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    Mahbod Ebrahimi

    2017-08-01

    Full Text Available Background: Gonadotropin-releasing hormone (GnRH antagonist protocol has been proposed as a potentially proper option for the patients with limited ovarian reserve. Nevertheless, there is no significant difference in terms of clinical pregnancy between the GnRH antagonist and agonist cycles. The use of aromatase inhibitors such as letrozole was suggested by some studies. Objective: The object of this study was to evaluate the efficacy of letrozole cotreatment with GnRH-antagonist protocol in ovarian stimulation of poor responder patients undergoing intracytoplasmic sperm injection. Materials and Methods: A double-blinded randomized control trial was conducted on 70 infertile women with poor ovarian response based on Bologna criteria in two groups: letrozole+GnRH-antagonist (LA group and placebo+GnRH-antagonist (PA group (n=35/each. The LA group involved at letrozole 2.5 mg daily over 5 days and recombinant human follicle stimulating hormone 225 IU/daily. The PA group received placebo over 5 days and recombinant human follicle stimulating hormone at the same starting day and dose, similar to LA group. GnRH-antagonist was introduced once one or more follicle reached ≥14 mm. The main outcome measures were the number of oocytes retrieved, fertilization rate, implantation rate, cycle cancellation rate, and clinical pregnancy rate. Results: There were no significant differences in demographic characteristics between groups. There were no significant differences between groups regarding the number of oocytes retrieved (p=0.81, number of embryos transferred (p=0.82, fertilization rate (p=0.225, implantation rate (p=0.72, total cycle cancelation rate (p=0.08, and clinical pregnancy rate (p=0.12. Conclusion: The use of letrozole in GnRH-antagonist cycles does not improve clinical outcomes in poor responder patients undergoing intracytoplasmic sperm injection.

  6. GnRH Antagonist/Letrozole Versus Microdose GnRH Agonist Flare Protocol in Poor Responders Undergoing In Vitro Fertilization

    Directory of Open Access Journals (Sweden)

    Robab Davar

    2010-09-01

    Conclusion: The addition of letrozole to the GnRH antagonist for poor responders does not improve the outcome of assisted reproductive technology cycles. The MF protocol remains the most appropriate protocol in poor responders.

  7. Use of a GnRH antagonist in controlled ovarian hyperstimulation for assisted conception in women with polycystic ovary disease: a randomized, prospective, pilot study.

    Science.gov (United States)

    Bahçeci, Mustafa; Ulug, Ulun; Ben-Shlomo, Izhar; Erden, Halit Firat; Akman, Mehmet Ali

    2005-02-01

    To compare the outcome of using gonadotropin-releasing hormone (GnRH) antagonists versus agonists in women with polycystic ovary disease (PCOD) who underwent controlled ovarian hyperstimulation (COH) for assisted reproductive techniques (ART). A total of 129 patients with PCOD were randomly allocated to undergo COH with a GnRH antagonist (59 patients) and GnRH agonist (leuprolide acetate) (70 patients) to prevent a premature luteinizing hormone (LH) surge. Assisted fertilization following oocyte retrieval and embryo transfer was performed. None of the cycles were cancelled due to a premature LH surge. There was no significant difference between the antagonist and agonist arms in the number of gonadotropin ampules consumed per cycle. However, in the antagonist arm a shorter duration of ovarian stimulation was recorded as compared to the agonist arm. Although similar numbers of oocytes was retrieved from both groups of patients, the quality of the oocytes, as measured by metaphase 2/total oocyte ratio, was lower in the antagonist arm as compared to the agonist arm. Pregnancy rates were 57.6% and 58.5% in the antagonist and agonist arms, respectively (p > 0.05). Implantation rates were not different (34.0% and 34.6%, respectively). The frequency of ovarian hyperstimulation syndrome also did not differ between the treatment groups (5% and 7.1%, respectively). The size of our study, on a specific subgroup of patients, does not allow a reliable conclusion regarding ART outcomefollowing the use of a GnRH antagonist versus agonist. Nevertheless, the protocol with the antagonist gave results that were as good as those of the protocol with the agonist in this PCOD patient population.

  8. The use of gonadotrophin-releasing hormone antagonists in polycystic ovarian disease.

    Science.gov (United States)

    Lubin, V; Charbonnel, B; Bouchard, P

    1998-12-01

    Polycystic ovarian disease (PCOD) is characterized by anovulation, eventually high luteinizing hormone (LH) levels, with increased LH pulse frequency, and hyperandrogenism. As the aetiology of the disease is still unknown, gonadotrophin-releasing hormone (GnRH) antagonists, competitive inhibitors of GnRH for its receptor, are interesting tools in order to study and treat the role of increased LH levels and pulse frequency in this disease. Their administration provokes a rapid decrease in bioactive and immunoactive LH followed by a slower decrease in follicle-stimulating hormone (FSH). In patients with PCOD, the suppression of gonadotrophin secretion eradicates the symptoms of the disease as long as the treatment lasts. Several authors have suggested that increased plasma LH levels have deleterious effects on the fertility of women with PCOD. Indeed, fewer spontaneous pregnancies with more miscarriages are observed when plasma LH levels are high. Assisted reproduction techniques such as in vitro fertilization (IVF) have provided other clues to the role of the LH secretory pattern in women with PCOD. The number of oocytes retrieved, the fertilization rate and the cleavage rate are lower in PCOD patients undergoing IVF and this is inversely correlated with FSH:LH ratio. These abnormalities are corrected when endogenous secretion of LH is suppressed. On the other hand, implantation and pregnancy rates after IVF are similar to those observed in control women. New GnRH antagonists are devoid of side effects and suppress LH secretion within a few hours without a flare-up effect. This action lasts for 10-100 hours. When GnRH antagonists are associated with i.v. pulsatile GnRH, this combination both suppresses the effect of endogenous GnRH and because of the competition for GnRH receptors restores a normal frequency of LH secretion. We have studied two women with PCOD, administering first 10 mg s.c. every 72 hours for 7 days of the GnRH antagonist Nal-Glu, then adding on

  9. Zebrafish adult-derived hypothalamic neurospheres generate gonadotropin-releasing hormone (GnRH neurons

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    Christian Cortés-Campos

    2015-09-01

    Full Text Available Gonadotropin-releasing hormone (GnRH is a hypothalamic decapeptide essential for fertility in vertebrates. Human male patients lacking GnRH and treated with hormone therapy can remain fertile after cessation of treatment suggesting that new GnRH neurons can be generated during adult life. We used zebrafish to investigate the neurogenic potential of the adult hypothalamus. Previously we have characterized the development of GnRH cells in the zebrafish linking genetic pathways to the differentiation of neuromodulatory and endocrine GnRH cells in specific regions of the brain. Here, we developed a new method to obtain neural progenitors from the adult hypothalamus in vitro. Using this system, we show that neurospheres derived from the adult hypothalamus can be maintained in culture and subsequently differentiate glia and neurons. Importantly, the adult derived progenitors differentiate into neurons containing GnRH and the number of cells is increased through exposure to either testosterone or GnRH, hormones used in therapeutic treatment in humans. Finally, we show in vivo that a neurogenic niche in the hypothalamus contains GnRH positive neurons. Thus, we demonstrated for the first time that neurospheres can be derived from the hypothalamus of the adult zebrafish and that these neural progenitors are capable of producing GnRH containing neurons.

  10. The comparision of effect of microdose GnRH-a flare-up, GnRH antagonist/aromatase inhibitor letrozole and GnRH antagonist/clomiphene citrate protocols on IVF outcomes in poor responder patients.

    Science.gov (United States)

    Ozcan Cenksoy, Pinar; Ficicioglu, Cem; Kizilkale, Ozge; Suhha Bostanci, Mehmet; Bakacak, Murat; Yesiladali, Mert; Kaspar, Cigdem

    2014-07-01

    To compare the effects of microdose GnRH-a flare-up, GnRH antagonist/aromatase inhibitor letrozole and GnRH antagonist/clomiphene citrate protocols on IVF outcomes in poor responder patients. Of 225 patients, 83 patients were in microdose flare-up group (Group 1), 70 patients were in GnRH antagonist/letrozole group (Group 2) and 72 patients were in GnRH antagonist/clomiphene citrate group (Group 3). Demographic and endocrine characteristics, the total number of oocytes retrieved, cancellation rate and clinical pregnancy rate were collected Results: Total dosage of gonadotropins (p=0.002) and serum E2 levels on the day of hCG administration (p=0.010) were significantly higher and duration of stimulations (p=0.03) was significantly longer in group 1. The number of oocytes retrieved was significantly greater in group 1 and 2 when compare to those of group 3 (p=0,000). There was a trend towards increasing cycle cancellation rates with GnRH antagonist/clomiphene citrate and GnRH antagonist/letrozole. Our finding suggest that the results of microdose flare-up protocol are better than other two used treatment protocols, in terms of maximum estradiol levels, number of mature oocytes retrieved, and cancellation rate and it still seems to be superior the ovarian stimulation regime for the poor responder patients.

  11. Return to fertility after extended chemical castration with a GnRH antagonist

    International Nuclear Information System (INIS)

    Kostanski, Janusz W; Jiang, Ge; Dani, Bhas A; Murty, Santos B; Qiu, Wei; Schrier, Bruce; Thanoo, B C; DeLuca, Patrick P

    2001-01-01

    Antagonistic analogues of GnRH for the treatment of prostate cancer may be used clinically in persons for whom return to fertility after such treatment is important or desirable. The purpose of this study was, therefore, to evaluate the effects of a long term treatment with orntide, a GnRH antagonist, on testosterone levels and fertility in male rats. Two groups of male rats received either 120-day orntide microspheres (8.8 mg orntide/kg/120 days) or vehicle alone (control group). Serum orntide and testosterone levels in both groups were monitored at certain intervals for 9 months from the initiation of treatment. After recovery of normal serum testosterone levels in the treated animals, each rat was housed with two proven breeder, but drug-naive, females. All mates of treated rats achieved pregnancy as rapidly as the mates of control rats although two of the control rats did not sire a litter with either female and one sired only one litter. The mean size of the litters of treated (12.3 offspring per litter) and control (10.6 offspring per litter) were similar. All offspring were grossly normal morphologically and behaviorally during the time to weaning. These results suggest that lack of fertility due to testosterone suppression is reversible after cessation of treatment with this GnRH antagonist

  12. Return to fertility after extended chemical castration with a GnRH antagonist

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    Schrier Bruce

    2001-10-01

    Full Text Available Abstract Background Antagonistic analogues of GnRH for the treatment of prostate cancer may be used clinically in persons for whom return to fertility after such treatment is important or desirable. The purpose of this study was, therefore, to evaluate the effects of a long term treatment with orntide, a GnRH antagonist, on testosterone levels and fertility in male rats. Methods Two groups of male rats received either 120-day orntide microspheres (8.8 mg orntide/kg/120 days or vehicle alone (control group. Serum orntide and testosterone levels in both groups were monitored at certain intervals for 9 months from the initiation of treatment. After recovery of normal serum testosterone levels in the treated animals, each rat was housed with two proven breeder, but drug-naive, females. Results All mates of treated rats achieved pregnancy as rapidly as the mates of control rats although two of the control rats did not sire a litter with either female and one sired only one litter. The mean size of the litters of treated (12.3 offspring per litter and control (10.6 offspring per litter were similar. All offspring were grossly normal morphologically and behaviorally during the time to weaning. Conclusions These results suggest that lack of fertility due to testosterone suppression is reversible after cessation of treatment with this GnRH antagonist.

  13. Melanin-concentrating hormone directly inhibits GnRH neurons and blocks kisspeptin activation, linking energy balance to reproduction.

    Science.gov (United States)

    Wu, Min; Dumalska, Iryna; Morozova, Elena; van den Pol, Anthony; Alreja, Meenakshi

    2009-10-06

    A link between energy balance and reproduction is critical for the survival of all species. Energy-consuming reproductive processes need to be aborted in the face of a negative energy balance, yet knowledge of the pathways mediating this link remains limited. Fasting and food restriction that inhibit fertility also upregulate the hypothalamic melanin-concentrating hormone (MCH) system that promotes feeding and decreases energy expenditure; MCH knockout mice are lean and have a higher metabolism but remain fertile. MCH also modulates sleep, drug abuse behavior, and mood, and MCH receptor antagonists are currently being developed as antiobesity and antidepressant drugs. Despite the clinical implications of MCH, the direct postsynaptic effects of MCH have never been reported in CNS neurons. Using patch-clamp recordings in brain slices from multiple lines of transgenic GFP mice, we demonstrate a strong inhibitory effect of MCH on an exclusive population of septal vGluT2-GnRH neurons that is activated by the puberty-triggering and preovulatory luteinizing hormone surge-mediating peptide, kisspeptin. MCH has no effect on kisspeptin-insensitive GnRH, vGluT2, cholinergic, or GABAergic neurons located within the same nucleus. The inhibitory effects of MCH are reproducible and nondesensitizing and are mediated via a direct postsynaptic Ba(2+)-sensitive K(+) channel mechanism involving the MCHR1 receptor. MCH immunoreactive fibers are in close proximity to vGluT2-GFP and GnRH-GFP neurons. Importantly, MCH blocks the excitatory effect of kisspeptin on vGluT2-GnRH neurons. Considering the role of MCH in regulating energy balance and of GnRH and kisspeptin in triggering puberty and maintaining fertility, MCH may provide a critical link between energy balance and reproduction directly at the level of the kisspeptin-activated vGluT2-GnRH neuron.

  14. Fanconi Anemia a Is a Nucleocytoplasmic Shuttling Molecule Required for Gonadotropin-Releasing Hormone (GnRH) Transduction of the GnRH Receptor

    OpenAIRE

    Larder, Rachel; Karali, Dimitra; Nelson, Nancy; Brown, Pamela

    2006-01-01

    GnRH binds its cognate G protein-coupled GnRH receptor (GnRHR) located on pituitary gonadotropes and drives expression of gonadotropin hormones. There are two gonadotropin hormones, comprised of a common α- and hormone-specific β-subunit, which are required for gonadal function. Recently we identified that Fanconi anemia a (Fanca), a DNA damage repair gene, is differentially expressed within the LβT2 gonadotrope cell line in response to stimulation with GnRH. FANCA is mutated in more than 60%...

  15. GnRH antagonist versus long agonist protocols in IVF: a systematic review and meta-analysis accounting for patient type.

    Science.gov (United States)

    Lambalk, C B; Banga, F R; Huirne, J A; Toftager, M; Pinborg, A; Homburg, R; van der Veen, F; van Wely, M

    2017-09-01

    pregnancy rate when the oral hormonal programming pill (OHP) pretreatment was combined with a flexible protocol (RR 0.74, 95% CI 0.59-0.91) while without OHP, the RR was 0.84, 95% CI 0.71-1.0. Subgroup analysis for the fixed antagonist schedule demonstrated no evidence of a significant difference with or without OHP (RR 0.94, 95% CI 0.79-1.12 and RR 0.94, 95% CI 0.83-1.05, respectively). Antagonists resulted in significantly lower OHSS rates both in the general IVF patients and in women with PCOS (RR 0.63, 95% CI 0.50-0.81 and RR 0.53, 95% CI 0.30-0.95, respectively). No data on OHSS was available from trials in poor responders. In a general IVF population, GnRH antagonists are associated with lower ongoing pregnancy rates when compared to long protocol agonists, but also with lower OHSS rates. Within this population, antagonist treatment prevents one case of OHSS in 40 patients but results in one less ongoing pregnancy out of every 28 women treated. Thus standard use of the long GnRH agonist treatment is perhaps still the approach of choice for prevention of premature luteinization. In couples with PCOS and poor responders, GnRH antagonists do not seem to compromise ongoing pregnancy rates and are associated with less OHSS and therefore could be considered as standard treatment. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  16. Pregnancy outcome in delayed start antagonist versus microdose flare GnRH agonist protocol in poor responders undergoing IVF/ICSI: An RCT

    Directory of Open Access Journals (Sweden)

    Robab Davar

    2018-04-01

    Full Text Available Background: Over the years, many article on different aspects of pathogenesis and management of poor ovarian responders have been published but there is no clear guideline for treating themyet. Objective: This study was designated to compare the effectiveness of a delayed start protocol with gonadotropin-releasing hormone (GnRH antagonist and microdose flare-up GnRH agonist protocol in poor ovarian responders. Materials and Methods: This randomized clinical trial consisted of 100 poor ovarian responder women in assisted reproductive technologies cycles. They were divided randomly in delayed-start antagonist protocol (with estrogen priming followed by early follicular-phase GnRH antagonist treatment for 7 days before ovarian stimulation and microdose flare-up GnRH agonist protocol. The main outcome was clinical pregnancy rate and second outcome was the number of retrieved oocytes, mature oocytes, 2PN number, fertilization rate, and implantation rate. Results: Fertilization rate, clinical pregnancy rate, and ongoing pregnancy rates were not significantly different between the two studied protocols. Number of retrieved oocytes (5.10±3.41 vs. 3.08±2.51 with p=0.002, mature oocytes (4.32±2.69 vs. 2.34±1.80 with p=0.003, number of 2PN (3.94±1.80 vs. 2.20±1.01 with p=0.001 and implantation rate (19.40% vs. 10.30% with p=0.022 were significantly higher in delayed antagonist group. Conclusion: The delayed-start protocol can improve ovarian response in poor responders by stimulating and synchronizing follicle development

  17. Prenatal androgenization of female mice programs an increase in firing activity of gonadotropin-releasing hormone (GnRH) neurons that is reversed by metformin treatment in adulthood.

    Science.gov (United States)

    Roland, Alison V; Moenter, Suzanne M

    2011-02-01

    Prenatal androgenization (PNA) of female mice with dihydrotestosterone programs reproductive dysfunction in adulthood, characterized by elevated luteinizing hormone levels, irregular estrous cycles, and central abnormalities. Here, we evaluated activity of GnRH neurons from PNA mice and the effects of in vivo treatment with metformin, an activator of AMP-activated protein kinase (AMPK) that is commonly used to treat the fertility disorder polycystic ovary syndrome. Estrous cycles were monitored in PNA and control mice before and after metformin administration. Before metformin, cycles were longer in PNA mice and percent time in estrus lower; metformin normalized cycles in PNA mice. Extracellular recordings were used to monitor GnRH neuron firing activity in brain slices from diestrous mice. Firing rate was higher and quiescence lower in GnRH neurons from PNA mice, demonstrating increased GnRH neuron activity. Metformin treatment of PNA mice restored firing activity and LH to control levels. To assess whether AMPK activation contributed to the metformin-induced reduction in GnRH neuron activity, the AMPK antagonist compound C was acutely applied to cells. Compound C stimulated cells from metformin-treated, but not untreated, mice, suggesting that AMPK was activated in GnRH neurons, or afferent neurons, in the former group. GnRH neurons from metformin-treated mice also showed a reduced inhibitory response to low glucose. These studies indicate that PNA causes enhanced firing activity of GnRH neurons and elevated LH that are reversible by metformin, raising the possibility that central AMPK activation by metformin may play a role in its restoration of reproductive cycles in polycystic ovary syndrome.

  18. Corifollitropin alfa followed by rFSH in a GnRH antagonist protocol for poor ovarian responder patients

    DEFF Research Database (Denmark)

    Polyzos, Nikolaos P; Devos, Michel; Humaidan, Peter

    2013-01-01

    OBJECTIVE: To identify whether women with poor ovarian response may benefit from treatment with corifollitropin alfa in a GnRH antagonist protocol. DESIGN: Retrospective pilot study. SETTING: University-based tertiary care center. PATIENT(S): Poor ovarian responders fulfilling the Bologna criteria...... developed by European Society for Human Reproduction and Embryology Consensus Group. INTERVENTION(S): Corifollitropin alfa (150 μg) followed by 300 IU rFSH in a GnRH antagonist protocol. MAIN OUTCOME MEASURE(S): Endocrinologic profile and ongoing pregnancy rates. RESULT(S): Among 43 women treated...

  19. Comparison Pregnancy Outcomes Between Minimal Stimulation Protocol and Conventional GnRH Antagonist Protocols in Poor Ovarian Responders

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    Shamim Pilehvari

    2016-05-01

    Full Text Available Objective: To compare the pregnancy outcomes achieved by in vitro fertilization (IVF between minimal stimulation and conventional antagonist protocols in poor ovarian responders (PORs.Materials and methods: In this randomized controlled trial, 77 PORs undergoing IVF were selected and divided into two groups. First group was the minimal stimulation group (n = 42 receiving 100 mg/day clomiphene citrate on day 2of the cycle for 5 day that was followed by150IU/day human menopausal gonadotropin (hMG on day 5 of the cycle. Second group was the conventional group (n = 35 receiving at least 300 IU/daygonadotropin on day 2 of the cycle. Gonadotropin-releasing hormone (GnRH antagonist protocol was applied for both groups according to flexible protocol. Number of retrieved oocytes and chemical pregnancy rate were the main outcomes.Results: There was no difference in number ofretrieved oocyte and pregnancy rate (2.79 ± 1.96 vs. 2.20 ± 1.71 and 5.6% vs. 4.1%; p > 0.05 between both groups. The gonadotropin dose used in the minimal stimulation group was lower than conventional group (1046 ± 596 vs. 2806 ± 583.Conclusion: Minimal stimulation protocol with lower gonadotropin used is likely to be considered as a patient- friendly and cost-effective substitute for PORs. 

  20. Degarelix: A Novel Gonadotropin-Releasing Hormone (GnRH) Receptor Blocker-Results from a 1-yr, Multicentre, Randomised, Phase 2 Dosage-Finding Study in the Treatment of Prostate Cancer

    NARCIS (Netherlands)

    van Poppel, Hendrik; Tombal, Bertrand; de la Rosette, Jean J.; Persson, Bo-Eric; Jensen, Jens-Kristian; Kold Olesen, Tine

    2008-01-01

    Background: Degarelix is a gonadotropin-releasing hormone antagonist (GnRH receptor blocker) with immediate onset of action, suppressing gonadotropins, testosterone, and prostate-specific antigen (PSA) in prostate cancer. Objective: To determine the efficacy and safety of initial doses of 200 mg or

  1. Corifollitropin alfa compared to daily rFSH or HP-HMG in GnRH antagonist controlled ovarian stimulation protocol for patients undergoing assisted reproduction.

    Science.gov (United States)

    Souza, Priscila Morais Galvão; Carvalho, Bruno Ramalho de; Nakagawa, Hitomi Miura; Rassi, Thalita Reis Esselin; Barbosa, Antônio César Paes; Silva, Adelino Amaral

    2017-06-01

    This study aimed to compare the outcomes of controlled ovarian stimulation (COS) with corifollitropin alfa versus daily recombinant follicle-stimulating hormone (rRFSH) or highly purified human menopausal gonadotropin (HP-HMG) in patients undergoing in vitro fertilization (IVF) cycles based on gonadotropin-releasing hormone (GnRH) antagonist protocols. The primary endpoints were total number of oocytes and mature oocytes. This retrospective study looked into 132 controlled ovarian stimulation cycles from IVF or oocyte cryopreservation performed in a private human reproduction center between January 1 and December 31, 2014. Enrollment criteria: women aged 0.05). There were no significant differences in fertilization (76.9% vs. 76.8%, p=1.0), biochemical pregnancy (66.7% vs. 47.2%, p=0.1561) or embryo implantation rates (68.7% vs. 50%, p=0.2588) between the groups using corifollitropin alfa and rFSH or HMG, respectively. Corifollitropin alfa seems to be as effective as rFSH or HP-HMG when used in the first seven days of ovulation induction for patients undergoing assisted reproduction in GnRH antagonist protocols.

  2. Ghrelin decreases firing activity of gonadotropin-releasing hormone (GnRH neurons in an estrous cycle and endocannabinoid signaling dependent manner.

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    Imre Farkas

    Full Text Available The orexigenic peptide, ghrelin is known to influence function of GnRH neurons, however, the direct effects of the hormone upon these neurons have not been explored, yet. The present study was undertaken to reveal expression of growth hormone secretagogue receptor (GHS-R in GnRH neurons and elucidate the mechanisms of ghrelin actions upon them. Ca(2+-imaging revealed a ghrelin-triggered increase of the Ca(2+-content in GT1-7 neurons kept in a steroid-free medium, which was abolished by GHS-R-antagonist JMV2959 (10 µM suggesting direct action of ghrelin. Estradiol (1nM eliminated the ghrelin-evoked rise of Ca(2+-content, indicating the estradiol dependency of the process. Expression of GHS-R mRNA was then confirmed in GnRH-GFP neurons of transgenic mice by single cell RT-PCR. Firing rate and burst frequency of GnRH-GFP neurons were lower in metestrous than proestrous mice. Ghrelin (40 nM-4 μM administration resulted in a decreased firing rate and burst frequency of GnRH neurons in metestrous, but not in proestrous mice. Ghrelin also decreased the firing rate of GnRH neurons in males. The ghrelin-evoked alterations of the firing parameters were prevented by JMV2959, supporting the receptor-specific actions of ghrelin on GnRH neurons. In metestrous mice, ghrelin decreased the frequency of GABAergic mPSCs in GnRH neurons. Effects of ghrelin were abolished by the cannabinoid receptor type-1 (CB1 antagonist AM251 (1µM and the intracellularly applied DAG-lipase inhibitor THL (10 µM, indicating the involvement of retrograde endocannabinoid signaling. These findings demonstrate that ghrelin exerts direct regulatory effects on GnRH neurons via GHS-R, and modulates the firing of GnRH neurons in an ovarian-cycle and endocannabinoid dependent manner.

  3. Studies on the relationship between thyroid hormones, ovarian hormones, GnRH and reproductive performance of egyptian buffaloes

    International Nuclear Information System (INIS)

    Farghaly, H.A.M.

    1992-01-01

    this study was carried out in the experimental farm of animal production department, faculty of agriculture, cairo university. hormonal analysis were performed in the laboratories of animal physiology unit, radiobiology department, nuclear research center, atomic energy authority (radiobiol. Dept., NRC, AEA). The aim of the study was to investigate the following : 1- post-partum reproductive activity of egyptian buffaloes and the factors affecting the resumption of ovarian activity after calving , with particular reference to the patterns of thyroid hormones (T 4 and T 3 ) and progesterone hormone.2- the effectiveness of using GnRH treatment on inducing ovarian activity after calving. 3- the effect of goitrogen administration (thiouracil) on ovarian activity during post-partum and on the response of buffaloes to GnRH treatment and their reproductive patterns

  4. Biosynthesis of gonadotropin-releasing hormone (GnRH) and GnRH receptor (GnRHR) in hypothalamic-pituitary unit of anoestrous and cyclic ewes.

    Science.gov (United States)

    Ciechanowska, M O; Łapot, M; Mateusiak, K; Paruszewska, E; Malewski, T; Przekop, F

    2017-02-01

    This study was performed to explain how the molecular processes governing the biosynthesis of gonadotropin-releasing hormone (GnRH) and GnRH receptor (GnRHR) in the hypothalamic-pituitary unit are reflected by luteinizing hormone (LH) secretion in sheep during anoestrous period and during luteal and follicular phases of the oestrous cycle. Using an enzyme-linked immunosorbent assay (ELISA), we analyzed the levels of GnRH and GnRHR in preoptic area (POA), anterior (AH) and ventromedial hypothalamus (VM), stalk-median eminence (SME), and GnRHR in the anterior pituitary gland (AP). Radioimmunoassay has also been used to define changes in plasma LH concentrations. The study provides evidence that the levels of GnRH in the whole hypothalamus of anoestrous ewes were lower than that in sheep during the follicular phase of the oestrous cycle (POA: p pituitary unit, as well as LH level, in the blood in anoestrous ewes were significantly lower than those detected in animals of both cyclic groups. Our data suggest that decrease in LH secretion during the long photoperiod in sheep may be due to low translational activity of genes encoding both GnRH and GnRHR.

  5. Microdose GnRH Agonist Flare-Up versus Ultrashort GnRH Agonist Combined with Fixed GnRH Antagonist in Poor Responders of Assisted Reproductive Techniques Cycles

    Directory of Open Access Journals (Sweden)

    Parisa Khani

    2013-01-01

    Full Text Available Background: This study compares the microdose flare-up protocol to the ultrashort gonadotropinreleasinghormone (GnRH agonist flare combined with the fixed multidose GnRH antagonistprotocol in poor responders undergoing ovarian stimulation.Materials and Methods: In this randomized clinical trial, 120 women who were candidates forassisted reproductive techniques (ART and had histories of one or more failed in vitro fertilization(IVF cycles with three or fewer retrieved oocytes were prospectively randomized into two groups.Group I (60 patients received the microdose flare-up regimen and group II (60 patients receivedthe ultrashort GnRH agonist combined with fixed GnRH antagonist.Results: There were no significant differences between the groups in the number of used gonadotropinampoules (p=0.591, duration of stimulation (p=0.610, number of retrieved oocytes (p=0.802,fertilization rate (p=0.456, and the number of transferred embryos (p=0.954. The clinical pregnancyrates were statistically similar in group I (10% compared with group II (13.3%, p=0.389.Conclusion: According to our results, there is no significant difference between these protocolsfor improving the ART outcome in poor responders. Additional prospective, randomizedstudies with more patients is necessary to determine the best protocol (Registration Number:IRCT201105096420N1.

  6. GnRH Neuron Activity and Pituitary Response in Estradiol-Induced vs Proestrous Luteinizing Hormone Surges in Female Mice.

    Science.gov (United States)

    Silveira, Marina A; Burger, Laura L; DeFazio, R Anthony; Wagenmaker, Elizabeth R; Moenter, Suzanne M

    2017-02-01

    During the female reproductive cycle, estradiol exerts negative and positive feedback at both the central level to alter gonadotropin-releasing hormone (GnRH) release and at the pituitary to affect response to GnRH. Many studies of the neurobiologic mechanisms underlying estradiol feedback have been done on ovariectomized, estradiol-replaced (OVX+E) mice. In this model, GnRH neuron activity depends on estradiol and time of day, increasing in estradiol-treated mice in the late afternoon, coincident with a daily luteinizing hormone (LH) surge. Amplitude of this surge appears lower than in proestrous mice, perhaps because other ovarian factors are not replaced. We hypothesized GnRH neuron activity is greater during the proestrous-preovulatory surge than the estradiol-induced surge. GnRH neuron activity was monitored by extracellular recordings from fluorescently tagged GnRH neurons in brain slices in the late afternoon from diestrous, proestrous, and OVX+E mice. Mean GnRH neuron firing rate was low on diestrus; firing rate was similarly increased in proestrous and OVX+E mice. Bursts of action potentials have been associated with hormone release in neuroendocrine systems. Examination of the patterning of action potentials revealed a shift toward longer burst duration in proestrous mice, whereas intervals between spikes were shorter in OVX+E mice. LH response to an early afternoon injection of GnRH was greater in proestrous than diestrous or OVX+E mice. These observations suggest the lower LH surge amplitude observed in the OVX+E model is likely not attributable to altered mean GnRH neuron activity, but because of reduced pituitary sensitivity, subtle shifts in action potential pattern, and/or excitation-secretion coupling in GnRH neurons. Copyright © 2017 by the Endocrine Society.

  7. Rescue of corpus luteum function with peri-ovulatory HCG supplementation in IVF/ICSI GnRH antagonist cycles in which ovulation was triggered with a GnRH agonist

    DEFF Research Database (Denmark)

    Al Humaidan, Peter Samir Heskjær; Bungum, L; Bungum, M

    2006-01-01

    Previous studies found a poor clinical outcome when a GnRH agonist (GnRHa) was used to trigger ovulation in GnRH antagonist IVF/ICSI cycles. This study aimed to determine the clinical and endocrine effects as well the optimal timing of HCG supplementation. Forty-five normogonadotrophic IVF/ICSI p......RHa supplemented with 1500 IU HCG 35 h later (group 3) seems to secure a normal luteal phase and a normal clinical pregnancy outcome....

  8. Afferent neuronal control of type-I gonadotropin releasing hormone (GnRH neurons in the human

    Directory of Open Access Journals (Sweden)

    Erik eHrabovszky

    2013-09-01

    Full Text Available Understanding the regulation of the human menstrual cycle represents an important ultimate challenge of reproductive neuroendocrine research. However, direct translation of information from laboratory animal experiments to the human is often complicated by strikingly different and unique reproductive strategies and central regulatory mechanisms that can be present in even closely related animal species. In all mammals studied so far, type-I gonadotropin releasing hormone (GnRH synthesizing neurons form the final common output way from the hypothalamus in the neuroendocrine control of the adenohypophysis. Under various physiological and pathological conditions, hormonal and metabolic signals either regulate GnRH neurons directly or act on upstream neuronal circuitries to influence the pattern of pulsatile GnRH secretion into the hypophysial portal circulation. Neuronal afferents to GnRH cells convey important metabolic-, stress-, sex steroid-, lactational- and circadian signals to the reproductive axis, among other effects. This article gives an overview of the available neuroanatomical literature that described the afferent regulation of human GnRH neurons by peptidergic, monoaminergic and amino acidergic neuronal systems. Recent studies of human genetics provided evidence that central peptidergic signaling by kisspeptins and neurokinin B play particularly important roles in puberty onset and later, in the sex steroid-dependent feedback regulation of GnRH neurons. This review article places special emphasis on the topographic distribution, sexual dimorphism, aging-dependent neuroanatomical changes and plastic connectivity to GnRH neurons of the critically important human hypothalamic kisspeptin and neurokinin B systems.

  9. Prediction of Ovarian Hyperstimulation Syndrome in Patients Treated with Corifollitropin alfa or rFSH in a GnRH Antagonist Protocol.

    Directory of Open Access Journals (Sweden)

    Georg Griesinger

    Full Text Available What is the threshold for the prediction of moderate to severe or severe ovarian hyperstimulation syndrome (OHSS based on the number of growing follicles ≥ 11 mm and/or estradiol (E2 levels?The optimal threshold of follicles ≥11 mm on the day of hCG to identify those at risk was 19 for both moderate to severe OHSS and for severe OHSS. Estradiol (E2 levels were less prognostic of OHSS than the number of follicles ≥ 11 mm.In comparison to long gonadotropin-releasing hormone (GnRH agonist protocols, the risk of severe OHSS is reduced by approximately 50% in a GnRH antagonist protocol for ovarian stimulation prior to in vitro fertilisation (IVF, while the two protocols provide equal chances of pregnancy per initiated cycle. Nevertheless, moderate to severe OHSS may still occur in GnRH antagonist protocols if human chorionic gonadotropin (hCG is administered to trigger final oocyte maturation, especially in high responder patients. Severe OHSS following hCG trigger may occur with an incidence of 1-2% in a relatively young (aged 18 to 36 years IVF population treated in a GnRH-antagonist protocol.From the Engage, Ensure and Trust trials, in total, 2,433 women who received hCG for oocyte maturation and for whom the number of follicles ≥ 11 mm and the level of E2 on the day of hCG administration were known were included in the analyses.The threshold for OHSS prediction of moderate and severe OHSS was assessed in women treated with corifollitropin alfa or daily recombinant follicle stimulation hormone (rFSH in a gonadotropin-releasing hormone (GnRH-antagonist protocol. Receiver operating characteristics curve analyses for moderate to severe OHSS and severe OHSS were performed on the combined dataset and the sensitivity and specificity for the optimal threshold of number of follicles ≥ 11 mm, E2 levels on the day of (hCG, and a combination of both, were determined.The optimal threshold of follicles ≥ 11 mm on the day of hCG to identify those at

  10. Gonadotropin-releasing hormone agonist trigger in oocyte donors co-treated with a gonadotropin-releasing hormone antagonist

    DEFF Research Database (Denmark)

    Vuong, T. N. L.; Ho, M. T.; Ha, T. D.

    2016-01-01

    -35 years, body mass index [BMI] hormone level >1.25 ng/mL, and antral follicle count >= 6). Intervention(s): Ovulation trigger with 0.2, 0.3, or 0.4 mg triptorelin in a GnRH antagonist cycle. Main Outcome Measure(s): The primary end point was number of metaphase II oocytes...... to number of metaphase II oocytes (16.0 +/- 8.5, 15.9 +/- 7.8, and 14.7 +/- 8.4, respectively), embryos (13.2 +/- 7.8, 11.7 +/- 6.9, 11.8 +/- 7.0), and number of top-quality embryos (3.8 +/- 2.9, 3.6 +/- 3.0, 4.1 +/- 3.0). Luteinizing hormone levels at 24 hours and 36 hours after trigger was significantly...

  11. Sexual dimorphism of gonadotropin-releasing hormone type-III (GnRH3) neurons and hormonal sex reversal of male reproductive behavior in Mozambique tilapia.

    Science.gov (United States)

    Kuramochi, Asami; Tsutiya, Atsuhiro; Kaneko, Toyoji; Ohtani-Kaneko, Ritsuko

    2011-10-01

    In tilapia, hormone treatment during the period of sexual differentiation can alter the phenotype of the gonads, indicating that endocrine factors can cause gonadal sex reversal. However, the endocrine mechanism underlying sex reversal of reproductive behaviors remains unsolved. In the present study, we detected sexual dimorphism of gonadotropin-releasing hormone type III (GnRH3) neurons in Mozambique tilapia Oreochromis mossambicus. Our immunohistochemical observations showed sex differences in the number of GnRH3 immunoreactive neurons in mature tilapia; males had a greater number of GnRH3 neurons in the terminal ganglion than females. Treatment with androgen (11-ketotestosterone (11-KT) or methyltestosterone), but not that with 17β-estradiol, increased the number of GnRH3 neurons in females to a level similar to that in males. Furthermore, male-specific nest-building behavior was induced in 70% of females treated with 11-KT within two weeks after the onset of the treatment. These results indicate androgen-dependent regulation of GnRH3 neurons and nest-building behavior, suggesting that GnRH3 is importantly involved in sex reversal of male-specific reproductive behavior.

  12. Comparison of microdose GnRH agonist protocol with GnRH antagonist / letrazole protocol in patients with poor ovarian response

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    Yiğit Çakıroğlu

    2013-09-01

    Full Text Available Objective: To compare microdose GnRH agonist (MDL protocol with GnRH antagonist/letrazole (AL protocol in patients with poor ovarian response. Design: Randomised clinical trial. Setting: Kocaeli University Assisted Reproductive Centre Interventions: POR was diagnosed according to ESHRE Bologna criteria in case of presence of 2 out of 3 criteria. In the MDL group (n=27, 40µg/0.2 cc subcutaneous leuprolid acetate was given two times a day starting on the first day of menstrual cycle. On the second day of the cycle, gonadotrophin stimulation was started at 450-600 IU and/or 150 IU human menopausal gonadotrophin (hMG along with leuprolid. In the AL group (n=28, 5 mg letrazole was given for 5 days starting on the second day of the spontaneous cycle and after the 5th day of the cycle, 450-600 IU and/or 150 IU hMG was given. Main Outcome Measures: To compare the outcomes of MDL protocol with AL protocol in patients with poor ovarian response. Results: Stimulation days, total gonadotrophin dose (IU, peak E2 (pg/ml levels, and endometrial thickness were found to be statistically significantly lower in the AL group. While no cases of cycle cancellation was detected in the MDL group, statistically significantly higher rates of cycle cancellation (%35.7, p<0.001 was detected in the AL group. No statistically significant differences were detected in total oocyte numbers (3.7±2.9 vs 2.7±2.2, number of transferred embryos (1.4±0.5 vs 1.4±1.9, pregnancy rates (3/27 (%11.1 vs 2/28 (%7.1 and implantation rates (3/36 (%8.3 vs 2/22 (%9.1 in between the groups. Comment: Although AL protocol is not superior to MDL protocol in poor ovarian response patients, it may be used as an alternative protocol.

  13. Comparison of the ultrashort gonadotropin-releasing hormone agonist-antagonist protocol with microdose flare -up protocol in poor responders: a preliminary study.

    Science.gov (United States)

    Berker, Bülent; Duvan, Candan İltemir; Kaya, Cemil; Aytaç, Ruşen; Satıroğlu, Hakan

    2010-01-01

    To determine the potential effect of the ultrashort gonadotropin-releasing hormone (GnRH) agonist/GnRH antagonist protocol versus the microdose GnRH agonist protocol in poor responders undergoing intracytoplasmic sperm injection (ICSI). The patients in the Agonist-Antagonist Group (n=41) were administered the ultrashort GnRH-agonist/ antagonist protocol, while the patients in the Microdose Group (n=41) were stimulated according to the microdose flare-up protocol. The mean number of mature oocytes retrieved was the primary outcome measure. Fertilization rate, implantation rate per embryo and clinical pregnancy rates were secondary outcome measures. There was no differenc between the mean number of mature oocytes retrieved in the two groups. There were also no statistical differences between the two groups in terms of peak serum E2 level, canceled cycles, endometrial thickness on hCG day, number of 2 pronucleus and number of embryos transferred. However, the total gonadotropin consumption and duration of stimulation were significantly higher with the Agonist-Antagonist Group compared with the Microdose Group. The implantation and clinical pregnancy rates were similar between the two groups. Despite the high dose of gonadotropin consumption and longer duration of stimulation with the ultrashort GnRH agonist/ antagonist protocol, it seems that the Agonist-Antagonist Protocol is not inferior to the microdose protocol in poor responders undergoing ICSI.

  14. The IVF Outcome Counseling Based on the Model Combining DHEAS and Age in Patients with Low AMH Prior to the First Cycle of GnRH Antagonist Protocol of Ovarian Stimulation

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    Miro Šimun Alebić

    2013-01-01

    Full Text Available Objective. To investigate the endocrine and/or clinical characteristics of women with low anti-Müllerian hormone (AMH that could improve the accuracy of IVF outcome prediction based on the female age alone prior to the first GnRH antagonist IVF cycle. Methods. Medical records of 129 patients with low AMH level (<6.5 pmol/L who underwent their first GnRH antagonist ovarian stimulation protocol for IVF/ICSI were retrospectively analyzed. The main outcome measure was the area under the ROC curve (AUC-ROC for the models combining age and other potential predictive factors for the clinical pregnancy. Results. Clinical pregnancy rate (CPR per initiated cycles was 11.6%. For the prediction of clinical pregnancy, DHEAS and age showed AUC-ROC of 0.726 (95%CI 0.641–0.801 and 0.662 (95%CI 0.573–0.743, respectively (. The predictive accuracy of the model combining age and DHEAS (AUC-ROC 0.796; 95%CI 0.716–0.862 was significantly higher compared to that of age alone (. In patients <37.5 years with DHEAS  pmol/L, 60% (9/15 of all pregnancies were achieved with CPR of 37.5%. Conclusions. DHEAS appears to be predictive for clinical pregnancy in younger women (<37.5 years with low AMH after the first GnRH antagonist IVF cycle. Therefore, DHEAS-age model could refine the pretreatment counseling on pregnancy prospects following IVF.

  15. GnRH neurons of young and aged female rhesus monkeys co-express GPER but are unaffected by long-term hormone replacement.

    Science.gov (United States)

    Naugle, Michelle M; Gore, Andrea C

    2014-01-01

    Menopause is caused by changes in the function of the hypothalamic-pituitary-gonadal axis that controls reproduction. Hypophysiotropic gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus orchestrate the activity of this axis and are regulated by hormonal feedback loops. The mechanisms by which GnRH responds to the primary regulatory sex steroid hormone, estradiol (E2), are still poorly understood in the context of menopause. Our goal was to determine whether the G protein-coupled estrogen receptor (GPER) is co-expressed in adult primate GnRH neurons and whether this changes with aging and/or E2 treatment. We used immunofluorescence double-labeling to characterize the co-expression of GPER in GnRH perikarya and terminals in the hypothalamus. Young and aged rhesus macaques were ovariectomized and given long-term (~2-year) hormone treatments (E2, E2 + progesterone, or vehicle) selected to mimic currently prescribed hormone replacement therapies used for the alleviation of menopausal symptoms in women. We found that about half of GnRH perikarya co-expressed GPER, while only about 12% of GnRH processes and terminals in the median eminence (ME) were double-labeled. Additionally, many GPER-labeled processes were in direct contact with GnRH neurons, often wrapped around the perikarya and processes and in close proximity in the ME. These results extend prior work by showing robust co-localization of GPER in GnRH in a clinically relevant model, and they support the possibility that GPER-mediated E2 regulation of GnRH occurs both in the soma and terminals in nonhuman primates.

  16. Gonadotropin Releasing Hormone Agonists or Antagonists for Preimplantation Genetic Diagnosis (PGD)? A Prospective Randomised Trial.

    Science.gov (United States)

    Verpoest, Willem; De Vos, Anick; De Rycke, Martine; Parikh, Shruti; Staessen, Catherine; Tournaye, Herman; De Vos, Michel; Vloeberghs, Veerle; Blockeel, Christophe

    2017-11-10

    The use of GnRH analogue medication is essential in reproductive medicine to avoid premature ovulation by pituitary suppression for the duration of ovarian stimulation by gonadotrophins. The type of pituitary suppression by either GnRH agonist analogues versus GnRH antagonist analogues may result in different embryological hence clinical results. Preimplantation genetic diagnosis is a subtype of IVF in which embryos are created for genetic diagnosis of hereditary disorders in order to avoid genetically affected children. Embryological quality hence ovarian stimulation in preimplantation genetic diagnosis is crucial as genetic selection will reduce the number of available embryos to a fraction of the total. The aim of this study was to assess the efficiency of GnRH antagonist versus GnRH agonist treatment for pituitary suppression in ovarian stimulation for PGD, by proxy of number and quality of embryos at cleavage stage available for biopsy. We conducted a prospective randomised controlled trial comparing pituitary suppression by GnRH antagonist versus GnRH agonist in ovarian stimulation for PGD. The primary outcome measure was the number of embryos of sufficient quality for biopsy at cleavage stage. Secondary outcome parameters were the number of blastocysts available of top quality, and clinical pregnancy rate. There was no difference in number of oocytes retrieved, embryos at cleavage stage available for biopsy or embryo quality. The clinical pregnancy rate was higher in the GnRH agonist group; however the sample size was insufficient to allow conclusions. The use of GnRH agonist versus antagonist treatment does not result in differences in a number of oocytes, embryos or embryo quality in ovarian stimulation for preimplantation genetic diagnosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Pituitary block with gonadotrophin-releasing hormone antagonist during intrauterine insemination cycles: a systematic review and meta-analysis of randomised controlled trials.

    Science.gov (United States)

    Vitagliano, A; Saccone, G; Noventa, M; Borini, A; Coccia, M E; Nardelli, G B; Saccardi, C; Bifulco, G; Litta, P S; Andrisani, A

    2018-06-03

    Several randomised controlled trials (RCTs) have investigated the usefulness of pituitary block with gonadotrophin-releasing hormone (GnRH) antagonists during intrauterine insemination (IUI) cycles, with conflicting results. The aim of the present systematic review and meta-analysis of RCTs was to evaluate the effectiveness of GnRH antagonist administration as an intervention to improve the success of IUI cycles. Electronic databases (MEDLINE, Scopus, EMBASE, Sciencedirect) and clinical registers were searched from their inception until October 2017. Randomised controlled trials of infertile women undergoing one or more IUI stimulated cycles with GnRH antagonists compared with a control group. The primary outcomes were ongoing pregnancy/live birth rate (OPR/LBR) and clinical pregnancy rate (CPR). Pooled results were expressed as odds ratio (OR) or mean differences with 95% confidence interval (95% CI). Sources of heterogeneity were investigated through sensitivity and subgroups analysis. The body of evidence was rated using GRADE methodology. Publication bias was assessed with funnel plot, Begg's and Egger's tests. Fifteen RCTs were included (3253 IUI cycles, 2345 participants). No differences in OPR/LBR (OR 1.14, 95% CI 0.82-1.57, P = 0.44) and CPR (OR 1.28, 95% CI 0.97-1.69, P = 0.08) were found. Sensitivity and subgroup analyses did not provide statistical changes in pooled results. The body of evidence was rated as low (GRADE 2/4). No publication bias was detected. Pituitary block with GnRH antagonists does not improve OPR/LBR and CPR in women undergoing IUI cycles. Pituitary block with GnRH antagonists does not improve the success of IUI cycles. © 2018 Royal College of Obstetricians and Gynaecologists.

  18. Chitosan-based DNA delivery vector targeted to gonadotropin-releasing hormone (GnRH) receptor.

    Science.gov (United States)

    Boonthum, Chatwalee; Namdee, Katawut; Boonrungsiman, Suwimon; Chatdarong, Kaywalee; Saengkrit, Nattika; Sajomsang, Warayuth; Ponglowhapan, Suppawiwat; Yata, Teerapong

    2017-02-10

    The main purpose of this study was to investigate the application of modified chitosan as a potential vector for gene delivery to gonadotropin-releasing hormone receptor (GnRHR)-expressing cells. Such design of gene carrier could be useful in particular for gene therapy for cancers related to the reproductive system, gene disorders of sexual development, and contraception and fertility control. In this study, a decapeptide GnRH was successfully conjugated to chitosan (CS) as confirmed by proton nuclear magnetic resonance spectroscopy ( 1 H NMR) and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The synthesized GnRH-conjugated chitosan (GnRH-CS) was able to condense DNA to form positively charged nanoparticles and specifically deliver plasmid DNA to targeted cells in both two-dimensional (2D) and three-dimensional (3D) cell cultures systems. Importantly, GnRH-CS exhibited higher transfection activity compared to unmodified CS. In conclusion, GnRH-conjugated chitosan can be a promising carrier for targeted DNA delivery to GnRHR-expressing cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Induction of spermatogenesis and fertility in hypogonadotropic azoospermic men by intravenous pulsatile gonadotropin-releasing hormone (GnRH).

    Science.gov (United States)

    Blumenfeld, Z; Makler, A; Frisch, L; Brandes, J M

    1988-06-01

    Gonadotropin-releasing hormone (GnRH) has only recently become a helpful tool in the medication of hypogonadotropic hypogonadism (HH). Two azoospermic patients with HH who had previously been treated with hCG/hMG because of delayed puberty and each of whom had fathered a child after previous gonadotropin therapy were referred due to secondary failure of hCG/hMG treatment to induce spermatogenesis and fertility. A pulse study where blood was drawn every 15 minutes for LH, FSH and PRL RIAs was performed in each patient, and afterwards a bolus of i.v. GnRH was injected to assess gonadotropin responsiveness. A portable GnRH pump was connected to each patient so that it administered 5-20 micrograms of GnRH i.v. every 89 minutes. Spermatogenesis was first detected after 42 and 78 days respectively in the 2 treated HH men and 4 1/2 months from the start of treatment their wives became pregnant. No thrombophlebitis or other complications of the i.v. therapy occurred. In the case of the first patient, the semen was washed and concentrated and intra-uterine inseminations were carried out in an attempt to shorten the time needed to achieve fertility. The first pregnancy was successfully terminated at 38 weeks with the delivery of 2 heterozygotic normal male babies. The second pregnancy ended in spontaneous delivery of a healthy female. We conclude that i.v. pulsatile, intermittent GnRH administration is a safe, efficient and highly successful means of treating azoospermic men with HH.

  20. Observational Study to Assess the Therapeutic Value of Four Ovarian Hyperstimulation Protocols in IVF After Pituitary Suppression with GnRH Antagonists in Normally Responding Women.

    Science.gov (United States)

    Ana, Monzó; Vicente, Montañana; María, Rubio José; Trinidad, García-Gimeno; Alberto, Romeu

    2011-02-22

    To compare the clinical results of four different protocols of COH for IVF-ICSI in normovulatory women, using in all cases pituitary suppression with GnRH antagonists. A single center, open label, parallel-controlled, prospective, post-authorization study under the approved conditions for use where 305 normal responders women who were candidates to COH were assigned to r-FSH +hp-hMG (n = 51, Group I), hp-hMG (n = 61, Group II), fixed-dose r-FSH (n = 118, Group III), and r-FSH with potential dose adjustment (n = 75, Group IV) to subsequently undergo IVF-ICSI. During stimulation, Group IV needed significantly more days of stimulation as compared to Group II [8.09 ± 1.25 vs. 7.62 ± 1.17; P women undergoing pituitary suppression with GnRH antagonists.

  1. Comparison of GnRh Agonist Microdose Flare Up and GnRh Antagonist/Letrozole in Treatment of Poor Responder Patients in Intra Cytoplaspic Sperm Injection: Randomized Clinical Trial.

    Science.gov (United States)

    Nabati, Azar; Peivandi, Sepideh; Khalilian, Alireza; Mirzaeirad, Sina; Hashemi, Seyyed Abbas

    2015-08-06

    the prevalence of infertility is up to 10 to 15 % which 9 to 24 % of them are Poor Ovarian Responders (POR). This study was designed to compare two methods of GnRH Agonist Microdose Flareup (MF) and GnRH Antagonist/Letrozole (AL) in treatment of these patients. this randomized clinical trial study consisted of 123 patients. In the first step of treatment in both methods FSH, LH, estradiol, anderostandion, testestron in third day of menstruation period and the thickness of endometrium by Transvaginal sonography were evaluated. At the time of HCG injection the thickness of endometrium and follicles which were more than 14mm ware established and hormones were evaluated. Two weeks later serum βhCG and after 6 to 8 weeks Transvaginal sonography were applied to prove the pregnancy. there were 61 patients with mean age of 38.7±4.58 in MF group and 62 patients with mean age of 38.5±4.6 in AL group (P=0.80). At the time of hCG injection there were significant increase in the level of LH,estradiol, thickness of endometrium and follicles more than 14mm in MF patients (P<0.0001). The mean time of ovary stimulation in MF group was 10.72±1.5 and in AL was 8.45±1.2 (P<0.0001). The mean level of gonadotropin which were used was 80.6±20.1 in MF patients and 64.7±16.4 in AL group (P<0.0001). 18 % of MF group and 38.7% in AL group had no normal cycle of ovulation (OR: 2.87, 95% CI: 1.25-6.57, P=0.011). The mean numbers of oocyte and normal fetus in MF was 5.83±3.5 and 3.7±2.5 and in AL was 3±1.69 and 1.4±1.33 (P<0.0001). The number of chemical pregnancy in MF group was 10 (16.4%) and in AL was 3 (4.8%) (OR:3.85, 95%CI:1.06-14.77, P=0.037). Clinical pregnancy in 10 patients (16.4%) of MF group and 3 (4.8%)in AL was reported. OR: 3.85, 95%CI: 1.06-14.77, P=0.037). this study showed that MF method of pregnancy leads to more positive results in pregnancy based on chemical and clinical evaluation in comparison with AL and is advised for poor responder patients.

  2. Outpatient management of severe early OHSS by administration of GnRH antagonist in the luteal phase: an observational cohort study

    Directory of Open Access Journals (Sweden)

    Lainas George T

    2012-08-01

    Full Text Available Abstract Background Management of established severe OHSS requires prolonged hospitalization, occasionally in intensive care units, accompanied by multiple ascites punctures, correction of intravascular fluid volume and electrolyte imbalance. The aim of the present study was to evaluate whether it is feasible to manage women with severe OHSS as outpatients by treating them with GnRH antagonists in the luteal phase. Methods This is a single-centre, prospective, observational, cohort study. Forty patients diagnosed with severe OHSS, five days post oocyte retrieval, were managed as outpatients after administration of GnRH antagonist (0.25 mg daily from days 5 to 8 post oocyte retrieval, combined with cryopreservation of all embryos. The primary outcome measure was the proportion of patients with severe OHSS, in whom outpatient management was not feasible. Results 11.3% (95% CI 8.3%-15.0% of patients (40/353 developed severe early OHSS. None of the 40 patients required hospitalization following luteal antagonist administration and embryo cryopreservation. Ovarian volume, ascites, hematocrit, WBC, serum oestradiol and progesterone decreased significantly (P  Conclusions The current study suggests, for the first time, that successful outpatient management of severe OHSS with antagonist treatment in the luteal phase is feasible and is associated with rapid regression of the syndrome, challenging the dogma of inpatient management. The proposed management is a flexible approach that minimizes unnecessary embryo transfer cancellations in the majority (88.7% of high risk for OHSS patients.

  3. Predicting the effect of gonadotropin-releasing hormone (GnRH) analogue treatment on uterine leiomyomas based on MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsuno, Y.; Yamashita, Y.; Takahashi, M. [Dept. of Radiology, Kumamoto Univ. School of Medicine, Kumamoto (Japan); Katabuchi, H.; Okamura, H. [Dept. of Gynecology and Obstetrics, Kumamoto Univ. School of Medicine, Kumamoto (Japan); Kitano, Y.; Shimamura, T. [Dept. of Gynecology and Obstetrics, Amakusa Chuou General Hospital, Hondo (Japan)

    1999-11-01

    Purpose: To test the hypothesis that the simple assessment of signal intensity on T2-weighted MR images is predictive of the effect of hormonal treatment with gonadotropin-releasing hormone (GnRH) analogue. Material and methods: The correlation between T2-weighted MR imaging of uterine leiomyomas and histologic findings was evaluated using 85 leiomyomas from 62 females who underwent myomectomy or hysterectomy. We also correlated the pretreatment MR images features obtained in 110 women with 143 leiomyomas with the effect of GnRH analogue treatment. The size (length x width x depth) of the leiomyoma was evaluated before and at 6 months after treatment by ultrasound. Results: The proportion of leiomyoma cell fascicles and that of extracellular matrix affected signal intensities of uterine leiomyomas on T2-weighted MR images. The amount of extracellular matrix was predominant in hypointense leiomyomas on T2-weighted images, while diffuse intermediate signal leiomyomas were predominantly composed of leiomyoma cell fascicles. Marked degenerative changes were noted in leiomyomas with heterogenous hyperintensity. The homogeneously intermediate signal intensity leiomyomas showed significant size reduction after treatment (size ratio; posttreatment volume/pretreatment volume 0.29{+-}0.11). The size ratio for the hypointense tumors was 0.82{+-}0.14, and 0.82{+-}0.18 for the heterogeneously hyperintense tumors. There was a significant difference in the response to treatment between the homogeneously intermediate signal intensity leiomyomas and the hypointense or heterogeneously hyperintense leiomyomas (both p<0.01). Conclusion: Signal intensity on T2-weighted MR images depends on the amount of leiomyoma cell fascicles and extracellular matrix. Simple assessment of the MR signal intensity is useful in predicting the effect of GnRH analogue on uterine leiomyomas. (orig.)

  4. Predicting the effect of gonadotropin-releasing hormone (GnRH) analogue treatment on uterine leiomyomas based on MR imaging

    International Nuclear Information System (INIS)

    Matsuno, Y.; Yamashita, Y.; Takahashi, M.; Katabuchi, H.; Okamura, H.; Kitano, Y.; Shimamura, T.

    1999-01-01

    Purpose: To test the hypothesis that the simple assessment of signal intensity on T2-weighted MR images is predictive of the effect of hormonal treatment with gonadotropin-releasing hormone (GnRH) analogue. Material and methods: The correlation between T2-weighted MR imaging of uterine leiomyomas and histologic findings was evaluated using 85 leiomyomas from 62 females who underwent myomectomy or hysterectomy. We also correlated the pretreatment MR images features obtained in 110 women with 143 leiomyomas with the effect of GnRH analogue treatment. The size (length x width x depth) of the leiomyoma was evaluated before and at 6 months after treatment by ultrasound. Results: The proportion of leiomyoma cell fascicles and that of extracellular matrix affected signal intensities of uterine leiomyomas on T2-weighted MR images. The amount of extracellular matrix was predominant in hypointense leiomyomas on T2-weighted images, while diffuse intermediate signal leiomyomas were predominantly composed of leiomyoma cell fascicles. Marked degenerative changes were noted in leiomyomas with heterogenous hyperintensity. The homogeneously intermediate signal intensity leiomyomas showed significant size reduction after treatment (size ratio; posttreatment volume/pretreatment volume 0.29±0.11). The size ratio for the hypointense tumors was 0.82±0.14, and 0.82±0.18 for the heterogeneously hyperintense tumors. There was a significant difference in the response to treatment between the homogeneously intermediate signal intensity leiomyomas and the hypointense or heterogeneously hyperintense leiomyomas (both p<0.01). Conclusion: Signal intensity on T2-weighted MR images depends on the amount of leiomyoma cell fascicles and extracellular matrix. Simple assessment of the MR signal intensity is useful in predicting the effect of GnRH analogue on uterine leiomyomas. (orig.)

  5. Ovulation induction with pulsatile gonadotropin-releasing hormone (GnRH) or gonadotropins in a case of hypothalamic amenorrhea and diabetes insipidus.

    Science.gov (United States)

    Georgopoulos, N A; Markou, K B; Pappas, A P; Protonatariou, A; Vagenakis, G A; Sykiotis, G P; Dimopoulos, P A; Tzingounis, V A

    2001-12-01

    Hypothalamic amenorrhea is a treatable cause of infertility. Our patient was presented with secondary amenorrhea and diabetes insipidus. Cortisol and prolactin responded normally to a combined insulin tolerance test (ITT) and thyrotropin-releasing hormone (TRH) challenge, while thyroid-stimulating hormone (TSH) response to TRH was diminished, and no response of growth hormone to ITT was detected. Both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels increased following gonadotropin-releasing hormone (GnRH) challenge. No response of LH to clomiphene citrate challenge was detected. Magnetic resonance imaging findings demonstrated a midline mass occupying the inferior hypothalamus, with posterior lobe not visible and thickened pituitary stalk. Ovulation induction was carried out first with combined human menopausal gonadotropins (hMG/LH/FSH) (150 IU/day) and afterwards with pulsatile GnRH (150 ng/kg/pulse). Ovulation was achieved with both pulsatile GnRH and combine gonadotropin therapy. Slightly better results were achieved with the pulsatile GnRH treatment.

  6. Hormonal responses to GnRH injection given at different stages of ...

    African Journals Online (AJOL)

    USER

    2010-04-05

    Apr 5, 2010 ... In conclusion, the results presented here indicate that. GnRH given at the beginning (days 5 to 7) or at the end. (days 15 to 17) of the estrous cycle did not alter the profile of progesterone and estradiol concentration in water buffaloes as previously described in cattle (Kohram et al., 1998a, b). REFERENCES.

  7. Clinical Value of Basal Serum Progesterone Prior to Initiate Ovarian Hyper-Stimulation with GnRH Antagonists: A Retrospective Cohort Study.

    Science.gov (United States)

    Faulisi, Sonia; Reschini, Marco; Borroni, Raffaella; Paffoni, Alessio; Busnelli, Andrea; Somigliana, Edgardo

    2017-01-01

    The routine assessment of day 3 serum progesterone prior to initiation of ovarian hyper-stimulation with the use of GnRH antagonists is under debate. In this study, we evaluated the clinical utility of this policy. Retrospective cohort study of women undergoing in vitro fertilization (IVF) with the use of GnRH antagonists aimed at determining the frequency of cases with progesterone levels exceeding the recommended threshold of 1,660 pg/ml and at evaluating whether this assessment may be predictive of pregnancy. Serum progesterone exceeded the recommended threshold in one case (0.3%, 95% CI 0.01-1.5). The median (interquartile range) basal progesterone in women who did (n = 95) and did not (n = 217) become pregnant were 351 (234-476) and 380 (237-531) pg/ml, respectively (p = 0.28). The 90th percentile of the basal progesterone distribution in women who became pregnant was 660 pg/ml. Cases with serum progesterone exceeding this threshold in successful and unsuccessful cycles were 10 (10%) and 30 (14%), respectively (p = 0.47). The capacity of basal progesterone to predict pregnancy was evaluated using receiver operating characteristic curve (area under the curve = 0.54, 95% CI 0.47-0.61, p = 0.28). No graphically evident threshold emerged. Routine day 3 serum progesterone assessment in IVF cycles with the use of GnRH antagonists is not justified. Further evidence is warranted prior to claiming its systematic use. © 2016 S. Karger AG, Basel.

  8. Observational Study to Assess the Therapeutic Value of Four Ovarian Hyperstimulation Protocols in IVF After Pituitary Suppression with GnRH Antagonists in Normally Responding Women

    OpenAIRE

    Ana, Monzó; Vicente, Montañana; María, Rubio José; Trinidad, García-Gimeno; Alberto, Romeu

    2011-01-01

    Objective To compare the clinical results of four different protocols of COH for IVF-ICSI in normovulatory women, using in all cases pituitary suppression with GnRH antagonists. Materials/methods A single center, open label, parallel-controlled, prospective, post-authorization study under the approved conditions for use where 305 normal responders women who were candidates to COH were assigned to r-FSH + hp-hMG (n = 51, Group I), hp-hMG (n = 61, Group II), fixed-dose r-FSH (n = 118, Group III...

  9. Progesterone treatment inhibits and dihydrotestosterone (DHT) treatment potentiates voltage-gated calcium currents in gonadotropin-releasing hormone (GnRH) neurons.

    Science.gov (United States)

    Sun, Jianli; Moenter, Suzanne M

    2010-11-01

    GnRH neurons are central regulators of fertility, and their activity is modulated by steroid feedback. In normal females, GnRH secretion is regulated by estradiol and progesterone (P). Excess androgens present in hyperandrogenemic fertility disorders may disrupt communication of negative feedback signals from P and/or independently stimulate GnRH release. Voltage-gated calcium channels (VGCCs) are important in regulating excitability and hormone release. Estradiol alters VGCCs in a time-of-day-dependent manner. To further elucidate ovarian steroid modulation of GnRH neuron VGCCs, we studied the effects of dihydrotestosterone (DHT) and P. Adult mice were ovariectomized (OVX) or OVX and treated with implants containing DHT (OVXD), estradiol (OVXE), estradiol and DHT (OVXED), estradiol and P (OVXEP), or estradiol, DHT, and P (OVXEDP). Macroscopic calcium current (I(Ca)) was recorded in the morning or afternoon 8-12 d after surgery using whole-cell voltage-clamp. I(Ca) was increased in afternoon vs. morning in GnRH neurons from OVXE mice but this increase was abolished in cells from OVXEP mice. I(Ca) in cells from OVXD mice was increased regardless of time of day; there was no additional effect in OVXED mice. P reduced N-type and DHT potentiated N- and R-type VGCCs; P blocked the DHT potentiation of N-type-mediated current. These data suggest P and DHT have opposing actions on VGCCs in GnRH neurons, but in the presence of both steroids, P dominates. VGCCs are targets of ovarian steroid feedback modulation of GnRH neuron activity and, more specifically, a potential mechanism whereby androgens could activate GnRH neuronal function.

  10. Origins of gonadotropin-releasing hormone (GnRH) in vertebrates: identification of a novel GnRH in a basal vertebrate, the sea lamprey.

    Science.gov (United States)

    Kavanaugh, Scott I; Nozaki, Masumi; Sower, Stacia A

    2008-08-01

    We cloned a cDNA encoding a novel (GnRH), named lamprey GnRH-II, from the sea lamprey, a basal vertebrate. The deduced amino acid sequence of the newly identified lamprey GnRH-II is QHWSHGWFPG. The architecture of the precursor is similar to that reported for other GnRH precursors consisting of a signal peptide, decapeptide, a downstream processing site, and a GnRH-associated peptide; however, the gene for lamprey GnRH-II does not have introns in comparison with the gene organization for all other vertebrate GnRHs. Lamprey GnRH-II precursor transcript was widely expressed in a variety of tissues. In situ hybridization of the brain showed expression and localization of the transcript in the hypothalamus, medulla, and olfactory regions, whereas immunohistochemistry using a specific antiserum showed only GnRH-II cell bodies and processes in the preoptic nucleus/hypothalamus areas. Lamprey GnRH-II was shown to stimulate the hypothalamic-pituitary axis using in vivo and in vitro studies. Lamprey GnRH-II was also shown to activate the inositol phosphate signaling system in COS-7 cells transiently transfected with the lamprey GnRH receptor. These studies provide evidence for a novel lamprey GnRH that has a role as a third hypothalamic GnRH. In summary, the newly discovered lamprey GnRH-II offers a new paradigm of the origin of the vertebrate GnRH family. We hypothesize that due to a genome/gene duplication event, an ancestral gene gave rise to two lineages of GnRHs: the gnathostome GnRH and lamprey GnRH-II.

  11. A short course of metformin does not reduce OHSS in a GnRH antagonist cycle for women with PCOS undergoing IVF: a randomised placebo-controlled trial.

    Science.gov (United States)

    Jacob, S L; Brewer, C; Tang, T; Picton, H M; Barth, J H; Balen, A H

    2016-12-01

    Does 'metformin' reduce the incidence of ovarian hyperstimulation syndrome (OHSS) for women with polycystic ovary syndrome (PCOS) undergoing a GnRH antagonist assisted conception treatment cycle? A short course of metformin does not reduce the incidence of OHSS for women with PCOS undergoing a GnRH antagonist treatment cycle. Metformin does reduce the incidence of OHSS in a GnRH-agonist treatment cycle. A randomised placebo-controlled trial (RCT) using metformin or placebo. Randomisation was blinded to both patient and investigator, using a random permuted blocks method with a 50:50 allocation ratio. The study was completed over 5 years (2009-2014) with 153 randomised patients. A sample size calculation based on the incidence of OHSS was completed prospectively suggesting a minimum of 146 recruits was required for the trial with a power of 80% and a type 1 error of 0.05. All patients met the Rotterdam criteria for PCOS and were treated with a standard GnRH antagonist IVF/ICSI treatment cycle in a tertiary infertility clinic. The study medication was started prior to stimulation and continued to oocyte retrieval. Of the 153 patients, 77 received metformin and 76 placebo. There was no reduction in the incidence of moderate-severe OHSS (Placebo (PLA) 12.2%, metformin (MET) = 16%, 95% CI -0.08-0.16, P = 0.66). There was no difference in total gonadotrophin dose (PLA = 1200, MET = 1200, 95% CI -118.67-118.67, P = 0.75), oocytes retrieved (PLA = 15, MET = 14, 95% CI -2.37-4.37, P = 0.66) or fertilisation rate (PLA = 60.7%, MET = 53.3%, 95% CI -0.96-14.94, P = 0.07). However, using metformin resulted in a reduced clinical pregnancy rate (CPR) per cycle started (PLA = 48.7%, MET = 28.6%, 95% CI 0.04-0.35, P = 0.02) and live birth rate (PLA = 51.6%, MET = 27.6%, 95% CI 0.05-0.40, P = 0.02). Furthermore, when ethnicity was taken into account there was a significant reduction in pregnancy outcome for the South Asian population irrespective of metformin or

  12. The role of corifollitropin alfa in controlled ovarian stimulation for IVF in combination with GnRH antagonist

    Directory of Open Access Journals (Sweden)

    Seyhan A

    2011-08-01

    Full Text Available Ayse Seyhan, Baris AtaDivision of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, McGill University, Montreal, QC, CanadaAbstract: Corifollitropin alfa is a synthetic recombinant follicle-stimulating hormone (rFSH molecule containing a hybrid beta subunit, which provides a plasma half-life of ∼65 hours while maintaining its pharmocodynamic activity. A single injection of corifollitropin alfa can replace daily FSH injections for the first week of ovarian stimulation for in vitro fertilization. Stimulation can be continued with daily FSH injections if the need arises. To date, more than 2500 anticipated normoresponder women have participated in clinical trials with corifollitropin alfa. It is noteworthy that one-third of women did not require additional gonadotropin injections and reached human chorionic gonadotropin criterion on day 8. The optimal corifollitropin dose has been calculated to be 100 µg for women with a body weight ≤ 60 kg and 150 µg for women with a body weight >60 kg, respectively. Combination of corifollitropin with daily gonadotropin-releasing hormone antagonist injections starting on stimulation day 5 seems to yield similar or significantly higher numbers of oocytes and good quality embryos, as well as similar ongoing pregnancy rates compared with women stimulated with daily rFSH injections. Stimulation characteristics, embryology, and clinical outcomes seem consistent with repeated corifollitropin-stimulated assisted reproductive technologies cycles. Multiple pregnancy or ovarian hyperstimulation syndrome rates with corifollitropin were not increased over daily FSH regimen. The corifollitropin alfa molecule does not seem to be immunogenic and does not induce neutralizing antibody formation. Drug hypersensitivity and injection-site reactions are not increased. Incidence and nature of adverse events and serious adverse events are similar to daily FSH injections. Current trials do not

  13. Growth Hormone Supplementation in the Luteal Phase Before Microdose GnRH Agonist Flare Protocol for In Vitro Fertilization.

    Science.gov (United States)

    Dunne, Caitlin; Seethram, Ken; Roberts, Jeffrey

    2015-09-01

    Growth hormone (GH) acts in both early and late follicular development to stimulate the proliferation and differentiation of granulosa cells and to increase the production of estradiol in animal and human ovaries. Investigators have therefore explored GH supplementation to improve outcomes in women undergoing in vitro fertilization, with the greatest interest in women with diminished ovarian reserve. Recent meta-analyses indicate that GH supplementation can be beneficial for poor responders undergoing IVF. In most studies, GH has been given concomitantly with gonadotropins during the follicular phase; this may not be optimal, since follicular recruitment begins during the preceding luteal phase. We therefore wished to examine the effect of GH supplementation in the luteal phase before controlled ovarian stimulation (COH) with a microdose GnRH agonist flare (MDF) protocol in women undergoing in vitro fertilization. We performed a retrospective matched case-control study of patients undergoing treatment at a private IVF facility between June 2012 and July 2013. Patients identified as poor responders to COH were offered adjuvant GH treatment as part of their ovarian stimulation regimen. The patients in the experimental group chose to take GH, 3.33 mg daily by subcutaneous injection for 14 days, before starting COH. All patients had an MDF stimulation protocol using 450 IU of follicle stimulating hormone (FSH) daily. A total of 42 women were included in the study. There were 14 women in the experimental group (GH) and 28 controls (C) matched for age, BMI, and day 3 FSH level. There was no difference between the groups in clinical pregnancy rate (GH = 29%, C = 32%, P = 0.99), number of mature oocytes retrieved (GH = 2.5, C = 5.0, P = 0.13), cycle cancellation rate (GH = 21%, C = 14%, P = 0.88), duration of COH (GH = 10.1, C = 10.1, P = 0.93), or mean peak estradiol level (GH = 4174 pmol/L, C = 5105 pmol/L, P = 0.44). The administration of growth hormone during the

  14. Highly potent antagonists of luteinizing hormone-releasing hormone free of edematogenic effects.

    Science.gov (United States)

    Bajusz, S; Kovacs, M; Gazdag, M; Bokser, L; Karashima, T; Csernus, V J; Janaky, T; Guoth, J; Schally, A V

    1988-03-01

    To eliminate the undesirable edematogenic effect of the luteinizing hormone-releasing hormone (LH-RH) antagonists containing basic D amino acids at position 6, exemplified by [Ac-D-Phe(pCl)1,2,D-Trp3,D-Arg6,D-Ala10]LH-RH [Phe(pCl) indicates 4-chlorophenylalanine], analogs with D-ureidoalkyl amino acids such as D-citrulline (D-Cit) or D-homocitrulline (D-Hci) at position 6 were synthesized and tested in several systems in vitro and in vivo. HPLC analysis revealed that the overall hydrophobicity of the D-Cit/D-Hci6 analogs was similar to that of the basic D-Arg6 antagonists. In vitro, most of the analogs completely inhibited LH-RH-mediated luteinizing hormone release in perfused rat pituitary cell systems at an antagonist to LH-RH molar ratio of 5:1. In vivo, the most active peptides, [Ac-D-Nal(2)1,D-Phe(pCl)2,D-Trp3,D-Cit6,D-Ala10]LH-RH [Nal(2) indicates 3-(2-naphthyl)alanine] and its D-Hci6 analog, caused 100% inhibition of ovulation in cycling rats in doses of 3 micrograms and suppressed the luteinizing hormone level in ovariectomized female rats for 47 hr when administered at doses of 25 micrograms. Characteristically, these peptides did not exert any edematogenic effects even at 1.5 mg/kg. These properties of the D-Cit/D-Hci6 antagonists may make them useful clinically.

  15. Observational Study to Assess the Therapeutic Value of Four Ovarian Hyperstimulation Protocols in IVF after Pituitary Suppression with GnRH Antagonists in Normally Responding Women

    Directory of Open Access Journals (Sweden)

    Monzó Ana

    2011-01-01

    Full Text Available Objective To compare the clinical results of four different protocols of COH for IVF-ICSI in normovulatory women, using in all cases pituitary suppression with GnRH antagonists. Materials/methods A single center, open label, parallel-controlled, prospective, post-authorization study under the approved conditions for use where 305 normal responders women who were candidates to COH were assigned to r-FSH + hp-hMG (n = 51, Group I, hp-hMG (n = 61, Group II, fixed-dose r-FSH (n = 118, Group III, and r-FSH with potential dose adjustment (n = 75, Group IV to subsequently undergo IVF-ICSI. Results During stimulation, Group IV needed significantly more days of stimulation as compared to Group II [8.09 ± 1.25 vs. 7.62 ± 1.17; P < 0.05], but was the group in which more oocytes were recovered [Group I: 9.43 ± 4.99 vs. Group II: 8.96 ± 4.82 vs. Group III: 8.78 ± 3.72 vs. Group IV: 11.62 ± 5.80; P < 0.05]. No significant differences were seen between the groups in terms of clinical and ongoing pregnancy, but among patients in whom two embryos with similar quality parameters (ASEBIR were transferred, the group treated with hp-hMG alone achieved a significantly greater clinical pregnancy rate as compared to all other groups [Group I: 31.6%, Group II: 56.4%, Group III: 28.7%, Group IV: 32.7%; P < 0.05]. Conclusions Although randomized clinical trials should be conducted to achieve a more reliable conclusion, these observations support the concept that stimulation with hp-hMG could be beneficial in normal responders women undergoing pituitary suppression with GnRH antagonists.

  16. GnRH agonist trigger for the induction of oocyte maturation in GnRH antagonist IVF cycles: a SWOT analysis.

    Science.gov (United States)

    Engmann, Lawrence; Benadiva, Claudio; Humaidan, Peter

    2016-03-01

    Gonadotrophin releasing hormone agonist (GnRHa) trigger is effective in the induction of oocyte maturation and prevention of ovarian hyperstimulation syndrome during IVF treatment. This trigger concept, however, results in early corpora lutea demise and consequently luteal phase dysfunction and impaired endometrial receptivity. The aim of this strenghths, weaknesses, opportunities and threats analysis was to summarize the progress made over the past 15 years to optimize ongoing pregnancy rates after GnRHa trigger. The advantages and potential drawbacks of this type of triggering are reviewed. The current approach to the management of GnRHa trigger in autologous cycles is based on the peak serum oestradiol level or follicle number and aims at a fresh embryo transfer or a segmentation approach with elective cryopreservation policy. We recommend intensive luteal support with transdermal oestradiol and intramuscular progesterone alone if peak serum oestradiol is 4000 or more pg/ml after GnRHa trigger or dual trigger with GnRHa and HCG 1000 IU if peak serum oestradiol is less than 4000 pg/mL. On the contrary, we recommend HCG 1500 IU 35 h after GnRHa trigger if there are less than 25 follicles, or freeze all oocytes or embryos if there are over 25 follicles. Copyright © 2015. Published by Elsevier Ltd.

  17. Hormonal changes during GnRH analogue therapy in children with central precocious puberty

    DEFF Research Database (Denmark)

    Müller, J; Juul, A; Andersson, A M

    2000-01-01

    Gonadotropin releasing hormone analogues (GnRHa) have been used for treatment of central precocious puberty (CPP) for more than 15 years. They are generally considered safe although data on potential long-term side effects are scarce. However, GnRHa therapy has profound effects on both the hypoth......Gonadotropin releasing hormone analogues (GnRHa) have been used for treatment of central precocious puberty (CPP) for more than 15 years. They are generally considered safe although data on potential long-term side effects are scarce. However, GnRHa therapy has profound effects on both...

  18. Use of the gonadotrophin-releasing hormone antagonist azaline B to control the oestrous cycle in the koala (Phascolarctos cinereus).

    Science.gov (United States)

    Ballantyne, K; Anderson, S T; Pyne, M; Nicolson, V; Mucci, A; Lisle, A; Johnston, S D

    2015-05-01

    The present study examined the effectiveness of the gonadotrophin-releasing hormone (GnRH) antagonist azaline B to suppress plasma LH and 17β-oestradiol concentrations in koalas and its potential application for oestrous synchronisation. In Experiment 1, single subcutaneous injections of azaline B successfully blocked the LH response to exogenous mammalian (m) GnRH in a dose-dependent manner; specifically, 0 mg (n = 4) did not suppress the LH response, 1 mg azaline B (n = 6) suppressed the LH response for 24 h (P < 0.05), 3.3 mg azaline B (n = 8) suppressed the LH response significantly in all animals only for 3 h (P < 0.05), although in half the animals LH remained suppressed for up to 3 days, and 10 mg azaline B (n = 4) suppressed the LH response for 7 days (P < 0.05). In Experiment 2, daily 1 mg, s.c., injections of azaline B over a 10-day period during seasonal anoestrus (June-July; n = 6) suppressed (P < 0.01) the LH response to mGnRH consecutively over the 10-day treatment period and, 4 days after cessation of treatment, the LH response had not recovered. Experiment 3 was designed to test the efficacy of daily 1 mg, s.c., azaline B over 10 days to suppress plasma LH and 17β-oestradiol concentrations and ultimately synchronise timed return to oestrus during the breeding season. Although azaline B treatment did not suppress basal LH or 17β-oestradiol, oestrus was delayed in all treated females by 24.2 days, but with high variability (range 9-39 days). Overall, the present study demonstrates that the GnRH antagonist azaline B is able to inhibit the LH response in koalas to exogenous mGnRH and successfully delay the return to oestrus. However, although azaline B clearly disrupts folliculogenesis, it has not been able to effectively synchronise return to oestrus in the koala.

  19. EFFECT OF POST-MATING GNRH TREATMET ON SERUM PROGESTERONE, LUTEINIZING HORMONE LEVELS, DURATION OF ESTROUS CYCLE AND PREGNANCY RATES IN COWS

    Directory of Open Access Journals (Sweden)

    H. YILDIZ, E. KAYGUSUZOĞLU, M. KAYA1 AND M. ÇENESIZ1

    2009-07-01

    Full Text Available Pregnancy rate, estrous cycle lenght, serum progesterone and luteinizing hormone (LH concentrations were determined in gonadotropin releasing hormone (GnRH; 10.5 μg synthetic gonadotrophin releasing hormone agonist, receptal administered cows on day 12 post-mating (n=9 compared to control cows (n=8. Their oestrous cycles were synchronised by intramuscular administration of prostaglandin F2 alpha (its analog, cloprostenol twice at 11 days interval. Estrous exhibited cows were mated naturally. Blood samples were collected every two days from all animals. Serum progesterone and LH concentrations were measured by ELISA method. GnRH administration significantly increased serum LH concentration which reached peak levels 2-3 h after treatment. However, serum progesterone concentration was not affected. There were no differences in mean progesterone concentrations on days 12 to 24 post-mating between GnRH administrated and control pregnant cows. However, in non pregnant animals, progesterone concentrations on days 16 in the treated group were lower than control group (P<0.01. Pregnancy diagnosis in animals made by B-mode ultrasonography between the 30th and 35th day showed that 77.7% of treated cows were pregnant compared to 50% in control group. Duration of the estrous cycle in the non-pregnant animals was not affected by the treatment (control, 21.3 ± 0.8 days; treated, 22.5 ± 0.5 days. In conclusion, this study supports the use of GnRH on day 12 post-mating as a method for enhancing pregnancy rates in lactating dairy cattle.

  20. Gonadotropin-releasing hormone antagonist use in controlled ovarian stimulation and intrauterine insemination cycles in women with polycystic ovary syndrome.

    Science.gov (United States)

    Ertunc, Devrim; Tok, Ekrem C; Savas, Aysun; Ozturk, Ilay; Dilek, Saffet

    2010-03-01

    To observe the effects of ganirelix on controlled ovarian stimulation and intrauterine insemination (COS/IUI) cycles in women with polycystic ovary syndrome (PCOS). Prospective, randomized, controlled clinical study. An academic clinical research center. Women with PCOS and anovulatory infertility undergoing COS/IUI. Recombinant FSH therapy was started on day 3. In women assigned to the control group (n = 47), treatment was continued up to the day of hCG administration. In patients assigned to receive GnRH antagonist (n = 42), ganirelix was added when the leading follicle was > or =14 mm. Pregnancy rates, serum E(2), P, and LH levels, and follicle numbers at hCG day, prevalence of premature luteinization, and cost of stimulation. Serum E(2), P, and LH levels were significantly lower in the ganirelix group. Although premature luteinization and cycle cancellation was encountered less in the ganirelix group, the pregnancy rates per cycle were similar (15.4% vs. 10.7%). Patients would pay 6,153 dollars more for each pregnancy when using ganirelix. Gonadotropin-releasing hormone antagonist resulted in more monofollicular development, less premature luteinization, and less cycle cancellation in IUI cycles of patients with PCOS; however, the cost of stimulation increased without an improvement in pregnancy rates. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  1. Anti-idiotypic antibody: A new strategy for the development of a growth hormone receptor antagonist.

    Science.gov (United States)

    Lan, Hainan; Zheng, Xin; Khan, Muhammad Akram; Li, Steven

    2015-11-01

    In general, traditional growth hormone receptor antagonist can be divided into two major classes: growth hormone (GH) analogues and anti-growth hormone receptor (GHR) antibodies. Herein, we tried to explore a new class of growth hormone receptor (GHR) antagonist that may have potential advantages over the traditional antagonists. For this, we developed a monoclonal anti-idiotypic antibody growth hormone, termed CG-86. A series of experiments were conducted to characterize and evaluate this antibody, and the results from a competitive receptor-binding assay, Enzyme Linked Immunosorbent Assays (ELISA) and epitope mapping demonstrate that CG-86 behaved as a typical Ab2β. Next, we examined its antagonistic activity using in vitro cell models, and the results showed that CG-86 could effectively inhibit growth hormone receptor-mediated signalling and effectively inhibit growth hormone-induced Ba/F3-GHR638 proliferation. In summary, these studies show that an anti-idiotypic antibody (CG-86) has promise as a novel growth hormone receptor antagonist. Furthermore, the current findings also suggest that anti-idiotypic antibody may represent a novel strategy to produce a new class of growth hormone receptor antagonist, and this strategy may be applied with other cytokines or growth factors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Hypersensitivity reaction with intravenous GnRH after pulsatile subcutaneous GnRH treatment in male hypogonadotrophic hypogonadism.

    OpenAIRE

    Popović, V.; Milosević, Z.; Djukanović, R.; Micić, D.; Nesović, M.; Manojlović, D.; Djordjević, P.; Mićić, J.

    1988-01-01

    Chronic pulsatile subcutaneous administration of low doses of gonadotrophin releasing hormone (GnRH) is an effective therapy for men with hypogonadotrophic hypogonadism. Hypersensitivity reactions to GnRH are rare. We wish to report hypersensitivity reactions with intravenous GnRH after low dose subcutaneous pulsatile GnRH treatment in two men with hypogonadotrophic hypogonadism due to suprasellar disease.

  3. Supplementation with a recombinant human chorionic gonadotropin microdose leads to similar outcomes in ovarian stimulation with recombinant follicle-stimulating hormone using either a gonadotropin-releasing hormone agonist or antagonist for pituitary suppression.

    Science.gov (United States)

    Cavagna, Mario; Maldonado, Luiz Guilherme Louzada; de Souza Bonetti, Tatiana Carvalho; de Almeida Ferreira Braga, Daniela Paes; Iaconelli, Assumpto; Borges, Edson

    2010-06-01

    To compare the outcomes of protocols for ovarian stimulation with recombinant hCG microdose, with GnRH agonists and antagonists for pituitary suppression. Prospective nonrandomized clinical trial. A private assisted reproduction center. We studied 182 patients undergoing intracytoplasmic sperm injection (ICSI) cycles, allocated into two groups: GnRH agonist group, in which patients received a GnRH agonist (n = 73), and a GnRH antagonist group, in which patients were administered a GnRH antagonist for pituitary suppression (n = 109). Pituitary suppression with GnRH agonist or GnRH antagonist. Ovarian stimulation carried out with recombinant FSH and supplemented with recombinant hCG microdose. Total dose of recombinant FSH and recombinant hCG administered; E(2) concentrations and endometrial width on the day of hCG trigger; number of follicles aspirated, oocytes and mature oocytes retrieved; fertilization, pregnancy (PR), implantation, and miscarriage rates. The total dose of recombinant FSH and recombinant hCG administered were similar between groups, as were the E(2) concentrations and endometrial width. The number of follicles aspirated, oocytes, and metaphase II oocytes collected were also comparable. There were no statistically significant differences in fertilization, PR, implantation, and miscarriage rates in the GnRH agonist and GnRH antagonist groups. When using recombinant hCG microdose supplementation for controlled ovarian stimulation (COS), there are no differences in laboratory or clinical outcomes with the use of either GnRH antagonist or agonist for pituitary suppression. Copyright (c) 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  4. Laparoscopic ovarian drilling versus GnRH antagonist combined with cabergoline as a prophylaxis against the re-development of ovarian hyperstimulation syndrome.

    Science.gov (United States)

    Seyam, Emaduldin; Hefzy, Enas

    2018-07-01

    The aim of this work was to investigate the value of laparoscopic ovarian drilling (LOD) compared with GnRH antagonist flexible protocol combined with cabergoline (Cb), as a prophylaxis against the re-development of ovarian hyperstimulation syndrome (OHSS) in women with clomiphene citrate-resistant polycystic ovary disease (CCR-PCOD) who had severe OHSS before in a previous ICSI cycle. It is a prospective controlled study, where 250 CCR-PCOD women (n = 250) with a history of severe OHSS before, had been recruited for the study. LOD had been performed for 120 (n = 120) of the recruited women before ovarian induction, and considered as group A. GnRH antagonist (Cetrotide 0.25 mg) was added when a leading follicle reaches 14-16 mm combined with oral Cb in a dose 0.5 mg a day before hCG, and for 8 d for another 130 (n = 130) women, and considered as group B. Pregnancy was diagnosed with BhCG level ≥25 IU/L, ± 14 d after embryo transfer, followed with transvaginal ultrasound scanning (TVS) 2 weeks later to confirm intra-uterine pregnancy (IUP). Women were followed up weekly for 3 months for the possible development of any signs and symptoms of OHSS. None of the participants in group A developed severe OHSS, and only six women (5%) developed mild to moderate OHSS. The incidence of severe OHSS was significantly higher (n = 3, 15%) in group B compared with group A (p < .001). Another (n = 17, 13.3%) women in group B developed mild to moderate OHSS. The probability of developing severe OHSS was also significantly higher in group B as well (p = .031). Pregnancy rate (PR) was significantly higher in group A more than group B (67% versus 39%, respectively), and all were single intrauterine pregnancies (IUP) and all developed after fresh embryo transfer (ET), compared with frozen embryo transfer (FET) which was performed in 42 cases in group B after postponing ET due to significantly severe OHSS developed. LOD could be considered

  5. Melanin concentrating hormone receptor 1 (MCHR1) antagonists - Still a viable approach for obesity treatment?

    DEFF Research Database (Denmark)

    Högberg, T.; Frimurer, T.M.; Sasmal, P.K.

    2012-01-01

    Obesity is a global epidemic associated with multiple severe diseases. Several pharmacotherapies have been investigated including the melanin concentrating hormone (MCH) and its receptor 1. The development of MCHR1 antagonists are described with a specific perspective on different chemotypes...

  6. Elevated basal progesterone levels are associated with increased preovulatory progesterone rise but not with higher pregnancy rates in ICSI cycles with GnRH antagonists.

    Science.gov (United States)

    Mutlu, Mehmet Firat; Erdem, Mehmet; Mutlu, Ilknur; Bulut, Berk; Erdem, Ahmet

    2017-09-01

    To ascertain the association between basal progesterone (P) levels and the occurrence of preovulatory progesterone rise (PPR) and clinical pregnancy rates (CPRs) in ICSI cycles with GnRH antagonists. Serum P levels of 464 patients were measured on day 2 and day of hCG of cycles. Cycles with basal P levels>1.6ng/mL were cancelled. All embryos were cryopreserved in cycles with P levels≥2ng/mL on the day of hCG. The primary outcome measures were the incidence of PPR (P>1.5ng/mL) and CPR with regard to basal P. Basal P levels were significantly higher in cycles with PPR than in those without PPR (0.63±0.31 vs. 0.48±0.28ng/mL). Area under the curve for basal P according to ROC analysis to discriminate between elevated and normal P levels on the day of hCG was 0.65 (0.58-0.71 95% CI, pcycles with and without PPR was 0.65ng/mL. Cycles with basal P levels above 0.65ng/mL had a significantly higher incidence of PPR (30.9% vs. 13.5%) but similar clinical and cumulative pregnancy rates (38.8% vs. 31.1% and 41.7% vs. 32.6%, respectively) in comparison to cycles with basal P levels below 0.65ng/mL. In multivariate regression analysis, basal P levels, LH level on the first day of antagonist administration, and estradiol levels on the day of hCG trigger were the variables that predicted PPR. Basal P levels were associated with increased incidence of PPR but not with CPR. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Circadian control of kisspeptin and a gated GnRH response mediate the preovulatory luteinizing hormone surge

    DEFF Research Database (Denmark)

    Williams, Wilbur P; Jarjisian, Stephan G; Mikkelsen, Jens D

    2011-01-01

    In spontaneously ovulating rodents, the preovulatory LH surge is initiated on the day of proestrus by a timed, stimulatory signal originating from the circadian clock in the suprachiasmatic nucleus (SCN). The present studies explored whether kisspeptin is part of the essential neural circuit...... linking the SCN to the GnRH system to stimulate ovulation in Syrian hamsters (Mesocricetus auratus). Kisspeptin neurons exhibit an estrogen-dependent, daily pattern of cellular activity consistent with a role in the circadian control of the LH surge. The SCN targets kisspeptin neurons via vasopressinergic...... of ovulatory control with interactions among the circadian system, kisspeptin signaling, and a GnRH gating mechanism of control....

  8. Antibodies against gonadotropin-releasing hormone (GnRH) in patients with diabetes mellitus is associated with lower body weight and autonomic neuropathy.

    Science.gov (United States)

    Berntorp, Kerstin; Frid, Anders; Alm, Ragnar; Fredrikson, Gunilla Nordin; Sjöberg, Klas; Ohlsson, Bodil

    2013-08-17

    Esophageal dysmotility and gastroparesis are common secondary complications in patients with diabetes mellitus. Patients with dysmotility express antibodies against gonadotropin-releasing hormone (GnRH) in serum. The aim of the present study was to scrutinize patients with diabetes mellitus with regard to the presence of GnRH antibodies, and to examine associations between antibodies and clinical findings. Thirty-nine consecutive patients with diabetes mellitus were included in the study after clinical examination and examination by esophageal manometry and gastric emptying scintigraphy. Serum was analyzed for the presence of antibodies against GnRH using an ELISA, and values are expressed as relative units (RU). Two age- and gender-matched healthy subjects per each patient served as controls. The prevalence of IgM GnRH antibodies in patients was 33% compared to 14% in controls (p = 0.027), with a higher antibody titer; 1.2 (0.6-5.0) and 0.2 (0.1-0.3) RU, respectively (p = 0.000). The expression of IgG antibodies was 15% in patients and none in controls (p = 0.000). Lower body mass index was associated with the presence of IgM antibodies (OR = 0.835, 95% CI = 0.699-0.998), and autonomic neuropathy with the presence IgG antibodies (OR = 9.000, 95% CI = 1.327-61.025). Esophageal dysmotility (69%) or gastroparesis (18%) were not associated with the presence of IgM antibodies (OR = 0.589, 95% CI = 0.143-2.424 and OR = 3.407, 95% CI = 0.633-18.350, respectively). Neither was esophageal dysmotility associated with IgG antibodies (OR = 2.500, 95% CI = 0.259-24.096). Antibodies against GnRH are more common in patients with diabetes mellitus compared with healthy controls. IgM antibodies are associated with lower body mass index and IgG antibodies are associated with autonomic neuropathy.

  9. Six-month gonadotropin releasing hormone (GnRH agonist depots provide efficacy, safety, convenience, and comfort

    Directory of Open Access Journals (Sweden)

    Phillips JM

    2011-07-01

    Full Text Available E David Crawford, Jason M PhillipsUniversity of Colorado Health Sciences Center, Aurora, CO, USAAbstract: Two different 6-month GnRH agonist depot formulations approved for palliative treatment of advanced and metastatic prostate cancer in the United States – leuprolide acetate 45 mg and triptorelinpalmoate 22.5 mg – provide patients with efficacy and safety comparable to those of existing 1-, 3-, and 4-month GnRH agonist depots. However, the 6-month formulations can increase patient convenience, comfort, and compliance by reducing the number of physician visits and injections required. At the conclusion of their pivotal trials, the 6-month formulations demonstrated efficacy rates in achieving chemical castration (serum testosterone #50 ng/dL that ranged between 93% and 99%. As with existing GnRH agonist depot formulations, hot flashes represented the most common adverse event reported in trials of 6-month leuprolide acetate or triptorelin. As such, these products may prove useful not only for their labeled indication, but also as adjuncts to other treatments such as radical prostatectomy, radiotherapy, and chemotherapy. We recommend further research, including head-to-head trials between the 6-month GnRH depots, to refine our understanding of these products.Keywords: prostate cancer, leuprorelin, leuprolide, triptorelin, 6-month depot, testosterone

  10. Feasibility of corifollitropin alfa/GnRH antagonist protocol combined with GnRH agonist triggering and freeze-all strategy in polycystic ovary syndrome patients

    Directory of Open Access Journals (Sweden)

    Jiann-Loung Hwang

    2018-06-01

    Full Text Available Background/Purpose: The long-acting corifollitropin alfa is comparable to FSH in terms of pregnancy outcomes in normal responders and poor responders. Corifollitropin alfa has never been studied in polycystic ovary syndrome (PCOS patients because of concerns of excessive ovarian stimulation and ovarian hyperstimulation syndrome (OHSS. The purpose of the study was to evaluate if corifollitropin alfa can be used in PCOS patients. Methods: Forty PCOS patients who were going to undergo in vitro fertilization were enrolled in this study. A single injection of corifollitropin alfa was administered on cycle day 2 or day 3. From stimulation day 8 onwards, daily FSH was administered until the day of final oocyte maturation. Cetrorelix was administered from stimulation day 5 to prevent premature LH surge. Final oocyte maturation was triggered by: acetate. All embryos were cryopreserved and replaced in subsequent cycles. Results: All 40 patients were subjected to oocyte retrieval, and none developed moderate or severe ovarian hyperstimulation syndrome (0%, 95% CI 0–0.088. For each patient, an average of 23.4 (±7.4; 95% CI 21.0–25.7 oocytes were retrieved and a mean of 11.7 (±6.4; 95% CI 9.6–13.8 embryos were frozen. Mean serum estradiol level on the day of GnRHa triggering was 7829.9 pg/ml (±3297; 95% CI 6775–8885. The cumulated ongoing pregnancy rate after 3 frozen-thawed embryo transfers was 75.0% (95% CI 61.6%–88.4%. Conclusion: The results suggest that corifollitropin alfa/GnRH antagonist protocol can be used in PCOS patients, in combination with GnRHa triggering and embryo cryopreservation. Keywords: Corifollitropin alfa, Cryopreservation, GnRH agonist, Polycystic ovary syndrome

  11. Endocrine profiles after triggering of final oocyte maturation with GnRH agonist after cotreatment with the GnRH antagonist ganirelix during ovarian hyperstimulation for in vitro fertilization

    NARCIS (Netherlands)

    B.C.J.M. Fauser (Bart); D. de Jong (Danielle); F. Olivennes; H. Wramsby; C. Tay; J. Itskovitz-Eldor; H.G. van Hooren

    2002-01-01

    textabstractIn a randomized multicenter study, the efficacies of two different GnRH agonists were compared with that of hCG for triggering final stages of oocyte maturation after ovarian hyperstimulation for in vitro fertilization. Ovarian stimulation was conducted by recombinant

  12. The utility of the gonadotrophin releasing hormone (GnRH) test in the diagnosis of polycystic ovary syndrome (PCOS).

    Science.gov (United States)

    Lewandowski, Krzysztof C; Cajdler-Łuba, Agata; Salata, Ireneusz; Bieńkiewicz, Małgorzata; Lewiński, Andrzej

    2011-01-01

    Polycystic ovary syndrome (PCOS) is characterised by increased frequency of hypothalamic GnRH pulses leading to a relative increase in LH synthesis by the pituitary. As GnRH stimulation can reveal a relative LH excess, we have endeavoured to assess whether GnRH test might be useful in the diagnosis of PCOS. The study involved 185 subjects: a PCOS group, n = 151, all with oligo- or amenorrhoea, aged (mean ± SD) 24.8 ± ± 5.4 years, BMI 24.5 ± 6.0 kg/m²; and regularly menstruating controls, n = 34, aged 26.6 ± 5.0 years, BMI 24.6 ± 5.5 kg/m². In 121 subjects with PCOS and in 32 controls, serum LH and FSH were measured before (0 minutes) and 30 and 60 minutes after GnRH stimulation (100 μg i.v.). Insulin resistance was assessed by HOMA and Insulin Resistance Index derived from glucose and insulin concentrations during 75 gram oral glucose tolerance test. Women with PCOS had higher testosterone (p = 0.0002), androstendione (p = 0.0021), 17OH-progesterone (p PCOS. Baseline and stimulated LH concentrations were higher in PCOS (9.09 ± 5.56 vs 4.83 ± 1.71 IU/L, 35.48 ± 31.4 vs 16.30 ± 6.68 IU/L, 33.86 ± 31.8 vs 13.45 ± 5.2 IU/L, at 0, 30 and 60 mins post GnRH, respectively, p PCOS in comparison to controls (LH0 min/FSH(₀ min) 1.59 ± 0.95 vs 0.76 ± 0.2, LH(₃₀ min) /FSH(₃₀ min) 4.07 ± 3.0 vs 1.89 ± 0.79, LH(₆₀ min)/FSH(₆₀ min) 3.56 ± 2.58 vs 1.55 ± 0.63, p 2.11 or LH(₆₀ min)/FSH(₆₀ min) > 1.72 had 78.3% and 87.5% sensitivity and 81.7% and 81.3% specificity for the diagnosis of PCOS, respectively. Women with PCOS have higher baseline and GnRH-stimulated LH concentrations. GnRH stimulation results in an increase in LH/FSH ratio in women with PCOS. Therefore we postulate that this phenomenon might be potentially useful as an additional tool in the diagnosis of PCOS.

  13. Circadian Control of the Estrogenic Circuits Regulating GnRH Secretion and the Preovulatory Luteinizing Hormone Surge

    Directory of Open Access Journals (Sweden)

    Lance J Kriegsfeld

    2012-05-01

    Full Text Available Female reproduction requires the precise temporal organization of interacting, estradiol-sensitive neural circuits that converge to optimally drive hypothalamo-pituitary-gonadal (HPG axis functioning. In mammals, the master circadian pacemaker in the suprachaismatic nucleus (SCN of the anterior hypothalamus coordinates reproductively-relevant neuroendocrine events necessary to maximize reproductive success. Likewise, in species where periods of fertility are brief, circadian oversight of reproductive function ensures that estradiol-dependent increases in sexual motivation coincide with ovulation. Across species, including humans, disruptions to circadian timing (e.g., through rotating shift work, night shift work, poor sleep hygiene lead to pronounced deficits in ovulation and fecundity. Despite the well-established roles for the circadian system in female reproductive functioning, the specific neural circuits and neurochemical mediators underlying these interactions are not fully understood. Most work to date has focused on the direct and indirect communication from the SCN to the GnRH system in control of the preovulatory LH surge. However, the same clock genes underlying circadian rhythms at the cellular level in SCN cells are also common to target cell populations of the SCN, including the GnRH neuronal network. Exploring the means by which the master clock synergizes with subordinate clocks in GnRH cells and its upstream modulatory systems represents an exciting opportunity to further understand the role of endogenous timing systems in female reproduction. Herein we provide an overview of the state of knowledge regarding interactions between the circadian timing system and estradiol-sensitive neural circuits driving GnRH secretion and the preovulatory LH surge.

  14. Gonadotropin Releasing Hormone (GnRH) Neuron Migration: Initiation, Maintenance and Cessation as Critical Steps to Ensure Normal Reproductive Function

    OpenAIRE

    Wierman, Margaret E.; Kiseljak-Vassiliades, Katja; Tobet, Stuart

    2010-01-01

    GnRH neurons follow a carefully orchestrated journey from their birth in the olfactory placode area. Initially, they migrate along with the vomeronasal nerve into the brain at the cribriform plate, then progress caudally to sites within the hypothalamus where they halt and send projections to the median eminence to activate pituitary gonadotropes. Many factors controlling this precise journey have been elucidated by the silencing or over expression of candidate genes in mouse models. Importan...

  15. New trends in combined use of gonadotropin-releasing hormone antagonists with gonadotropins or pulsatile gonadotropin-releasing hormone in ovulation induction and assisted reproductive technologies.

    Science.gov (United States)

    Gordon, K; Danforth, D R; Williams, R F; Hodgen, G D

    1992-10-01

    The use of gonadotropin-releasing hormone agonists as adjunctive therapy with gonadotropins for ovulation induction in in vitro fertilization and other assisted reproductive technologies has become common clinical practice. With the recent advent of potent gonadotropin-releasing hormone antagonists free from the marked histamine-release effects that stymied earlier compounds, an attractive alternative method may be available. We have established the feasibility of combining gonadotropin-releasing hormone antagonist-induced inhibition of endogenous gonadotropins with exogenous gonadotropin therapy for ovulation induction in a nonhuman primate model. Here, the principal benefits to be gained from using the gonadotropin-releasing hormone antagonist rather than the gonadotropin-releasing hormone agonist are the immediate inhibition of pituitary gonadotropin secretion without the "flare effect," which brings greater safety and convenience for patients and the medical team and saves time and money. We have also recently demonstrated the feasibility of combining gonadotropin-releasing hormone antagonist with pulsatile gonadotropin-releasing hormone therapy for the controlled restoration of gonadotropin secretion and gonadal steroidogenesis culminating in apparently normal (singleton) ovulatory cycles. This is feasible only with gonadotropin-releasing hormone antagonists because, unlike gonadotropin-releasing hormone agonists, they achieve control of the pituitary-ovarian axis without down regulation of the gonadotropin-releasing hormone receptor system. This capacity to override gonadotropin-releasing hormone antagonist-induced suppression of pituitary-ovarian function may allow new treatment modalities to be employed for women who suffer from chronic hyperandrogenemia with polycystic ovarian disease.

  16. Features of natural and gonadotropin-releasing hormone antagonist-induced corpus luteum regression and effects of in vivo human chorionic gonadotropin.

    Science.gov (United States)

    Del Canto, Felipe; Sierralta, Walter; Kohen, Paulina; Muñoz, Alex; Strauss, Jerome F; Devoto, Luigi

    2007-11-01

    The natural process of luteolysis and luteal regression is induced by withdrawal of gonadotropin support. The objectives of this study were: 1) to compare the functional changes and apoptotic features of natural human luteal regression and induced luteal regression; 2) to define the ultrastructural characteristics of the corpus luteum at the time of natural luteal regression and induced luteal regression; and 3) to examine the effect of human chorionic gonadotropin (hCG) on the steroidogenic response and apoptotic markers within the regressing corpus luteum. Twenty-three women with normal menstrual cycles undergoing tubal ligation donated corpus luteum at specific stages in the luteal phase. Some women received a GnRH antagonist prior to collection of corpus luteum, others received an injection of hCG with or without prior treatment with a GnRH antagonist. Main outcome measures were plasma hormone levels and analysis of excised luteal tissue for markers of apoptosis, histology, and ultrastructure. The progesterone and estradiol levels, corpus luteum DNA, and protein contents in induced luteal regression resembled those of natural luteal regression. hCG treatment raised progesterone and estradiol in both natural luteal regression and induced luteal regression. The increase in apoptosis detected in induced luteal regression by cytochrome c in the cytosol, activated caspase-3, and nuclear DNA fragmentation, was similar to that observed in natural luteal regression. The antiapoptotic protein Bcl-2 was significantly lower during natural luteal regression. The proapoptotic proteins Bax and Bak were at a constant level. Apoptotic and nonapoptotic death of luteal cells was observed in natural luteal regression and induced luteal regression at the ultrastructural level. hCG prevented apoptotic cell death, but not autophagy. The low number of apoptotic cells disclosed and the frequent autophagocytic suggest that multiple mechanisms are involved in cell death at luteal

  17. A Proof-of-Concept Clinical Trial of A Single Luteal Use of Long-Acting Gonadotropin-Releasing Hormone Antagonist Degarelix in Controlled Ovarian Stimulation for In Vitro Fertilization: Long Antagonist Protocol

    Directory of Open Access Journals (Sweden)

    Evangelos G. Papanikolaou

    2018-03-01

    Full Text Available IntroductionA drawback of gonadotropin-releasing hormone (GnRH antagonist protocols in in vitro fertilization (IVF is that they have limited flexibility in cycle programming. This proof of concept study explored the efficacy of a single-dose, long-acting GnRH antagonist IVF protocol. Trial registration number is NCT03240159, retrospectively registered on March 08, 2017.Materials and methodsThe efficacy of a single-dose long-acting antagonist, degarelix, was explored initially in healthy donors and subsequently in infertile patients. In the first part, five healthy oocyte donors underwent ovarian stimulation with this new protocol: in the late luteal phase, at day 24, a bolus injection of degarelix was administered subcutaneously to control the LH surge in the follicular phase. Ovarian stimulation with gonadotropins was initiated subsequently from day 7 to day 10. End points were first to inhibit the LH surge later in the follicular phase and, second, to retrieve mature oocytes for IVF. In the second part, five infertile women received the same bolus injection of degarelix administered during the luteal phase at day 24. Different gonadotropin starting days (day 2 through day 8 were tested in order to observe possible differences in ovarian stimulation. In these infertile patients, fresh embryo transfers were performed to assess the pregnancy efficacy of this protocol on pregnancy outcomes and to address any possible negative effects on endometrium receptivity.ResultsIn the first part of the study, all donors were effectively downregulated with a single luteal dose of 0.5 ml of degarelix for up to 22 days until the final oocyte maturation triggering day. Mature oocytes were retrieved after 36 h from all patients and all produced 2–7 blastocysts. In the second part, all five infertile patients achieved sufficient LH downregulation and completed ovarian stimulation without any LH surge. All patients (except one with freeze all strategy had

  18. Biphasic action of cyclic adenosine 3',5'- monophosphate in gonadotropin-releasing hormone (GnRH) analog-stimulated hormone release from GH3 cells stably transfected with GnRH receptor complementary deoxyribonucleic acid.

    Science.gov (United States)

    Stanislaus, D; Arora, V; Awara, W M; Conn, P M

    1996-03-01

    GH3 cells are a PRL-secreting adenoma cell line derived from pituitary lactotropes. These cells have been stably transfected with rat GnRH receptor complementary DNA to produce four cell lines: GGH(3)1', GGH(3)2', GGH(3)6', and GGH(3)12'. In response to either GnRH or Buserelin (a metabolically stable GnRH agonist), these cell lines synthesize PRL in a cAMP-dependent manner. Only GGH(3)6' cells desensitize in response to persistent treatment with 10(-7) g/ml Buserelin. GGH(3)1', GGH(3)2', and GGH(3)12' cells, however, can be made refractory to Buserelin stimulation by raising cAMP levels either by the addition of (Bu)2cAMP to the medium or by treatment with cholera toxin. In GGH(3) cells, low levels of cAMP fulfill the requirements for a second messenger, whereas higher levels appear to mediate the development of desensitization. The observation that in GGH(3)6' cells, cAMP production persists after the onset of desensitization is consistent with the view that the mechanism responsible for desensitization is distal to the production of cAMP. Moreover, the absence of any significant difference in the amount of cAMP produced per cell in GGH(3)2', GGH(3)6', or GGH(3)12' cells suggests that elevated cAMP production per cell does not explain the development of desensitization in GGH(3)6' cells. We suggest that Buserelin-stimulated PRL synthesis in GGH(3)6' cells is mediated by a different cAMP-dependent protein kinase pool(s) than that in nondesensitizing GGH(3) cells. Such a protein kinase A pool(s) may be more susceptible to degradation via cAMP-mediated mechanisms than the protein kinase pools mediating the Buserelin response in nondesensitizing GGH(3) cells. A similar mechanism has been reported in other systems.

  19. Anti-Mullerian hormone levels do not predict response to pulsatile GnRH in women with hypothalamic amenorrhea.

    Science.gov (United States)

    Billington, Emma O; Corenblum, Bernard

    2016-09-01

    Pulsatile GnRH is used to induce ovulation in women with hypothalamic amenorrhea (HA), but tools to predict response are lacking. We assessed whether baseline AMH levels are associated with response to pulsatile GnRH in 16 women with HA. AMH levels were compared between non-responders and women who achieved follicular development or pregnancy. Median AMH for the cohort was 2.2 ng/mL. AMH levels were undetectable or low in four women, normal in nine and high in three. Follicular development was observed in 13 (81%) women (82% of cycles) and pregnancy achieved in 10 (63%) women (29% of cycles). All four women with low or undetectable AMH had follicular response and three achieved pregnancy. Of the 12 women with normal or high AMH, 10 had a follicular response and seven achieved pregnancy. Median AMH levels were comparable in those who achieved follicular development and those who did not (2.2 ng/mL versus 1.3 ng/mL, p = 0.78) and in those who became pregnant and those who did not (2.2 ng/mL versus 1.9 ng/mL, p = 0.52). In summary, low AMH does not preclude response to ovulation induction in women with HA, suggesting that ovarian potential may not be the primary determinant of AMH concentrations in this population.

  20. Growth Hormone Receptor Antagonist Treatment Reduces Exercise Performance in Young Males

    DEFF Research Database (Denmark)

    Goto, K.; Doessing, S.; Nielsen, R.H.

    2009-01-01

    between the groups in terms of changes in serum free fatty acids, glycerol, (V) over dotO(2), or relative fat oxidation. Conclusion: GH might be an important determinant of exercise capacity during prolonged exercise, but GHR antagonist did not alter fat metabolism during exercise. (J Clin Endocrinol......Context: The effects of GH on exercise performance remain unclear. Objective: The aim of the study was to examine the effects of GH receptor (GHR) antagonist treatment on exercise performance. Design: Subjects were treated with the GHR antagonist pegvisomant or placebo for 16 d. After the treatment...... period, they exercised to determine exercise performance and hormonal and metabolic responses. Participants: Twenty healthy males participated in the study. Intervention: Subjects were treated with the GHR antagonist (n = 10; 10 mg/d) or placebo (n = 10). After the treatment period, they performed...

  1. Fresh versus frozen embryo transfer after gonadotropin-releasing hormone agonist trigger in gonadotropin-releasing hormone antagonist cycles among high responder women: A randomized, multi-center study

    Directory of Open Access Journals (Sweden)

    Abbas Aflatoonian

    2018-02-01

    Full Text Available Background: The use of embryo cryopreservation excludes the possible detrimental effects of ovarian stimulation on the endometrium, and higher reproductive outcomes following this policy have been reported. Moreover, gonadotropin-releasing hormone agonist trigger in gonadotropin-releasing hormone (GnRH antagonist cycles as a substitute for standard human chorionic gonadotropin trigger, minimizes the risk of ovarian hyperstimulation syndrome (OHSS in fresh as well as frozen embryo transfer cycles (FET. Objective: To compare the reproductive outcomes and risk of OHSS in fresh vs frozen embryo transfer in high responder patients, undergoing in vitro fertilization triggered with a bolus of GnRH agonist. Materials and Methods: In this randomized, multi-centre study, 121 women undergoing FET and 119 women undergoing fresh ET were investigated as regards clinical pregnancy as the primary outcome and the chemical pregnancy, live birth, OHSS development, and perinatal data as secondary outcomes. Results: There were no significant differences between FET and fresh groups regarding chemical (46.4% vs. 40.2%, p=0.352, clinical (35.8% vs. 38.3%, p=0.699, and ongoing (30.3% vs. 32.7%, p=0.700 pregnancy rates, also live birth (30.3% vs. 29.9%, p=0.953, perinatal outcomes, and OHSS development (35.6% vs. 42.9%, p=0.337. No woman developed severe OHSS and no one required admission to hospital. Conclusion: Our findings suggest that GnRHa trigger followed by fresh transfer with modified luteal phase support in terms of a small human chorionic gonadotropin bolus is a good strategy to secure good live birth rates and a low risk of clinically relevant OHSS development in in vitro fertilization patients at risk of OHSS.

  2. Microdose gonadotropin-releasing hormone agonist flare-up protocol versus multiple dose gonadotropin-releasing hormone antagonist protocol in poor responders undergoing intracytoplasmic sperm injection-embryo transfer cycle.

    Science.gov (United States)

    Kahraman, Korhan; Berker, Bulent; Atabekoglu, Cem Somer; Sonmezer, Murat; Cetinkaya, Esra; Aytac, Rusen; Satiroglu, Hakan

    2009-06-01

    To compare the efficacy of microdose GnRH agonist (GnRH-a) flare-up and multiple dose GnRH antagonist protocols in patients who have a poor response to a long luteal GnRH-a protocol. Prospective, randomized, clinical study. University hospital. Forty-two poor responder patients undergoing intracytoplasmic sperm injection (ICSI)-embryo transfer cycle. Twenty-one patients received microdose leuprolide acetate (LA) (50 microg twice daily) starting on the second day of withdrawal bleeding. The other 21 patients received 0.25 mg of cetrorelix daily when the leading follicle reached 14 mm in diameter. Serum E(2) levels, number of growing follicles and mature oocytes, embryo quality, dose of gonadotropin used, cancellation, fertilization, implantation rate and pregnancy rate (PR). The mean serum E(2) concentration on the day of hCG administration was significantly higher in the microdose GnRH-a group than in the GnRH antagonist group (1,904 vs. 1,362 pg/mL). The clinical PRs per started cycle of microdose GnRH-a and GnRH antagonist groups were 14.2% and 9.5%, respectively. There were no statistically significant differences in the other ovulation induction characteristics, fertilization and implantation rates. Microdose GnRH-a flare-up protocol and multiple dose GnRH antagonist protocol seem to have similar efficacy in improving treatment outcomes of poor responder patients.

  3. Pharmacological and toxicological assessment of a potential GnRH vaccine in young-adult male pigs

    NARCIS (Netherlands)

    Turkstra, J.A.; Staay, van der F.J.; Stockhofe-Zurwieden, N.; Woelders, H.; Meloen, R.H.; Schuurman, T.

    2011-01-01

    Active immunization against gonadotrophin-releasing hormone (GnRH) is successfully applied to prevent boar taint in pork. In men, GnRH immunization could be an alternative to hormone therapy in patients with prostate cancer. In this study, a new GnRH vaccine formulation (a modified GnRH peptide

  4. Time- and dose-related effects of a gonadotropin-releasing hormone agonist and dopamine antagonist on reproduction in the Northern leopard frog (Lithobates pipiens).

    Science.gov (United States)

    Vu, Maria; Weiler, Bradley; Trudeau, Vance L

    2017-12-01

    Gonadotropin-releasing hormone (GnRH) stimulates luteinizing hormone release to control ovulation and spermiation in vertebrates. Dopamine (DA) has a clear inhibitory role in the control of reproduction in numerous teleosts, and emerging evidence suggests that similar mechanisms may exist in amphibians. The interactions between GnRH and DA on spawning success and pituitary gene expression in the Northern leopard frog (Lithobates pipiens) were therefore investigated. Frogs were injected during the natural breeding season with a GnRH agonist [GnRH-A; (Des-Gly 10 , D-Ala 6 , Pro-NHEt 9 )-LHRH; 0.1μg/g and 0.4μg/g] alone and in combination with the dopamine receptor D2 antagonist metoclopramide (MET; 5μg/g and 10μg/g). Injected animals were allowed to breed in outdoor mesocosms. Time to amplexus and oviposition were assessed, and egg mass release, incidences of amplexus, egg mass weight, total egg numbers and fertilization rates were measured. To examine gene expression, female pituitaries were sampled at 12, 24 and 36h following injection of GnRH-A (0.4μg/g) alone and in combination with MET (10μg/g). The mRNA levels of the genes lhb, fshb, gpha, drd2 and gnrhr1 were measured using quantitative real-time PCR. Data were analyzed by a two-way ANOVA. Both GnRH-A doses increased amplexus, oviposition and fertilization alone. Co-injection of MET with GnRH-A did not further enhance spawning success. Injection of GnRH-A alone time-dependently increased expression of lhb, fshb, gpha and gnrhr1. The major effect of MET alone was to decrease expression of drd2. Importantly, the stimulatory effects of GnRH-A on lhb, gpha and gnrhr1 were potentiated by the co-injection of MET at 36h. At this time, expression of fshb was increased only in animals injected with both GnRH-A and MET. Spawning success was primarily driven by the actions of GnRH-A. The hypothesized inhibitory action of DA was supported by pituitary gene expression analysis. The results from this study provide a

  5. GnRH Analogues in the Prevention of Ovarian Hyperstimulation Syndrome

    Science.gov (United States)

    Alama, Pilar; Bellver, Jose; Vidal, Carmen; Giles, Juan

    2013-01-01

    The GnRH analogue (agonist and antagonist GnRH) changed ovarian stimulation. On the one hand, it improved chances of pregnancy to obtain more oocytes and better embryos. This leads to an ovarian hyper-response, which can be complicated by the ovarian hyperstimulation syndrome (OHSS). On the other hand, the GnRH analogue can prevent the incidence of OHSS: GnRH antagonist protocols, GnRH agonist for triggering final oocyte maturation, either together or separately, coasting, and the GnRH analogue may prove useful for avoiding OHSS in high-risk patients. We review these topics in this article. PMID:23825982

  6. (−) Arctigenin and (+) Pinoresinol Are Antagonists of the Human Thyroid Hormone Receptor β

    Science.gov (United States)

    2015-01-01

    Lignans are important biologically active dietary polyphenolic compounds. Consumption of foods that are rich in lignans is associated with positive health effects. Using modeling tools to probe the ligand-binding pockets of molecular receptors, we found that lignans have high docking affinity for the human thyroid hormone receptor β. Follow-up experimental results show that lignans (−) arctigenin and (+) pinoresinol are antagonists of the human thyroid hormone receptor β. The modeled complexes show key plausible interactions between the two ligands and important amino acid residues of the receptor. PMID:25383984

  7. Thyroid Hormone Receptor Antagonists: From Environmental Pollution to Novel Small Molecules.

    Science.gov (United States)

    Mackenzie, Louise S

    2018-01-01

    Thyroid hormone receptors (TRs) are nuclear receptors which control transcription, and thereby have effects in all cells within the body. TRs are an important regulator in many basic physiological processes including development, growth, metabolism, and cardiac function. The hyperthyroid condition results from an over production of thyroid hormones resulting in a continual stimulation of thyroid receptors which is detrimental for the patient. Therapies for hyperthyroidism are available, but there is a need for new small molecules that act as TR antagonists to treat hyperthyroidism. Many compounds exhibit TR antagonism and are considered detrimental to health. Some drugs in the clinic (most importantly, amiodarone) and environmental pollution exhibit TR antagonist properties and thus have the potential to induce hypothyroidism in some people. This chapter provides an overview of novel small molecules that have been specifically designed or screened for their TR antagonist activity as novel treatments for hyperthyroidism. While novel compounds have been identified, to date none have been developed sufficiently to enter clinical trials. Furthermore, a discussion on other sources of TR antagonists is discussed in terms of side effects of current drugs in the clinic as well as environmental pollution. © 2018 Elsevier Inc. All rights reserved.

  8. Preparation and Characterization of an Antibody Antagonist That Targets the Porcine Growth Hormone Receptor

    Directory of Open Access Journals (Sweden)

    Huanzhong Cui

    2016-10-01

    Full Text Available A series of antagonists specifically targeting growth hormone receptors (GHR in different species, such as humans, rats, bovines, and mice, have been designed; however, there are currently no antagonists that target the porcine growth hormone (GH. Therefore, in this study, we developed and characterized a porcine GHR (pGHR antibody antagonist (denoted by AN98 via the hybridoma technique. The results from enzyme-linked immunosorbent assay, fluorescence activated cell sorter, indirect immunoinfluscent assay, and competitive receptor binding analysis showed that AN98 could specifically recognize pGHR, and further experiments indicated that AN98 could effectively inhibit pGH-induced signalling in CHO-pGHR cells and porcine hepatocytes. In addition, AN98 also inhibited GH-induced insulin-like growth factor-1 (IGF-1 secretion in porcine hepatocytes. In summary, these findings indicated that AN98, as a pGHR-specific antagonist, has potential applications in pGH-pGHR-related research on domestic pigs.

  9. Cloning and functional analysis of promoters of three GnRH genes in a cichlid

    International Nuclear Information System (INIS)

    Kitahashi, Takashi; Sato, Hideki; Sakuma, Yasuo; Parhar, Ishwar S.

    2005-01-01

    Mechanisms regulating gonadotropin-releasing hormone (GnRH) types, a key molecule for reproductive physiology, remain unclear. In the present study, we cloned the promoters of GnRH1, GnRH2, and GnRH3 genes in the tilapia, Oreochromis niloticus; and found putative binding sites for glucocorticoid receptors, Sp1, C/EBP, GATA, and Oct-1, but not for androgen receptors in all three GnRH promoters using computer analysis. The presence of binding sites for progesterone receptors in GnRH1, estrogen receptors in GnRH1 and GnRH2, and thyroid hormone receptors in GnRH1 and GnRH3 suggests direct action of steroid hormones on GnRH types. Our observation of SOX and LINE-like sequences exclusively in GnRH1, COUP in GnRH2, and retinoid X receptors in GnRH3 suggests their role in sexual differentiation, midbrain segmentation, and visual cue integration, respectively. Thus, the characteristic binding sites for nuclear receptors and transcription factors support the notion that each GnRH type is regulated differently and has distinct physiological roles

  10. Sex differences in immune responses: Hormonal effects, antagonistic selection, and evolutionary consequences.

    Science.gov (United States)

    Roved, Jacob; Westerdahl, Helena; Hasselquist, Dennis

    2017-02-01

    Males and females differ in both parasite load and the strength of immune responses and these effects have been verified in humans and other vertebrates. Sex hormones act as important modulators of immune responses; the male sex hormone testosterone is generally immunosuppressive while the female sex hormone estrogen tends to be immunoenhancing. Different sets of T-helper cells (Th) have important roles in adaptive immunity, e.g. Th1 cells trigger type 1 responses which are primarily cell-mediated, and Th2 cells trigger type 2 responses which are primarily humoral responses. In our review of the literature, we find that estrogen and progesterone enhance type 2 and suppress type 1 responses in females, whereas testosterone suppresses type 2 responses and shows an inconsistent pattern for type 1 responses in males. When we combine these patterns of generally immunosuppressive and immunoenhancing effects of the sex hormones, our results imply that the sex differences in immune responses should be particularly strong in immune functions associated with type 2 responses, and less pronounced with type 1 responses. In general the hormone-mediated sex differences in immune responses may lead to genetic sexual conflicts on immunity. Thus, we propose the novel hypothesis that sexually antagonistic selection may act on immune genes shared by the sexes, and that the strength of this sexually antagonistic selection should be stronger for type 2- as compared with type 1-associated immune genes. Finally, we put the consequences of sex hormone-induced effects on immune responses into behavioral and ecological contexts, considering social mating system, sexual selection, geographical distribution of hosts, and parasite abundance. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Nonpeptide corticotropin-releasing hormone receptor type 1 antagonists and their applications in psychosomatic disorders.

    Science.gov (United States)

    Contoreggi, Carlo; Rice, Kenner C; Chrousos, George

    2004-01-01

    Overproduction of corticotropin-releasing hormone (CRH) and stress system abnormalities are seen in psychiatric diseases such as depression, anxiety, eating disorders, and addiction. Investigations of CRH type 1 receptor (CRHR1) nonpeptide antagonists suggest therapeutic potential for treatment of these and other neuropsychiatric diseases. However, overproduction of CRH in the brain and on its periphery and disruption of the hypothalamic-pituitary-adrenal axis are also found in 'somatic' disorders. Some rare forms of Cushing's disease and related pituitary/adrenal disorders are obvious applications for CRHR1 antagonists. In addition, however, these antagonists may also be effective in treating more common somatic diseases. Patients with obesity and metabolic syndrome who often have subtle, but chronic hypothalamic-pituitary-adrenal hyperactivity, which may reflect central dysregulation of CRH and consequently glucocorticoid hypersecretion, could possibly be treated by administration of CRHR1 antagonists. Hormonal, autonomic, and immune aberrations are also present in chronic inflammatory, autoimmune, and allergic diseases, with considerable evidence linking CRH with the observed abnormalities. Furthermore, autonomic dysregulation is a prominent feature of common gastrointestinal disorders, such as irritable bowel syndrome and peptic ulcer disease. Patients with irritable bowel syndrome and other gastrointestinal disorders frequently develop altered pain perception and affective symptoms. CRH acts peripherally to modulate bowel activity both directly through the autonomic system and centrally by processing viscerosensory and visceromotor neural signals. This review presents clinical and preclinical evidence for the role of CRH in the pathophysiology of these disorders and for potential diagnostic and therapeutic applications of CRHR1 antagonists. Recognition of a dysfunctional stress system in these and other diseases will alter the understanding and treatment of

  12. Antiproliferative effect of growth hormone-releasing hormone (GHRH antagonist on ovarian cancer cells through the EGFR-Akt pathway

    Directory of Open Access Journals (Sweden)

    Varga Jozsef

    2010-05-01

    Full Text Available Abstract Background Antagonists of growth hormone-releasing hormone (GHRH are being developed for the treatment of various human cancers. Methods MTT assay was used to test the proliferation of SKOV3 and CaOV3. The splice variant expression of GHRH receptors was examined by RT-PCR. The expression of protein in signal pathway was examined by Western blotting. siRNA was used to block the effect of EGFR. Results In this study, we investigated the effects of a new GHRH antagonist JMR-132, in ovarian cancer cell lines SKOV3 and CaOV3 expressing splice variant (SV1 of GHRH receptors. MTT assay showed that JMR-132 had strong antiproliferative effects on SKOV3 and CaOV3 cells in both a time-dependent and dose-dependent fashion. JMR-132 also induced the activation and increased cleaved caspase3 in a time- and dose-dependent manner in both cell lines. In addition, JMR-132 treatments decreased significantly the epidermal growth factor receptor (EGFR level and the phosphorylation of Akt (p-Akt, suggesting that JMR-132 inhibits the EGFR-Akt pathway in ovarian cancer cells. More importantly, treatment of SKOV3 and CaOV3 cells with 100 nM JMR-132 attenuated proliferation and the antiapoptotic effect induced by EGF in both cell lines. After the knockdown of the expression of EGFR by siRNA, the antiproliferative effect of JMR-132 was abolished in SKOV3 and CaOV3 cells. Conclusions The present study demonstrates that the inhibitory effect of the GHRH antagonist JMR-132 on proliferation is due, in part, to an interference with the EGFR-Akt pathway in ovarian cancer cells.

  13. Gonadotropin-releasing hormone 2 suppresses food intake in the zebrafish, Danio rerio

    Directory of Open Access Journals (Sweden)

    Ryo eNishiguchi

    2012-10-01

    Full Text Available Gonadotropin-releasing hormone (GnRH is an evolutionarily conserved neuropeptide with 10 amino acid residues, of which several structural variants exist. A molecular form known as GnRH2 ([His5 Trp7 Tyr8]GnRH, also known as chicken GnRH II is widely distributed in vertebrates except for rodents, and has recently been implicated in the regulation of feeding behavior in goldfish. However, the influence of GnRH2 on feeding behavior in other fish has not yet been studied. In the present study, therefore, we investigated the role of GnRH2 in the regulation of feeding behavior in a zebrafish model, and examined its involvement in food intake after intracerebroventricular (ICV administration. ICV injection of GnRH2 at 0.1 and 1 pmol/g body weight (BW induced a marked decrease of food consumption in a dose-dependent manner during 30 min after feeding. Cumulative food intake was significantly decreased by ICV injection of GnRH2 at 1 pmol/g BW during the 30-min post-treatment observation period. The anorexigenic action of GnRH2 was completely blocked by treatment with the GnRH type I receptor antagonist Antide at 50 pmol/g BW. We also examined the effect of feeding condition on the expression level of the GnRH2 transcript in the hypothalamus. Levels of GnRH2 mRNA obtained from fish that had been provided excess food for 7 days were higher than those in fish that had been fed normally. These results suggest that, in zebrafish, GnRH2 acts as an anorexigenic factor, as is the case in goldfish.

  14. First Irish birth following IVF therapy using antagonist protocol.

    LENUS (Irish Health Repository)

    Mocanu, E V

    2012-02-01

    BACKGROUND: During in vitro fertilization (IVF), the prevention of a premature LH surge was traditionally achieved using a gonadotrophin releasing hormone agonist (GnRH-a), and more recently, a GnRH antagonist. AIMS: We report a case of a 37 year old treated using the GnRH antagonist in a second completed cycle of IVF. METHODS: IVF was performed for primary infertility of 5-year duration due to frozen pelvis secondary to endometriosis. RESULTS: Following controlled ovarian hyperstimulation, oocyte recovery and fertilization, cleavage and transfer of two zygotes, a pregnancy established. A twin gestation was diagnosed at 7-weeks scan and pregnancy ended with the delivery of twin girls by emergency caesarean section. CONCLUSION: This is a first report of a delivery following IVF using the antagonist protocol in Ireland. Such therapy is patient friendly and its use should be introduced on a larger scale in clinical practice.

  15. Effects of an Antagonistic Analog of Growth Hormone-Releasing Hormone on Endometriosis in a Mouse Model and In Vitro.

    Science.gov (United States)

    Köster, Frank; Jin, Li; Shen, Yuanming; Schally, Andrew V; Cai, Ren-Zhi; Block, Norman L; Hornung, Daniela; Marschner, Gabriele; Rody, Achim; Engel, Jörg B; Finas, Dominique

    2017-11-01

    Endometriosis is a benign gynecologic disorder causing dysmenorrhea, pelvic pain, and subfertility. Receptors for the growth hormone-releasing hormone (GHRH) were found in endometriotic tissues. Antagonists of GHRH have been used to inhibit the growth of endometriotic endometrial stromal cells. In this study, the GHRH receptor splice variant (SV) 1 was detected in human endometrial tissue samples by Western blots and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The highest messenger RNA (mRNA) and protein levels of SV1 were found in eutopic endometrium from patients with endometriosis compared to ectopic endometriotic tissues and endometrium from normal patients. The highest expression for GHRH mRNA was found by qRT-PCR in ectopic endometriosis lesions. In an in vivo mouse model with human endometrial explants from patients with endometriosis, 10 μg MIA-602 per day resulted in significantly smaller human endometrial xenotransplants after 4 weeks compared to mice treated with vehicle. The endometrial tissues expressed SV1 before and after xenotransplantation. The proliferation of endometrial stromal cells as well as the endometriosis cell lines 12-Z and 49-Z was decreased by exposure to 1 μM MIA-602 after 72 hours. The protein levels of epithelial growth factor receptors in 12-Z and 49-Z cell lines were reduced 48 and 72 hours after the administration of 1 μM MIA-602. MIA-602 decreased the activation of the MAP-kinases ERK-1/2. Our study demonstrates the presence of SV1 receptor as a target for treatment with GHRH antagonist in endometriosis. Endometrial tissues respond to MIA-602 with inhibition of proliferation in vitro and in vivo. The use of MIA-602 could be an effective supplement to the treatment strategies in endometriosis.

  16. Circulating Estradiol Regulates Brain-Derived Estradiol via Actions at GnRH Receptors to Impact Memory in Ovariectomized Rats.

    Science.gov (United States)

    Nelson, Britta S; Black, Katelyn L; Daniel, Jill M

    2016-01-01

    Systemic estradiol treatment enhances hippocampus-dependent memory in ovariectomized rats. Although these enhancements are traditionally thought to be due to circulating estradiol, recent data suggest these changes are brought on by hippocampus-derived estradiol, the synthesis of which depends on gonadotropin-releasing hormone (GnRH) activity. The goal of the current work is to test the hypothesis that peripheral estradiol affects hippocampus-dependent memory through brain-derived estradiol regulated via hippocampal GnRH receptor activity. In the first experiment, intracerebroventricular infusion of letrozole, which prevents the synthesis of estradiol, blocked the ability of peripheral estradiol administration in ovariectomized rats to enhance hippocampus-dependent memory in a radial-maze task. In the second experiment, hippocampal infusion of antide, a long-lasting GnRH receptor antagonist, blocked the ability of peripheral estradiol administration in ovariectomized rats to enhance hippocampus-dependent memory. In the third experiment, hippocampal infusion of GnRH enhanced hippocampus-dependent memory, the effects of which were blocked by letrozole infusion. Results indicate that peripheral estradiol-induced enhancement of cognition is mediated by brain-derived estradiol via hippocampal GnRH receptor activity.

  17. Pegvisomant: a growth hormone receptor antagonist used in the treatment of acromegaly.

    Science.gov (United States)

    Tritos, Nicholas A; Biller, Beverly M K

    2017-02-01

    To review published data on pegvisomant and its therapeutic role in acromegaly. Electronic searches of the published literature were conducted using the keywords: acromegaly, growth hormone (GH) receptor (antagonist), pegvisomant, therapy. Relevant articles (n = 141) were retrieved and considered for inclusion in this manuscript. Pegvisomant is a genetically engineered, recombinant growth hormone receptor antagonist, which is effective in normalizing serum insulin-like growth factor 1 (IGF-1) levels in the majority of patients with acromegaly and ameliorating symptoms and signs associated with GH excess. Pegvisomant does not have direct antiproliferative effects on the underlying somatotroph pituitary adenoma, which is the etiology of GH excess in the vast majority of patients with acromegaly. Therefore, patients receiving pegvisomant monotherapy require regular pituitary imaging in order to monitor for possible increase in tumor size. Adverse events in patients on pegvisomant therapy include skin rashes, lipohypertrophy at injection sites, and idiosyncratic liver toxicity (generally asymptomatic transaminitis that is reversible upon drug discontinuation), thus necessitating regular patient monitoring. Pegvisomant is an effective therapeutic agent in patients with acromegaly who are not in remission after undergoing pituitary surgery. It mitigates excess GH action, as demonstrated by IGF-1 normalization, but has no direct effects on pituitary tumors causing acromegaly. Regular surveillance for possible tumor growth and adverse effects (hepatotoxicity, skin manifestations) is warranted.

  18. Conditional Viral Tract Tracing Delineates the Projections of the Distinct Kisspeptin Neuron Populations to Gonadotropin-Releasing Hormone (GnRH) Neurons in the Mouse.

    Science.gov (United States)

    Yip, Siew Hoong; Boehm, Ulrich; Herbison, Allan E; Campbell, Rebecca E

    2015-07-01

    Kisspeptin neurons play an essential role in the regulation of fertility through direct regulation of the GnRH neurons. However, the relative contributions of the two functionally distinct kisspeptin neuron subpopulations to this critical regulation are not fully understood. Here we analyzed the specific projection patterns of kisspeptin neurons originating from either the rostral periventricular nucleus of the third ventricle (RP3V) or the arcuate nucleus (ARN) using a cell-specific, viral-mediated tract-tracing approach. We stereotaxically injected a Cre-dependent recombinant adenovirus encoding farnesylated enhanced green fluorescent protein into the ARN or RP3V of adult male and female mice expressing Cre recombinase in kisspeptin neurons. Fibers from ARN kisspeptin neurons projected widely; however, we did not find any evidence for direct contact with GnRH neuron somata or proximal dendrites in either sex. In contrast, we identified RP3V kisspeptin fibers in close contact with GnRH neuron somata and dendrites in both sexes. Fibers originating from both the RP3V and ARN were observed in close contact with distal GnRH neuron processes in the ARN and in the lateral and internal aspects of the median eminence. Furthermore, GnRH nerve terminals were found in close contact with the proximal dendrites of ARN kisspeptin neurons in the ARN, and ARN kisspeptin fibers were found contacting RP3V kisspeptin neurons in both sexes. Together these data delineate selective zones of kisspeptin neuron inputs to GnRH neurons and demonstrate complex interconnections between the distinct kisspeptin populations and GnRH neurons.

  19. GnRH injection before artificial insemination (AI) alters follicle ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... releasing hormone (GnRH) injection on day 6 of the estrous cycle. The estrous cycles ... follicle at the time of GnRH injection (Silcox et al., 1993;. Twagiramungu .... Waves and their Effect on pregnancy rate in the Cow. Reprod.

  20. GnRH antagonist versus long agonist protocols in IVF: a systematic review and meta-analysis accounting for patient type

    NARCIS (Netherlands)

    Lambalk, C. B.; Banga, F. R.; Huirne, J. A.; Toftager, M.; Pinborg, A.; Homburg, R.; van der Veen, F.; van Wely, M.

    2017-01-01

    Most reviews of IVF ovarian stimulation protocols have insufficiently accounted for various patient populations, such as ovulatory women, women with polycystic ovary syndrome (PCOS) or women with poor ovarian response, and have included studies in which the agonist or antagonist was not the only

  1. Rapid elimination kinetics of free PSA or human kallikrein-related peptidase 2 after initiation of gonadotropin-releasing hormone-antagonist treatment of prostate cancer

    DEFF Research Database (Denmark)

    Ulmert, David; Vickers, Andrew J; Scher, Howard I

    2012-01-01

    The utility of conventional prostate-specific antigen (PSA) measurements in blood for monitoring rapid responses to treatment for prostate cancer is limited because of its slow elimination rate. Prior studies have shown that free PSA (fPSA), intact PSA (iPSA) and human kallikrein-related peptidase...... of tPSA, fPSA, iPSA and hK2 after rapid induction of castration with degarelix (Firmagon(®)), a novel GnRH antagonist....

  2. Effects of GnRH immunization in sexually mature pony stallions

    NARCIS (Netherlands)

    Turkstra, J.A.; Meer, F.J.U.M.; Knaap, J.; Rottier, P.J.M.; Teerds, K.J.; Colenbrander, B.; Meloen, R.H.

    2005-01-01

    Immunization against gonadotrophin releasing hormone (GnRH) was studied as an alternative for the commonly used surgical castration in stallions. Two GnRH vaccines comprising non-mineral oil adjuvants were evaluated for their potential to induce high antibody titers directed against GnRH and

  3. In-vitro maturation versus IVF with GnRH antagonist for women with polycystic ovary syndrome: treatment outcome and rates of ovarian hyperstimulation syndrome.

    Science.gov (United States)

    Das, Mausumi; Son, Weon-Young; Buckett, William; Tulandi, Togas; Holzer, Hananel

    2014-11-01

    In-vitro maturation (IVM) treatment has gained popularity for decreasing the incidence of ovarian hyperstimulation syndrome (OHSS) by eliminating or minimizing the use of gonadotrophins in women with polycystic ovary syndrome (PCOS). Studies have shown that IVF with GnRH-antagonist protocol is associated with a lower incidence of OHSS. Data comparing the relative success of these two treatments is, however, lacking. Treatment outcome and rates of OHSS were compared in patients with PCOS who underwent assisted conception with either IVM or IVF with GnRH-antagonist protocol between 2006 and 2011. The number of oocytes retrieved was higher in the IVM group, whereas the number of mature oocytes, fertilization rate and number of embryos cleaved were comparable. The implantation rate was higher in the IVF group. The clinical pregnancy rates per embryo transfer were not statistically different (IVF: 45.8% versus IVM: 32.4%). The live-birth rate was higher in the IVF group (IVF: 40.7% versus IVM: 23.5%; P = 0.04). Five women developed moderate or severe OHSS in the IVF group, whereas none did in the IVM group. Both IVM and IVF with GnRH-antagonist protocol seem to be effective treatment regimens in women with PCOS, although IVM is associated with a lower risk of OHSS. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  4. Follicular synchronization using transdermal estradiol patch and GnRH antagonists in the luteal phase; does it increase oocyte yield in poor responders to gonadotropin stimulation for in vitro fertilization (IVF)? A comparative study with microdose flare-up protocol.

    Science.gov (United States)

    Ata, Baris; Zeng, Xing; Son, Weon Y; Holzer, Hananel; Tan, Seang L

    2011-11-01

    The aim of this retrospective study was to compare the oocyte yield with the luteal estradiol patch (LPA) - GnRH antagonist and microdose (MD) flare-up protocols in anticipated poor responders. Fifty-seven women who underwent IVF treatment following stimulation with LPA or MD protocols at McGill Reproductive Centre were matched for age and markers of ovarian reserve. Numbers of oocytes collected (6 vs 7), mature oocytes collected (5 vs 5), and oocyte maturation rates (72% vs 74%) were similar. The numbers of good quality embryos available (2 vs 1) and embryos transferred (3 vs 3) were likewise similar. Embryo implantation rate of 16.7% and clinical pregnancy rate of 38.9% achieved in the LPA group were almost 50% higher than the corresponding figures at 10.3% and 22.2% in the MD group; however, the differences were not statistically significant (p > 0.05 for all comparisons). Although the results do not suggest an increased oocyte yield or follicular synchronization with the LPA protocol, the observed trend toward higher embryo implantation and clinical pregnancy rates requires further research.

  5. Prolonged inhibition of luteinizing hormone and testosterone levels in male rats with the luteinizing hormone-releasing hormone antagonist SB-75.

    Science.gov (United States)

    Bokser, L; Bajusz, S; Groot, K; Schally, A V

    1990-09-01

    Inhibitory effects of the potent antagonist of luteinizing hormone-releasing hormone N-Ac-[3-(2-naphthyl)-D-alanine1,4-chloro-D-phenylalanine2,3- (3-pyridyl)-D- alanine3,D-citrulline6,D-alanine10]luteinizing hormone-releasing hormone (SB-75) free of edematogenic effects were investigated in male rats. In a study to determine the effect on luteinizing hormone levels in castrated male rats, SB-75 was injected s.c. in doses of 0.625, 1.25, 2.5, 5.0, and 10 micrograms. Blood samples were taken at different intervals for 48 hr. All doses of SB-75 significantly decreased luteinizing hormone levels for greater than 6 hr (P less than 0.01); this inhibition lasted for greater than 24 hr (P less than 0.01) with a dose of 5.0 micrograms and greater than 48 hr with 10 micrograms (P less than 0.05). Serum testosterone levels were also measured in intact male rats injected with SB-75 in doses of 25, 50, and 100 micrograms. All doses produced a dramatic fall in testosterone to castration levels 6 hr after injection (P less than 0.01); this inhibition of serum testosterone was maintained for greater than 72 hr, but only the 100-micrograms dose could keep testosterone in the castration range for greater than 24 hr (P less than 0.01). In another study using a specific RIA, we obtained the pharmacokinetic release pattern of SB-75 from two sustained delivery formulations of SB-75 pamoate microgranules and examined their effect on serum testosterone. After a single i.m. injection of 20 mg of one batch of microgranules, a large peak corresponding to SB-75 at 45.8 ng/ml was observed, corresponding to the "burst" effect. Levels of the analog decreased to 19.6 ng/ml on day 2, gradually reached a concentration of 4.7 ng/ml on day 7, and kept declining thereafter. Testosterone levels were reduced on day 1 (P less than 0.01) and were maintained at low values for greater than 7 days (P less than 0.05). In rats injected with 10 mg of SB-75 pamoate microgranules of the second batch, SB-75 serum

  6. Non-invasive assessment of the reproductive cycle in free-ranging female African elephants (Loxodonta africana treated with a gonadotropin-releasing hormone (GnRH vaccine for inducing anoestrus

    Directory of Open Access Journals (Sweden)

    Benavides Valades Gabriela

    2012-08-01

    Full Text Available Abstract Background In southern Africa, various options to manage elephant populations are being considered. Immunocontraception is considered to be the most ethically acceptable and logistically feasible method for control of smaller and confined populations. In this regard, the use of gonadotropin-releasing hormone (GnRH vaccine has not been investigated in female elephants, although it has been reported to be safe and effective in several domestic and wildlife species. The aims of this study were to monitor the oestrous cycles of free-ranging African elephant cows using faecal progestagen metabolites and to evaluate the efficacy of a GnRH vaccine to induce anoestrus in treated cows. Methods Between May 2009 - June 2010, luteal activity of 12 elephant cows was monitored non-invasively using an enzyme immunoassay detecting faecal 5alpha-reduced pregnanes (faecal progestagen metabolites, FPM on a private game reserve in South Africa. No bulls of breeding age were present on the reserve prior to and for the duration of the study. After a 3-month control period, 8 randomly-selected females were treated twice with 600 micrograms of GnRH vaccine (Improvac®, Pfizer Animal Health, Sandton, South Africa 5-7 weeks apart. Four of these females had been treated previously with the porcine zona pellucida (pZP vaccine for four years (2004-2007. Results All 12 monitored females (8 treated and 4 controls showed signs of luteal activity as evidenced by FPM concentrations exceeding individual baseline values more than once. A total of 16 oestrous cycles could be identified in 8 cows with four of these within the 13 to 17 weeks range previously reported for captive African elephants. According to the FPM concentrations the GnRH vaccine was unable to induce anoestrus in the treated cows. Overall FPM levels in samples collected during the wet season (mean 4.03 micrograms/gram dry faeces were significantly higher (P Conclusions The GnRH vaccination protocol failed

  7. Gonadotrophin-Releasing Hormone (GnRH Analogues in the Treatment of Mixed Mullerian Tumours of the Uterus: Two Case Reports and Review

    Directory of Open Access Journals (Sweden)

    Michael Katesmark

    1998-01-01

    Full Text Available Subjects/Discussion. Two cases of clinical and radiological response of recurrent mixed Mullerian tumours following treatment with either nasal (Buserilin or intramuscular (Goserilin GnRH analogues are reported and a short review of the evidence to support this treatment option presented.

  8. Cytokine modulation by stress hormones and antagonist specific hormonal inhibition in rainbow trout (Oncorhynchus mykiss) and gilthead sea bream (Sparus aurata) head kidney primary cell culture.

    Science.gov (United States)

    Khansari, Ali Reza; Parra, David; Reyes-López, Felipe E; Tort, Lluís

    2017-09-01

    A tight interaction between endocrine and immune systems takes place mainly due to the key role of head kidney in both hormone and cytokine secretion, particularly under stress situations in which the physiological response promotes the synthesis and release of stress hormones which may lead into immunomodulation as side effect. Although such interaction has been previously investigated, this study evaluated for the first time the effect of stress-associated hormones together with their receptor antagonists on the expression of cytokine genes in head kidney primary cell culture (HKPCC) of the freshwater rainbow trout (Oncorhynchus mykiss) and the seawater gilthead sea bream (Sparus aurata). The results showed a striking difference when comparing the response obtained in trout and seabream. Cortisol and adrenocorticotropic hormone (ACTH) decreased the expression of immune-related genes in sea bream but not in rainbow trout and this cortisol effect was reverted by the antagonist mifepristone but not spironolactone. On the other hand, while adrenaline reduced the expression of pro-inflammatory cytokines (IL-1β, IL-6) in rainbow trout, the opposite effect was observed in sea bream showing an increased expression (IL-1β, IL-6). Interestingly, this effect was reverted by antagonist propranolol but not phentolamine. Overall, our results confirm the regional interaction between endocrine and cytokine messengers and a clear difference in the sensitivity to the hormonal stimuli between the two species. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Extended high dose letrozole regimen versus short low dose letrozole regimen as an adjuvant to gonadotropin releasing hormone antagonist protocol in poor responders undergoing IVF-ET.

    Science.gov (United States)

    Fouda, Usama M; Sayed, Ahmed M

    2011-12-01

    To compare the efficacy and cost-effectiveness of extended high dose letrozole regimen/HPuFSH-gonadotropin releasing hormone antagonist (GnRHant) protocol with short low dose letrozole regimen/HPuFSH-GnRHant protocol in poor responders undergoing IVF-ET. In this randomized controlled trial, 136 women who responded poorly to GnRH agonist long protocol in their first IVF cycle were randomized into two equal groups using computer generated list and were treated in the second IVF cycle by either extended letrozole regimen (5 mg/day during the first 5 days of cycle and 2.5 mg/day during the subsequent 3 days) combined with HPuFSH-GnRHant protocol or short letrozole regimen (2.5 mg/day from cycle day 3-7) combined with HPuFSH-GnRHant protocol. There were no significant differences between both groups with regard to number of oocytes retrieved and clinical pregnancy rate (5.39 ± 2.08 vs. 5.20 ± 1.88 and 22.06% vs. 16.18%, respectively).The total gonadotropins dose and medications cost per cycle were significantly lower in extended letrozole group (44.87 ± 9.16 vs. 59.97 ± 14.91 ampoules and 616.52 ± 94.97 vs. 746.84 ± 149.21 US Dollars ($), respectively).The cost-effectiveness ratio was 2794 $ in extended letrozole group and 4616 $ in short letrozole group. Extended letrozole regimen/HPuFSH-GnRHant protocol was more cost-effective than short letrozole regimen/HPuFSH-GnRHant protocol in poor responders undergoing IVF-ET.

  10. Non-invasive assessment of the reproductive cycle in free-ranging female African elephants (Loxodonta africana) treated with a gonadotropin-releasing hormone (GnRH) vaccine for inducing anoestrus.

    Science.gov (United States)

    Benavides Valades, Gabriela; Ganswindt, Andre; Annandale, Henry; Schulman, Martin L; Bertschinger, Henk J

    2012-08-25

    In southern Africa, various options to manage elephant populations are being considered. Immunocontraception is considered to be the most ethically acceptable and logistically feasible method for control of smaller and confined populations. In this regard, the use of gonadotropin-releasing hormone (GnRH) vaccine has not been investigated in female elephants, although it has been reported to be safe and effective in several domestic and wildlife species. The aims of this study were to monitor the oestrous cycles of free-ranging African elephant cows using faecal progestagen metabolites and to evaluate the efficacy of a GnRH vaccine to induce anoestrus in treated cows. Between May 2009-June 2010, luteal activity of 12 elephant cows was monitored non-invasively using an enzyme immunoassay detecting faecal 5alpha-reduced pregnanes (faecal progestagen metabolites, FPM) on a private game reserve in South Africa. No bulls of breeding age were present on the reserve prior to and for the duration of the study. After a 3-month control period, 8 randomly-selected females were treated twice with 600 micrograms of GnRH vaccine (Improvac®, Pfizer Animal Health, Sandton, South Africa) 5-7 weeks apart. Four of these females had been treated previously with the porcine zona pellucida (pZP) vaccine for four years (2004-2007). All 12 monitored females (8 treated and 4 controls) showed signs of luteal activity as evidenced by FPM concentrations exceeding individual baseline values more than once. A total of 16 oestrous cycles could be identified in 8 cows with four of these within the 13 to 17 weeks range previously reported for captive African elephants. According to the FPM concentrations the GnRH vaccine was unable to induce anoestrus in the treated cows. Overall FPM levels in samples collected during the wet season (mean 4.03 micrograms/gram dry faeces) were significantly higher (Pelephants. These results indicate that irregular oestrous cycles occur amongst free

  11. Evaluation of growth hormone (GH) action in mice: discovery of GH receptor antagonists and clinical indications.

    Science.gov (United States)

    Kopchick, John J; List, Edward O; Kelder, Bruce; Gosney, Elahu S; Berryman, Darlene E

    2014-04-05

    The discovery of a growth hormone receptor antagonist (GHA) was initially established via expression of mutated GH genes in transgenic mice. Following this discovery, development of the compound resulted in a drug termed pegvisomant, which has been approved for use in patients with acromegaly. Pegvisomant treatment in a dose dependent manner results in normalization of IGF-1 levels in most patients. Thus, it is a very efficacious and safe drug. Since the GH/IGF-1 axis has been implicated in the progression of several types of cancers, many have suggested the use of pegvisomant as an anti-cancer therapeutic. In this manuscript, we will review the use of mouse strains that possess elevated or depressed levels of GH action for unraveling many of GH actions. Additionally, we will describe experiments in which the GHA was discovered, review results of pegvisomant's preclinical and clinical trials, and provide data suggesting pegvisomant's therapeutic value in selected types of cancer. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Uso de antagonista de GnRH (cetrorelix em dose única para evitar ovulações prematuras em ciclos de fertilização assistida Single dose of GnRH antagonist (cetrorelix to avoid premature ovulation in assisted fertilization cycles

    Directory of Open Access Journals (Sweden)

    Pedro Luís Rosan

    2003-09-01

    gravidez foram semelhantes entre os dois grupos. Estudos prospectivos com maior número de pacientes são necessários para confirmar estes achados.PURPOSE: to verify the efficacy of a single subcutaneous dose of cetrorelix acetate to avoid premature ovulation in assisted fertilization cycles. METHODS: this is a prospective, controlled and randomized study, with 20 women undergoing ovarian stimulation for assisted fertilization, 10 of whom were submitted to classical GnRH agonist protocol (control group while 10 utilized a 3-mg subcutaneous dose of the GnRH antagonist on the 7th day of ovarian stimulation (cetrorelix group. Serum FSH, LH, estradiol and progesterone concentrations were assessed on the first, seventh, HCG administration and oocyte retrieval days. Both groups were compared for pituitary suppression (progesterone concentration on HCG day and assisted fertilization cycle performance (gonadotropin ampoules utilized, follicles over 18 mm, retrieved oocytes, fertilization, implantation and pregnancy rates, utilizing Mann-Whitney and Fisher exact tests. RESULTS: no significant difference was observed between control and cetrorelix groups, respectively, for medians of age (31.5 and 34 years, body mass index (24 and 22, gonadotropin ampoles utilized (34 and 32, follicles over 18 mm (3.5 and 3.3, retrieved oocytes (11 and 5, obtained embryos (4 and 3, fertilization (93,7 and 60%, p=0.07 and pregnancy rates (50 and 60%, p=0.07. Efficient pituitary blockade through the ovarian stimulation period was observed for both groups. CONCLUSIONS: these results confirm the efficacy of a 3-mg dose of cetrorelix acetate to prevent premature ovulation in patients undergoing assisted fertilization and suggest a tendency towards a smaller number of embryos and fertilization rates in the cetrorelix group than in the control group. Implantation and pregnancy rates were similar between groups. Other prospective studies with a greater number of patients should be performed to confirm

  13. Cost-effectiveness of short COH protocols with GnRH antagonists using different types of gonadotropins for in vitro fertilization

    Directory of Open Access Journals (Sweden)

    Guenka Petrova

    2016-05-01

    Full Text Available The aim of this study was to explore the cost-effectiveness of short protocols including different types of gonadotropins for controlled ovarian hyperstimulation (COH for in vitro fertilization (IVF. A retrospective, observational study of the real-life practice in a specialized IVF gynaecology clinic in 2009–2013 was carried out. All women on short COH protocols were recruited into three groups: COH including recombinant follicle stimulating hormone (rFSH and urinary-FSH (urFSH (n = 173; including urFSH alone (n = 289; and including rFSH alone (n = 212. The cost-effectiveness of the COH protocols was explored in two different case scenarios for possible outcomes. The first case scenario took into consideration a successful live birth, and the second one, the women to achieve pregnancy with live birth. Decision modelling was done using the TreeAge 2014 Software. According to the results in the first case scenario, the rFSH plus urFSH COH approach showed the highest weighted probability (p = 0.38 of live birth, but the urFSH alternative was cost-effective. The results in the second case scenario demonstrated that the urFSH protocol was again the cost-effective alternative. These results suggest that the strategy with urFSH should be preferred in both cases, but rFSH could also be considered as a cost-effective alternative for successful live birth and achieving pregnancy and delivery, since the incremental cost-effectiveness ratio in comparison with the urFSH protocol is below the gross domestic product per capita. The combined approach of rFSH and urFSH was shown not to be cost-effective in both explored scenarios.

  14. Comparison of luteal estradiol patch and gonadotropin-releasing hormone antagonist suppression protocol before gonadotropin stimulation versus microdose gonadotropin-releasing hormone agonist protocol for patients with a history of poor in vitro fertilization outcomes.

    Science.gov (United States)

    Weitzman, Vanessa N; Engmann, Lawrence; DiLuigi, Andrea; Maier, Donald; Nulsen, John; Benadiva, Claudio

    2009-07-01

    To compare IVF outcomes in poor-responder patients undergoing stimulation after luteal phase E(2) patch/GnRH antagonist (LPG) protocol versus microdose GnRH agonist protocol. Retrospective analysis. University-based IVF center. Forty-five women undergoing ovarian stimulation for IVF using the LPG protocol were compared with 76 women stimulated with the microdose GnRH agonist protocol from May 2005 to April 2006. Cancellation rate, number of oocytes retrieved, and clinical pregnancy rates. The mean number of oocytes (9.1 +/- 4.1 vs. 8.9 +/- 4.3) and mature oocytes (6.7 +/- 3.5 vs. 6.8 +/- 3.1) retrieved were similar, as were the fertilization rates (70.0% +/- 24.2% vs. 69.9% +/- 21.5%) and the number of embryos transferred (2.5 +/- 1.1 vs. 2.7 +/- 1.3). The cancellation rate was not significantly different between the groups (13/45, 28.9% vs. 23/76, 30.3%). Likewise, there were no significant differences among the implantation rate (15.0% vs. 12.5%), clinical pregnancy rate (43.3% vs. 45.1%), and ongoing pregnancy rate per transfer (33.3% vs. 26.0%) between both groups. This study demonstrates that the use of an E(2) patch and a GnRH antagonist during the preceding luteal phase in patients with a history of failed cycles can provide similar IVF outcomes when compared with the microdose GnRH agonist protocol.

  15. Effect of a corticotropin releasing hormone receptor antagonist on colonic sensory and motor function in patients with irritable bowel syndrome

    OpenAIRE

    Sagami, Y; Shimada, Y; Tayama, J; Nomura, T; Satake, M; Endo, Y; Shoji, T; Karahashi, K; Hongo, M; Fukudo, S

    2004-01-01

    Background and aims: Corticotropin releasing hormone (CRH) is a major mediator of the stress response in the brain-gut axis. Irritable bowel syndrome (IBS) is presumed to be a disorder of the brain-gut link associated with an exaggerated response to stress. We hypothesised that peripheral administration of α-helical CRH (αhCRH), a non-selective CRH receptor antagonist, would improve gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation in IBS patient...

  16. Utilização da contagem de folículos antrais para predição do padrão de resposta em ciclos de hiperestimulação controlada com antagonista de GnRH Use of antral follicle count to predict the response pattern in controlled ovarian hyperstimulation cycles with GnRH antagonist

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Borges de Souza

    2008-01-01

    Full Text Available OBJETIVO: verificar se existe relação preditiva entre a contagem de folículos antrais (CFA no segundo dia do ciclo com o padrão de resposta em ciclos de hiperestimulação ovariana controlada para injeção intracitoplasmática de espermatozóide (ICSI. MÉTODOS: estudo prospectivo, desenvolvido de maio de 2004 a maio de 2005, no qual 51 pacientes com idade 15 mm no dia do desencadeamento da ovulação, número total e em metáfase II de oócitos captados, número de embriões de boa qualidade transferidos e taxa de gestação. A análise estatística foi realizada pelos testes t de Student e de Mann-Whitney, com significância estatística de 5% (pPURPOSE: to establish whether there is a predictive relationship between the antral follicle count (AFC on the second day of the cycle and the response pattern in controlled ovarian hyperstimulation cycles for intracytoplasmic sperm injection (ICSI. METHODS: a prospective study developed from May 2004 to May 2005, in which 51 patients aged 15 mm on the day of ovulation triggering, the total number of oocytes retrieved and in metaphases II, the number of good quality embryos transferred and pregnancy rate. The statistical analysis was performed by the t-Student test and the Mann-Whitney test, with statistical significance of 5% (p15 mm on the day of ovulation triggering (p=0.0001, the total number of oocytes retrieved (p=0.0001 and those in metaphases II (p=0.0001. Such correlation between AFC and pregnancy was not observed (p=0.43. There was no significant correlation between AFC and the number of good quality embryos transferred (p=0.081. CONCLUSIONS: AFC on the second day of the stimulated cycle can be used to predict the quality of ovarian stimulation, the number of oocytes retrieved and the number of mature oocytes in in vitro fertilization cycles using GnRH antagonist.

  17. Gonadotropin releasing hormone agonists: Expanding vistas

    Directory of Open Access Journals (Sweden)

    Navneet Magon

    2011-01-01

    Full Text Available Gonadotropin-releasing hormone (GnRH agonists are derived from native GnRH by amino acid substitution which yields the agonist resistant to degradation and increases its half-life. The hypogonadotropic hypogonadal state produced by GnRH agonists has been often dubbed as "pseudomenopause" or "medical oophorectomy," which are both misnomers. GnRH analogues (GnRH-a work by temporarily "switching off" the ovaries. Ovaries can be "switched off" for the therapy and therapeutic trial of many conditions which include but are not limited to subfertility, endometriosis, adenomyosis, uterine leiomyomas, precocious puberty, premenstrual dysphoric disorder, chronic pelvic pain, or the prevention of menstrual bleeding in special clinical situations. Rapidly expanding vistas of usage of GnRH agonists encompass use in sex reassignment of male to female transsexuals, management of final height in cases of congenital adrenal hyperplasia, and preserving ovarian function in women undergoing cytotoxic chemotherapy. Hypogonadic side effects caused by the use of GnRH agonists can be tackled with use of "add-back" therapy. Goserelin, leuprolide, and nafarelin are commonly used in clinical practice. GnRH-a have provided us a powerful therapeutic approach to the treatment of numerous conditions in reproductive medicine. Recent synthesis of GnRH antagonists with a better tolerability profile may open new avenues for both research and clinical applications. All stakeholders who are partners in women′s healthcare need to join hands to spread awareness so that these drugs can be used to realize their full potential.

  18. Action of specific thyroid hormone receptor α(1) and β(1) antagonists in the central and peripheral regulation of thyroid hormone metabolism in the rat.

    Science.gov (United States)

    van Beeren, Hermina C; Kwakkel, Joan; Ackermans, Mariëtte T; Wiersinga, Wilmar M; Fliers, Eric; Boelen, Anita

    2012-12-01

    The iodine-containing drug amiodarone (Amio) and its noniodine containing analogue dronedarone (Dron) are potent antiarrhythmic drugs. Previous in vivo and in vitro studies have shown that the major metabolite of Amio, desethylamiodarone, acts as a thyroid hormone receptor (TR) α(1) and β(1) antagonist, whereas the major metabolite of Dron debutyldronedarone acts as a selective TRα(1) antagonist. In the present study, Amio and Dron were used as tools to discriminate between TRα(1) or TRβ(1) regulated genes in central and peripheral thyroid hormone metabolism. Three groups of male rats received either Amio, Dron, or vehicle by daily intragastric administration for 2 weeks. We assessed the effects of treatment on triiodothyronine (T(3)) and thyroxine (T(4)) plasma and tissue concentrations, deiodinase type 1, 2, and 3 mRNA expressions and activities, and thyroid hormone transporters monocarboxylate transporter 8 (MCT8), monocarboxylate transporter 10 (MCT10), and organic anion transporter 1C1 (OATP1C1). Amio treatment decreased serum T(3), while serum T(4) and thyrotropin (TSH) increased compared to Dron-treated and control rats. At the central level of the hypothalamus-pituitary-thyroid axis, Amio treatment decreased hypothalamic thyrotropin releasing hormone (TRH) expression, while increasing pituitary TSHβ and MCT10 mRNA expression. Amio decreased the pituitary D2 activity. By contrast, Dron treatment resulted in decreased hypothalamic TRH mRNA expression only. Upon Amio treatment, liver T(3) concentration decreased substantially compared to Dron and control rats (50%, p<0.01), but liver T(4) concentration was unaffected. In addition, liver D1, mRNA, and activity decreased, while the D3 activity and mRNA increased. Liver MCT8, MCT10, and OATP1C1 mRNA expression were similar between groups. Our results suggest an important role for TRα1 in the regulation of hypothalamic TRH mRNA expression, whereas TRβ plays a dominant role in pituitary and liver thyroid

  19. The role of GABA in the regulation of GnRH neurons

    Directory of Open Access Journals (Sweden)

    Miho eWatanabe

    2014-11-01

    Full Text Available Gonadotropin-releasing hormone (GnRH neurons form the final common pathway for the central regulation of reproduction. Gamma-amino butyric acid (GABA has long been implicated as one of the major players in the regulation of GnRH neurons. Although GABA is typically an inhibitory neurotransmitter in the mature adult central nervous system, most mature GnRH neurons show the unusual characteristic of being excited by GABA. While many reports have provided much insight into the contribution of GABA to the activity of GnRH neurons, the precise physiological role of the excitatory action of GABA on GnRH neurons remains elusive. This brief review presents the current knowledge of the role of GABA signaling in GnRH neuronal activity. We also discuss the modulation of GABA signaling by neurotransmitters and neuromodulators and the functional consequence of GABAergic inputs to GnRH neurons in both the physiology and pathology of reproduction.

  20. Design, synthesis and biological activity of new neurohypophyseal hormones analogues conformationally restricted in the N-terminal part of the molecule. Highly potent OT receptor antagonists

    Czech Academy of Sciences Publication Activity Database

    Kwiatkowska, A.; Ptach, M.; Borovičková, Lenka; Slaninová, Jiřina; Lammek, B.; Prahl, A.

    2012-01-01

    Roč. 43, č. 2 (2012), s. 617-627 ISSN 0939-4451 Institutional research plan: CEZ:AV0Z40550506 Keywords : oxitocin antagonists * Atosiban * neurohypophyseal hormones analogues * arginine vasopressin (AVP) * antidiuretic hormone * binding affinity Subject RIV: CE - Biochemistry Impact factor: 3.914, year: 2012

  1. Inhibition of growth of experimental prostate cancer with sustained delivery systems (microcapsules and microgranules) of the luteinizing hormone-releasing hormone antagonist SB-75.

    Science.gov (United States)

    Korkut, E; Bokser, L; Comaru-Schally, A M; Groot, K; Schally, A V

    1991-02-01

    Inhibitory effects of the sustained delivery systems (microcapsules and microgranules) of a potent antagonist of luteinizing hormone-releasing hormone N-Ac-[3-(2-naphthyl)-D-alanine1, 4-chloro-D-phenylalanine2, 3-(3-pyridyl)-D-alanine3, D-citrulline6, D-alanine10]LH-RH (SB-75) on the growth of experimental prostate cancers were investigated. In the first experiment, three doses of a microcapsule preparation releasing 23.8, 47.6, and 71.4 micrograms of antagonist SB-75 per day were compared with microcapsules of agonist [D-Trp6]LH-RH liberating 25 micrograms/day in rats bearing Dunning R3327H transplantable prostate carcinoma. During 8 weeks of treatment, tumor growth was decreased by [D-Trp6]LH-RH and all three doses of SB-75 as compared to untreated controls. The highest dose of SB-75 (71.4 micrograms/day) caused a greater inhibition of prostate cancer growth than [D-Trp6]LH-RH as based on measurement of tumor volume and percentage change in tumor volume. Doses of 23.8 and 47.6 micrograms of SB-75 per day induced a partial and submaximal decrease, respectively, in tumor weight and volume. Tumor doubling time was the longest (50 days) with the high dose of SB-75 vs. 15 days for controls. The body weights were unchanged. The weights of testes, seminal vesicles, and ventral prostate were greatly reduced in all three groups that received SB-75, and testosterone levels were decreased to nondetectable values in the case of the two higher doses of SB-75. LH levels were also diminished. Similar results were obtained in the second experiment, in which the animals were treated for a period of 8 weeks with microgranules of SB-75. Therapy with microgranules of SB-75 significantly decreased tumor growth as measured by the final tumor volume, the percentage change from the initial tumor volume, and the reduction in tumor weight. The results indicate that antagonist SB-75, released from sustained delivery systems, can produce a state of chemical castration and effectively

  2. Role of color Doppler US in the evaluation of uterine leiomyoma treated with gonadotrophin-releasing hormone (GnRH) agonist (Zoladex)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Sik; Sohn, Cheol Ho; Lee, Tae Sung [Keimyung University Dongsan Medical Center, Taegu (Korea, Republic of)

    1999-03-15

    To access the role of color Doppler US in the evaluation of uterine leiomyoma treated with GnRH agonist (Zoladex). Out of 25 patients with uterine leiomyoma treated with Zoladex, nineteen cases of leiomyoma in 18 women who had US examination before and after medication were included in this study. Zoladex was injected subcutaneously three times within three months. Both gray scale and color Doppler US were obtained before and 1-3 months after the medication. The size, volume, location and internal echoes of the leiomyoma were recorded with gray scale US. Changes in the amount of color signal within leiomyomas were recorded. Pulsatility index (PI), resistive index (RI), peak systolic velocity (PSV) of both uterine artery and arteries within leiomyomas were also recorded. The image findings of good response group and poor response group in which the volume reduction of the leiomyoma was above or below 50% respectively were compared with each other. The reduction of the volume of leiomyoma was compared between a group with decrease in the amount of color signals during follow-up US and a group with increase or no change. Mean reduction of the volume of leiomyomas was 52%. Changes in the amount of color signals of the leiomyoma, PI, RI, PSV obtained from the arteries within leiomyomas were not correlated with the change of the volume of leiomyomas. PSV of uterine artery in one month follow-up and PI of two month follow-up were correlated with the changes of the volume of leiomyomas (p<0.05). RI of uterine artery in two month follow-up was useful in prediction of the good response group and the poor response group (p<0.05). The prediction of the volume reduction of leiomyoma following Zoladex medication might be possible by obtaining RI of uterine artery in two month follow-up. Doppler US of the arteries within the leiomyoma was not useful.

  3. Role of color Doppler US in the evaluation of uterine leiomyoma treated with gonadotrophin-releasing hormone (GnRH) agonist (Zoladex)

    International Nuclear Information System (INIS)

    Kim, Jung Sik; Sohn, Cheol Ho; Lee, Tae Sung

    1999-01-01

    To access the role of color Doppler US in the evaluation of uterine leiomyoma treated with GnRH agonist (Zoladex). Out of 25 patients with uterine leiomyoma treated with Zoladex, nineteen cases of leiomyoma in 18 women who had US examination before and after medication were included in this study. Zoladex was injected subcutaneously three times within three months. Both gray scale and color Doppler US were obtained before and 1-3 months after the medication. The size, volume, location and internal echoes of the leiomyoma were recorded with gray scale US. Changes in the amount of color signal within leiomyomas were recorded. Pulsatility index (PI), resistive index (RI), peak systolic velocity (PSV) of both uterine artery and arteries within leiomyomas were also recorded. The image findings of good response group and poor response group in which the volume reduction of the leiomyoma was above or below 50% respectively were compared with each other. The reduction of the volume of leiomyoma was compared between a group with decrease in the amount of color signals during follow-up US and a group with increase or no change. Mean reduction of the volume of leiomyomas was 52%. Changes in the amount of color signals of the leiomyoma, PI, RI, PSV obtained from the arteries within leiomyomas were not correlated with the change of the volume of leiomyomas. PSV of uterine artery in one month follow-up and PI of two month follow-up were correlated with the changes of the volume of leiomyomas (p<0.05). RI of uterine artery in two month follow-up was useful in prediction of the good response group and the poor response group (p<0.05). The prediction of the volume reduction of leiomyoma following Zoladex medication might be possible by obtaining RI of uterine artery in two month follow-up. Doppler US of the arteries within the leiomyoma was not useful.

  4. GnRH mRNA levels in male three-spined sticklebacks, Gasterosteus aculeatus, under different reproductive conditions.

    Science.gov (United States)

    Shao, Yi Ta; Tseng, Yung Che; Chang, Chia-Hao; Yan, Hong Young; Hwang, Pung Pung; Borg, Bertil

    2015-02-01

    In vertebrates, reproduction is regulated by the brain-pituitary-gonad (BPG) axis, where the gonadotropin-releasing hormone (GnRH) is one of the key components. However, very little is known about the possible role of GnRH in the environmental and feedback control of fish reproduction. To investigate this, full-length gnrh2 (chicken GnRH II) and gnrh3 (salmon GnRH) sequences of male three-spined sticklebacks (Gasterosteus aculeatus), which are clustered with the taxa of the same GnRH type as other Euteleostei, were cloned and annotated. gnrh1 is absent in this species. The mRNA levels of gnrh2 and gnrh3 in the sticklebacks' brain were measured under breeding and post-breeding conditions as well as in castrated and sham-operated breeding fish and castrated/sham-operated fish kept under long-day (LD 16:8) and short-day (LD 8:16) conditions. Fully breeding males had considerably higher mRNA levels of gnrh2 and gnrh3 in the thalamus (Th) and in the telencephalon and preoptic area (T+POA), respectively, than post-breeding males. Sham-operated breeding males have higher gnrh3 mRNA levels than the corresponding castrated males. Moreover, higher gnrh2 mRNA levels in the Th and higher gnrh3 mRNA levels in the T+POA and hypothalamus (HypTh) were also found in long-day sham-operated males than in sham-operated fish kept under an inhibitory short day photoperiod. Nevertheless, gnrh2 and gnrh3 mRNA levels were not up-regulated in castrated males kept under long-day photoperiod, which suggests that positive feedbacks on the brain-pituitary-gonad axis are necessary for this response. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. A small population of hypothalamic neurons govern fertility: the critical role of VAX1 in GnRH neuron development and fertility maintenance.

    Science.gov (United States)

    Hoffmann, Hanne M; Mellon, Pamela L

    2016-01-01

    Fertility depends on the correct maturation and function of approximately 800 gonadotropin-releasing hormone (GnRH) neurons in the brain. GnRH neurons are at the apex of the hypothalamic-pituitary-gonadal axis that regulates fertility. In adulthood, GnRH neurons are scattered throughout the anterior hypothalamic area and project to the median eminence, where GnRH is released into the portal vasculature to stimulate release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary. LH and FSH then regulate gonadal steroidogenesis and gametogenesis. Absence of GnRH neurons or inappropriate GnRH release leads to infertility. Despite the critical role of GnRH neurons in fertility, we still have a limited understanding of the genes responsible for proper GnRH neuron development and function in adulthood. GnRH neurons originate in the olfactory placode then migrate into the brain. Homeodomain transcription factors expressed within GnRH neurons or along their migratory path are candidate genes for inherited infertility. Using a combined in vitro and in vivo approach, we have identified Ventral Anterior Homeobox 1 ( Vax1 ) as a novel homeodomain transcription factor responsible for GnRH neuron maturation and fertility. GnRH neuron counts in Vax1 knock-out embryos revealed Vax1 to be required for the presence of GnRH-expressing cells at embryonic day 17.5 (E17.5), but not at E13.5. To localize the effects of Vax1 on fertility, we generated Vax1 flox mice and crossed them with Gnrh cre mice to specifically delete Vax1 within GnRH neurons. GnRH staining in Vax1 flox/flox :GnRH cre mice show a total absence of GnRH expression in the adult. We performed lineage tracing in Vax1 flox/flox :GnRH cre :RosaLacZ mice which proved GnRH neurons to be alive, but incapable of expressing GnRH. The absence of GnRH leads to delayed puberty, hypogonadism and complete infertility in both sexes. Finally, using the immortalized model GnRH neuron cell lines, GN11 and

  6. 4-Acylamino-and 4-ureidobenzamides as melanin-concentrating hormone (MCH) receptor 1 antagonists

    DEFF Research Database (Denmark)

    Receveur, Jean-Marie; Bjurling, Emelie; Ulven, Trond

    2004-01-01

    Synthesis, in vitro biological evaluation and structure-activity relationships of 4-acylamino-and 4-ureidobenzamides as novel hMCH1R-antagonists are disclosed. The nature of the amine side chains could be varied considerably in contrast to the central benzamide scaffold and aromatic substituents....

  7. Evidence that diclofenac and celecoxib are thyroid hormone receptor beta antagonists.

    Science.gov (United States)

    Zloh, Mire; Perez-Diaz, Noelia; Tang, Leslie; Patel, Pryank; Mackenzie, Louise S

    2016-02-01

    Long term use of NSAIDs is linked to side effects such as gastric bleeding and myocardial infarction. Use of in silico methods and pharmacology to investigate the potential for NSAIDs diclofenac, celecoxib and naproxen to bind to nuclear receptors. In silico screening predicted that both diclofenac and celecoxib has the potential to bind to a number of different nuclear receptors; docking analysis confirmed a theoretical ability for diclofenac and celecoxib but not naproxen to bind to TRβ. Results from TRβ luciferase reporter assays confirmed that both diclofenac and celecoxib display TRβ antagonistic properties; celecoxib, IC50 3.6 × 10(-6)M, and diclofenac IC50 5.3 × 10(-6)M, comparable to the TRβ antagonist MLS (IC50 3.1 × 10(-6)M). In contrast naproxen, a cardio-sparing NSAID, lacked TRβ antagonist effects. In order to determine the effects of NSAIDs in whole organ in vitro, we used isometric wire myography to measure the changes to Triiodothyronine (T3) induced vasodilation of rat mesenteric arteries. Incubation of arteries in the presence of the TRβ antagonist MLS000389544 (10(-5)M), as well as diclofenac (10(-5)M) and celecoxib (10(-5)M) but not naproxen significantly inhibited T3 induced vasodilation compared to controls. These results highlight the benefits of computational chemistry methods used to retrospectively analyse well known drugs for side effects. Using in silico and in vitro methods we have shown that both celecoxib and diclofenac but not naproxen exhibit off-target TRβ antagonist behaviour, which may be linked to their detrimental side effects. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. A conserved non-reproductive GnRH system in chordates.

    Directory of Open Access Journals (Sweden)

    Takehiro G Kusakabe

    Full Text Available Gonadotropin-releasing hormone (GnRH is a neuroendocrine peptide that plays a central role in the vertebrate hypothalamo-pituitary axis. The roles of GnRH in the control of vertebrate reproductive functions have been established, while its non-reproductive function has been suggested but less well understood. Here we show that the tunicate Ciona intestinalis has in its non-reproductive larval stage a prominent GnRH system spanning the entire length of the nervous system. Tunicate GnRH receptors are phylogenetically closest to vertebrate GnRH receptors, yet functional analysis of the receptors revealed that these simple chordates have evolved a unique GnRH system with multiple ligands and receptor heterodimerization enabling complex regulation. One of the gnrh genes is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord of vertebrates. Correspondingly, GnRH receptor genes were found to be expressed in the tail muscle and notochord of embryos, both of which are phylotypic axial structures along the nerve cord. Our findings suggest a novel non-reproductive role of GnRH in tunicates. Furthermore, we present evidence that GnRH-producing cells are present in the hindbrain and spinal cord of the medaka, Oryzias latipes, thereby suggesting the deep evolutionary origin of a non-reproductive GnRH system in chordates.

  9. Does the use of gonadotropin-releasing hormone antagonists in natural IVF cycles for poor responder patients cause more harm than benefit?

    Science.gov (United States)

    Aksoy, Senai; Yakin, Kayhan; Seyhan, Ayse; Oktem, Ozgur; Alatas, Cengiz; Ata, Baris; Urman, Bulent

    2016-06-01

    Poor ovarian response to controlled ovarian stimulation (COS) is one of the most critical factors that substantially limits the success of assisted reproduction techniques (ARTs). Natural and modified natural cycle IVF are two options that could be considered as a last resort. Blocking gonadotropin-releasing hormone (GnRH) actions in the endometrium via GnRH receptor antagonism may have a negative impact on endometrial receptivity. We analysed IVF outcomes in 142 natural (n = 30) or modified natural (n = 112) IVF cycles performed in 82 women retrospectively. A significantly lower proportion of natural cycles reached follicular aspiration compared to modified natural cycles (56.7% vs. 85.7%, p cycles ending in embryo transfer (26.7% vs. 44.6%) was not statistically significant between natural cycle and modified natural IVF cycles. Clinical pregnancy (6.7% vs. 7.1%) and live birth rates per initiated cycle (6.7% vs. 5.4%) were similar between the two groups. Notably, the implantation rate was slightly lower in modified natural cycles (16% vs. 25%, p > 0.05). There was a trend towards higher clinical pregnancy (25% vs. 16%) and live birth (25% vs. 12%) rates per embryo transfer in natural cycles compared to modified natural cycles, but the differences did not reach statistical significance.

  10. The Phytophthora mating hormone α2 is an antagonist of the counterhormone α1.

    Science.gov (United States)

    Zhang, Li; Yajima, Arata; Ojika, Makoto

    2016-06-01

    The crop destroyer Phytophthora uses mating hormones α1 and α2 to commence its sexual reproduction. The α1-induced sexual reproduction of the A2 mating type was unexpectedly found to be interfered with by the counterhormone α2 that the A2 type itself produces to induce the sexual reproduction of the A1 type. A plausible mechanism is proposed based on structure-activity relationships.

  11. GnRH-agonist versus GnRH-antagonist IVF cycles

    DEFF Research Database (Denmark)

    Papanikolaou, E G; Pados, G; Grimbizis, G

    2012-01-01

    In view of the current debate concerning possible differences in efficacy between the two GnRH analogues used in IVF stimulated cycles, the current study aimed to explore whether progesterone control in the late follicular phase differs when GnRH antagonist is used as compared with GnRH agonist...

  12. Knockout of the Gnrh genes in zebrafish: effects on reproduction and potential compensation by reproductive and feeding-related neuropeptides.

    Science.gov (United States)

    Marvel, Miranda; Spicer, Olivia Smith; Wong, Ten-Tsao; Zmora, Nilli; Zohar, Yonathan

    2018-04-04

    Gonadotropin-releasing hormone (GnRH) is known as a pivotal upstream regulator of reproduction in vertebrates. However, reproduction is not compromised in the hypophysiotropic Gnrh3 knockout line in zebrafish (gnrh3-/-). In order to determine if Gnrh2, the only other Gnrh isoform in zebrafish brains, is compensating for the loss of Gnrh3, we generated a double Gnrh knockout zebrafish line. Surprisingly, the loss of both Gnrh isoforms resulted in no major impact on reproduction, indicating that a compensatory response, outside of the Gnrh system, was evoked. A plethora of factors acting along the reproductive hypothalamus-pituitary axis were evaluated as possible compensators based on neuroanatomical and differential gene expression studies. In addition, we also examined the involvement of feeding factors in the brain as potential compensators for Gnrh2, which has known anorexigenic effects. We found that the double knockout fish exhibited upregulation of several genes in the brain, specifically gonadotropin-inhibitory hormone (gnih), secretogranin 2 (scg2), tachykinin 3a (tac3a), and pituitary adenylate cyclase-activating peptide 1 (pacap1), and downregulation of agouti-related peptide 1 (agrp1), indicating the compensation occurs outside of Gnrh cells and therefore is a non-cell autonomous response to the loss of Gnrh. While the differential expression of gnih and agrp1 in the double knockout line was confined to the periventricular nucleus and hypothalamus, respectively, the upregulation of scg2 corresponded with a broader neuronal redistribution in the lateral hypothalamus and hindbrain. In conclusion, our results demonstrate the existence of a redundant reproductive regulatory system that comes into play when Gnrh2 and Gnrh3 are lost.

  13. Recovery of pituitary-gonadal function in male and female rats after prolonged administration of a potent antagonist of luteinizing hormone-releasing hormone (SB-75).

    Science.gov (United States)

    Bokser, L; Srkalovic, G; Szepeshazi, K; Schally, A V

    1991-08-01

    estradiol (p less than 0.01) levels than controls. The histology of the ovaries from the SB-75-treated group showed that the ratio of small to large maturing follicles increased significantly (p less than 0.01) and corpora lutea were absent. Two months after the cessation of treatment, a complete recovery in the organ weights and in hormonal levels was observed and no histological differences were found between the ovaries in treated and untreated rats. These collective results indicate that the suppression of gonadal function induced by the treatment with LH-RH antagonist SB-75 is completely reversible both in male and female animals.(ABSTRACT TRUNCATED AT 400 WORDS)

  14. Expression and role of gonadotropin-releasing hormone 2 and its receptor in mammals

    Science.gov (United States)

    Gonadotropin-releasing hormone (GnRH1) and its receptor (GnRHR1) drive mammalian reproduction via regulation of the gonadotropins. Yet, a second form of GnRH (GnRH2) and its receptor (GnRHR2) also exist in some mammals. GnRH2 has been completely conserved throughout 500 million years of evolution, s...

  15. Ontogenic and sexual differences in pituitary GnRH receptors and intracellular Ca2+ mobilization induced by GnRH.

    Science.gov (United States)

    Lacau-Mengido, I M; González Iglesias, A; Lux-Lantos, V; Libertun, C; Becú-Villalobos, D

    1998-04-01

    The present experiments were designed in order to elucidate the participation of the developing hypophysis in determining the changing sensitivity of gonadotrophins to gonadotropin-releasing hormone (GnRH) during ontogeny in the rat. To that end, we chose two well defined developmental ages that differ markedly in sexual and ontogenic characteristics of hypophyseal sensitivity to GnRH, 15 and 30 d. In order to study sex differences and the role of early sexual organization of the hypothalamus, experiments were carried out in males, females, and neonatally androgenized females (TP females). We evaluated (1) the characteristics of pituitary GnRH receptors, and (2) associated changes in GnRH-induced mobilization of intracellular Ca2+ (a second messenger involved in gonadotropins exocytosis). We measured binding characteristics of the GnRH analog D-Ser(TBu)6-des-Gly10-GnRH ethylamide in pituitary homogenates. We found that Kds did not vary among the different sex groups. Total number and concentration of receptors decreased in the female rat from 15-30 d of age, whereas in the male and TP female, receptors/pituitary increased, and the concentration/mg tissue did not change. Also, at 30 days of age, males presented higher content and concentration of receptors than females, and higher content than TP females. In order to evaluate if developmental and sexual differences in pituitary sensitivity to GnRH might be expressed through variations in the intracellular Ca2+ signal, we studied the mobilization of intracellular Ca2+ induced by GnRH (1 x 10(-8) to 1 x 10(-11) M) in a suspension of dispersed pituitary cells in the six groups. In cells from 15-d-old females, Ca2+ response was greater than in 30-d-old females at the doses of 10(-8) to 10(-10) M, indicating that in the infantile female rat activation of highly concentrated GnRH receptors is reflected in an increase in signal transduction mediated by Ca2+. In males and in female rats androgenized at birth, there was also

  16. Treatment of pituitary gigantism with the growth hormone receptor antagonist pegvisomant.

    Science.gov (United States)

    Goldenberg, Naila; Racine, Michael S; Thomas, Pamela; Degnan, Bernard; Chandler, William; Barkan, Ariel

    2008-08-01

    Treatment of pituitary gigantism is complex and the results are usually unsatisfactory. The objective of the study was to describe the results of therapy of three children with pituitary gigantism by a GH receptor antagonist, pegvisomant. This was a descriptive case series of up to 3.5 yr duration. The study was conducted at a university hospital. Patients included three children (one female, two males) with pituitary gigantism whose GH hypersecretion was incompletely controlled by surgery, somatostatin analog, and dopamine agonist. The intervention was administration of pegvisomant. Plasma IGF-I and growth velocity were measured. In all three children, pegvisomant rapidly decreased plasma IGF-I concentrations. Growth velocity declined to subnormal or normal values. Statural growth fell into lower growth percentiles and acromegalic features resolved. Pituitary tumor size did not change in two children but increased in one boy despite concomitant therapy with a somatostatin analog. Pegvisomant may be an effective modality for the therapy of pituitary gigantism in children. Titration of the dose is necessary for optimal efficacy, and regular surveillance of tumor size is mandatory.

  17. Effect of a corticotropin releasing hormone receptor antagonist on colonic sensory and motor function in patients with irritable bowel syndrome.

    Science.gov (United States)

    Sagami, Y; Shimada, Y; Tayama, J; Nomura, T; Satake, M; Endo, Y; Shoji, T; Karahashi, K; Hongo, M; Fukudo, S

    2004-07-01

    Corticotropin releasing hormone (CRH) is a major mediator of the stress response in the brain-gut axis. Irritable bowel syndrome (IBS) is presumed to be a disorder of the brain-gut link associated with an exaggerated response to stress. We hypothesised that peripheral administration of alpha-helical CRH (alphahCRH), a non-selective CRH receptor antagonist, would improve gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation in IBS patients. Ten normal healthy subjects and 10 IBS patients, diagnosed according to the Rome II criteria, were studied. The tone of the descending colon and intraluminal pressure of the sigmoid colon were measured at baseline, during rectal electrical stimulation (ES), and at recovery after administration of saline. Visceral perception after colonic distension or rectal ES was evaluated as threshold values on an ordinate scale. The same measurements were repeated after administration of alphahCRH (10 micro g/kg). ES induced significantly higher motility indices of the colon in IBS patients compared with controls. This response was significantly suppressed in IBS patients but not in controls after administration of alphahCRH. Administration of alphahCRH induced a significant increase in the barostat bag volume of controls but not in that of IBS patients. alphahCRH significantly reduced the ordinate scale of abdominal pain and anxiety evoked by ES in IBS patients. Plasma adrenocorticotropic hormone and serum cortisol levels were generally not suppressed by alphahCRH. Peripheral administration of alphahCRH improves gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation, without affecting the hypothalamo-pituitary-adrenal axis in IBS patients.

  18. Genetics of Isolated Hypogonadotropic Hypogonadism: Role of GnRH Receptor and Other Genes

    Directory of Open Access Journals (Sweden)

    Karges Beate

    2012-01-01

    Full Text Available Hypothalamic gonadotropin releasing hormone (GnRH is a key player in normal puberty and sexual development and function. Genetic causes of isolated hypogonadotropic hypogonadism (IHH have been identified during the recent years affecting the synthesis, secretion, or action of GnRH. Developmental defects of GnRH neurons and the olfactory bulb are associated with hyposmia, rarely associated with the clinical phenotypes of synkinesia, cleft palate, ear anomalies, or choanal atresia, and may be due to mutations of KAL1, FGFR1/FGF8, PROKR2/PROK2, or CHD7. Impaired GnRH secretion in normosmic patients with IHH may be caused by deficient hypothalamic GPR54/KISS1, TACR3/TAC3, and leptinR/leptin signalling or mutations within the GNRH1 gene itself. Normosmic IHH is predominantly caused by inactivating mutations in the pituitary GnRH receptor inducing GnRH resistance, while mutations of the β-subunits of LH or FSH are very rare. Inheritance of GnRH deficiency may be oligogenic, explaining variable phenotypes. Future research should identify additional genes involved in the complex network of normal and disturbed puberty and reproduction.

  19. Identification of Genes Enriched in GnRH Neurons by Translating Ribosome Affinity Purification and RNAseq in Mice.

    Science.gov (United States)

    Burger, Laura L; Vanacker, Charlotte; Phumsatitpong, Chayarndorn; Wagenmaker, Elizabeth R; Wang, Luhong; Olson, David P; Moenter, Suzanne M

    2018-04-01

    Gonadotropin-releasing hormone (GnRH) neurons are a nexus of fertility regulation. We used translating ribosome affinity purification coupled with RNA sequencing to examine messenger RNAs of GnRH neurons in adult intact and gonadectomized (GDX) male and female mice. GnRH neuron ribosomes were tagged with green fluorescent protein (GFP) and GFP-labeled polysomes isolated by immunoprecipitation, producing one RNA fraction enhanced for GnRH neuron transcripts and one RNA fraction depleted. Complementary DNA libraries were created from each fraction and 50-base, paired-end sequencing done and differential expression (enhanced fraction/depleted fraction) determined with a threshold of >1.5- or <0.66-fold (false discovery rate P ≤ 0.05). A core of ∼840 genes was differentially expressed in GnRH neurons in all treatments, including enrichment for Gnrh1 (∼40-fold), and genes critical for GnRH neuron and/or gonadotrope development. In contrast, non-neuronal transcripts were not enriched or were de-enriched. Several epithelial markers were also enriched, consistent with the olfactory epithelial origins of GnRH neurons. Interestingly, many synaptic transmission pathways were de-enriched, in accordance with relatively low innervation of GnRH neurons. The most striking difference between intact and GDX mice of both sexes was a marked downregulation of genes associated with oxidative phosphorylation and upregulation of glucose transporters in GnRH neurons from GDX mice. This may suggest that GnRH neurons switch to an alternate fuel to increase adenosine triphosphate production in the absence of negative feedback when GnRH release is elevated. Knowledge of the GnRH neuron translatome and its regulation can guide functional studies and can be extended to disease states, such as polycystic ovary syndrome.

  20. Effects of melanocortin-4 receptor agonists and antagonists on expression of genes related to reproduction in spotted scat, Scatophagus argus.

    Science.gov (United States)

    Jiang, Dong-Neng; Li, Jian-Tao; Tao, Ya-Xiong; Chen, Hua-Pu; Deng, Si-Ping; Zhu, Chun-Hua; Li, Guang-Li

    2017-05-01

    Melanocortin-4 receptor (Mc4r) function related to reproduction in fish has not been extensively investigated. Here, we report on gene expression changes by real-time PCR following treatment with Mc4r agonists and antagonists in the spotted scat (Scatophagus argus). Using in vitro incubated hypothalamus, the Mc4r nonselective agonist NDP-MSH ([Nle 4 , D-Phe 7 ]-α-melanocyte stimulating hormone; 10 -6 M) and selective agonist THIQ (N-[(3R)-1, 2, 3, 4-Tetrahydroisoquinolinium-3-ylcarbonyl]- (1R)-1-(4-chlorobenzyl)-2-[4-cyclohexyl-4-(1H-1,2,4-triazol-1-ylmethyl) piperidin-1-yl]-2-oxoethylamine; 10 -7 M) significantly increased the expression of gnrh (Gonadotropin releasing hormone), while the Mc4r nonselective antagonist SHU9119 (Ac-Nle-[Asp-His-DPhe/DNal(2')-Arg-Trp-Lys]-NH2; 10 -6 M) and selective antagonist Ipsen 5i (compound 5i synthesized in Ipsen Research Laboratories; 10 -6 M) significantly inhibited gnrh expression after 3 h of incubation. In incubated pituitary tissue, NDP-MSH and THIQ significantly increased the expression of fshb (Follicle-stimulating hormone beta subunit) and lhb (Luteinizing hormone beta subunit), while SHU9119 and Ipsen 5i significantly decreased fshb and lhb expression after 3 h of incubation. During the in vivo experiment, THIQ (1 mg/kg bw) significantly increased gnrh expression in hypothalamic tissue, as well as the fshb and lhb expression in pituitary tissue 12 h after abdominal injection. Furthermore, Ipsen 5i (1 mg/kg bw) significantly inhibited gnrh expression in hypothalamic tissue, as well as fshb and lhb gene expression in pituitary tissue 12 h after abdominal injection. In summary, Mc4r singling appears to stimulate gnrh expression in the hypothalamus, thereby modulating the synthesis of Fsh and Lh in the pituitary. In addition, Mc4r also appears to directly regulate fshb and lhb levels in the pituitary in spotted scat. Our study suggests that Mc4r, through the hypothalamus and pituitary, participates in reproductive

  1. Evaluation of GnRH analogue testing in diagnosis and management of children with pubertal disorders

    Directory of Open Access Journals (Sweden)

    Hemchand K Prasad

    2012-01-01

    Full Text Available Context: Gonadotrophin releasing hormone (GnRH stimulation test is pivotal in the assessment of children with pubertal disorders. However, lack of availability and high cost often result in the test falling into disfavor. We routinely use the GnRH analogue stimulation test as an alternative at our center. Aim: To present the data on children with endocrine disorders who underwent GnRH agonist stimulation test in pediatric endocrine clinic of a tertiary care referral hospital. Setting and Design: Pediatric endocrine clinic of a tertiary care referral hospital. Retrospective analysis of case records. Materials and Methods: The details pertaining to clinical and radiological parameters and hormonal tests were retrieved from case records of 15 children who underwent GnRH agonist stimulation test from May 2010 to April 2011. Results: Indications for testing with GnRH analogue were evaluation of delayed puberty, diagnosis of precocious puberty, assessment of hormonal suppression in treatment of precocious puberty and micropenis in two, nine, three and one cases, respectively. The results of the test and clinical and radiological parameters were in concordance. The test was also crucial in diagnosing the onset of central precocious puberty in two children with congenital adrenal hyperplasia. Conclusion: GnRH agonist test is a convenient, safe test that can be performed on an out-patient basis and can help the clinicians in the correct diagnosis and appropriate treatment of various puberty-related disorders.

  2. Regulation versus modulation in GnRH receptor function

    International Nuclear Information System (INIS)

    Zolman, J.C.; Theodoropoulos, T.J.

    1985-01-01

    Serum luteinizing hormone (LH) concentration after exposure to gonadotropin-releasing hormone (GnRH) indicates that an instantaneous increase occurs in the rate of release of LH directly from the anterior pituitary, as measured dynamically during superfusion in vitro. On the other hand, estradiol-17 beta (E2) alone shows no such instantaneous effect on LH release rate (at least for the first four hours), in either physiologic or pharmacologic concentrations. At the same time, brief (ten to 30 minute) exposure of isolated anterior pituitary plasma membranes to physiologic concentrations of E2 significantly alters the binding of a fully biologically active 125 I-GnRH to its plasma membrane receptor protein. In order to characterize the effect of E2 on GnRH binding further, dispersed bovine anterior pituitary cells were preincubated for six hours in the presence or absence of physiologic concentrations of E2 (10(-10)M). Following preincubation in the presence of E2, the cell suspension was incubated for 30 minutes with physiologic concentrations (5 x 10(-11) - 5 x 10(-10)M) of a fully biologically active 125 I-GnRH. The treatment, at least, doubled the number of biologically important high affinity GnRH binding sites (Kd's . 7.5 x -10(-11) - 4.5 x 10(-10)M), and changed the binding capacity of some of the binding sites up to three fold, which altered the cooperativity of GnRH-receptor interaction. Thus, the interaction of E2 with GnRH at the level of GnRH receptor is mandatory for the short-term pituitary effect of E2 on LH release in vitro and in vivo

  3. Should we give up hormone treatment in menopause?

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    Mehmet Aral Atalay

    2013-12-01

    Full Text Available The first paper entitled intrauterine insemination (IUI was published in 1962. By time, several methods involving the technique and the ovulation induction schedules have evolved in order to improve the success rates. Although gonadotrophin releasing hormone antagonists (GnRHa is a crucial part of assisted reproductive treatments now, concerns also arouse regarding the need for the use of it in IUI cycles. These drugs may be considered in IUI programs basically in order to prevent premature LH surges and related cycle cancellations. Although administration of a GnRH antagonist almost completely abolishes premature luteinization, it does not substantially improve the pregnancy rate. The decision of using GnRH antagonists in IUI cycles should be based primarily on the local cost/benefit analysis of individual centers. It will be prudent to limit the involvement of the antagonists in ovulation induction protocols to: patients who frequently exhibit premature LH discharges and therefore either fail to complete treatment or result in unsuccessful outcome; initiated cycles intented for IUI but converted to ART; if it is not possible for logistic reasons (weekend to perform the insemination or for medical centers in which a gynecologist on call is not available and in order to decrease clinical task burden resulting from strict cycle monitoring such as serial transvaginal sonography and/or frequent urine tests.

  4. Immunohistochemical evidence for the involvement of gonadotropin releasing hormone in neuroleptic and cataleptic effects of haloperidol in mice.

    Science.gov (United States)

    Fegade, Harshal A; Umathe, Sudhir N

    2016-04-01

    Blockade of dopamine D2 receptor by haloperidol is attributed for neuroleptic and cataleptic effects; and also for the release of gonadotropin releasing hormone (GnRH) from the hypothalamus. GnRH agonist is reported to exhibit similar behavioural effects as that of haloperidol, and pre-treatment with GnRH antagonist is shown to attenuate the effects of haloperidol, suggesting a possibility that GnRH might mediate the effects of haloperidol. To substantiate such possibility, the influence of haloperidol on GnRH immunoreactivity (GnRH-ir) in the brain was studied in vehicle/antide pre-treated mice by peroxidase-antiperoxidase method. Initially, an earlier reported antide-haloperidol interaction in rat was confirmed in mice, wherein haloperidol (250μg/kg, i.p.) exhibited suppression of conditioned avoidance response (CAR) on two-way shuttle box, and induced catalepsy in bar test; and pre-treatment with antide (50μg/kg, s.c., GnRH antagonist) attenuated both effects of haloperidol. Immunohistochemical study was carried out to identify GnRH-ir in the brain, isolated 1h after haloperidol treatment to mice pre-treated with vehicle/antide. The morphometric analysis of microphotographs of brain sections revealed that haloperidol treatment increased integrated density units of GnRH-ir in various regions of the limbic system. Considering basal GnRH-ir in vehicle treated group as 100%, the increase in GnRH-ir after haloperidol treatment was by 100.98% in the medial septum; 54.26% in the bed nucleus of the stria terminalis; 1152.85% in the anteroventral periventricular nucleus; 120.79% in the preoptic area-organum vasculosum of the lamina terminalis and 138.82% in the arcuate nucleus. Antide did not influence basal and haloperidol induced increase in GnRH-ir in any of the regions. As significant increase in GnRH-ir after haloperidol treatment was observed in such regions of the brain which are reported to directly or indirectly communicate with the hippocampus and basal

  5. [Protective effect of GnRH analogues on the reproductive capacity of women with neoplasia or autoimmune disease who require chemotherapy. Final results of a phase ii clinical trial].

    Science.gov (United States)

    Gris-Martínez, José M; Trillo-Urrutia, Lourdes; Gómez-Cabeza, Juan José; Encabo-Duró, Gloria

    2016-02-05

    In order to avoid the toxic effect of chemotherapy, it has been proposed to use GnRH agonist analogues (GnRHa) to inhibit the depletion of ovarian follicles. Nevertheless, there is controversy about its effectiveness. This clinical trial has been conducted with the aim to assess the protective effect of GnRH analogues on the reproductive capacity of women with malignancies or autoimmune diseases, which require chemotherapy. Open phase ii single-center clinical trial. During chemotherapy, a total of 5 doses of GnRH antagonist analogue at a dose interval of 3 days and/or a monthly dose of GnRHa were administered. Hormonal determinations prior to the start of the CT treatment were conducted during treatment and at the end of it. The inclusion of patients was prematurely concluded when incorporating the determination of anti-Müllerian hormone (AMH) as a parameter for assessing the ovarian reserve. Out of 38 patients, 23 (60.5%, 95%CI 43.4-76.0) had AMH values below normal following completion of treatment. An intermediate analysis was carried out observing that while most patients were recovering the menstrual cycle (86.6% 95%CI 71.9-95.6), they had reduced levels of AMH. Although most patients recovered their menstrual cycles, the ovarian reserve, assessed by the concentration of AMH, decreased in many patients. Therefore, we can conclude that the concomitant treatment of chemotherapy and GnRH analogues does not preserve the loss of follicular ovarian reserve. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  6. Hormones

    Science.gov (United States)

    Hormones are your body's chemical messengers. They travel in your bloodstream to tissues or organs. They work ... glands, which are special groups of cells, make hormones. The major endocrine glands are the pituitary, pineal, ...

  7. Hedgehog-PKA signaling and gnrh3 regulate the development of zebrafish gnrh3 neurons.

    Directory of Open Access Journals (Sweden)

    Ming-Wei Kuo

    Full Text Available GnRH neurons secrete GnRH that controls the development of the reproduction system. Despite many studies, the signals controlling the development of GnRH neurons from its progenitors have not been fully established. To understand the development of GnRH neurons, we examined the development of gnrh3-expressing cells using a transgenic zebrafish line that expresses green fluorescent protein (GFP and LacZ driven by the gnrh3 promoter. GFP and LacZ expression recapitulated that of gnrh3 in the olfactory region, olfactory bulb and telencephalon. Depletion of gnrh3 by morpholinos led to a reduction of GFP- and gnrh3-expressing cells, while over-expression of gnrh3 mRNA increased the number of these cells. This result indicates a positive feed-forward regulation of gnrh3 cells by gnrh3. The gnrh3 cells were absent in embryos that lack Hedgehog signaling, but their numbers were increased in embryos overexpressing shhb. We manipulated the amounts of kinase that antagonizes the Hedgehog signaling pathway, protein kinase A (PKA, by treating embryos with PKA activator forskolin or by injecting mRNAs encoding its constitutively active catalytic subunit (PKA* and dominant negative regulatory subunit (PKI into zebrafish embryos. PKA* misexpression or forskolin treatment decreased GFP cell numbers, while PKI misexpression led to ectopic production of GFP cells. Our data indicate that the Hedgehog-PKA pathway participates in the development of gnrh3-expressing neurons during embryogenesis.

  8. Minimal stimulation protocol using letrozole versus microdose flare up GnRH agonist protocol in women with poor ovarian response undergoing ICSI.

    Science.gov (United States)

    Mohsen, Iman Abdel; El Din, Rasha Ezz

    2013-02-01

    To compare the IVF outcomes of letrozole/antagonist and microdose GnRH agonist flare up protocols in poor ovarian responders undergoing intracytoplasmic sperm injection. A randomized controlled trial was performed in patients with one or more previous failed IVF cycles in which four or less oocytes were retrieved when the gonadotrophin starting dose was at least 300 IU/day. Sixty patients were randomized by computer-generated list to receive either letrozole/antagonist (mild stimulation) n = 30 or GnRH-a protocol (microdose flare) n = 30. Both groups were similar with respect to background and hormonal characteristics (age, duration of infertility, BMI, FSH, LH and E2). The clinical pregnancy rate per cycle was similar in both groups (13.3 vs. 16.6%; OR = 0.769; 95% CI = 0.185, 3.198). The doses of used gonadotropins and the number of stimulation days were significantly lower in the letrozole/antagonist protocol. The peak E2 level on the day of hCG, the endometrial thickness, the retrieved oocytes, the number of fertilized oocytes, the number of transferred embryos and the cancellation rate were statistically similar in both groups. The letrozole/antagonist protocol is a cost-effective and patient-friendly protocol that may be used in poor ovarian responders for IVF/ICSI.

  9. Impact of GnRH analogues on oocyte/embryo quality and embryo development in in vitro fertilization/intracytoplasmic sperm injection cycles: a case control study

    Directory of Open Access Journals (Sweden)

    Rigó János

    2009-09-01

    Full Text Available Abstract Background Despite the clinical outcomes of ovarian stimulation with either GnRH-agonist or GnRH-antagonist analogues for in vitro fertilization (IVF being well analysed, the effect of analogues on oocyte/embryo quality and embryo development is still not known in detail. The aim of this case-control study was to compare the efficacy of a multiple-dose GnRH antagonist protocol with that of the GnRH agonist long protocol with a view to oocyte and embryo quality, embryo development and IVF treatment outcome. Methods Between October 2001 and December 2008, 100 patients were stimulated with human menopausal gonadotrophin (HMG and GnRH antagonist in their first treatment cycle for IVF or intracytoplasmic sperm injection (ICSI. One hundred combined GnRH agonist + HMG (long protocol cycles were matched to the GnRH antagonist + HMG cycles by age, BMI, baseline FSH levels and by cause of infertility. We determined the number and quality of retrieved oocytes, the rate of early-cleavage embryos, the morphology and development of embryos, as well as clinical pregnancy rates. Statistical analysis was performed using Wilcoxon's matched pairs rank sum test and McNemar's chi-square test. P Results The rate of cytoplasmic abnormalities in retrieved oocytes was significantly higher with the use of GnRH antagonist than in GnRH agonist cycles (62.1% vs. 49.9%; P Conclusion Antagonist seemed to influence favourably some parameters of early embryo development dynamics, while other morphological parameters seemed not to be altered according to GnRH analogue used for ovarian stimulation in IVF cycles.

  10. GnRH Neurons on LSD: A Year of Rejecting Hypotheses That May Have Made Karl Popper Proud.

    Science.gov (United States)

    Moenter, Suzanne M

    2018-01-01

    Gonadotropin-releasing hormone (GnRH) neurons are critical to many aspects of fertility regulation, from producing episodic release critical to both sexes, to providing a central signal to induce the ovulatory cascade in females. This year saw progress through the rejection, and occasional support, of hypotheses in understanding how GnRH neurons contribute to these processes. This brief review provides one laboratory's view of new insights into possible roles for these cells in development, adult reproductive function, and what may go wrong with GnRH neurons in some cases of infertility. Copyright © 2018 Endocrine Society.

  11. Action of Specific Thyroid Hormone Receptor alpha(1) and beta(1) Antagonists in the Central and Peripheral Regulation of Thyroid Hormone Metabolism in the Rat

    NARCIS (Netherlands)

    van Beeren, Hermina C.; Kwakkel, Joan; Ackermans, Mariëtte T.; Wiersinga, Wilmar M.; Fliers, Eric; Boelen, Anita

    2012-01-01

    Background: The iodine-containing drug amiodarone (Amio) and its noniodine containing analogue dronedarone (Dron) are potent antiarrhythmic drugs. Previous in vivo and in vitro studies have shown that the major metabolite of Amio, desethylamiodarone, acts as a thyroid hormone receptor (TR) alpha(1)

  12. Receptors for luteinizing hormone-releasing hormone (LHRH) in benign prostatic hyperplasia (BPH) as potential molecular targets for therapy with LHRH antagonist cetrorelix.

    Science.gov (United States)

    Rozsa, Bernadett; Nadji, Mehrdad; Schally, Andrew V; Dezso, Balazs; Flasko, Tibor; Toth, Gyorgy; Mile, Melinda; Block, Norman L; Halmos, Gabor

    2011-04-01

    The majority of men will develop symptoms of benign prostatic hyperplasia (BPH) after 70 years of age. Various studies indicate that antagonists of LHRH, such as cetrorelix, exert direct inhibitory effects on BPH mediated by specific LHRH receptors. Our aim was to investigate the mRNA for LHRH and LHRH receptors and the expression of LHRH receptors in specimens of human BPH. The expression of mRNA for LHRH (n=35) and LHRH receptors (n=55) was investigated by RT-PCR in surgical specimens of BPH, using specific primers. The characteristics of binding sites for LHRH on 20 samples were determined by ligand competition assays. The LHRH receptor expression was also examined in 64 BPH specimens by immunohistochemistry. PCR products for LHRH were found in 18 of 35 (51%) BPH tissues and mRNA for LHRH receptors was detected in 39 of 55 (71%) BPH specimens. Eighteen of 20 (90%) samples showed a single class of high affinity binding sites for [D-Trp(6) ]LHRH with a mean K(d) of 4.04 nM and a mean B(max) of 527.6 fmol/mg membrane protein. LHRH antagonist cetrorelix showed high affinity binding to LHRH receptors in BPH. Positive immunohistochemical reaction for LHRH receptors was present in 42 of 64 (67%) BPH specimens. A high incidence of LHRH receptors in BPH supports the use of LHRH antagonists such as cetrorelix, for treatment of patients with lower urinary tract symptoms from BPH. Copyright © 2010 Wiley-Liss, Inc.

  13. FSH inhibits the augmentation by oestradiol of the pituitary responsiveness to GnRH in the female rat

    NARCIS (Netherlands)

    Schuiling, GA; Valkhof, N; Koiter, TR

    The effect of follicle stimulating hormone (FSH) treatment on the pituitary response to gonadotrophin-releasing hormone (GnRH) was studied in rats in various reproductive conditions. A 3-day treatment of cycling rats with FSH (Metrodin(R); 10 IU/injection) lowered the spontaneous pre-ovulatory

  14. In vitro regulation of LH biosynthesis and release by GnRH and estradiol

    International Nuclear Information System (INIS)

    Ramey, J.W.

    1986-01-01

    Anterior pituitaries were taken from female rats at random stages of the estrous cycle, enzymatically dispersed, and cultured for 48h in steroid-free α-modified Eagles medium followed by 24h in fresh medium +/- estradiol (E 2 ). The pituitary cells were then incubated in fresh medium containing radiolabeled precursors +/- gonadotropin releasing hormone (GnRH). Radioactive precursor incorporation into LH was determined by immuno-precipitation. The dose-dependent effects of E 2 (10 -11 to 10 -8 M) on 3 H-glucosamine ( 3 H-Gln) and 35 S-methionine ( 35 S-Met) incorporation into LH +/- 1 nM GnRH (4h) were investigated. GnRH (10 -9 M) and E 2 (all doses) significantly increased total 3 H-Gln LH. Moreover, E 2 at 10 -9 M and 10 -8 M significantly enhanced GnRH stimulated LH glycosylation. In contrast, addition of GnRH and/or E 2 did not significantly increase 35 S-Met incorporation into LH over a 4h period. The effects of various GnRH concentrations (10 -11 to 10 -9 M; 8h) +/- E 2 (0.05 nM) on 3 H-Gln LH and 35 S-Met LH production were also investigated. In the absence of E 2 , only 10 -9 M GnRH was effective in increasing total 3 H-Gln LH and 35 S-Met LH synthesis. However, in the presence of E 2 , all concentrations of GnRH stimulated LH synthesis with 3 H-Gln LH production responding in a dose related manner whereas 35 S-Met LH production was maximally stimulated at all doses of GnRH. In the final series of experiments, pituitary cells previously exposed to estradiol were incubated for 4 h in normal calcium or low calcium medium containing 3 H-Gln or 35 S-Met +/- GnRH. Removal of extracellular calcium completely inhibited GnRH stimulated 3 H-Gln LH and 35 S-Met LH production

  15. Development of a radioimmunoassay for circulating levels of gonadotropin releasing hormone

    International Nuclear Information System (INIS)

    Moodbidri, S.B.; Joshi, L.R.; Sheth, A.R.; Rao, S.S.

    1976-01-01

    A specific and sensitive radioimmunoassay system has been developed for measuring gonadotropin releasing hormone (GnRH) in unextracted human serum. Circulating levels of GnRH, LH and FSH were determined in 37 serum samples obtained from twenty normal healthy women on different days of the menstrual cycle. GnRH and LH but not FSH exhibited similar patterns during the menstrual cycle. 125 I-labelled GnRH was used in the RIA system. (author)

  16. Growth hormone (GH) activity is associated with increased serum oestradiol and reduced Anti-Müllerian Hormone in healthy male volunteers treated with GH and a GH antagonist

    DEFF Research Database (Denmark)

    Andreassen, M; Frystyk, Jan; Faber, J

    2013-01-01

    Growth hormone (GH) and insulin-like growth factor I (IGF-I) receptors are present on pituitary gonadotrophs and on testicular Leydig and Sertoli cells. Thus, the GH/IGF-I system may modulate the pituitary-gonadal axis in males. This is a randomized cross-over study. Eight healthy male volunteers...... (160-290) vs. 106 (97-157) μg/L, p = 0.001) and oestradiol (86 ± 28 vs. 79 ± 25 pm, p = 0.060) decreased. No significant changes or trends in the other reproductive hormones occurred during the two treatment regimens. GH/IGF-I activity was positively associated with serum oestradiol, suggesting that GH...

  17. Dynamic GnRH and hCG testing

    DEFF Research Database (Denmark)

    Bang, A. Kirstine; Nordkap, Loa; Almstrup, Kristian

    2017-01-01

    OBJECTIVE: Gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) stimulation tests may be used to evaluate the pituitary and testicular capacity. Our aim was to evaluate changes in follicular-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone after Gn...... influence of the tests was illustrated by results from 45 patients suspected of disordered hypothalamic-pituitary-gonadal axis. METHODS: Baseline, stimulated, relative and absolute changes in serum FSH and LH were determined by ultrasensitive TRIFMA, and testosterone was determined by LC-MS/MS. RESULTS......: For the reference group, LH and FSH increased almost 400% and 40% during GnRH testing, stimulated levels varied from 4.4 to 58.8 U/L and 0.2 to 11.8 U/L and FSH decreased in nine men. Testosterone increased approximately 110% (range: 18.7-67.6 nmol/L) during hCG testing. None of the polymorphisms had any major...

  18. Pulsatile luteinising hormone releasing hormone for ovulation induction in subfertility associated with polycystic ovary syndrome

    NARCIS (Netherlands)

    Bayram, N.; van Wely, M.; Vandekerckhove, P.; Lilford, R.; van der Veen, F.

    2000-01-01

    BACKGROUND: In normal menstrual cycles, gonadotrophin releasing hormone (GnRH) secretion is pulsatile, with intervals of 60-120 minutes in the follicular phase. Treatment with pulsatile GnRH infusion by the intra-venous or subcutaneous route using a portable pump has been used successfully in

  19. Endocannabinoids and Endovanilloids: A Possible Balance in the Regulation of the Testicular GnRH Signalling

    Directory of Open Access Journals (Sweden)

    Rosanna Chianese

    2013-01-01

    Full Text Available Reproductive functions are regulated both at central (brain and gonadal levels. In this respect, the endocannabinoid system (eCS has a very influential role. Interestingly, the characterization of eCS has taken many advantages from the usage of animal models different from mammals. Therefore, this review is oriented to summarize the main pieces of evidence regarding eCS coming from the anuran amphibian Rana esculenta, with particular interest to the morphofunctional relationship between eCS and gonadotropin releasing hormone (GnRH. Furthermore, a novel role for endovanilloids in the regulation of a testicular GnRH system will be also discussed.

  20. The influence of exogenous progestin on the occurrence of proestrous or estrous signs, plasma concentrations of luteinizing hormone and estradiol in deslorelin (GnRH agonist) treated anestrous bitches.

    Science.gov (United States)

    Sung, M; Armour, A F; Wright, P J

    2006-10-01

    The objectives of this study were to confirm: (i) whether progestin treatment suppressed GnRH agonist-induced estrus in anestrous greyhound bitches; and (ii) the site of progestin action (i.e. pituitary, ovary). All bitches received a deslorelin implant on Day 0 and blood samples were taken from -1 h to +6 h. Five bitches were treated with megestrol acetate (2 mg/kg orally once daily) from -7 d to +6 d (Group 1) and 10 bitches were untreated controls (Group 2). Proestrous or estrous signs were observed in 4 of 5 bitches in Group 1, and 4 of 10 bitches in Group 2 (P = 0.28). The plasma LH responses (area under the curve from 0 to 6h after implantation) were higher (P = 0.008) in Group 2 than in Group 1. Plasma LH responses were similar (P = 0.59) in bitches showing signs of proestrus or estrus (responders) and in non-responders. The plasma estradiol responses (calculated as for LH response) were greater in Group 1 than in Group 2 (P = 0.048), and in responders than in non-responders (P = 0.02). (i) progestin treatment (a) did not suppress the incidence of bitches showing deslorelin-induced proestrus or estrus, and (b) was associated with a reduced pituitary responsiveness and an increased ovarian responsiveness to deslorelin treatment; (ii) the occurrence of proestrous or estrous signs reflected increased ovarian responsiveness to induced gonadotrophin secretion and not increased pituitary responsiveness to deslorelin.

  1. Genetic polymorphisms of the GNRH1 and GNRHR genes and risk of breast cancer in the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3

    Directory of Open Access Journals (Sweden)

    Lund Eiliv

    2009-07-01

    Full Text Available Abstract Background Gonadotropin releasing hormone (GNRH1 triggers the release of follicle stimulating hormone and luteinizing hormone from the pituitary. Genetic variants in the gene encoding GNRH1 or its receptor may influence breast cancer risk by modulating production of ovarian steroid hormones. We studied the association between breast cancer risk and polymorphisms in genes that code for GNRH1 and its receptor (GNRHR in the large National Cancer Institute Breast and Prostate Cancer Cohort Consortium (NCI-BPC3. Methods We sequenced exons of GNRH1 and GNRHR in 95 invasive breast cancer cases. Resulting single nucleotide polymorphisms (SNPs were genotyped and used to identify haplotype-tagging SNPs (htSNPS in a panel of 349 healthy women. The htSNPs were genotyped in 5,603 invasive breast cancer cases and 7,480 controls from the Cancer Prevention Study-II (CPS-II, European Prospective Investigation on Cancer and Nutrition (EPIC, Multiethnic Cohort (MEC, Nurses' Health Study (NHS, and Women's Health Study (WHS. Circulating levels of sex steroids (androstenedione, estradiol, estrone and testosterone were also measured in 4713 study subjects. Results Breast cancer risk was not associated with any polymorphism or haplotype in the GNRH1 and GNRHR genes, nor were there any statistically significant interactions with known breast cancer risk factors. Polymorphisms in these two genes were not strongly associated with circulating hormone levels. Conclusion Common variants of the GNRH1 and GNRHR genes are not associated with risk of invasive breast cancer in Caucasians.

  2. Genetic polymorphisms of the GNRH1 and GNRHR genes and risk of breast cancer in the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3)

    International Nuclear Information System (INIS)

    Canzian, Federico; Calle, Eugenia E; Chanock, Stephen; Clavel-Chapelon, Francoise; Dossus, Laure; Feigelson, Heather Spencer; Haiman, Christopher A; Hankinson, Susan E; Hoover, Robert; Hunter, David J; Isaacs, Claudine; Kaaks, Rudolf; Lenner, Per; Lund, Eiliv; Overvad, Kim; Palli, Domenico; Pearce, Celeste Leigh; Quiros, Jose R; Riboli, Elio; Stram, Daniel O; Thomas, Gilles; Thun, Michael J; Cox, David G; Trichopoulos, Dimitrios; Gils, Carla H van; Ziegler, Regina G; Henderson, Katherine D; Henderson, Brian E; Berg, Christine; Bingham, Sheila; Boeing, Heiner; Buring, Julie

    2009-01-01

    Gonadotropin releasing hormone (GNRH1) triggers the release of follicle stimulating hormone and luteinizing hormone from the pituitary. Genetic variants in the gene encoding GNRH1 or its receptor may influence breast cancer risk by modulating production of ovarian steroid hormones. We studied the association between breast cancer risk and polymorphisms in genes that code for GNRH1 and its receptor (GNRHR) in the large National Cancer Institute Breast and Prostate Cancer Cohort Consortium (NCI-BPC3). We sequenced exons of GNRH1 and GNRHR in 95 invasive breast cancer cases. Resulting single nucleotide polymorphisms (SNPs) were genotyped and used to identify haplotype-tagging SNPs (htSNPS) in a panel of 349 healthy women. The htSNPs were genotyped in 5,603 invasive breast cancer cases and 7,480 controls from the Cancer Prevention Study-II (CPS-II), European Prospective Investigation on Cancer and Nutrition (EPIC), Multiethnic Cohort (MEC), Nurses' Health Study (NHS), and Women's Health Study (WHS). Circulating levels of sex steroids (androstenedione, estradiol, estrone and testosterone) were also measured in 4713 study subjects. Breast cancer risk was not associated with any polymorphism or haplotype in the GNRH1 and GNRHR genes, nor were there any statistically significant interactions with known breast cancer risk factors. Polymorphisms in these two genes were not strongly associated with circulating hormone levels. Common variants of the GNRH1 and GNRHR genes are not associated with risk of invasive breast cancer in Caucasians

  3. Effect of endotoxin on the expression of GnRH and GnRHR genes in the hypothalamus and anterior pituitary gland of anestrous ewes.

    Science.gov (United States)

    Herman, Andrzej Przemysław; Tomaszewska-Zaremba, Dorota

    2010-07-01

    An immune/inflammatory challenge can affect reproduction at the level of the hypothalamus, pituitary gland, or gonads. Nonetheless, the major impact is thought to occur within the brain or the pituitary gland. The present study was designed to examine the effect of intravenous (i.v.) lipopolysaccharide (LPS) injection on the expression of gonadotropin-releasing hormone (GnRH) and the gonadotropin-releasing hormone receptor (GnRHR) genes in the hypothalamic structures where GnRH neurons are located as well as in the anterior pituitary gland (AP) of anestrous ewes. We also determined the effect of LPS on luteinizing hormone (LH) release. It was found that i.v. LPS injection significantly decreased GnRH and GnRHR mRNAs levels in the preoptic area (40%, ppituitary cells to GnRH stimulation. The presence of GnRH mRNA in the median eminence, the hypothalamic structure where GnRH-ergic neurons' terminals are located, suggests that the axonal transport of GnRH mRNA may occur in these neurons. This phenomenon could play an important role in the physiology of GnRH neurons. Our data demonstrate that immune stress could be important inhibitor of this process. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Transcriptome analysis of endometrial tissues following GnRH agonist treatment in a mouse adenomyosis model

    Directory of Open Access Journals (Sweden)

    Guo S

    2017-03-01

    Full Text Available Song Guo,1,* Xiaowei Lu,1,* Ruihuan Gu,2 Di Zhang,3 Yijuan Sun,2 Yun Feng1 1Department of Obstetrics and Gynecology, Reproductive Medicine Center, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China; 2Gynecology, Shanghai Ji Ai Genetics & In Vitro Fertilization Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, People’s Republic of China; 3Department of Gynecology and Obstetrics, Jinan Military General Hospital, Jinan, People’s Republic of China *These authors contributed equally to this work Purpose: Adenomyosis is a common, benign gynecological condition of the female reproductive tract characterized by heavy menstrual bleeding and dysmenorrhea. Gonadotropin-releasing hormone (GnRH agonists are one of the medications used in adenomyosis treatment; however, their underlying mechanisms are poorly understood. Moreover, it is difficult to obtain endometrial samples from women undergoing such treatment. To overcome this, we generated an adenomyosis mouse model, which we treated with an GnRH agonist to determine its effect on pregnancy outcomes. We also analyzed endometrial gene expression following GnRH agonist treatment to determine the mechanisms that may affect pregnancy outcome in individuals with adenomyosis.Methods: Neonatal female mice were divided into a control group, an untreated adenomyosis group, and an adenomyosis group treated with a GnRH agonist (n=6 each. The pregnancy outcome was observed and compared among the groups. Then, three randomly chosen transcriptomes from endometrial tissues from day 4 of pregnancy were analyzed between the adenomyosis group and the GnRH agonist treatment group by RNA sequencing and quantitative reverse transcription polymerase chain reaction (PCR.Results: The litter size was significantly smaller in the adenomyosis group than in the control group (7±0.28 vs 11±0.26; P<0.05. However, the average live litter

  5. Selective enhancement of main olfactory input to the medial amygdala by GnRH.

    Science.gov (United States)

    Blake, Camille Bond; Meredith, Michael

    2010-03-04

    In male hamsters mating behavior is dependent on chemosensory input from the main olfactory and vomeronasal systems, whose central pathways contain cell bodies and fibers of gonadotropin-releasing hormone (GnRH) neurons. In sexually naive males, vomeronasal organ removal (VNX), but not main olfactory lesions, impairs mating behavior. Intracerebroventricular (i.c.v.)-GnRH restores mating in sexually naive VNX males and enhances medial amygdala (Me) immediate-early gene activation by chemosensory stimulation. In sexually experienced males, VNX does not impair mating and i.c.v.-GnRH suppresses Me activation. Thus, the main olfactory system is sufficient for mating in experienced-VNX males, but not in naive-VNX males. We investigated the possibility that GnRH enhances main olfactory input to the amygdala in naive-VNX males using i.c.v.-GnRH and pharmacological stimulation (bicuculline/D,L-homocysteic acid mixture) of the main olfactory bulb (MOB). In sexually naive intact males there was a robust increase of Fos protein expression in the anteroventral medial amygdala (MeAv) with MOB stimulation, but no effect of GnRH. There was no effect of stimulation or GnRH in posterodorsal medial amygdala (MePd). In naive-VNX animals, GnRH increased Fos in MeAv and MePv. Only combined MOB stimulation and i.c.v.-GnRH produced a significant increase in Fos in the dorsal (reproduction-related) portion of MeP (MePd). When the animals were sexually experienced before VNX, a condition in which GnRH does not enhance mating, i.c.v.-GnRH combined with MOB stimulation suppressed Fos expression in MePd. This suggests a more selective effect of GnRH on olfactory input in MePd than elsewhere in medial amygdala of VNX males. 2009 Elsevier B.V. All rights reserved.

  6. Photoaffinity labeling of pituitary GnRH receptors: significance of the position of photolabel on the ligand

    International Nuclear Information System (INIS)

    Nikolics, K.; Szonyi, E.; Ramachandran, J.

    1988-01-01

    Photoreactive derivatives of GnRH and its analogues were prepared by incorporation of the 2-nitro-4(5)-azidophenylsulfenyl [2,4(5)-NAPS] group into amino acid residues at position 1, 3, 6, or 8 of the decapeptide sequence. The modification of Trp 3 by the 2,4-NAPS group led to a complete loss of the luteinizing hormone (LH) releasing as well as LH-release-inhibiting activity of the peptide. The [D-Lys(2,4-NAPS)] 6 analog was a very potent agonist that, after covalent attachment by photoaffinity labeling, caused prolonged LH secretion at a submaximal rate. [Orn(2,4-NAPS)] 8 -GnRH, a full agonist with a relative potency of 7% of GnRH, after photoaffinity labeling caused prolonged maximal LH release from cultured pituitary cells. In contrast, [Orn(2,5-NAPS)] 8 -GnRH, although being equipotent with the 2,4-NAPS isomer in terms of LH releasing ability, was unable to cause prolonged LH release after photoaffinity labeling. Thus, [Orn(2,4-NAPS)] 8 GnRH is very effective photolabeling ligand of the functionally significant pituitary GnRH receptor. Based on this compound, a pituitary peptidase resistant derivative, D-Phe 6 , [Orn(2,4-NAPS)] 8 -GnRH-(1-9)-ethylamide, was synthesized. This derivative showed high-affinity binding to pituitary membranes with a K/sub d/ comparable to those of other GnRH analogues. A radioiodinated form of this peptide was used for pituitary GnRH-receptor labeling. This derivative labeled 59- and 57-kDa proteins in rat and 58- and 56-kDa proteins in bovine pituitary membrane preparations, respectively. This peptide also labeled pituitary GnRH receptors in the solubilized state and therefore appears to be a suitable ligand for the isolation and further characterization of the receptor

  7. [Effectiveness and safety of pulsatile GnRH pump therapy on female patients with IHH].

    Science.gov (United States)

    Liu, Zhaoxiang; Mao, Jiangfeng; Wu, Xueyan; Nie, Min; Huang, Bingkun; Xu, Hongli; Wang, Xi; Zheng, Junjie

    2015-11-10

    To investigate the therapeutic effect of pulsatile GnRH (gonadorelin) pump on female patients with idiopathic hypogonadotropic hypogonadism (IHH). In this retrospective study, five female IHH patients were recruited. Patients were treated with pulsatile gonadorelin (10 µg per 90 min) via a pump for at least 12 weeks. Serum gonadotropins and sex steroid levels were measured, and menses were recorded. After one-week treatment, luteinizing hormone (LH) level increased from (2.2 ± 2.0) U/L to (5.4 ± 2.5) U/L (P=0.028), follicle-stimulating hormone(FSH) level increased from (3.7 ± 2.7) U/L to(6.3 ± 1.0) U/L (P=0.162), and estradiol (E2) level increased from (58 ± 13) pmol/L to (260 ± 97) pmol/L (P=0.011). Menstrual bleeding was observed in 4 patients after starting treatment for 35-55 days and two natural pregnancies were reported. No menstrual bleeding was reported in another patient. The frequency of pulsatile GnRH had to be adjusted according to endogenous GnRH secretion during the follicular phase of normal women and regular menses were induced. Pulsatile GnRH is effective in treating female IHH. A constant frequency of pulsatile GnRH is suitable for most of IHH patients. However, for those who failed to produce regular menses, adjusting pulsatile frequency to imitate the physiological rhythm of GnRH may be an alternative option.

  8. Cost-effectiveness comparison between pituitary down-regulation with a gonadotropin-releasing hormone agonist short regimen on alternate days and an antagonist protocol for assisted fertilization treatments.

    Science.gov (United States)

    Maldonado, Luiz Guilherme Louzada; Franco, José Gonçalves; Setti, Amanda Souza; Iaconelli, Assumpto; Borges, Edson

    2013-05-01

    To compare cost-effectiveness between pituitary down-regulation with a GnRH agonist (GnRHa) short regimen on alternate days and GnRH antagonist (GnRHant) multidose protocol on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcome. Prospective, randomized. A private center. Patients were randomized into GnRHa (n = 48) and GnRHant (n = 48) groups. GnRHa stimulation protocol: administration of triptorelin on alternate days starting on the first day of the cycle, recombinant FSH (rFSH), and recombinant hCG (rhCG) microdose. GnRHant protocol: administration of a daily dose of rFSH, cetrorelix, and rhCG microdose. ICSI outcomes and treatment costs. A significantly lower number of patients underwent embryo transfer in the GnRHa group. Clinical pregnancy rate was significantly lower and miscarriage rate was significantly higher in the GnRHa group. It was observed a significant lower cost per cycle in the GnRHa group compared with the GnRHant group ($5,327.80 ± 387.30 vs. $5,900.40 ± 472.50). However, mean cost per pregnancy in the GnRHa was higher than in the GnRHant group ($19,671.80 ± 1,430.00 vs. $11,328.70 ± 907.20). Although the short controlled ovarian stimulation protocol with GnRHa on alternate days, rFSH, and rhCG microdose may lower the cost of an individual IVF cycle, it requires more cycles to achieve pregnancy. NCT01468441. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  9. Validation of serum IGF-I as a biomarker to monitor the bioactivity of exogenous growth hormone agonists and antagonists in rabbits

    Science.gov (United States)

    Bielohuby, Maximilian; Zarkesh-Esfahani, Sayyed Hamid; Manolopoulou, Jenny; Wirthgen, Elisa; Walpurgis, Katja; Toghiany Khorasgani, Mohaddeseh; Aghili, Zahra Sadat; Wilkinson, Ian Robert; Hoeflich, Andreas; Thevis, Mario; Ross, Richard J.; Bidlingmaier, Martin

    2014-01-01

    The development of new growth hormone (GH) agonists and growth hormone antagonists (GHAs) requires animal models for pre-clinical testing. Ideally, the effects of treatment are monitored using the same pharmacodynamic marker that is later used in clinical practice. However, intact rodents are of limited value for this purpose because serum IGF-I, the most sensitive pharmacodynamic marker for the action of GH in humans, shows no response to treatment with recombinant human GH and there is little evidence for the effects of GHAs, except when administered at very high doses or when overexpressed. As an alternative, more suitable model, we explored pharmacodynamic markers of GH action in intact rabbits. We performed the first validation of an IGF-I assay for the analysis of rabbit serum and tested precision, sensitivity, linearity and recovery using an automated human IGF-I assay (IDS-iSYS). Furthermore, IGF-I was measured in rabbits of different strains, age groups and sexes, and we monitored IGF-I response to treatment with recombinant human GH or the GHA Pegvisomant. For a subset of samples, we used LC-MS/MS to measure IGF-I, and quantitative western ligand blot to analyze IGF-binding proteins (IGFBPs). Although recovery of recombinant rabbit IGF-I was only 50% in the human IGF-I assay, our results show that the sensitivity, precision (1.7–3.3% coefficient of variation) and linearity (90.4–105.6%) were excellent in rabbit samples. As expected, sex, age and genetic background were major determinants of IGF-I concentration in rabbits. IGF-I and IGFBP-2 levels increased after single and multiple injections of recombinant human GH (IGF-I: 286±22 versus 434±26 ng/ml; PIGF-I levels from the fourth injection onwards (PIGF-I immunoassay can be used in rabbits. Similar to rodents, rabbits display variations in IGF-I depending on sex, age and genetic background. Unlike in rodents, the IGF-I response to treatment with recombinant human GH or a GHA closely mimics the

  10. Glucosensing by GnRH Neurons: Inhibition by Androgens and Involvement of AMP-Activated Protein Kinase

    Science.gov (United States)

    Roland, Alison V.

    2011-01-01

    GnRH neurons integrate steroidal and metabolic cues to regulate fertility centrally. Central glucoprivation reduces LH secretion, which is governed by GnRH release, suggesting GnRH neuron activity is modulated by glucose availability. Here we tested whether GnRH neurons can sense changes in extracellular glucose, and whether glucosensing is altered by the steroids dihydrotestosterone (DHT) and/or estradiol (E). Extracellular recordings were made from GnRH neurons in brain slices from ovariectomized (OVX) mice ± DHT and/or E implants. Firing rate was reduced by a switch from 4.5 to 0.2 mm glucose in cells from OVX, OVX+E, and OVX+DHT+E mice, but not OVX+DHT mice. This suggests that androgens reduce the sensitivity of GnRH neurons to changes in extracellular glucose, but E mitigates this effect. Next we investigated potential mechanisms. In the presence of the ATP-sensitive potassium channel antagonist tolbutamide, glucosensing persisted. In contrast, glucosensing was attenuated in the presence of compound C, an antagonist of AMP-activated protein kinase (AMPK), suggesting a role for AMPK in glucosensing. The AMPK activator N1-(b-d-ribofuranosyl)-5-aminoimidazole-4-carboxamide (AICAR) mimicked the effect of low glucose and was less effective in cells from DHT-treated mice. The effect of DHT to diminish responses to low glucose and AICAR was abolished by blockade of fast synaptic transmission. Both AICAR and low glucose activated a current with a reversal potential near −50 mV, suggesting a nonspecific cation current. These studies indicate that glucosensing is one mechanism by which GnRH neurons sense fuel availability and point to a novel role for AMPK in the central regulation of fertility. PMID:21393446

  11. Prenatal androgen excess enhances stimulation of the GNRH pulse in pubertal female rats.

    Science.gov (United States)

    Yan, Xiaonan; Yuan, Chun; Zhao, Nannan; Cui, Yugui; Liu, Jiayin

    2014-07-01

    In adolescent girls with polycystic ovary syndrome (PCOS), neuroendocrine derangements manifest after the onset of puberty, characterized by rapid LH pulse frequency. The early mechanism underlying the pubertal regulation of the GNRH/LH pulsatile release in adolescents with PCOS remains uncertain. To determine the effects of prenatal androgen exposure on the activation of GNRH neurons and generation of LH pulse at puberty, we administrated 5α-dihydrotestosterone to pregnant rats and observed serum LH levels and expression of hypothalamic genes in female offspring from postnatal 4 to 8 weeks. The 6-week-old prenatally androgenized (PNA) female rats exhibited an increase in LH pulse frequency. The hypothalamic expression of neurokinin B (Nkb (Tac2)) and Lepr mRNA levels in PNA rats increased remarkably before puberty and remained high during puberty, whereas elevated Kiss1 mRNA levels were detected only after the onset of puberty. Exogenous kisspeptin, NK3R agonist, and leptin triggered tonic stimulation of GNRH neurons and increased LH secretion in 6-week-old PNA rats. Leptin upregulated Kiss1 mRNA levels in the hypothalamus of pubertal PNA rats; however, pretreatment with a kisspeptin antagonist failed to suppress the elevated serum LH stimulated by leptin, indicating that the stimulatory effects of leptin may be conveyed indirectly to GNRH neurons via other neural components within the GNRH neuronal network, rather than through the kisspeptin-GPR54 pathway. These findings validate the hypotheses that NKB and leptin play an essential role in the activation of GNRH neurons and initiation of increased LH pulse frequency in PNA female rats at puberty and that kisspeptin may coordinate their stimulatory effects on LH release. © 2014 Society for Endocrinology.

  12. Morphological and Physiological Interactions Between GnRH3 and Hypocretin/Orexin Neuronal Systems in Zebrafish (Danio rerio).

    Science.gov (United States)

    Zhao, Yali; Singh, Chanpreet; Prober, David A; Wayne, Nancy L

    2016-10-01

    GnRH neurons integrate internal and external cues to control sexual maturation and fertility. Homeostasis of energy balance and food intake correlates strongly with the status of reproduction. Neuropeptides secreted by the hypothalamus involved in modulating energy balance and feeding may play additional roles in the regulation of reproduction. Hypocretin (Hcrt) (also known as orexin) is one such peptide, primarily controlling sleep/wakefulness, food intake, and reward processing. There is a growing body of evidence indicating that Hcrt/orexin (Hcrt) modulates reproduction through interacting with the hypothalamo-pituitary-gonadal axis in mammals. To explore potential morphological and functional interactions between the GnRH and Hcrt neuronal systems, we employed a variety of experimental approaches including confocal imaging, immunohistochemistry, and electrophysiology in transgenic zebrafish, in which fluorescent proteins are genetically expressed in GnRH3 and Hcrt neurons. Our imaging data revealed close apposition and direct connection between GnRH3 and Hcrt neuronal systems in the hypothalamus during larval development through adulthood. Furthermore, the Hcrt receptor (HcrtR) is expressed in GnRH3 neurons. Electrophysiological data revealed a reversible inhibitory effect of Hcrt on GnRH3 neuron electrical activity, which was blocked by the HcrtR antagonist almorexant. In addition, Hcrt had no effect on the electrical activity of GnRH3 neurons in the HcrtR null mutant zebrafish (HcrtR -/- ). Our findings demonstrate a close anatomical and functional relationship between Hcrt and GnRH neuronal systems in zebrafish. It is the first demonstration of a link between neuronal circuits controlling sleeping/arousal/feeding and reproduction in zebrafish, an important animal model for investigating the molecular genetics of development.

  13. Mathematical modeling of gonadotropin-releasing hormone signaling.

    Science.gov (United States)

    Pratap, Amitesh; Garner, Kathryn L; Voliotis, Margaritis; Tsaneva-Atanasova, Krasimira; McArdle, Craig A

    2017-07-05

    Gonadotropin-releasing hormone (GnRH) acts via G-protein coupled receptors on pituitary gonadotropes to control reproduction. These are G q -coupled receptors that mediate acute effects of GnRH on the exocytotic secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as the chronic regulation of their synthesis. GnRH is secreted in short pulses and GnRH effects on its target cells are dependent upon the dynamics of these pulses. Here we overview GnRH receptors and their signaling network, placing emphasis on pulsatile signaling, and how mechanistic mathematical models and an information theoretic approach have helped further this field. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Stimulation of the young poor responder: comparison of the luteal estradiol/gonadotropin-releasing hormone antagonist priming protocol versus oral contraceptive microdose leuprolide.

    Science.gov (United States)

    Shastri, Shefali M; Barbieri, Elizabeth; Kligman, Isaac; Schoyer, Katherine D; Davis, Owen K; Rosenwaks, Zev

    2011-02-01

    To evaluate in vitro fertilization (IVF) cycle outcomes in young poor responders treated with a luteal estradiol/gonadotropin-releasing hormone antagonist (E(2)/ANT) protocol versus an oral contraceptive pill microdose leuprolide protocol (OCP-MDL). Retrospective cohort. Academic practice. Poor responders: 186 women, aged <35 years undergoing IVF with either E(2)/ANT or OCP-MDL protocols. None. Clinical pregnancies, oocytes retrieved, cancellation rate. Patients in the E(2)/ANT group had a greater gonadotropin requirement (71.9 ± 22.2 vs. 57.6 ± 25.7) and lower E(2) level (1,178.6 ± 668 vs. 1,627 ± 889), yet achieved similar numbers of oocytes retrieved and fertilized, and a greater number of embryos transferred (2.3 ± 0.9 vs. 2.0 ± 1.1) with a better mean grade (2.14 ± .06 vs. 2.7 ± 1.8) compared with the OCP/MDL group. The E2/ANT group exhibited a trend toward improved implantation rates (30.5% vs. 21.1%) and ongoing pregnancy rates per started cycle: 44 out of 117 (37%) versus 17 out of 69 (25%). Poor responders aged <35 years may be treated with the aggressive E(2)/ANT protocol to improve cycle outcomes. Both protocols remain viable options for this group. Adequately powered, randomized clinical comparison appears justified. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Translational Modeling to Guide Study Design and Dose Choice in Obesity Exemplified by AZD1979, a Melanin-concentrating Hormone Receptor 1 Antagonist.

    Science.gov (United States)

    Gennemark, P; Trägårdh, M; Lindén, D; Ploj, K; Johansson, A; Turnbull, A; Carlsson, B; Antonsson, M

    2017-07-01

    In this study, we present the translational modeling used in the discovery of AZD1979, a melanin-concentrating hormone receptor 1 (MCHr1) antagonist aimed for treatment of obesity. The model quantitatively connects the relevant biomarkers and thereby closes the scaling path from rodent to man, as well as from dose to effect level. The complexity of individual modeling steps depends on the quality and quantity of data as well as the prior information; from semimechanistic body-composition models to standard linear regression. Key predictions are obtained by standard forward simulation (e.g., predicting effect from exposure), as well as non-parametric input estimation (e.g., predicting energy intake from longitudinal body-weight data), across species. The work illustrates how modeling integrates data from several species, fills critical gaps between biomarkers, and supports experimental design and human dose-prediction. We believe this approach can be of general interest for translation in the obesity field, and might inspire translational reasoning more broadly. © 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  16. Usefulness of L-carnitine, a naturally occurring peripheral antagonist of thyroid hormone action, in iatrogenic hyperthyroidism: a randomized, double-blind, placebo-controlled clinical trial.

    Science.gov (United States)

    Benvenga, S; Ruggeri, R M; Russo, A; Lapa, D; Campenni, A; Trimarchi, F

    2001-08-01

    Old studies in animals and unblinded studies in a few hyperthyroid patients suggested that L -carnitine is a periferal antagonist of thyroid hormone action at least in some tissues. This conclusion was substantiated by our recent observation that carnitine inhibits thyroid hormone entry into the nucleus of hepatocytes, neurons, and fibroblasts. In the randomized, double-blind, placebo-controlled 6-month trial reported here, we assessed whether 2 or 4 g/d oral L-carnitine were able to both reverse and prevent/minimize nine hyperthyroidism- related symptoms. We also evaluated changes on nine thyroid hormone-sensitive biochemical parameters and on vertebral and hip mineral density (bone mineral density). Fifty women under a fixed TSH-suppressive dose of L -T(4) for all 6 months were randomly allocated to five groups of 10 subjects each. Group 0 associated placebo for 6 months; groups A2 and A4 started associating placebo (first bimester), substituted placebo with 2 or 4 g/d carnitine (second bimester), and then returned to the association with placebo. Groups B2 and B4 started associating 2 and 4 g/d carnitine for the first two bimesters, and then substituted carnitine with placebo (third bimester). Symptoms and biochemical parameters worsened in group 0. In group A, symptoms and biochemical parameters worsened during the first bimester, returned to baseline or increased minimally during the second bimester (except osteocalcin and urinary OH-proline), and worsened again in the third bimester. In group B, symptoms and biochemical parameters (except osteocalcin and urinary OH-proline) did not worsen or even improved over the first 4 months; they tended to worsen in the third bimester. In both the A and B groups, the two doses of carnitine were similarly effective. At the end of the trial, bone mineral density tended to increase in groups B and A (B > A). In conclusion, L-carnitine is effective in both reversing and preventing symptoms of hyperthyroidism and has a

  17. Melatonin Inhibits GnRH-1, GnRH-3 and GnRH Receptor Expression in the Brain of the European Sea Bass, Dicentrarchus labrax

    Directory of Open Access Journals (Sweden)

    José Antonio Muñoz-Cueto

    2013-04-01

    Full Text Available Several evidences supported the existence of melatonin effects on reproductive system in fish. In order to investigate whether melatonin is involved in the modulation of GnRH systems in the European sea bass, we have injected melatonin (0.5 µg/g body mass in male specimens. The brain mRNA transcript levels of the three GnRH forms and the five GnRH receptors present in this species were determined by real time quantitative PCR. Our findings revealed day–night variations in the brain expression of GnRH-1, GnRH-3 and several GnRH receptors (dlGnRHR-II-1c, -2a, which exhibited higher transcript levels at mid-light compared to mid-dark phase of the photocycle. Moreover, an inhibitory effect of melatonin on the nocturnal expression of GnRH-1, GnRH-3, and GnRH receptors subtypes 1c, 2a and 2b was also demonstrated. Interestingly, the inhibitory effect of melatonin affected the expression of hypophysiotrophic GnRH forms and GnRH receptors that exhibit day–night fluctuations, suggesting that exogenous melatonin reinforce physiological mechanisms already established. These interactions between melatoninergic and GnRH systems could be mediating photoperiod effects on reproductive and other rhythmic physiological events in the European sea bass.

  18. Administration of single-dose GnRH agonist in the luteal phase in ICSI cycles: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Oliveira João

    2010-09-01

    Full Text Available Abstract Background The effects of gonadotrophin-releasing hormone agonist (GnRH-a administered in the luteal phase remains controversial. This meta-analysis aimed to evaluate the effect of the administration of a single-dose of GnRH-a in the luteal phase on ICSI clinical outcomes. Methods The research strategy included the online search of databases. Only randomized studies were included. The outcomes analyzed were implantation rate, clinical pregnancy rate (CPR per transfer and ongoing pregnancy rate. The fixed effects model was used for odds ratio. In all trials, a single dose of GnRH-a was administered at day 5/6 after ICSI procedures. Results All cycles presented statistically significantly higher rates of implantation (P Conclusions These findings demonstrate that the luteal-phase single-dose GnRH-a administration can increase implantation rate in all cycles and CPR per transfer and ongoing pregnancy rate in cycles with GnRH antagonist ovarian stimulation protocol. Nevertheless, by considering the heterogeneity between the trials, it seems premature to recommend the use of GnRH-a in the luteal phase. Additional randomized controlled trials are necessary before evidence-based recommendations can be provided.

  19. In silico and in situ characterization of the zebrafish (Danio rerio gnrh3 (sGnRH gene

    Directory of Open Access Journals (Sweden)

    Husebye Harald

    2002-08-01

    Full Text Available Abstract Background Gonadotropin releasing hormone (GnRH is responsible for stimulation of gonadotropic hormone (GtH in the hypothalamus-pituitary-gonadal axis (HPG. The regulatory mechanisms responsible for brain specificity make the promoter attractive for in silico analysis and reporter gene studies in zebrafish (Danio rerio. Results We have characterized a zebrafish [Trp7, Leu8] or salmon (s GnRH variant, gnrh3. The gene includes a 1.6 Kb upstream regulatory region and displays the conserved structure of 4 exons and 3 introns, as seen in other species. An in silico defined enhancer at -976 in the zebrafish promoter, containing adjacent binding sites for Oct-1, CREB and Sp1, was predicted in 2 mammalian and 5 teleost GnRH promoters. Reporter gene studies confirmed the importance of this enhancer for cell specific expression in zebrafish. Interestingly the promoter of human GnRH-I, known as mammalian GnRH (mGnRH, was shown capable of driving cell specific reporter gene expression in transgenic zebrafish. Conclusions The characterized zebrafish Gnrh3 decapeptide exhibits complete homology to the Atlantic salmon (Salmo salar GnRH-III variant. In silico analysis of mammalian and teleost GnRH promoters revealed a conserved enhancer possessing binding sites for Oct-1, CREB and Sp1. Transgenic and transient reporter gene expression in zebrafish larvae, confirmed the importance of the in silico defined zebrafish enhancer at -976. The capability of the human GnRH-I promoter of directing cell specific reporter gene expression in zebrafish supports orthology between GnRH-I and GnRH-III.

  20. The type of GnRH analogue used during controlled ovarian stimulation influences early embryo developmental kinetics

    DEFF Research Database (Denmark)

    Muñoz, Manuel; Cruz, María; Humaidan, Peter

    2013-01-01

    in the Instituto Valenciano de Infertilidad (IVI) Alicante and the Instituto Universitario-IVI Valencia, Spain, 2817 embryos deriving from 400 couples undergoing oocyte donation were analysed. After controlled ovarian stimulation and IVF/intracytoplamic sperm injection, the timing of embryonic cleavages......OBJECTIVE: To explore if the GnRH analogue used for controlled ovarian stimulation (COS) and the ovulation triggering factor (GnRH agonist+hCG triggering versus GnRH antagonist+GnRH agonist triggering) affect embryo development and kinetics. STUDY DESIGN: In a retrospective cohort study...... was assessed by a video time-lapse system. The results were analysed using Student's t test for comparison of timings (hours) and Chi-squared test for comparison of proportions. A p-value...

  1. Characterization of 12 GnRH peptide agonists - a kinetic perspective.

    Science.gov (United States)

    Nederpelt, Indira; Georgi, Victoria; Schiele, Felix; Nowak-Reppel, Katrin; Fernández-Montalván, Amaury E; IJzerman, Adriaan P; Heitman, Laura H

    2016-01-01

    Drug-target residence time is an important, yet often overlooked, parameter in drug discovery. Multiple studies have proposed an increased residence time to be beneficial for improved drug efficacy and/or longer duration of action. Currently, there are many drugs on the market targeting the gonadotropin-releasing hormone (GnRH) receptor for the treatment of hormone-dependent diseases. Surprisingly, the kinetic receptor-binding parameters of these analogues have not yet been reported. Therefore, this project focused on determining the receptor-binding kinetics of 12 GnRH peptide agonists, including many marketed drugs. A novel radioligand-binding competition association assay was developed and optimized for the human GnRH receptor with the use of a radiolabelled peptide agonist, [(125) I]-triptorelin. In addition to radioligand-binding studies, a homogeneous time-resolved FRET Tag-lite™ method was developed as an alternative assay for the same purpose. Two novel competition association assays were successfully developed and applied to determine the kinetic receptor-binding characteristics of 12 high-affinity GnRH peptide agonists. Results obtained from both methods were highly correlated. Interestingly, the binding kinetics of the peptide agonists were more divergent than their affinities with residence times ranging from 5.6 min (goserelin) to 125 min (deslorelin). Our research provides new insights by incorporating kinetic, next to equilibrium, binding parameters in current research and development that can potentially improve future drug discovery targeting the GnRH receptor. © 2015 The British Pharmacological Society.

  2. Growth hormone receptor antagonist (GHA) transgenic mice have increased subcutaneous adipose tissue mass, altered glucose homeostasis, and no change in white adipose tissue cellular senescence

    Science.gov (United States)

    Comisford, Ross; Lubbers, Ellen R.; Householder, Lara; Suer, Ozan; Tchkonia, Tamara; Kirkland, James L.; List, Edward O.; Kopchick, John J.; Berryman, Darlene E.

    2015-01-01

    Background Growth hormone (GH) resistant/deficient mice experience improved glucose homeostasis and substantially increased lifespan. Recent evidence suggests long-lived GH resistant/deficient mice are protected from white adipose tissue (WAT) dysfunction, including WAT cellular senescence, impaired adipogenesis and loss of subcutaneous WAT in old age. This preservation of WAT function has been suggested to be a potential mechanism for the extended lifespan of these mice. OBJECTIVE The objective of this study was to examine white adipose tissue (WAT) senescence, WAT distribution, and glucose homeostasis in dwarf growth hormone receptor antagonist (GHA) transgenic mice, a unique mouse strain having decreased GH action but normal longevity. METHODS 18mo old female GHA mice and wild type (WT) littermate controls were used. Prior to dissection, body composition, fasting blood glucose, and glucose and insulin tolerance tests were performed. WAT distribution was determined by weighing four distinct WAT depots at the time of dissection. Cellular senescence in four WAT depots was assessed using senescence-associated β-galactosidase (SA-β-gal) staining to quantify the senescent cell burden and real time qPCR to quantify gene expression of senescence markers p16 and IL-6. RESULTS GHA mice had a 22% reduction in total body weight, 33% reduction in lean mass, and a 10% increase in body fat percentage compared to WT controls. GHA mice had normal fasting blood glucose and improved insulin sensitivity; however, they exhibited impaired glucose tolerance. Moreover, GHA mice displayed enhanced lipid storage in the inguinal subcutaneous WAT depot (p<.05) and a 1.7 fold increase in extra-/intraperitoneal WAT ratio compared to controls (p<.05). Measurements of WAT cellular senescence showed no difference between GHA mice and WT controls. CONCLUSIONS Similar to other mice with decreased GH action, female GHA mice display reduced age-related lipid redistribution and improved insulin

  3. Gonadotropin-Releasing Hormone Regulates Expression of the DNA Damage Repair Gene, Fanconi anemia A, in Pituitary Gonadotroph Cells1

    OpenAIRE

    Larder, Rachel; Chang, Lynda; Clinton, Michael; Brown, Pamela

    2004-01-01

    Gonadal function is critically dependant on regulated secretion of the gonadotropin hormones from anterior pituitary gonadotroph cells. Gonadotropin biosynthesis and release is triggered by the binding of hypothalamic GnRH to GnRH receptor expressed on the gonadotroph cell surface. The repertoire of regulatory molecules involved in this process are still being defined. We used the mouse LβT2 gonadotroph cell line, which expresses both gonadotropin hormones, as a model to investigate GnRH regu...

  4. Necdin, a Prader-Willi syndrome candidate gene, regulates gonadotropin-releasing hormone neurons during development.

    Science.gov (United States)

    Miller, Nichol L G; Wevrick, Rachel; Mellon, Pamela L

    2009-01-15

    Prader-Willi syndrome (PWS) is a complex genetic disorder characterized by hyperphagia, obesity and hypogonadotrophic hypogonadism, all highly suggestive of hypothalamic dysfunction. The NDN gene, encoding the MAGE family protein, necdin, maps to the PWS chromosome region and is highly expressed in mature hypothalamic neurons. Adult mice lacking necdin have reduced numbers of gonadotropin-releasing hormone (GnRH) neurons, but the mechanism for this reduction is unknown. Herein, we show that, although necdin is not expressed in an immature, migratory GnRH neuronal cell line (GN11), high levels are present in a mature GnRH neuronal cell line (GT1-7). Furthermore, overexpression of necdin activates GnRH transcription through cis elements bound by the homeodomain repressor Msx that are located in the enhancer and promoter of the GnRH gene, and knock-down of necdin expression reduces GnRH gene expression. In fact, overexpression of Necdin relieves Msx repression of GnRH transcription through these elements and necdin co-immunoprecipitates with Msx from GnRH neuronal cells, indicating that necdin may activate GnRH gene expression by preventing repression of GnRH gene expression by Msx. Finally, necdin is necessary for generation of the full complement of GnRH neurons during mouse development and extension of GnRH axons to the median eminence. Together, these results indicate that lack of necdin during development likely contributes to the hypogonadotrophic hypogonadal phenotype in individuals with PWS.

  5. Necdin, a Prader–Willi syndrome candidate gene, regulates gonadotropin-releasing hormone neurons during development

    Science.gov (United States)

    Miller, Nichol L.G.; Wevrick, Rachel; Mellon, Pamela L.

    2009-01-01

    Prader–Willi syndrome (PWS) is a complex genetic disorder characterized by hyperphagia, obesity and hypogonadotrophic hypogonadism, all highly suggestive of hypothalamic dysfunction. The NDN gene, encoding the MAGE family protein, necdin, maps to the PWS chromosome region and is highly expressed in mature hypothalamic neurons. Adult mice lacking necdin have reduced numbers of gonadotropin-releasing hormone (GnRH) neurons, but the mechanism for this reduction is unknown. Herein, we show that, although necdin is not expressed in an immature, migratory GnRH neuronal cell line (GN11), high levels are present in a mature GnRH neuronal cell line (GT1-7). Furthermore, overexpression of necdin activates GnRH transcription through cis elements bound by the homeodomain repressor Msx that are located in the enhancer and promoter of the GnRH gene, and knock-down of necdin expression reduces GnRH gene expression. In fact, overexpression of Necdin relieves Msx repression of GnRH transcription through these elements and necdin co-immunoprecipitates with Msx from GnRH neuronal cells, indicating that necdin may activate GnRH gene expression by preventing repression of GnRH gene expression by Msx. Finally, necdin is necessary for generation of the full complement of GnRH neurons during mouse development and extension of GnRH axons to the median eminence. Together, these results indicate that lack of necdin during development likely contributes to the hypogonadotrophic hypogonadal phenotype in individuals with PWS. PMID:18930956

  6. Neuroregulatory and neuroendocrine GnRH pathways in the hypothalamus and forebrain of the baboon.

    Science.gov (United States)

    Marshall, P E; Goldsmith, P C

    1980-07-14

    The distribution of neurons containing gonadotropin-releasing hormone (GnRH) in the baboon hypothalamus and forebrain was studied immunocytochemically by light and electron microscopy. GnRH was present in the perikarya, axonal and dendritic processes of immunoreactive neurons. Three populations of GnRH neurons could be distinguished. Most of the GnRH neurons which are assumed to directly influence the anterior pituitary were in the medial basal hypothalamus. Other cells that projected to the median eminence were found scattered throughout the hypothalamus. A second, larger population of neurons apparently was not involved with control of the anterior pituitary. These neurons were generally found within afferent and efferent pathways of the hypothalamus and forebrain, and may receive external information affecting reproduction. A few neurons projecting to the median eminence were also observed sending collaterals to other brain areas. Thus, in addition to their neuroendocrine role, these cells possibly have neuroregulatory functions. The inference is made that these bifunctional neurons, together with the widely observed GnRH-GnRH cellular interactions may help to synchronize ovulation and sexual behavior.

  7. Etude du rôle de l’expression du récepteur Neuropiline-1 et de l’exocytose Calcium-dépendante dans le neurone à GnRH sur le développement et la maturation du système à GnRH et la physiologie de la reproduction

    OpenAIRE

    Vanacker , Charlotte

    2015-01-01

    Fertility in mammals is the result of a long development and maturation process of the hypothalamic-pituitary-gonadal axis. The reproductive function is orchestrated by a small population of neurons, located in preoptic area of hypothalamus in rodents, and releasing in a pulsatile manner Gonadotropin-releasing hormon (GnRH) in the portal blood vessels, where it is transported to the anterior pituitary gland. GnRH neuropeptide triggers synthesis and release of the gonadotropins LH and FSH, whi...

  8. Effects of progesterone injection on performance, plasma hormones ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... triggers gonadotropin-releasing hormone (GnRH) release ... open period has been shown to have positive effect on inducing a preovulatory ..... release, injectable levonorgestrel and depot medroxyprogesterone acetate on.

  9. The GnRH receptor and the response of gonadotrope cells to GnRH pulse frequency code. A story of an atypical adaptation of cell function relying on a lack of receptor homologous desensitization.

    Directory of Open Access Journals (Sweden)

    Christian Bleux

    2010-01-01

    Full Text Available Brain control of the reproductive system is mediated through hypothalamic gonadotropin-releasing hormone (GnRH which activates specific receptors (GnRHR present at the surface of the pituitary gonadotropes to trigger secretion of the two gonadotropins LH and FSH. A unique feature of this system is the high dependence on the secretion mode of GnRH, which is basically pulsatile but undergoes considerable fluctuations in pulse frequency pattern in response to endogenous or external factors. How the physiological fluctuations of GnRH secretion that orchestrate normal reproduction are decoded by the gonadotrope cell machinery to ultimately control gonadotropin release and/or subunit gene transcription has been the subject of intensive studies during the past decades. Surprisingly, the mammalian GnRHR is unique among G protein-coupled receptor family as it lacks the carboxy-terminal tail usually involved in classical endocytotic process. Accordingly, it does not desensitize properly and internalizes very poorly. Both this atypical intrinsic property and post-receptor events may thus contribute to decode the GnRH signal. This includes the participation of a network of signaling pathways that differently respond to GnRH together with a growing amount of genes differentially sensitive to pulse frequency. Among these are two pairs of genes, the transcription factors EGR-1 and NAB, and the regulatory factors activin and follistatin, that function as intracellular autoregulatory feedback loops controlling respectively LHbeta and FSHbeta gene expression and hence, LH and FSH synthesis. Pituitary gonadotropes thus represent a unique model of cells functionally adapted to respond to a considerably fluctuating neuroendocrine stimulation, from short individual pulses to sustained GnRH as observed at the proestrus of ovarian cycle. Altogether, the data emphasize the adaptative reciprocal complementarity of hypothalamic GnRH neurones and pituitary gonadotropes to

  10. Blastocyst transfer does not improve cycle outcome as compared to D3 transfer in antagonist cycles with an elevated progesterone level on the day of hCG.

    Science.gov (United States)

    Demirel, Cem; Aydoğdu, Serkan; Özdemir, Arzu İlknur; Keskin, Gülşah; Baştu, Ercan; Buyru, Faruk

    2017-09-01

    To evaluate the association between progesterone elevation on the day of human chorionic gonadotropin (hCG) administration and clinical pregnancy rates of gonadotropin-releasing hormone (GnRH) antagonist in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles with the transfer of embryos at different developmental stages (day-3 versus day-5 ETs). This is a retrospective analysis of fresh IVF/ICSI; 194 cycles out of 2676 conducted in a single center. A total of 2676 cycles were analyzed, of which 386 had no progesterone measurements available. Two hundred eighteen cycles had progesterone elevation (p>1.5 ng/mL) giving an overall incidence of 9.5%. Twenty-four cycles were excluded from further analysis. Of the remaining 194 cycles, 151 had day-3 transfers and 43 had blastocyst transfers. There was no statistically significant difference in pregnancy and clinical pregnancy rates per transfer between the D3-ET and D5-ET groups (46% vs. 49%, and 39% vs. 35%, respectively). The results of this study suggest that blastocyst transfer does not improve cycle outcomes compared with D3 transfer in GnRH antagonist cycles with an elevated progesterone level on the day of hCG.

  11. GnRH agonist ovulation trigger and hCG-based, progesterone-free luteal support: a proof of concept study

    DEFF Research Database (Denmark)

    Kol, Shahar; Humaidan, Peter; Itskovitz-Eldor, Joseph

    2011-01-01

    in normal responder IVF patients. We here present a novel approach for luteal support after a GnRHa trigger. METHODS Normal responder patients who failed at least one previous IVF attempt, during which a conventional hCG trigger was used, were consecutively enrolled in the study. A GnRH antagonist...

  12. Does polycystic ovarian morphology influence the response to treatment with pulsatile GnRH in functional hypothalamic amenorrhea?

    Science.gov (United States)

    Dumont, Agathe; Dewailly, Didier; Plouvier, Pauline; Catteau-Jonard, Sophie; Robin, Geoffroy

    2016-04-29

    Pulsatile GnRH therapy is the gold standard treatment for ovulation induction in women having functional hypothalamic amenorrhea (FHA). The use of pulsatile GnRH therapy in FHA patients with polycystic ovarian morphology (PCOM), called "FHA-PCOM", has been little studied in the literature and results remain contradictory. The aim of this study was to compare the outcomes of pulsatile GnRH therapy for ovulation induction between FHA and "FHA-PCOM" patients in order to search for an eventual impact of PCOM. Retrospective study from August 2002 to June 2015, including 27 patients with FHA and 40 "FHA-PCOM" patients (85 and 104 initiated cycles, respectively) treated by pulsatile GnRH therapy for induction ovulation. The two groups were similar except for markers of PCOM (follicle number per ovary, serum Anti-Müllerian Hormone level and ovarian area), which were significantly higher in patients with "FHA-PCOM". There was no significant difference between the groups concerning the ovarian response: with equivalent doses of GnRH, both groups had similar ovulation (80.8 vs 77.7 %, NS) and excessive response rates (12.5 vs 10.6 %, NS). There was no significant difference in on-going pregnancy rates (26.9 vs 20 % per initiated cycle, NS), as well as in miscarriage, multiple pregnancy or biochemical pregnancy rates. Pulsatile GnRH seems to be a successful and safe method for ovulation induction in "FHA-PCOM" patients. If results were confirmed by prospective studies, GnRH therapy could therefore become a first-line treatment for this specific population, just as it is for women with FHA without PCOM.

  13. Growth Hormone Receptor Antagonist Transgenic Mice Have Increased Subcutaneous Adipose Tissue Mass, Altered Glucose Homeostasis and No Change in White Adipose Tissue Cellular Senescence.

    Science.gov (United States)

    Comisford, Ross; Lubbers, Ellen R; Householder, Lara A; Suer, Ozan; Tchkonia, Tamara; Kirkland, James L; List, Edward O; Kopchick, John J; Berryman, Darlene E

    2016-01-01

    Growth hormone (GH)-resistant/deficient mice experience improved glucose homeostasis and substantially increased lifespan. Recent evidence suggests that long-lived GH-resistant/deficient mice are protected from white adipose tissue (WAT) dysfunction, including WAT cellular senescence, impaired adipogenesis and loss of subcutaneous WAT in old age. This preservation of WAT function has been suggested to be a potential mechanism for the extended lifespan of these mice. The objective of this study was to examine WAT senescence, WAT distribution and glucose homeostasis in dwarf GH receptor antagonist (GHA) transgenic mice, a unique mouse strain having decreased GH action but normal longevity. 18-month-old female GHA mice and wild-type (WT) littermate controls were used. Prior to dissection, body composition, fasting blood glucose as well as glucose and insulin tolerance tests were performed. WAT distribution was determined by weighing four distinct WAT depots at the time of dissection. Cellular senescence in four WAT depots was assessed using senescence-associated β-galactosidase staining to quantify the senescent cell burden, and real-time qPCR to quantify gene expression of senescence markers p16 and IL-6. GHA mice had a 22% reduction in total body weight, a 33% reduction in lean mass and a 10% increase in body fat percentage compared to WT controls. GHA mice had normal fasting blood glucose and improved insulin sensitivity; however, they exhibited impaired glucose tolerance. Moreover, GHA mice displayed enhanced lipid storage in the inguinal subcutaneous WAT depot (p < 0.05) and a 1.7-fold increase in extra-/intraperitoneal WAT ratio compared to controls (p < 0.05). Measurements of WAT cellular senescence showed no difference between GHA mice and WT controls. Similar to other mice with decreased GH action, female GHA mice display reduced age-related lipid redistribution and improved insulin sensitivity, but no change in cellular senescence. The similar abundance of

  14. Function of gonadotropin-releasing hormone in olfaction.

    Science.gov (United States)

    Wirsig-Wiechmann, C R

    2001-06-01

    Gonadotropin-releasing hormone (GnRH) is present within neurons of the nervus terminalis, the zeroeth cranial nerve. In all vertebrate species, except in sharks where it is a separate nerve, the nervus terminalis consists of a chain of neurons embedded within olfactory or vomeronasal nerves in the nasal cavity. The function of the GnRH component of the nervus terminalis is thought to be neuromodulatory. Our research on GnRH effects on olfaction confirms this hypothesis. The processes of GnRH neural cell bodies located within chemosensory nerves project centrally into the ventral forebrain and peripherally into the lamina propria of the nasal chemosensory mucosa. GnRH receptors are expressed by chemosensory neurons as shown by RT-PCR/Southern blotting and GnRH agonist binding studies. Patch-clamp studies have shown that GnRH alters the responses of isolated chemosensory neurons to natural or electrophysiological stimulation through the modulation of voltage-gated and receptor-gated channels. Behavioral experiments demonstrate that interfering with the nasal GnRH system leads to deficits in mating behavior. These studies suggest that the function of the intranasal GnRH system is to modify olfactory information, perhaps at reproductively auspicious times. We speculate that the purpose of this altered olfactory sense is to make pheromones more detectable and salient.

  15. Lack of effect of the dopamine D1 antagonist, NNC 01-0687, on unstimulated and stimulated release of anterior pituitary hormones in males

    DEFF Research Database (Denmark)

    Grodum, E; Andersen, M; Hangaard, J

    1998-01-01

    -blind placebo controlled cross-over study for three days with a wash-out period of 14 days. Hormonal responses (PRL, LH, FSH, GH, TSH, thyroid hormones and testosterone), unstimulated and LHRH/TRH stimulated, were studied on days 1 and 3. No significant difference (p > 0.05) between placebo and active periods...

  16. Inhibition of RM-1 prostate carcinoma and eliciting robust immune responses in the mouse model by using VEGF-M2-GnRH3-hinge-MVP vaccine.

    Science.gov (United States)

    Wang, Yiqin; Alahdal, Murad; Ye, Jia; Jing, Liangliang; Liu, Xiaoxin; Chen, Huan; Jin, Liang; Cao, Rongyue

    2018-01-23

    GnRH and VEGF have been investigated as prostate carcinoma enhancers that support tumor spread and progression. Although both have documented roles in prostate carcinoma and many cancer types, the weak immunogenicity of these peptides has remained a major challenge for use in immunotherapy. Here, we describe a novel strategy to inhibit GnRH and VEGF production and assess the effect on the immune responses against these hormones using the RM-1 prostate cancer model. We designed a novel recombinant fusion protein which combined GnRH and VEGF as a vaccine against this tumor. The newly constructed fusion protein hVEGF121-M2-GnRH3-hinge-MVP contains the human vascular endothelial growth factor (hVEGF121) and three copies of GnRH in sequential linear alignment and T helper epitope MVP as an immunogenic vaccine. The effectiveness of the vaccine in eliciting an immune response and attenuating the prostate tumor growth was evaluated. Results showed that administration of a new vaccine effectively elicited humoral and cellular immune responses. We found that, a novel fusion protein, hVEGF121-M2-GnRH3-hinge-MVP, effectively inhibited growth of RM-1 prostate model and effectively promoted immune response. In conclusion, hVEGF121-M2-GnRH3-hinge-MVP is an effective dual mechanism tumor vaccine that limits RM-1 prostate growth. This vaccine may be a promising strategy for the treatment of hormone refractory prostate malignancies.

  17. Pulsatile gonadotrophin releasing hormone for ovulation induction in subfertility associated with polycystic ovary syndrome

    NARCIS (Netherlands)

    Bayram, N.; van Wely, M.; van der Veen, F.

    2004-01-01

    BACKGROUND: In normal menstrual cycles, gonadotrophin releasing hormone (GnRH) secretion is pulsatile, with intervals of 60-120 minutes in the follicular phase. Treatment with pulsatile GnRH infusion by the intravenous or subcutaneous route using a portable pump has been used successfully in

  18. Effects of cetrorelix, a GnRH-receptor antagonist, on gonadal axis in women with functional hypothalamic amenorrhea.

    Science.gov (United States)

    Berardelli, Rita; Gianotti, Laura; Karamouzis, Ioannis; Picu, Andreea; Giordano, Roberta; D'Angelo, Valentina; Zinnà, Domenico; Lanfranco, Fabio; Ghigo, Ezio; Arvat, Emanuela

    2011-10-01

    Gonadotropin Releasing Hormone (GnRH) antagonists (GnRHa) suppress gonadotropin and sex-steroid secretion. In normal women, acute GnRHa administration induces inhibitory effect on pituitary-gonadal axis, followed by Luteinizing Hormone (LH) rebound. Functional hypothalamic amenorrhea (HA) is characterised by impaired gonadotropin secretion and hypogonadism secondary to blunted GnRH pulsatility. We studied the effects of a GnRHa, cetrorelix (CTX 3.0 mg), in six women with HA (age 30.7 ± 3.2 years; BMI 21.5 ± 1.7 kg/m(2)) and six control subjects (CS, 28.2 ± 0.6 years; 22.6 ± 0.9 kg/m(2)) on LH, Follicle-Stimulating Hormone (FSH) and oestradiol levels over 4 h (08.00-12.00 am) before, +24 h and +96 h after CTX; LH, FSH, and oestradiol were also evaluated at +6, +8, +12, +48, +72 h after CTX. CS: CTX reduced (p < 0.05) LH, FSH, and oestradiol (nadir at +12 h, +24 h, and +24 h); LH rebounded at +96 h, FSH and oestradiol recovered at +48 h and +72 h. The 4-h evaluation showed LH and FSH reduction (p < 0.05) at +24 h, with LH rebound at +96 h. HA: CTX reduced (p < 0.05) LH, FSH, and oestradiol, (nadir at +24 h, +48 h, and +48 h, recovery at +48 h, +72 h, and +96 h). The 4-h evaluation showed gonadotropin reduction (p < 0.05) 24 h after CTX, without any rebound effect. One single CTX dose still modulates gonadotropin secretion in HA. Its 'paradoxical' stimulatory effect on gonadotropins needs to be verified after prolonged administration.

  19. Male hormonal contraception: concept proven, product in sight?

    Science.gov (United States)

    Matthiesson, Kati L; McLachlan, Robert I

    2006-01-01

    Current male hormonal contraceptive (MHC) regimens act at various levels within the hypothalamic pituitary testicular axis, principally to induce the withdrawal of the pituitary gonadotrophins and in turn intratesticular androgen production and spermatogenesis. Azoospermia or severe oligozoospermia result from the inhibition of spermatogonial maturation and sperm release (spermiation). All regimens include an androgen to maintain virilization, while in many the suppression of gonadotrophins/spermatogenesis is augmented by the addition of another anti-gonadotrophic agent (progestin, GnRH antagonist). The suppression of sperm concentration to 1 x 10(6)/ml appears to provide comparable contraceptive efficacy to female hormonal methods, but the confidence intervals around these estimates remain relatively large, reflecting the limited number of exposure years reported. Also, inconsistencies in the rapidity and depth of spermatogenic suppression, potential for secondary escape of sperm into the ejaculate and onset of fertility return not readily explainable by analysis of subject serum hormone levels, germ cell number or intratesticular steroidogenesis, are apparent. As such, a better understanding of the endocrine and genetic regulation of spermatogenesis is necessary and may allow for new treatment paradigms. The development of an effective, consumer-friendly male contraceptive remains challenging, as it requires strong translational cooperation not only between basic scientists and clinicians but also between public and private sectors. At present, a prototype MHC product using a long-acting injectable testosterone and depot progestin is well advanced.

  20. [Anthology of the first clinical studies with hypothalamic hormones: a story of successful international cooperation].

    Science.gov (United States)

    Schally, Andrew V; Gual, Carlos

    2002-01-01

    Our early pioneering clinical trials in Mexico with natural and synthetic thyrotropin-releasing hormone (TRH) and luteinizing hormone releasing hormone (LH-RH) also known as gonadotropin releasing hormone (Gn-RH), were reviewed. Highly purified TRH of porcine origin was shown to stimulate Thyrotropin (TSH) release in hypothyroid cretins. Subsequent tests with synthetic TRH also demonstrated significant increases in plasma TSH in normal men and women as well as in patients with primary hypothyroidism and other endocrine disorders. Even more extensive clinical studies were carried out with highly purified natural porcine LH-RH. Subjects with normal basal serum levels of gonadotropins, low levels (men and women pretreated with steroids) and high levels (e.g. post menopausal women) all responded to LH-RH with a release of LH and FSH. The results of these early studies with the natural LH-RH were confirmed by the use of synthetic LH-RH. These investigations made in Mexico with TRH and LH-RH preceded all other clinical studies by a wide margin. Subsequently various clinical investigations with LH-RH agonists and antagonists were also carried out. All these studies played a major role in introducing hypothalamic-releasing hormones into clinical medicine.

  1. Genetic variation in total number and locations of GnRH neurons identified using in situ hybridization in a wild-source population.

    Science.gov (United States)

    Kaugars, Katherine E; Rivers, Charlotte I; Saha, Margaret S; Heideman, Paul D

    2016-02-01

    The evolution of brain function in the regulation of physiology may depend in part upon the numbers and locations of neurons. Wild populations of rodents contain natural genetic variation in the inhibition of reproduction by winter-like short photoperiod, and it has been hypothesized that this functional variation might be due in part to heritable variation in the numbers or location of gonadotropin releasing hormone (GnRH) neurons. A naturally variable wild-source population of white-footed mice was used to develop lines artificially selected for or against mature gonads in short, winter-like photoperiods. We compared a selection line that is reproductively inhibited in short photoperiod (Responsive) to a line that is weakly inhibited by short photoperiod (Nonresponsive) for differences in counts of neurons identified using in situ hybridization for GnRH mRNA. There was no effect of photoperiod, but there were 60% more GnRH neurons in total in the Nonresponsive selection line than the Responsive selection line. The lines differed specifically in numbers of GnRH neurons in more anterior regions, whereas numbers of GnRH neurons in posterior areas were not statistically different between lines. We compare these results to those of an earlier study that used immunohistochemical labeling for GnRH neurons. The results are consistent with the hypothesis that the selection lines and natural source population contain significant genetic variation in the number and location of GnRH neurons. The variation in GnRH neurons may contribute to functional variation in fertility that occurs in short photoperiods in the laboratory and in the wild source population in winter. © 2015 Wiley Periodicals, Inc.

  2. Differential co-localization with choline acetyltransferase in nervus terminalis suggests functional differences for GnRH isoforms in bonnethead sharks (Sphyrna tiburo).

    Science.gov (United States)

    Moeller, John F; Meredith, Michael

    2010-12-17

    The nervus terminalis (NT) is a vertebrate cranial nerve whose function in adults is unknown. In bonnethead sharks, the nerve is anatomically independent of the olfactory system, with two major cell populations within one or more ganglia along its exposed length. Most cells are immunoreactive for either gonadotropin-releasing hormone (GnRH) or RF-amide-like peptides. To define further the cell populations and connectivity, we used double-label immunocytochemistry with antisera to different isoforms of GnRH and to choline acetyltransferase (ChAT). The labeling patterns of two GnRH antisera revealed different populations of GnRH-immunoreactive (ir) cell profiles in the NT ganglion. One antiserum labeled a large group of cells and fibers, which likely contain mammalian GnRH (GnRH-I) as described in previous studies and which were ChAT immunoreactive. The other antiserum labeled large club-like structures, which were anuclear, and a sparse number of fibers, but with no clear labeling of cell bodies in the ganglion. These club structures were choline acetyltrasferase (ChAT)-negative, and preabsorption control tests suggest they may contain chicken-GnRH-II (GnRH-II) or dogfish GnRH. The second major NT ganglion cell-type was immunoreactive for RF-amides, which regulate GnRH release in other vertebrates, and may provide an intraganglionic influence on GnRH release. The immunocytochemical and anatomical differences between the two GnRH-immunoreactive profile types indicate possible functional differences for these isoforms in the NT. The club-like structures may be sites of GnRH release into the general circulation since these structures were observed near blood vessels and resembled structures seen in the median eminence of rats. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Do GnRH analogues directly affect human endometrial epithelial cell gene expression?

    KAUST Repository

    Zhang, Xiaomei

    2010-03-04

    We examined whether Gonadotrophin-releasing hormone (GnRH) analogues [leuprolide acetate (LA) and ganirelix acetate (GA)] modulate gene expression in Ishikawa cells used as surrogate for human endometrial epithelial cells in vitro. The specific aims were: (i) to study the modulatory effect of GnRH analogues by RT-PCR [in the absence and presence of E2 and P4, and cyclic adenosine monophos-phate (cAMP)] on mRNA expression of genes modulated during the window of implantation in GnRH analogues/rFSH-treated assisted reproductive technology cycles including OPTINEURIN (OPTN), CHROMATIN MODIFYING PROTEIN (CHMP1A), PROSAPOSIN (PSAP), IGFBP-5 and SORTING NEXIN 7 (SNX7), and (ii) to analyze the 5\\'-flanking regions of such genes for the presence of putative steroid-response elements [estrogen-response elements (EREs) and P4-response element (PREs)]. Ishikawa cells were cytokeratin+/vimentin2 and expressed ERa,ERb, PR and GnRH-R proteins. At 6 and 24 h, neither LA nor GA alone had an effect on gene expression. GnRH analogues alone or following E2 and/or P4 co-incubation for 24 h also had no effect on gene expression, but P4 significantly increased expression of CHMP1A.E2 + P4 treatment for 4 days, alone or followed by GA, had no effect, but E2 + P4 treatment followed by LA significantly decreased IGFBP-5 expression. The addition of 8-Br cAMP did not modify gene expression, with the exception of IGFBP-5 that was significantly increased. The GnRH analogues did not modify intracellular cAMP levels. We identified conserved EREs for OPN, CHMP1A, SNX7 and PSAP and PREs for SNX7. We conclude that GnRH analogues appear not to have major direct effects on gene expression of human endo-metrial epithelial cells in vitro. © The Author 2010. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org.

  4. Identification and characterization of a reptilian GnRH receptor from the leopard gecko.

    Science.gov (United States)

    Ikemoto, T; Enomoto, M; Park, M K

    2004-02-12

    Gonadotropin-releasing hormone (GnRH) plays a pivotal role in the regulation of reproductive functions through interactions with its specific receptor. We describe the first molecular cloning and characterization of a full-length GnRH receptor (GnRHR) from the leopard gecko Eublepharis macularius. It has a distinct genomic structure consisting of five exons and four introns, compared with all the other reported GnRHR genes. A native GnRH form, cGnRH-II, stimulated inositol phosphate (IP) production in COS-7 cells transiently transfected with the GnRHR, in a dose dependent manner. The mRNA was expressed in all the tissues and organs examined. Molecular phylogenetic analysis revealed that the cloned GnRHR belongs to the type 2/nonmammalian I GnRHR. Low-expression levels were observed from the pituitary glands of reproductively active leopard geckos, indicating the possibility that there is at least one more type of GnRHR highly expressed in the pituitary gland for the gonadotropin secretion in this reptile.

  5. Estrogen receptor beta and 2-arachydonoylglycerol mediate the suppressive effects of estradiol on frequency of postsynaptic currents in gonadotropin-releasing hormone neurons of metestrous mice: an acute slice electrophysiological study

    Directory of Open Access Journals (Sweden)

    Flóra eBálint

    2016-03-01

    Full Text Available Gonadotropin-releasing hormone (GnRH neurons are controlled by 17β-estradiol (E2 contributing to the steroid feedback regulation of the reproductive axis. In rodents, E2 exerts a negative feedback effect upon GnRH neurons throughout the estrus-diestrus phase of the ovarian cycle. The present study was undertaken to reveal the role of estrogen receptor subtypes in the mediation of the E2 signal and elucidate the downstream molecular machinery of suppression. The effect of E2 administration at low physiological concentration (10 pM on GnRH neurons in acute brain slices obtained from metestrous GnRH-GFP mice was studied under paradigms of blocking or activating estrogen receptor subtypes and interfering with retrograde 2-arachydonoylglycerol (2-AG signaling. Whole-cell patch clamp recordings revealed that E2 significantly diminished the frequency of spontaneous postsynaptic currents (sPSCs in GnRH neurons (49. 62±7.6% which effect was abolished by application of the ERα/β blocker Faslodex (1 µM. Pretreatment of the brain slices with cannabinoid receptor type 1 (CB1 inverse agonist AM251 (1 µM and intracellularly applied endocannabinoid synthesis blocker THL (10 µM significantly attenuated the effect of E2 on the sPSCs. E2 remained effective in the presence of TTX indicating a direct action of E2 on GnRH cells. The ERβ specific agonist DPN (10 pM also significantly decreased the frequency of miniature postsynaptic currents (mPSCs in GnRH neurons. In addition, the suppressive effect of E2 was completely blocked by the selective ERβ antagonist PHTPP (1 µM indicating that ERβ is required for the observed rapid effect of the E2. In contrast, the ERα agonist PPT (10 pM or the membrane-associated G protein-coupled estrogen receptor (GPR30 agonist G1 (10 pM had no significant effect on the frequency of mPSCs in these neurons. AM251 and THL significantly abolished the effect of E2 whereas AM251 eliminated the action of DPN on the mPSCs. These

  6. Kisspeptin Activates Ankrd 26 Gene Expression in Migrating Embryonic GnRH Neurons

    Directory of Open Access Journals (Sweden)

    Tomoko eSoga

    2016-03-01

    Full Text Available Kisspeptin, a newly discovered neuropeptide regulates gonadotropin-releasing hormone (GnRH. Kisspeptins are a large RF-amide family of peptides. The kisspeptin coded by kiss1 gene is a 145-amino acid- protein that is cleaved to C-terminal peptide kisspeptin-10. G-protein coupled receptor 54 (GPR54 has been identified as a kisspeptin receptor, and it is expressed in GnRH neurons and in a variety of cancer cells. In this study, enhanced green fluorescent protein (EGFP labelled GnRH cells with migratory properties, which express GPR54, served as a model to study the effects of kisspeptin on cell migration. We monitored EGFP–GnRH neuronal migration in brain slide culture of embryonic day 14 transgenic rat by live cell imaging system and studied the effects of kisspeptin-10 (1nM treatment for 36h on GnRH migration. Furthermore to determine kisspeptin-induced molecular pathways related with apoptosis, and cytoskeletal changes during neuronal migration, we studied the expression levels of candidate genes in laser captured EGFP–GnRH neurons by real time PCR. We found that there was no change in the expression level of genes related to cell proliferation and apoptosis. The expression of ankyrin repeat domain-containing protein (ankrd 26 in EGFP–GnRH neurons was up-regulated by the exposure to kisspeptin. These studies suggest that ankrd26 gene plays an unidentified role in regulating neuronal movement mediated by kisspeptin-GPR54 signaling, which could be a potential pathway to suppress cell migration.

  7. The effects of a slow release GnRH agonist implant on male rabbits

    DEFF Research Database (Denmark)

    Goericke-Pesch, Sandra Kathrin; Groeger, Gesa; Wehrend, Axel

    2015-01-01

    Surgical castration is done in male pet rabbits for reproduction control, to reduce inter-male aggression and to control hyper-sexuality, territory marking and aggression against humans. Alternatives to surgical castration are requested because of a relatively great anaesthetic risk in rabbits....... Long-term application of a GnRH agonist implant results in a fully reversible "hormonal" castration in male dogs, cats, boars and many other species. Therefore, the present study using New Zealand White hybrid and German Giant rabbits aimed to investigate the effects of a 4.7mg deslorelin implant...

  8. A mathematical model for LH release in response to continuous and pulsatile exposure of gonadotrophs to GnRH

    Directory of Open Access Journals (Sweden)

    Reed Michael C

    2004-09-01

    Full Text Available Abstract In a previous study, a model was developed to investigate the release of luteinizing hormone (LH from pituitary cells in response to a short pulse of gonadotropin-releasing hormone (GnRH. The model included: binding of GnRH to its receptor (R, dimerization and internalization of the hormone receptor complex, interaction with a G protein, production of inositol 1,4,5-trisphosphate (IP3, release of calcium from the endoplasmic reticulum (ER, entrance of calcium into the cytosol via voltage gated membrane channels, pumping of calcium out of the cytosol via membrane and ER pumps, and release of LH. The extended model, presented in this paper, also includes the following physiologically important phenomena: desensitization of calcium channels; internalization of the dimerized receptors and recycling of some of the internalized receptors; an increase in Gq concentration near the plasma membrane in response to receptor dimerization; and basal rates of synthesis and degradation of the receptors. With suitable choices of the parameters, good agreement with a variety of experimental data of the LH release pattern in response to pulses of various durations, repetition rates, and concentrations of GnRH were obtained. The mathematical model allows us to assess the effects of internalization and desensitization on the shapes and time courses of LH response curves.

  9. The effect of intracerebroventricular injection of L-glutamate on the hypothalamic GnRH content in rat

    International Nuclear Information System (INIS)

    Fu Qiang; He Haoming

    2001-01-01

    Objective: To investigate the effect of intracerebroventricular injection of L-Glutamate (L-Glu) on hypothalamic gonadotrophin-releasing hormone (GnRH) content in male rats. Methods: The GnRH content in the supernatant of hypothalamic homogenates was measured by RIA. Results: The mean values of hypothalamic GnRH content in rat were 1.59 +- 0.41, 0.88 +- 0.34, 0.70 +- 0.42 ng/10mg wet tissue 40 min after intracerebroventricular injection of 0.01176, 0.1176, 1.176 μg/20 μl L-Glu respectively, which were significantly lower than those in controls with saline injections (P 3 H-Glu in rat at 40 min the author found that the intake of 3 H-glu by MBH was 1069.82 +- 490.33 cpm/10 mg wet tissues, the highest value among those taken by cerebrum, cerebellum, pituitary, POA and MBH itself. Conclusion: L-Glu probably participates in the regulation of functional activity of GnRH neurons in the hypothalamus

  10. Reproductive physiology of a humanized GnRH receptor mouse model: application in evaluation of human-specific analogs.

    Science.gov (United States)

    Tello, Javier A; Kohout, Trudy; Pineda, Rafael; Maki, Richard A; Scott Struthers, R; Millar, Robert P

    2013-07-01

    The human GnRH receptor (GNRHR1) has a specific set of properties with physiological and pharmacological influences not appropriately modeled in laboratory animals or cell-based systems. To address this deficiency, we have generated human GNRHR1 knock-in mice and described their reproductive phenotype. Measurement of pituitary GNRHR1 transcripts from homozygous human GNRHR1 knock-in (ki/ki) mice revealed a severe reduction (7- to 8-fold) compared with the mouse Gnrhr1 in wild-type mice. ¹²⁵I-GnRH binding assays on pituitary membrane fractions corroborated reduced human GNRHR1 protein expression in ki/ki mice, as occurs with transfection of human GNRHR1 in cell lines. Female homozygous knock-in mice displayed normal pubertal onset, indicating that a large reduction in GNRHR1 expression is sufficient for this process. However, ki/ki females exhibited periods of prolonged estrous and/or metestrous and reduced fertility. No impairment was found in reproductive maturity or adult fertility in male ki/ki mice. Interestingly, the serum LH response to GnRH challenge was reduced in both knock-in males and females, indicating a reduced GNRHR1 signaling capacity. Small molecules targeting human GPCRs usually have poor activities at homologous rodent receptors, thus limiting their use in preclinical development. Therefore, we tested a human-specific GnRH1 antagonist, NBI-42902, in our mouse model and demonstrated abrogation of a GnRH1-induced serum LH rise in ki/ki mice and an absence of effect in littermates expressing the wild-type murine receptor. This novel model provides the opportunity to study the human receptor in vivo and for screening the activity of human-specific GnRH analogs.

  11. Gonadotropin-releasing hormone radioimmunoassay and its measurement in normal human plasma, secondary amenorrhea, and postmenopausal syndrome

    International Nuclear Information System (INIS)

    Rosenblum, N.G.; Schlaff, S.

    1976-01-01

    A sensitive and specific double antibody radioimmunoassay for gonadotropin-releasing hormone (GnRH) has been developed for measurement in ethanol extracts of human plasma. Iodinated hormone was prepared with the use of the chloramine-T method, and antibodies were developed in rabbits over a six-month period with a GnRH synthetic copolymer immunogen. A Scatchard plot revealed at least three species of antibody. The assay can measure conservatively at the 5 pg. per milliliter level and shows no cross-reactivity with other available hypothalamic and pituitary hormones. The releasing hormone was quantitatively recovered from human plasma with immunologic identity to native hormone. Unextracted plasma could not be used because of nonspecific displacement. The measurement of GnRH in individuals receiving 100 μg of intravenous bolus infusions of the synthetic decapeptide show extremely elevated values with two half-lives: one of two to four minutes and another of 35 to 40 minutes. In our experiments, we have found measurable GnRH in patients with secondary amenorrhea and at the midcycle in normal women. In the normal cycling woman during the follicular and luteal phases, GnRH was undetectable. In postmenopausal women with extreme hypoestrogenism and markedly elevated luteinizing hormone values, GnRH was also undetectable. No bursts of GnRH could be detected in normal men when sampled every ten minutes over a two-hour period and every two hours throughout the day

  12. The gonadotropin-releasing hormone antagonist protocol--the protocol of choice for the polycystic ovary syndrome patient undergoing controlled ovarian stimulation

    DEFF Research Database (Denmark)

    Kol, Shahar; Homburg, Roy; Alsbjerg, Birgit

    2012-01-01

    Polycystic ovary syndrome (PCOS) patients are prone to develop ovarian hyperstimulation syndrome (OHSS), a condition which can be minimized or completely eliminated by the use of a gonadotropin-releasing hormone agonist (GnRHa) trigger. In this commentary paper, we maintain that the gonadotropin-...... ongoing pregnancy rates in the subsequent frozen-thawed transfer cycles....

  13. Amine-free melanin-concentrating hormone receptor 1 antagonists: Novel 1-(1H-benzimidazol-6-yl)pyridin-2(1H)-one derivatives and design to avoid CYP3A4 time-dependent inhibition.

    Science.gov (United States)

    Igawa, Hideyuki; Takahashi, Masashi; Shirasaki, Mikio; Kakegawa, Keiko; Kina, Asato; Ikoma, Minoru; Aida, Jumpei; Yasuma, Tsuneo; Okuda, Shoki; Kawata, Yayoi; Noguchi, Toshihiro; Yamamoto, Syunsuke; Fujioka, Yasushi; Kundu, Mrinalkanti; Khamrai, Uttam; Nakayama, Masaharu; Nagisa, Yasutaka; Kasai, Shizuo; Maekawa, Tsuyoshi

    2016-06-01

    Melanin-concentrating hormone (MCH) is an attractive target for antiobesity agents, and numerous drug discovery programs are dedicated to finding small-molecule MCH receptor 1 (MCHR1) antagonists. We recently reported novel pyridine-2(1H)-ones as aliphatic amine-free MCHR1 antagonists that structurally featured an imidazo[1,2-a]pyridine-based bicyclic motif. To investigate imidazopyridine variants with lower basicity and less potential to inhibit cytochrome P450 3A4 (CYP3A4), we designed pyridine-2(1H)-ones bearing various less basic bicyclic motifs. Among these, a lead compound 6a bearing a 1H-benzimidazole motif showed comparable binding affinity to MCHR1 to the corresponding imidazopyridine derivative 1. Optimization of 6a afforded a series of potent thiophene derivatives (6q-u); however, most of these were found to cause time-dependent inhibition (TDI) of CYP3A4. As bioactivation of thiophenes to form sulfoxide or epoxide species was considered to be a major cause of CYP3A4 TDI, we introduced electron withdrawing groups on the thiophene and found that a CF3 group on the ring or a Cl adjacent to the sulfur atom helped prevent CYP3A4 TDI. Consequently, 4-[(5-chlorothiophen-2-yl)methoxy]-1-(2-cyclopropyl-1-methyl-1H-benzimidazol-6-yl)pyridin-2(1H)-one (6s) was identified as a potent MCHR1 antagonist without the risk of CYP3A4 TDI, which exhibited a promising safety profile including low CYP3A4 inhibition and exerted significant antiobesity effects in diet-induced obese F344 rats. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris)

    OpenAIRE

    Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

    2006-01-01

    GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homo-logue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnR...

  15. Active immunization against gonadotropin-releasing hormone : an effective tool to block the fertility axis in mammals

    NARCIS (Netherlands)

    Turkstra, Jouwert Anne

    2005-01-01

    Gonadotropin releasing hormone (GnRH) plays a pivotal role in fertility and reproduction in mammals. It induces the release of luteinising hormone (LH) en follicle stimulating hormone (FSH) from the pituitary. These hormones are responsible for gonadal steroid production and indirectly for

  16. Developmental expression of the G protein-coupled receptor 54 and three GnRH mRNAs in the teleost fish cobia.

    Science.gov (United States)

    Mohamed, J Shaik; Benninghoff, Abby D; Holt, G Joan; Khan, Izhar A

    2007-02-01

    The cDNAs of the G protein-coupled receptor 54 (GPR54) and three prepro-gonadotropin-releasing hormones, GnRH-I (seabream GnRH), GnRH-II (chicken GnRH-II), and GnRH-III (salmon GnRH) were isolated and cloned from the brain of the teleost fish cobia, Rachycentron canadum. The cobia GPR54 cDNA was 95 and 51-56% identical to those of tilapia and mammalian models respectively. The GnRH cDNA sequences of cobia showed strong identities to those of tilapia, Atlantic croaker, red drum, and the seabass and seabream species. The real-time quantitative RT-PCR methods allowed detection of all three GnRH mRNAs on the first day after hatching (DAH). The GnRH-I mRNA levels, which were the lowest among the three GnRHs, increased gradually with two distinct peaks in larvae at 3 and 4 DAH. On the other hand, GnRH-II and GnRH-III mRNAs were significantly higher in larvae at 2 and 6 DAH compared with those on the preceding days. In addition, significant peaks of all the three GnRH mRNAs were observed in the brains of 26-day-old fish. The finding of higher GnRH-I and GnRH-II mRNAs in males than females at 153 DAH may be related to early puberty observed during the first year in laboratory-reared male cobia. Moreover, this study demonstrates for the first time the expression of GPR54 mRNA during larval development in a vertebrate species. The concomitant expression patterns of GPR54 and GnRH mRNAs during different stages of larval and juvenile developments, and during early puberty in male cobia suggest a potential relationship between GPR54 and multiple GnRHs during these stages of development consistent with the role of GPR54 in controlling GnRH release in mammals. The increase in GPR54 and GnRH mRNAs observed during early puberty in cobia is consistent with a similar change reported in pubertal rats. This finding together with the localization of GPR54 mRNAs on GnRH neurons in fish and mammals suggests that the GPR54-GnRH interactions may be conserved in different vertebrate groups.

  17. Effects of GnRH, a progesterone-releasing device, and energy balance on an oestrus synchronisation program in anoestrous dairy cows.

    Science.gov (United States)

    Sahu, S K; Cockrem, J F; Parkinson, T J; Laven, R A

    2017-08-01

    The aim of this research was to study the roles of the day 0 energy balance and gonadotrophin-releasing hormone (GnRH) and progesterone levels on dominant follicle (DF) and corpus luteum (CL) development during the first 7 days of a gonadotrophin-prostaglandin-gonadotrophin (GPG) + progesterone (P4) program in anoestrous dairy cows. Cows (n = 81) were allocated to one of the three treatments: (1) GPG + P4 (days 0 and 9, 100 µg GnRH; day 0-7, intravaginal P4 device; day 7, 500 µg PGF 2α ); (2) GPG (as for treatment 1 but excluding the P4 device) and (3) prostaglandin + GnRH + P4 (as for treatment 1, but excluding day 0 GnRH). DF and CL size, plasma concentrations of insulin, insulin-like growth factor-I (IGF-I) and non-esterified fatty acid (NEFA) were measured on days 0 and 7. The proportion of cows with a CL on day 7 was significantly different between groups (GPG: 78%, GPG+P4: 69%, PGF 2α + GnRH + P4: 42%, P = 0.02). The CL volume on day 7 was significantly associated with treatment, treatment by time postpartum and plasma concentrations of insulin, IGF-I and NEFA. In cows without a CL present on day 0 of an oestrus synchronisation program, removal of the day 0 GnRH treatment led to reduced CL development; however, no effect of adding progesterone was found. In contrast, in cows with a CL present on day 0 inclusion of a progesterone device led to a higher CL volume, but removal of the first GnRH injection had no effect. Response to the treatment was affected by plasma concentrations of insulin, IGF-I and NEFA. © 2017 Australian Veterinary Association.

  18. Combined Treatment with Gonadotropin-releasing Hormone Analog and Anabolic Steroid Hormone Increased Pubertal Height Gain and Adult Height in Boys with Early Puberty for Height.

    Science.gov (United States)

    Tanaka, Toshiaki; Naiki, Yasuhiro; Horikawa, Reiko

    2012-04-01

    Twenty-one boys with a height of 135 cm or less at onset of puberty were treated with a combination of GnRH analog and anabolic steroid hormone, and their pubertal height gain and adult height were compared with those of untreated 29 boys who enter puberty below 135 cm. The mean age at the start of treatment with a GnRH analog, leuprorelin acetate depot (Leuplin(®)) was 12.3 yr, a mean of 1.3 yr after the onset of puberty, and GnRH analog was administered every 3 to 5 wk thereafter for a mean duration of 4.1 yr. The anabolic steroid hormone was started approximately 1 yr after initiation of treatment with the GnRH analog. The mean pubertal height gain from onset of puberty till adult height was significantly greater in the combination treatment group (33.9 cm) than in the untreated group (26.4 cm) (ppenis and pubic hair is promoted by the anabolic steroid hormone, no psychosocial problems arose because of delayed puberty. No clinically significant adverse events appeared. Combined treatment with GnRH analog and anabolic steroid hormone significantly increased height gain during puberty and adult height in boys who entered puberty with a short stature, since the period until epiphyseal closure was extended due to deceleration of the bone age maturation by administration of the GnRH analog and the growth rate at this time was maintained by the anabolic steroid hormone.

  19. Does the time interval between antimüllerian hormone serum sampling and initiation of ovarian stimulation affect its predictive ability in in vitro fertilization-intracytoplasmic sperm injection cycles with a gonadotropin-releasing hormone antagonist?

    DEFF Research Database (Denmark)

    Polyzos, Nikolaos P; Nelson, Scott M; Stoop, Dominic

    2013-01-01

    To investigate whether the time interval between serum antimüllerian hormone (AMH) sampling and initiation of ovarian stimulation for in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) may affect the predictive ability of the marker for low and excessive ovarian response.......To investigate whether the time interval between serum antimüllerian hormone (AMH) sampling and initiation of ovarian stimulation for in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) may affect the predictive ability of the marker for low and excessive ovarian response....

  20. Endocrine dynamics during pulsatile GnRH administration in patients with hypothalamic amenorrhea and polycystic ovarian disease.

    Science.gov (United States)

    Rossmanith, W G; Wirth, U; Benz, R; Wolf, A S

    1989-01-01

    The LH secretory patterns and ovarian endocrine responses have been determined during pulsatile gonadotropin-releasing hormone (GnRH) administration for induction of ovulation in patients with hypothalamic amenorrhea (HA). However, until now these endocrine dynamics during GnRH therapy have not been thoroughly investigated in patients with polycystic ovarian disease (PCOD). Seven patients with HA and 4 patients with PCOD have therefore been studied to determine changes in LH pulsatile activity and in serum sex steroid levels in response to chronic intermittent GnRH stimulation. GnRH was administered intravenously (5-10 micrograms/90 minutes) by means of a portable infusion pump. Blood samples were obtained at 15-minute intervals for 4 hours on the day before the start of GnRH stimulation (control day) and on treatment days 5, 10 and 15. LH was determined in all samples and FSH, serum androgens and estrogens were measured in baseline samples by RIA. While 8 (62%) ovulations and 5 conceptions were observed in 13 treatment cycles in patients with HA, no ovulations were achieved during 9 treatment cycles in patients with PCOD. On the control day significantly (p less than 0.05) higher basal LH and testosterone (T) levels and significantly (p less than 0.05) lower FSH levels were found in the PCOD patients. The LH pulsatile profiles of the PCOD patients showed significantly (p less than 0.05) higher pulse amplitudes and areas under the curve (integrated responses). Pulsatile GnRH administration induced a significant (p less than 0.05) increase in LH pulse amplitudes in both HA and PCOD patients, and also increased (p less than 0.05) the integrated responses in patients with HA. During the GnRH stimulation, the LH interpulse intervals of both HA and PCOD patients were found to be similar to the frequency in which exogenous GnRH was administered. FSH levels rose continuously (p less than 0.001) during stimulation in patients with HA, but remained unchanged in patients

  1. Brain penetrant small molecule 18F-GnRH receptor (GnRH-R) antagonists: Synthesis and preliminary positron emission tomography imaging in rats

    International Nuclear Information System (INIS)

    Olberg, Dag E.; Bauer, Nadine; Andressen, Kjetil W.; Hjørnevik, Trine; Cumming, Paul; Levy, Finn O.; Klaveness, Jo; Haraldsen, Ira; Sutcliffe, Julie L.

    2016-01-01

    Introduction: The gonadotropin releasing hormone receptor (GnRH-R) has a well-described neuroendocrine function in the anterior pituitary. However, little is known about its function in the central nervous system (CNS), where it is most abundantly expressed in hippocampus and amygdala. Since peptide ligands based upon the endogenous decapetide GnRH do not pass the blood–brain-barrier, we are seeking a high-affinity small molecule GnRH-R ligand suitable for brain imaging by positron emission tomography. We have previously reported the radiosynthesis and in vitro evaluation of two novel [ 18 F]fluorinated GnRH-R ligands belonging to the furamide class of antagonists, with molecular weight less than 500 Da. We now extend this work using palladium coupling for the synthesis of four novel radioligands, with putatively reduced polar surface area and hydrophilicity relative to the two previously described compounds, and report the uptake of these 18 F-labeled compounds in brain of living rats. Methods: We synthesized reference standards of the small molecule GnRH-R antagonists as well as mesylate precursors for 18 F-labeling. The antagonists were tested for binding affinity for both human and rat GnRH-R. Serum and blood stability in vitro and in vivo were studied. Biodistribution and PET imaging studies were performed in male rats in order to assess brain penetration in vivo. Results: A palladium coupling methodology served for the synthesis of four novel fluorinated furamide GnRH receptor antagonists with reduced heteroatomic count. Radioligand binding assays in vitro revealed subnanomolar affinity of the new fluorinated compounds for both human and rat GnRH-R. The 18 F-GnRH antagonists were synthesized from the corresponding mesylate precursors in 5–15% overall radiochemical yield. The radiolabeled compounds demonstrated good in vivo stability. PET imaging with the 18 F-radiotracers in naive rats showed good permeability into brain and rapid washout, but absence of

  2. Genomic structure and promoter functional analysis of GnRH3 gene in large yellow croaker (Larimichthys crocea).

    Science.gov (United States)

    Huang, Wei; Zhang, Jianshe; Liao, Zhi; Lv, Zhenming; Wu, Huifei; Zhu, Aiyi; Wu, Changwen

    2016-01-15

    Gonadotropin-releasing hormone III (GnRH3) is considered to be a key neurohormone in fish reproduction control. In the present study, the cDNA and genomic sequences of GnRH3 were cloned and characterized from large yellow croaker Larimichthys crocea. The cDNA encoded a protein of 99 amino acids with four functional motifs. The full-length genome sequence was composed of 3797 nucleotides, including four exons and three introns. Higher identities of amino acid sequences and conserved exon-intron organizations were found between LcGnRH3 and other GnRH3 genes. In addition, some special features of the sequences were detected in partial species. For example, two specific residues (V and A) were found in the family Sciaenidae, and the unique 75-72 bp type of the open reading frame 2 and 3 existed in the family Cyprinidae. Analysis of the 2576 bp promoter fragment of LcGnRH3 showed a number of transcription factor binding sites, such as AP1, CREB, GATA-1, HSF, FOXA2, and FOXL1. Promoter functional analysis using an EGFP reporter fusion in zebrafish larvae presented positive signals in the brain, including the olfactory region, the terminal nerve ganglion, the telencephalon, and the hypothalamus. The expression pattern was generally consistent with the endogenous GnRH3 GFP-expressing transgenic zebrafish lines, but the details were different. These results indicate that the structure and function of LcGnRH3 are generally similar to the other teleost GnRH3 genes, but there exist some distinctions among them. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Synchronisation of the follicular wave with GnRH and PGF2α analogue for a timed breeding programme in dromedary camels (Camelus dromedarius).

    Science.gov (United States)

    Manjunatha, B M; Al-Bulushi, Samir; Pratap, N

    2015-09-01

    This study was conducted to develop a hormone protocol that precisely synchronises follicular development for a timed breeding (TB) programme in dromedary camels. To examine the effect of GnRH treatment at four known stages of follicular development, animals were treated with GnRH when the largest follicle of the wave was 4-7, 8-11, 12-17 and 18-27 mm in diameter. Transrectal ultrasonography was carried out daily up to 20 days after treatment. A hormone protocol (FWsynch) for the synchronisation of follicular wave and TB consisting of GnRH-1 (GnRH) on Day 0, PG-1 (PGF2α) on Day 7, GnRH-2 on Day 10 and PG-2 on Day 17 was initiated at four known stages of follicular development. Ovarian structures were monitored by ultrasonography. The FWsynch protocol was initiated at random stages of follicle development and animals were bred by natural mating at a fixed time at the research facility and in field. The pregnancy was diagnosed by ultrasonography. GnRH treatment in animals with a dominant follicle (DF) of ≥ 11 mm in diameter resulted in synchronous new follicular wave emergence, whereas in animals with a DF ≤ 10 mm, the treatment did not alter the development of the existing follicular wave. The FWsynch protocol was effective in synchronising the follicular wave for TB irrespective of the stage of follicular development at the beginning of the protocol. TB using FWsynch protocol resulted in a pregnancy rate of 60.2% in a research facility and 53.6% and 45.6% in normal and infertile camels respectively under field conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. The growth hormone-releasing hormone (GHRH) antagonist JV-1-36 inhibits proliferation and survival of human ectopic endometriotic stromal cells (ESCs) and the T HESC cell line.

    Science.gov (United States)

    Annunziata, Marta; Grande, Cristina; Scarlatti, Francesca; Deltetto, Francesco; Delpiano, Elena; Camanni, Marco; Ghigo, Ezio; Granata, Riccarda

    2010-08-01

    To determine the effect of the GHRH antagonist JV-1-36 on proliferation and survival of primary ectopic human endometriotic stromal cells (ESCs) and the T HESC cell line. Prospective laboratory study. University hospital. 22 women with endometriosis (aged 34.8+/-5.7 years) undergoing therapeutic laparoscopy. Eutopic (n=10) and ectopic (n=22) endometrial tissues were collected from women who underwent therapeutic laparoscopic surgery for endometriosis (stage III/IV). Expression of GHRH, GHRH receptor (GHRH-R) and GHRH-R splice variant (SV) 1 mRNA was determined by reverse-transcription polymerase chain reaction (RT-PCR). The ESC proliferation was assessed by 5-bromo-2-deoxyuridine incorporation, cell survival by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and Trypan blue assay. The T HESC survival was evaluated by MTT, cyclic adenosine monophosphate (cAMP) levels by ELISA, extracellular signal-regulated kinases 1 and 2 (ERK1/2) phosphorylation by Western blot, and insulin-like growth factor (IGF)-2 mRNA by real-time PCR. The ESCs and T HESCs, but not normal endometrial tissues, expressed GHRH-R mRNA; SV1 mRNA was determined in normal endometrial tissues, ESCs, and T HESCs; GHRH mRNAwas found in T HESCs; JV-1-36 inhibited ESC proliferation and ESC and T HESC survival. In T HESCs, JV-1-36 reduced cAMP production and ERK1/2 phosphorylation but had no effect on IGF-2 mRNA expression. The GHRH antagonist JV-1-36 inhibits endometriotic cell proliferation and survival, suggesting that GHRH antagonist may represent promising tools for treatment of endometriosis. Copyright (c) 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  5. Cytokines and Bone Loss in a 5-Year Longitudinal Study—Hormone Replacement Therapy Suppresses Serum Soluble Interleukin-6 Receptor and Increases Interleukin-1-Receptor Antagonist

    DEFF Research Database (Denmark)

    Abrahamsen, B.; Bonnevie-Nielsen, V.; Ebbesen, E.N.

    2000-01-01

    ) and the soluble IL-6 receptor (sIL-6R) potentially modify cytokine bioactivity. We therefore assessed the impact of menopause and hormone replacement therapy (HRT) on cytokines and activity modifiers in serum within a 5-year longitudinal study. One hundred sixty perimenopausal women (age 50.1 +/- 2.8 years) were.......16; p = 0.17). In conclusion, serum IL-1ra and sIL-6R are influenced by HRT and are associated with the rate of bone loss in perimenopausal women....

  6. Bilateral Salpingo-Oophorectomy Versus GnRH Analogue in the Adjuvant Treatment of Premenopausal Breast Cancer Patients: Cost-Effectiveness Evaluation of Breast Cancer Outcome, Ovarian Cancer Prevention and Treatment.

    Science.gov (United States)

    Ferrandina, Gabriella; Amadio, Giulia; Marcellusi, Andrea; Azzolini, Elena; Puggina, Anna; Pastorino, Roberta; Ricciardi, Walter; Scambia, Giovanni

    2017-11-01

    BACKGROUND AND OBJECTIVE: There is no available evidence to recommend gonadotropin-releasing hormone (GnRH) analogue-based ovarian suppression versus bilateral salpingo-oophorectomy (BSO) in the adjuvant treatment of early breast cancer, since the two approaches are considered equivalent in terms of oncologic outcome. The role of surgical ovarian ablation has been revitalized based on the advances of minimally invasive surgery, and a better understanding of clinical and molecular basis of hereditary breast/ovarian cancer syndromes. The aim of this study is to analyze the cost-effectiveness of laparoscopic BSO and GnRH analogue administration in patients aged 40-49 years with hormone-sensitive breast cancer. A probabilistic decision tree model was developed to evaluate costs and outcomes of ovarian ablation through laparoscopic BSO, or ovarian suppression through monthly injections of GnRH analogue. Results were expressed as incremental costs per quality-adjusted life years (QALYs) gained. Laparoscopic BSO strategy was associated with a lower mean total cost per patient than GnRH treatment, and considering the difference in terms of QALYs, the incremental effectiveness did not demonstrate a notable difference between the two approaches. From the National Health Service perspective, and for a time horizon of 5 years, laparoscopic BSO was the dominant option compared to GnRH treatment; laparoscopic BSO was less expensive than GnRH, €2385 [95% confidence interval (CI) = 2044, 2753] vs €7093 (95% CI = 3409, 12,105), respectively, and more effective. Surgical ovarian ablation is more cost-effective than GnRH administration in the adjuvant treatment of hormone-sensitive breast cancer patients aged 40-49 years, and the advantage of preventing ovarian cancer through laparoscopic BSO should be considered.

  7. Estradiol-Dependent Stimulation and Suppression of Gonadotropin-Releasing Hormone Neuron Firing Activity by Corticotropin-Releasing Hormone in Female Mice.

    Science.gov (United States)

    Phumsatitpong, Chayarndorn; Moenter, Suzanne M

    2018-01-01

    Gonadotropin-releasing hormone (GnRH) neurons are the final central regulators of reproduction, integrating various inputs that modulate fertility. Stress typically inhibits reproduction but can be stimulatory; stress effects can also be modulated by steroid milieu. Corticotropin-releasing hormone (CRH) released during the stress response may suppress reproduction independent of downstream glucocorticoids. We hypothesized CRH suppresses fertility by decreasing GnRH neuron firing activity. To test this, mice were ovariectomized (OVX) and either implanted with an estradiol capsule (OVX+E) or not treated further to examine the influence of estradiol on GnRH neuron response to CRH. Targeted extracellular recordings were used to record firing activity from green fluorescent protein-identified GnRH neurons in brain slices before and during CRH treatment; recordings were done in the afternoon when estradiol has a positive feedback effect to increase GnRH neuron firing. In OVX mice, CRH did not affect the firing rate of GnRH neurons. In contrast, CRH exhibited dose-dependent stimulatory (30 nM) or inhibitory (100 nM) effects on GnRH neuron firing activity in OVX+E mice; both effects were reversible. The dose-dependent effects of CRH appear to result from activation of different receptor populations; a CRH receptor type-1 agonist increased firing activity in GnRH neurons, whereas a CRH receptor type-2 agonist decreased firing activity. CRH and specific agonists also differentially regulated short-term burst frequency and burst properties, including burst duration, spikes/burst, and/or intraburst interval. These results indicate that CRH alters GnRH neuron activity and that estradiol is required for CRH to exert both stimulatory and inhibitory effects on GnRH neurons. Copyright © 2018 Endocrine Society.

  8. Involvement of phospholipase C and intracellular calcium signaling in the gonadotropin-releasing hormone regulation of prolactin release from lactotrophs of tilapia (Oreochromis mossambicus)

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbæk; Weber, G M; Strom, C N

    2005-01-01

    Gonadotropin-releasing hormone (GnRH) is a potent stimulator of prolactin (PRL) secretion in various vertebrates including the tilapia, Oreochromis mossambicus. The mechanism by which GnRH regulates lactotroph cell function is poorly understood. Using the advantageous characteristics of the teleost...

  9. Regulation of gonadotropin-releasing hormone neurons by glucose

    Science.gov (United States)

    Roland, Alison V.; Moenter, Suzanne M.

    2011-01-01

    Reproduction is influenced by energy balance, but the physiological pathways mediating their relationship have not been fully elucidated. As the central regulators of fertility, gonadotropin-releasing hormone (GnRH) neurons integrate numerous physiological signals, including metabolic cues. Circulating glucose levels regulate GnRH release and may in part mediate the effects of negative energy balance on fertility. Existing evidence suggests that neural pathways originating in the hindbrain, as well as in the hypothalamic feeding nuclei, transmit information concerning glucose availability to GnRH neurons. Here we review recent evidence suggesting that GnRH neurons may directly sense changes in glucose availability by a mechanism involving adenosine monophosphate-activated protein kinase (AMPK). These findings expand our understanding of how metabolic signaling in the brain regulates reproduction. PMID:21855365

  10. GnRH signalling pathways and GnRH-induced homologous desensitization in a gonadotrope cell line (alphaT3-1).

    Science.gov (United States)

    Poulin, B; Rich, N; Mas, J L; Kordon, C; Enjalbert, A; Drouva, S V

    1998-07-25

    Exposure of the gonadotrope cells to gonadotropin-releasing hormone (GnRH) reduces their responsiveness to a new GnRH stimulation (homologous desensitization). The time frame as well as the mechanisms underlying this phenomenon are yet unclear. We studied in a gonadotrope cell line (alphaT3-1) the effects of short as well as long term GnRH pretreatments on the GnRH-induced phospholipases-C (PLC), -A2 (PLA2) and -D (PLD) activities, by measuring the production of IP3, total inositol phosphates (IPs), arachidonic acid (AA) and phosphatidylethanol (PEt) respectively. We demonstrated that although rapid desensitization of GnRH-induced IP3 formation did not occur in these cells, persistent stimulation of cells with GnRH or its analogue resulted in a time-dependent attenuation of GnRH-elicited IPs formation. GnRH-induced IPs desensitization was potentiated after direct activation of PKC by the phorbol ester TPA, suggesting the involvement of distinct mechanisms in the uncoupling exerted by either GnRH or TPA on GnRH-stimulated PI hydrolysis. The levels of individual phosphoinositides remained unchanged under any desensitization condition applied. Interestingly, while the GnRH-induced PLA2 activity was rapidly desensitized (2.5 min) after GnRH pretreatments, the neuropeptide-evoked PLD activation was affected at later times, indicating an important time-dependent contribution of these enzymatic activities in the sequential events underlying the GnRH-induced homologous desensitization processes in the gonadotropes. Under GnRH desensitization conditions, TPA was still able to induce PLD activation and to further potentiate the GnRH-evoked PLD activity. AlphaT3-1 cells possess several PKC isoforms which, except PKCzeta, were differentially down-regulated by TPA (PKCalpha, betaII, delta, epsilon, eta) or GnRH (PKCbetaII, delta, epsilon, eta). In spite of the presence of PKC inhibitors or down-regulation of PKC isoforms by TPA, the desensitizing effect of the neuropeptide on

  11. Growth hormone receptor antagonist transgenic mice are protected from hyperinsulinemia and glucose intolerance despite obesity when placed on a HF diet.

    Science.gov (United States)

    Yang, Tianxu; Householder, Lara A; Lubbers, Ellen R; List, Edward O; Troike, Katie; Vesel, Clare; Duran-Ortiz, Silvana; Kopchick, John J; Berryman, Darlene E

    2015-02-01

    Reduced GH levels have been associated with improved glucose metabolism and increased longevity despite obesity in multiple mouse lines. However, one mouse line, the GH receptor antagonist (GHA) transgenic mouse, defies this trend because it has reduced GH action and increased adiposity, but glucose metabolism and life span are similar to controls. Slight differences in glucose metabolism and adiposity profiles can become exaggerated on a high-fat (HF) diet. Thus, in this study, male and female GHA and wild-type (WT) mice in a C57BL/6 background were placed on HF and low-fat (LF) diets for 11 weeks, starting at 10 weeks of age, to assess how GHA mice respond to additional metabolic stress of HF feeding. On a HF diet, all mice showed significant weight gain, although GHA gained weight more dramatically than WT mice, with males gaining more than females. Most of this weight gain was due to an increase in fat mass with WT mice increasing primarily in the white adipose tissue perigonadal depots, whereas GHA mice gained in both the sc and perigonadal white adipose tissue regions. Notably, GHA mice were somewhat protected from detrimental glucose metabolism changes on a HF diet because they had only modest increases in serum glucose levels, remained glucose tolerant, and did not develop hyperinsulinemia. Sex differences were observed in many measures with males reacting more dramatically to both a reduction in GH action and HF diet. In conclusion, our findings show that GHA mice, which are already obese, are susceptible to further adipose tissue expansion with HF feeding while remaining resilient to alterations in glucose homeostasis.

  12. Increased cortisol responsivity to adrenocorticotropic hormone and low plasma levels of interleukin-1 receptor antagonist in women with functional hypothalamic amenorrhea.

    Science.gov (United States)

    Lindahl, Magnus S; Olovsson, Matts; Nyberg, Sigrid; Thorsen, Kim; Olsson, Tommy; Sundström Poromaa, Inger

    2007-01-01

    To assess the hypothalamic-pituitary-adrenal (HPA) axis at all levels, to determine the origin of the previously reported hypercortisolism in patients with functional hypothalamic amenorrhea. A secondary aim was to evaluate factors outside the central nervous system which are known to affect the HPA axis, i.e., circulating levels of interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1Ra), and fat mass-adjusted leptin levels, in patients with functional hypothalamic amenorrhea and healthy controls. Cross-sectional study. Umeå University Hospital, Umeå, Sweden. Fifteen subjects with hypothalamic amenorrhea, and 14 age- and weight-matched controls. None. We collected blood samples four times during a 24-hour interval for analysis of cortisol, leptin, IL-1Ra, and IL-6 levels. We performed a low-dose oral dexamethasone test and a low-dose ACTH test. We measured body-fat percentage using a dual-energy X-ray absorptiometer. Patients with hypothalamic amenorrhea had increased diurnal cortisol levels (P<.001). The cortisol response to intravenous low-dose ACTH was increased in functional hypothalamic amenorrhea patients compared to control subjects (P<.01), but they had similar rates of dexamethasone suppression. Patients with hypothalamic amenorrhea also had decreased diurnal leptin (P<.05), and decreased diurnal IL-1Ra levels (P<.05), compared to controls. Body-fat percentage was the main predictor of leptin levels. The present study suggests novel links for the development of functional hypothalamic amenorrhea, including increased adrenal responsiveness and impairments in proinflammatory cytokine pathways.

  13. Combined Treatment with Gonadotropin-releasing Hormone Analog and Anabolic Steroid Hormone Increased Pubertal Height Gain and Adult Height in Boys with Early Puberty for Height

    OpenAIRE

    Tanaka, Toshiaki; Naiki, Yasuhiro; Horikawa, Reiko

    2012-01-01

    Twenty-one boys with a height of 135 cm or less at onset of puberty were treated with a combination of GnRH analog and anabolic steroid hormone, and their pubertal height gain and adult height were compared with those of untreated 29 boys who enter puberty below 135 cm. The mean age at the start of treatment with a GnRH analog, leuprorelin acetate depot (Leuplin?) was 12.3 yr, a mean of 1.3 yr after the onset of puberty, and GnRH analog was administered every 3 to 5 wk thereafter for a mean d...

  14. Role of calcium in gonadotropin releasing hormone-induced luteinizing hormone secretion from the bovine pituitary

    International Nuclear Information System (INIS)

    Kile, J.P.

    1986-01-01

    The hypothesis was tested that GnRH acts to release LH by increasing calcium uptake by gonadotroph which in turn stimulates calcium-calmodulin activity and results in LH release from bovine pituitary cells as it does in the rat. Pituitary glands of calves (4-10 months of age) were enzymatically dispersed (0.2% collagenase) and grown for 5 days to confluency in multiwell plates (3 x 10 5 /well). Cells treated with GnRH Ca ++ ionophore A23187, and ouabain all produced significant releases of LH release in a pronounced all or none fashion, while thorough washing of the cells with 0.5 mM EGTA in Ca ++ -free media prevented the action of GnRH. GnRH caused a rapid efflux of 45 Ca ++ . Both GnRH-stimulated 45 Ca efflux and LH release could be partially blocked by verapamil GnRH-induced LH release could also be blocked by nifedipine and tetrodotoxin, although these agents did not affect 45 Ca efflux. The calmodulin antagonists calmidazolium and W7 were found to block GnRH induced LH release, as well as LH release induced by theophylline, KC PGE 2 and estradiol. These data indicated that: (1) calcium is required for GnRH action, but extracellular Ca ++ does not regulate LH release; (2) GnRH elevates intracellular Ca ++ by opening both voltage sensitive and receptor mediated Ca ++ channels; (3) activation of calmodulin is one mechanism involved in GnRH-induced LH release

  15. The potential for castration of domestic animals by active immunization against GnRH

    International Nuclear Information System (INIS)

    Gonzalez, A.; Allen, A.F.; Murphy, B.D.; Mapletoft, R.J.; Cohen, R.

    1990-01-01

    Trials have been carried out in sheep and beef cattle in attempts to induce immunity against gonadotropin releasing hormone (GnRH), with the objective of using immunocastration as a replacement for surgical castration. Of the protein carriers used, ovalbumin and horse albumin yielded highest responses, with keyhole limpet haemocyanin (KLH) being a potent substitute for both. Different adjuvants were also used. In these trials, highest titre responses were obtained using Freund's complete (FCA) or Freund's incomplete (FIA) adjuvant in cattle and sheep. Although no adjuvant was found to yield as high a response as FCA and Alhydrogel, an aluminium hydroxide adjuvant generally yielded a high response in cattle and sheep. The results from the trials in beef calves indicate that active immunization against GnRH does not affect average daily gains, total body weight gain or carcass dressing percentage. The results suggest the potential of immunocastration as a substitute for surgical castration in cattle and sheep. (author). 30 refs, 8 figs, 2 tabs

  16. Prepubertal Development of Gonadotropin-Releasing Hormone Neuron Activity Is Altered by Sex, Age, and Prenatal Androgen Exposure.

    Science.gov (United States)

    Dulka, Eden A; Moenter, Suzanne M

    2017-11-01

    Gonadotropin-releasing hormone (GnRH) neurons regulate reproduction though pulsatile hormone release. Disruption of GnRH release as measured via luteinizing hormone (LH) pulses occurs in polycystic ovary syndrome (PCOS), and in young hyperandrogenemic girls. In adult prenatally androgenized (PNA) mice, which exhibit many aspects of PCOS, increased LH is associated with increased GnRH neuron action potential firing. How GnRH neuron activity develops over the prepubertal period and whether this is altered by sex or prenatal androgen treatment are unknown. We hypothesized GnRH neurons are active before puberty and that this activity is sexually differentiated and altered by PNA. Dams were injected with dihydrotestosterone (DHT) on days 16 to 18 post copulation to generate PNA mice. Action potential firing of GFP-identified GnRH neurons in brain slices from 1-, 2-, 3-, and 4-week-old and adult mice was monitored. GnRH neurons were active at all ages tested. In control females, activity increased with age through 3 weeks, then decreased to adult levels. In contrast, activity did not change in PNA females and was reduced at 3 weeks. Activity was higher in control females than males from 2 to 3 weeks. PNA did not affect GnRH neuron firing rate in males at any age. Short-term action potential patterns were also affected by age and PNA treatment. GnRH neurons are thus typically more active during the prepubertal period than adulthood, and PNA reduces prepubertal activity in females. Prepubertal activity may play a role in establishing sexually differentiated neuronal networks upstream of GnRH neurons; androgen-induced changes during this time may contribute to the adult PNA, and possibly PCOS, phenotype. Copyright © 2017 Endocrine Society.

  17. High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons

    Science.gov (United States)

    Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Padilla, Stephanie L; Palmiter, Richard D

    2016-01-01

    Kisspeptin (Kiss1) and neurokinin B (NKB) neurocircuits are essential for pubertal development and fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (Kiss1ARH) co-express Kiss1, NKB, dynorphin and glutamate and are postulated to provide an episodic, excitatory drive to gonadotropin-releasing hormone 1 (GnRH) neurons, the synaptic mechanisms of which are unknown. We characterized the cellular basis for synchronized Kiss1ARH neuronal activity using optogenetics, whole-cell electrophysiology, molecular pharmacology and single cell RT-PCR in mice. High-frequency photostimulation of Kiss1ARH neurons evoked local release of excitatory (NKB) and inhibitory (dynorphin) neuropeptides, which were found to synchronize the Kiss1ARH neuronal firing. The light-evoked synchronous activity caused robust excitation of GnRH neurons by a synaptic mechanism that also involved glutamatergic input to preoptic Kiss1 neurons from Kiss1ARH neurons. We propose that Kiss1ARH neurons play a dual role of driving episodic secretion of GnRH through the differential release of peptide and amino acid neurotransmitters to coordinate reproductive function. DOI: http://dx.doi.org/10.7554/eLife.16246.001 PMID:27549338

  18. Receptors for luteinizing hormone-releasing hormone (LHRH) in Dunning R3327 prostate cancers and rat anterior pituitaries after treatment with a sustained delivery system of LHRH antagonist SB-75.

    Science.gov (United States)

    Srkalovic, G; Bokser, L; Radulovic, S; Korkut, E; Schally, A V

    1990-12-01

    Membrane receptors for LHRH were evaluated in Dunning R3327 prostate cancers and rat anterior pituitaries. The receptors were characterized both in untreated animals and after in vivo treatment with microcapsules of the agonist D-Trp6-LHRH and a sustained delivery system releasing different doses (23.8, 47.6, 71.4 micrograms/day) of LHRH antagonist [Ac-D-Nal(2)1-D-Phe(4Cl)2-D-Pal(3)3,D-Cit6, D-Ala10]-LHRH (SB-75). The therapy, which lasted 8 weeks, strongly inhibited tumor growth. A group of normal Sprague-Dawley male rats was also treated for 6 weeks with microcapsules of SB-75 releasing 25 micrograms/day. In the Dunning tumors from the control group, ligand [125I, D-Trp6]-LHRH was bound to two classes of binding sites [dissociation constant, class a (Kda) = 1.01 +/- 0.30 x 10(-9) M; Kdb = 1.71 +/- 0.41 x 10(-6) M; maximal binding capacity of receptors, class a (Bmaxa) = 48.66 +/- 22.13 fmol/mg of protein; Bmaxb = 92.10 +/- 29.40 pmol/mg of protein] in both kinetic and equilibrium studies. Treatment with D-Trp6-LHRH produced down-regulation of membrane receptors for LHRH in Dunning tumors. Microcapsules of SB-75 resulted in dose-dependent up-regulation of binding sites for LHRH in Dunning tumors. Analysis of the binding data showed that interaction of labeled D-Trp6-LHRH with binding sites in anterior pituitaries was consistent with the presence of a single class of noncooperative receptors (Kd = 43.75 x 10(-9) M; Bmax = 5.25 pmol/mg membrane proteins). Prolonged treatment with microcapsules of D-Trp6-LHRH reduced both Bmax and Kd. Lower doses of SB-75 (23.8 and 47.6 micrograms/day) produced up-regulation, whereas the highest dose (71.4 micrograms/day) resulted in down-regulation of binding sites for LHRH in rat pituitaries. In normal Sprague-Dawley rats, treatment with microcapsules of SB-75 (25 micrograms/day) for 6 weeks produced a slight increase in the number of available binding sites (Bmax = 2.35 +/- 0.82 pmol/mg membrane protein) and a moderate decrease in

  19. Comparison of mild and microdose GnRH agonist flare protocols on IVF outcome in poor responders.

    Science.gov (United States)

    Karimzadeh, Mohammad Ali; Mashayekhy, Mehri; Mohammadian, Farnaz; Moghaddam, Fatemeh Mansoori

    2011-05-01

    To compare the IVF outcome of clomiphene citrate/gonadotropin/antagonist (mild protocol) and microdose GnRH agonist flare protocols for poor responders undergoing in vitro fertilization. 159 poor responder patients were randomized and ovarian stimulation was performed with clomiphene citrate, gonadotropin and antagonist (group I) or microdose GnRH agonist flare (group II) protocols. Main outcome was clinical pregnancy rate and secondary outcomes were doses of gonadotropin administration and duration of stimulation. There were no significant differences in age, causes of infertility, basal FSH, BMI, duration of infertility, E(2) level on the day of hCG injection in both groups. Although the cancellation, fertilization, and clinical pregnancy rates were similar in both groups, the endometrial thickness, number of retrieved oocytes, mature oocytes and implantation rate were significantly higher in mild protocol. The doses of gonadotropin administration and duration of stimulation were significantly lower in mild protocol. We recommend mild protocol in assisted reproductive technology cycles for poor responders based on our results regarding less doses of used gonadotropin and a shorter duration of stimulation.

  20. Evaluation of the pituitary-gonadal response to GnRH, and adrenal status, in the leopard (Panthera pardus japonensis) and tiger (Panthera tigris).

    Science.gov (United States)

    Brown, J L; Goodrowe, K L; Simmons, L G; Armstrong, D L; Wildt, D E

    1988-01-01

    Frequent blood samples were collected to study hormonal responses to GnRH in male and female leopards and tigers. Animals were anaesthetized with ketamine-HCl and blood samples were collected every 5 min for 15 min before and 160 min after i.v. administration of GnRH (1 micrograms/kg body weight) or saline. No differences in serum cortisol concentrations were observed between sexes within species, but mean cortisol was 2-fold greater in leopards than tigers. GnRH induced a rapid rise in LH in all animals (18.3 +/- 0.9 min to peak). Net LH peak height above pretreatment levels was 3-fold greater in males than conspecific females and was also greater in tigers than leopards. Serum FSH increased after GnRH, although the magnitude of response was less than that observed for LH. Basal LH and FSH and GnRH-stimulated FSH concentrations were not influenced by sex or species. Serum testosterone increased within 30-40 min after GnRH in 3/3 leopard and 1/3 tiger males. Basal testosterone was 3-fold greater in tiger than leopard males. LH pulses (1-2 pulses/3 h) were detected in 60% of saline-treated animals, suggesting pulsatile gonadotrophin secretion; however, in males concomitant testosterone pulses were not observed. These results indicate that there are marked sex and species differences in basal and GnRH-stimulated hormonal responses between felids of the genus Panthera which may be related to differences in adrenal activity.

  1. Expression and Role of Gonadotropin-Releasing Hormone 2 and Its Receptor in Mammals

    Directory of Open Access Journals (Sweden)

    Amy T. Desaulniers

    2017-12-01

    Full Text Available Gonadotropin-releasing hormone 1 (GnRH1 and its receptor (GnRHR1 drive mammalian reproduction via regulation of the gonadotropins. Yet, a second form of GnRH (GnRH2 and its receptor (GnRHR2 also exist in mammals. GnRH2 has been completely conserved throughout 500 million years of evolution, signifying high selection pressure and a critical biological role. However, the GnRH2 gene is absent (e.g., rat or inactivated (e.g., cow and sheep in some species but retained in others (e.g., human, horse, and pig. Likewise, many species (e.g., human, chimpanzee, cow, and sheep retain the GnRHR2 gene but lack the appropriate coding sequence to produce a full-length protein due to gene coding errors; although production of GnRHR2 in humans remains controversial. Certain mammals lack the GnRHR2 gene (e.g., mouse or most exons entirely (e.g., rat. In contrast, old world monkeys, musk shrews, and pigs maintain the coding sequence required to produce a functional GnRHR2. Like GnRHR1, GnRHR2 is a 7-transmembrane, G protein-coupled receptor that interacts with Gαq/11 to mediate cell signaling. However, GnRHR2 retains a cytoplasmic tail and is only 40% homologous to GnRHR1. A role for GnRH2 and its receptor in mammals has been elusive, likely because common laboratory models lack both the ligand and receptor. Uniquely, both GnRH2 and GnRHR2 are ubiquitously expressed; transcript levels are abundant in peripheral tissues and scarcely found in regions of the brain associated with gonadotropin secretion, suggesting a divergent role from GnRH1/GnRHR1. Indeed, GnRH2 and its receptor are not physiological modulators of gonadotropin secretion in mammals. Instead, GnRH2 and GnRHR2 coordinate the interaction between nutritional status and sexual behavior in the female brain. Within peripheral tissues, GnRH2 and its receptor are novel regulators of reproductive organs. GnRH2 and GnRHR2 directly stimulate steroidogenesis within the porcine testis. In the female, GnRH2 and

  2. Effects of Huang Bai (Phellodendri Cortex and Three Other Herbs on GnRH and GH Levels in GT1–7 and GH3 Cells

    Directory of Open Access Journals (Sweden)

    Sun Haeng Lee

    2016-01-01

    Full Text Available The present study was to evaluate the effects of Huang Bai, Zhi Mu, Mai Ya, and Xia Ku Cao on hormone using the GT1–7 and GH3 cells. The GT1–7 and GH3 cell lines were incubated with DW; DMSO; and 30, 100, or 300 μg/mL of one of the four extract solutions in serum-free media for 24 hours. The MTT assay was performed to determine the cytotoxicity of the four herbs. The GT1–7 and GH3 cells were incubated in DW, estradiol (GT1–7 only, or noncytotoxic herb solutions in serum-free medium for 24 hours. A quantitative RT-PCR and western blot were performed to measure the GnRH expression in GT1–7 cells and GH expression in GH3 cells. Huang Bai, Zhi Mu, Xia Ku Cao, and Mai Ya inhibited the GnRH mRNA expression in GT1–7 cells, whereas Huang Bai enhanced GH mRNA expression in GH3 cells. Additionally, Xia Ku Cao inhibited GnRH protein expression in GT1–7 cells and Huang Bai promoted GH protein expression in GH3 cells. The findings suggest that Huang Bai can delay puberty by inhibiting GnRH synthesis in the hypothalamus while also accelerating growth by promoting GH synthesis and secretion in the pituitary.

  3. A comparative therapeutic management of anoestrus in buffaloes using insulin and GnRH

    Directory of Open Access Journals (Sweden)

    R. D. Purkayastha

    2015-06-01

    Full Text Available Aim: Anoestrus is one of the most common functional disorders of the reproductive cycle in buffaloes. In spite of technical advancement, there is no single cure for the management of anoestrus. Therefore, the aim of this study was to find out the efficacy of gonadotropic releasing hormone (GnRH and metabolic hormone for the management of true anoestrus in buffaloes. Materials and Methods: The experimental animals were selected on the basis of history, gyneco-clinical examinations and progesterone estimation. Deworming was done with Fenbendazole and thereafter mineral mixture was given @ 50 g per animal per day for 10 days in all the selected buffaloes before the start of treatment. The selected buffaloes were randomly divided into four groups (n=25. In Group I, buffaloes were administered 20 μg of buserelin intramuscularly. Buffaloes of Group II were administered long-acting insulin @ 0.25 IU/Kg body weight subcutaneously for 5 consecutive days. In Group III, buffaloes were treated with a combination of insulin and buserelin in the above-mentioned doses whereas buffaloes of Group IV were kept as untreated control. Results: The higher oestrus induction (64% vs. 28% was found in Group III and differed significantly (p<0.05 as compared to control group. The conception rate (69.23% vs. 66.66% was also found higher in Group III but did not differ significantly among the treated groups. The mean time taken for the onset of oestrus was recorded significantly shorter in insulin (8.80±0.69 and GnRH (7.60±0.92 days alone and as compared to other (Group III, 14.43±0.83 and Group IV, 20.57±1.69 days groups. Conclusion: The results of this study indicated better fertility response using Insulin plus Buserelin in true anoestrus buffaloes under field conditions.

  4. Neurokinin B and serum albumin limit copper binding to mammalian gonadotropin releasing hormone.

    Science.gov (United States)

    Gul, Ahmad Samir; Tran, Kevin K; Jones, Christopher E

    2018-02-26

    Gonadotropin releasing hormone (GnRH) triggers secretion of luteinizing hormone and follicle stimulating hormone from gonadotropic cells in the anterior pituitary gland. GnRH is able to bind copper, and both in vitro and in vivo studies have suggested that the copper-GnRH complex is more potent at triggering gonadotropin release than GnRH alone. However, it remains unclear whether copper-GnRH is the active species in vivo. To explore this we have estimated the GnRH-copper affinity and have examined whether GnRH remains copper-bound in the presence of serum albumin and the neuropeptide neurokinin B, both copper-binding proteins that GnRH will encounter in vivo. We show that GnRH has a copper dissociation constant of ∼0.9 × 10 -9  M, however serum albumin and neurokinin B can extract metal from the copper-GnRH complex. It is therefore unlikely that a copper-GnRH complex will survive transit through the pituitary portal circulation and that any effect of copper must occur outside the bloodstream in the absence of neurokinin B. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Internalization and recycling of receptor-bound gonadotropin-releasing hormone agonist in pituitary gonadotropes

    International Nuclear Information System (INIS)

    Schvartz, I.; Hazum, E.

    1987-01-01

    The fate of cell surface gonadotropin-releasing hormone (GnRH) receptors on pituitary cells was studied utilizing lysosomotropic agents and monensin. Labeling of pituitary cells with a photoreactive GnRH derivative, [azidobenzoyl-D-Lys6]GnRH, revealed a specific band of Mr = 60,000. When photoaffinity-labeled cells were exposed to trypsin immediately after completion of the binding, the radioactivity incorporated into the Mr = 60,000 band decreased, with a concomitant appearance of a proteolytic fragment (Mr = 45,000). This fragment reflects cell surface receptors. Following GnRH binding, the hormone-receptor complexes underwent internalization, partial degradation, and recycling. The process of hormone-receptor complex degradation was substantially prevented by lysosomotropic agents, such as chloroquine and methylamine, or the proton ionophore, monensin. Chloroquine and monensin, however, did not affect receptor recycling, since the tryptic fragment of Mr = 45,000 was evident after treatment with these agents. This suggests that recycling of GnRH receptors in gonadotropes occurs whether or not the internal environment is acidic. Based on these findings, we propose a model describing the intracellular pathway of GnRH receptors

  6. Adipokinetic hormones and their G protein-coupled receptors emerged in Lophotrochozoa

    DEFF Research Database (Denmark)

    Li, Shizhong; Hauser, Frank; Skadborg, Signe K.

    2016-01-01

    the neuropeptide systems used by proto- or deuterostomes. An exception, however, are members of the gonadotropin-releasing hormone (GnRH) receptor superfamily, which occur in both evolutionary lineages, where GnRHs are the ligands in Deuterostomia and GnRH-like peptides, adipokinetic hormone (AKH), corazonin...

  7. Radioiodinated nondegradable gonadotropin-releasing hormone analogs: new probes for the investigation of pituitary gonadotropin-releasing hormone receptors.

    Science.gov (United States)

    Clayton, R N; Shakespear, R A; Duncan, J A; Marshall, J C; Munson, P J; Rodbard, D

    1979-12-01

    Studies of pituitary plasma membrane gonadotropin-releasing hormone (GnRH) receptors using [125I]-iodo-GnRH suffer major disadvantages. Only a small (less than 25%) proportion of specific tracer binding is to high affinity sites, with more than 70% bound to low affinity sites (Ka = 1 x 10(6) M-1). [125I]Iodo-GnRH is also inactivated during incubation with pituitary plasma membrane preparations. Two superactive analongs of GnRH, substituted in positions 6 and 10, were used as the labeled ligand to overcome these problems. Both analogs bound to the same high affinity sites as GnRH on bovine pituitary plasma membranes, though the affinity of the analogs was higher than that of the natural decapeptide (Ka = 2.0 x 10(9), 6.0 x 10(9), and 3.0 x 10(8) M-1 for [D-Ser(TBu)6]des-Gly10-GnRH ethylamide, [D-Ala6]des-Gly10-GnRH ethylamide, and GnRH, respectively. The labeled analogs bound to a single class of high affinity sites with less than 15% of the specific binding being to low affinity sites (Ka approximately equal to 1 x 10(6) M-1). The labeled analogs were not inactivated during incubation with the pituitary membrane preparations. Using the analogs as tracer, a single class of high affinity sites (K1 = 4.0 x 10(9) M-1) was also demonstrated on crude 10,800 x g rat pituitary membrane preparations. Use of these analogs as both the labeled and unlabeled ligand offers substantial advantages over GnRH for investigation of GnRH receptors, allowing accurate determination of changes in their numbers and affinities under various physiological conditions.

  8. Differentially expressed miRNAs after GnRH treatment and their potential roles in FSH regulation in porcine anterior pituitary cell.

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    Rui-Song Ye

    Full Text Available Hypothalamic gonadotropin-releasing hormone (GnRH is a major regulator of follicle-stimulating hormone (FSH secretion in gonadotrope cell in the anterior pituitary gland. microRNAs (miRNAs are small RNA molecules that control gene expression by imperfect binding to the 3'-untranslated region (3'-UTR of mRNA at the post-transcriptional level. It has been proven that miRNAs play an important role in hormone response and/or regulation. However, little is known about miRNAs in the regulation of FSH secretion. In this study, primary anterior pituitary cells were treated with 100 nM GnRH. The supernatant of pituitary cell was collected for FSH determination by enzyme-linked immunosorbent assay (ELISA at 3 hours and 6 hours post GnRH treatment respectively. Results revealed that GnRH significantly promoted FSH secretion at 3 h and 6 h post-treatment by 1.40-fold and 1.80-fold, respectively. FSHβ mRNA at 6 h post GnRH treatment significantly increased by 1.60-fold. At 6 hours, cells were collected for miRNA expression profile analysis using MiRCURY LNA Array and quantitative PCR (qPCR. Consequently, 21 up-regulated and 10 down-regulated miRNAs were identified, and qPCR verification of 10 randomly selected miRNAs showed a strong correlation with microarray results. Chromosome location analysis indicated that 8 miRNAs were mapped to chromosome 12 and 4 miRNAs to chromosome X. Target and pathway analysis showed that some miRNAs may be associated with GnRH regulation pathways. In addition, In-depth analysis indicated that 10 up-regulated and 3 down-regulated miRNAs probably target FSHβ mRNA 3'-UTR directly, including miR-361-3p, a highly conserved X-linked miRNA. Most importantly, functional experimental results showed that miR-361-3p was involved in FSH secretion regulation, and up-regulated miR-361-3p expression inhibited FSH secretion, while down-regulated miR-361-3p expression promoted FSH secretion in pig pituitary cell model. These differentially

  9. Development of New Gonadotropin-Releasing Hormone-Modified Dendrimer Platforms with Direct Antiproliferative and Gonadotropin Releasing Activity.

    Science.gov (United States)

    Varamini, Pegah; Rafiee, Amirreza; Giddam, Ashwini Kumar; Mansfeld, Friederike M; Steyn, Frederik; Toth, Istvan

    2017-10-26

    Gonadotropin-releasing hormone (GnRH) agonists (e.g., triptorelin) are used for androgen suppression therapy. They possess improved stability as compared to the natural GnRH, yet they suffer from a poor pharmacokinetic profile. To address this, we used a GnRH peptide-modified dendrimer platform with and without lipidation strategy. Dendrimers were synthesized on a polylysine core and bore either native GnRH (1, 2, and 5) or lipid-modified GnRH (3 and 4). Compound 3, which bore a lipidic moiety in a branched tetramer structure, showed approximately 10-fold higher permeability and metabolic stability and 39 times higher antitumor activity against hormone-resistant prostate cancer cells (DU145) relative to triptorelin. In gonadotropin-release experiments, dendrimer 3 was shown to be the most potent construct. Dendrimer 3 showed similar luteinizing hormone (LH)-release activity to triptorelin in mice. Our findings indicate that dendrimer 3 is a promising analog with higher potency for the treatment of hormone-resistant prostate cancer than the currently available GnRH agonists.

  10. ACTH antagonists

    Directory of Open Access Journals (Sweden)

    Adrian John Clark

    2016-08-01

    Full Text Available ACTH acts via a highly selective receptor that is a member of the melanocortin receptor subfamily of type 1 G protein-coupled receptors. The ACTH receptor, also known as the melanocortin 2 receptor (MC2R is unusual in that it is absolutely dependent on a small accessory protein, melanocortin receptor accessory protein (MRAP for cell surface expression and function. ACTH is the only known naturally occurring agonist for this receptor. This lack of redundancy and high degree of ligand specificity suggests that antagonism of this receptor could provide a useful therapeutic aid and a potential investigational tool. Clinical situations in which this could be useful include (1 Cushing’s disease and ectopic ACTH syndrome – especially whilst preparing for definitive treatment of a causative tumour, or in refractory cases, or (2 congenital adrenal hyperplasia – as an adjunct to glucocorticoid replacement. A case for antagonism in other clinical situations in which there is ACTH excess can also be made. In this article we will explore the scientific and clinical case for an ACTH antagonist, and will review the evidence for existing and recently described peptides and modified peptides in this role.

  11. Evidence That Dopamine Acts via Kisspeptin to Hold GnRH Pulse Frequency in Check in Anestrous Ewes

    Science.gov (United States)

    Maltby, Matthew J.; Millar, Robert P.; Hileman, Stanley M.; Nestor, Casey C; Whited, Brant; Tseng, Ashlie S.; Coolen, Lique M.; Lehman, Michael N.

    2012-01-01

    Recent work has implicated stimulatory kisspeptin neurons in the arcuate nucleus (ARC) as important for seasonal changes in reproductive function in sheep, but earlier studies support a role for inhibitory A15 dopaminergic (DA) neurons in the suppression of GnRH (and LH) pulse frequency in the nonbreeding (anestrous) season. Because A15 neurons project to the ARC, we performed three experiments to test the hypothesis that A15 neurons act via ARC kisspeptin neurons to inhibit LH in anestrus: 1) we used dual immunocytochemistry to determine whether these ARC neurons contain D2 dopamine receptor (D2-R), the receptor responsible for inhibition of LH in anestrus; 2) we tested the ability of local administration of sulpiride, a D2-R antagonist, into the ARC to increase LH secretion in anestrus; and 3) we determined whether an antagonist to the kisspeptin receptor could block the increase in LH secretion induced by sulpiride in anestrus. In experiment 1, 40% of this ARC neuronal subpopulation contained D2-R in breeding season ewes, but this increased to approximately 80% in anestrus. In experiment 2, local microinjection of the two highest doses (10 and 50 nmol) of sulpiride into the ARC significantly increased LH pulse frequency to levels 3 times that seen with vehicle injections. Finally, intracerebroventricular infusion of a kisspeptin receptor antagonist completely blocked the increase in LH pulse frequency induced by systemic administration of sulpiride to anestrous ewes. These results support the hypothesis that DA acts to inhibit GnRH (and LH) secretion in anestrus by suppressing the activity of ARC kisspeptin neurons. PMID:23038740

  12. Developmental Regulation of Gonadotropin-releasing Hormone Gene Expression by the MSX and DLX Homeodomain Protein Families*

    Science.gov (United States)

    Givens, Marjory L.; Rave-Harel, Naama; Goonewardena, Vinodha D.; Kurotani, Reiko; Berdy, Sara E.; Swan, Christo H.; Rubenstein, John L. R.; Robert, Benoit; Mellon, Pamela L.

    2010-01-01

    Gonadotropin-releasing hormone (GnRH) is the central regulator of the hypothalamic-pituitary-gonadal axis, controlling sexual maturation and fertility in diverse species from fish to humans. GnRH gene expression is limited to a discrete population of neurons that migrate through the nasal region into the hypothalamus during embryonic development. The GnRH regulatory region contains four conserved homeodomain binding sites (ATTA) that are essential for basal promoter activity and cell-specific expression of the GnRH gene. MSX and DLX are members of the Antennapedia class of non-Hox homeodomain transcription factors that regulate gene expression and influence development of the craniofacial structures and anterior forebrain. Here, we report that expression patterns of the Msx and Dlx families of homeodomain transcription factors largely coincide with the migratory route of GnRH neurons and co-express with GnRH in neurons during embryonic development. In addition, MSX and DLX family members bind directly to the ATTA consensus sequences and regulate transcriptional activity of the GnRH promoter. Finally, mice lacking MSX1 or DLX1 and 2 show altered numbers of GnRH-expressing cells in regions where these factors likely function. These findings strongly support a role for MSX and DLX in contributing to spatiotemporal regulation of GnRH transcription during development. PMID:15743757

  13. Developmental regulation of gonadotropin-releasing hormone gene expression by the MSX and DLX homeodomain protein families.

    Science.gov (United States)

    Givens, Marjory L; Rave-Harel, Naama; Goonewardena, Vinodha D; Kurotani, Reiko; Berdy, Sara E; Swan, Christo H; Rubenstein, John L R; Robert, Benoit; Mellon, Pamela L

    2005-05-13

    Gonadotropin-releasing hormone (GnRH) is the central regulator of the hypothalamic-pituitary-gonadal axis, controlling sexual maturation and fertility in diverse species from fish to humans. GnRH gene expression is limited to a discrete population of neurons that migrate through the nasal region into the hypothalamus during embryonic development. The GnRH regulatory region contains four conserved homeodomain binding sites (ATTA) that are essential for basal promoter activity and cell-specific expression of the GnRH gene. MSX and DLX are members of the Antennapedia class of non-Hox homeodomain transcription factors that regulate gene expression and influence development of the craniofacial structures and anterior forebrain. Here, we report that expression patterns of the Msx and Dlx families of homeodomain transcription factors largely coincide with the migratory route of GnRH neurons and co-express with GnRH in neurons during embryonic development. In addition, MSX and DLX family members bind directly to the ATTA consensus sequences and regulate transcriptional activity of the GnRH promoter. Finally, mice lacking MSX1 or DLX1 and 2 show altered numbers of GnRH-expressing cells in regions where these factors likely function. These findings strongly support a role for MSX and DLX in contributing to spatiotemporal regulation of GnRH transcription during development.

  14. Is the use of a GnRH antagonist effective in patients with polycystic ...

    African Journals Online (AJOL)

    Introduction. Polycystic ovarian disease (PCOS) can account for up to 35 - 40% of the female factor causes of infertility. These patients present as medically complex cases and are challenging to manage and treat successfully. They are resistant to treatment and are often offered controlled ovarian stimulation (COS) and in ...

  15. Premenstrual Exacerbation of Life-Threatening Asthma: Effect of Gonadotrophin Releasing Hormone Analogue Therapy

    Directory of Open Access Journals (Sweden)

    Alun L Edwards

    1996-01-01

    Full Text Available Variability in the severity of asthma during various phases of the menstrual cycle has been frequently suspected. However, the hormonal changes that might affect mediators of bronchospasm have yet to be elucidated. The case of a 41-year-old woman suffering from longstanding asthma with life-threatening exacerbations is reported. The patient was treated with buserelin, a gonadotropin releasing hormone (GnRH analogue, which created a temporary chemical menopause and thus permitted diagnosis of a premenstrual exacerbation of asthma and offered insight into potential therapy. GnRH analogues may therefore be of value in assessing women with severe asthma suspected to vary with the menstrual cycle. The addition of estrogens and progestins at the same time as treatment with GnRH analogue may be of value in determining the role of these hormones in the pathogenesis of menstrually related exacerbations of asthma.

  16. Parity Differences in Heat Expression of Dairy Cows Synchronized with GnRH, CIDR and PGF2α during Dry Season in Zambia

    Directory of Open Access Journals (Sweden)

    E. S. Mwaanga*, K. Choongo, H. Simukoko and C. Chama1

    2012-01-01

    Full Text Available A study was conducted to investigate parity differences in heat expression of dairy cows heat-synchronized during the dry season when feed scarcity is common. Cyclic cows (n=65 aged 2 to 10 years with parity range of 0 to 7 were selected from small-holder dairy farms around Lusaka. Cows were divided into 3 groups of nulliparous, primiparous and pluriparous. Heat-was synchronized using gonadotrophin releasing hormone (GnRH and controlled intra-vaginal drug releasing device (CIDR. Heat detection was observed after CIDR withdraw. The study showed a significantly (P<0.05 lower number of primiparous cows (68% coming into heat compared to nulliparous (81.8% and pluriparous cows (83.3%. It was concluded that parity influences estrus expression rate in dairy cows following synchronization with GnRH, CIDR and PGF2α during the dry season in the sub-tropics.

  17. CHARACTERIZATION OF THE RECEPTOR FOR GONADOTROPIN-RELEASING HORMONE IN THE PITUITARY OF THE AFRICAN CATFISH, CLARIAS-GARIEPINUS

    NARCIS (Netherlands)

    de Leeuw, R.; Conn, P. M.; van't Veer, C.; Goos, H. J.; van Oordt, P. G.

    1988-01-01

    Receptors for gonadotropin-releasing hormone (GnRH) were characterized using a radioligand prepared from a superactive analog of salmon GnRH (sGnRH), D-Arg(6)-Pro(9)-sGnRH-NEt (sGnRHa). Binding of(125)I-sGnRHa to catfish pituitary membrane fractions reached equilibrium after 2 h incubation at 4°C.

  18. Characterization and differential expression of three GnRH forms during reproductive development in cultured turbot Schophthalmus maximus

    Science.gov (United States)

    Zhao, Chunyan; Xu, Shihong; Feng, Chengcheng; Liu, Yifan; Yang, Yang; Wang, Yanfeng; Xiao, Yongshuang; Song, Zongcheng; Liu, Qinghua; Li, Jun

    2017-10-01

    Turbots (Schophthalmus maximus), one of the most important economic marine flatfish species, fail to undergo final spawning and spermiation naturally under artificial farming conditions. In vertebrates, reproduction is regulated by the brain-pituitary-gonadal axis (BPG-axis), and gonadotropin releasing hormone (GnRH) is one of its key components. Therefore, to better understand the physiology of reproduction in the turbot, three of the genes encoding GnRH subtypes—sbGnRH, cGnRH-II and sGnRH—were cloned and sequenced by isolating the cDNA sequences. The localizations and patterns of expression of their mRNAs were also evaluated during seasonal gonadal development. All three mRNAs were expressed abundantly in the brain; sbGnRH and sGnRH mRNAs were also detected in the gonads and pituitary gland, and sbGnRH expression was much higher than that of sGnRH, indicating the critical role of sbGnRH in regulating the BPG-axis. Moreover, the brain expression patterns of sbGnRH and sGnRH mRNAs showed an increased trend during gonadal development, peaking in mature stages. This indicated the direct regulation of gonadal development by the GnRH system. In addition, cGnRH-II mRNA expression showed no significant variations, suggesting that cGnRH-II is not critically involved in the control of reproduction. Further, the mRNA abundances of the three GnRH forms in the breeding season were significantly higher than those in immature and post-breeding stages in all analyzed brain areas. Therefore, we propose that sbGnRH is the most important hormone for the regulation of reproduction in turbot via the BPG-axis. These results will help in better understanding the reproductive endocrine mechanisms of turbots and lay the groundwork for additional studies aimed at comparing the reproductive physiology of wild individuals with those raised under artificial conditions.

  19. The GnRH analogue triptorelin confers ovarian radio-protection to adult female rats

    International Nuclear Information System (INIS)

    Camats, N.; Garcia, F.; Parrilla, J.J.; Calaf, J.; Martin-Mateo, M.; Caldes, M. Garcia

    2009-01-01

    There is a controversy regarding the effects of the analogues of the gonadotrophin-releasing hormone (GnRH) in radiotherapy. This has led us to study the possible radio-protection of the ovarian function of a GnRH agonist analogue (GnRHa), triptorelin, in adult, female rats (Rattus norvegicus sp.). The effects of the X-irradiation on the oocytes of ovarian primordial follicles, with and without GnRHa treatment, were compared, directly in the female rats (F 0 ) with reproductive parameters, and in the somatic cells of the resulting foetuses (F 1 ) with cytogenetical parameters. In order to do this, the ovaries and uteri from 82 females were extracted for the reproductive analysis and 236 foetuses were obtained for cytogenetical analysis. The cytogenetical study was based on the data from 22,151 metaphases analysed. The cytogenetical parameters analysed to assess the existence of chromosomal instability were the number of aberrant metaphases (2234) and the number (2854) and type of structural chromosomal aberrations, including gaps and breaks. Concerning the reproductive analysis of the ovaries and the uteri, the parameters analysed were the number of corpora lutea, implantations, implantation losses and foetuses. Triptorelin confers radio-protection of the ovaries in front of chromosomal instability, which is different, with respect to the single and fractioned dose. The cytogenetical analysis shows a general decrease in most of the parameters of the triptorelin-treated groups, with respect to their controls, and some of these differences were considered to be statistically significant. The reproductive analysis indicates that there is also radio-protection by the agonist, although minor to the cytogenetical one. Only some of the analysed parameters show a statistically significant decrease in the triptorelin-treated groups.

  20. The GnRH analogue triptorelin confers ovarian radio-protection to adult female rats

    Energy Technology Data Exchange (ETDEWEB)

    Camats, N. [Institut de Biotecnologia i de Biomedicina (I.B.B.), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, F. [Institut de Biotecnologia i de Biomedicina (I.B.B.), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Parrilla, J.J. [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, 30120 El Palmar, Murcia (Spain); Calaf, J. [Servei de Ginecologia i Obstetricia, Hospital Universitari de la Santa Creu i Sant Pau, 08025 Barcelona (Spain); Martin-Mateo, M. [Departament de Pediatria, d' Obstetricia i Ginecologia i de Medicina Preventiva, Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Caldes, M. Garcia, E-mail: Montserrat.Garcia.Caldes@uab.es [Institut de Biotecnologia i de Biomedicina (I.B.B.), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Barcelona (Spain)

    2009-10-02

    There is a controversy regarding the effects of the analogues of the gonadotrophin-releasing hormone (GnRH) in radiotherapy. This has led us to study the possible radio-protection of the ovarian function of a GnRH agonist analogue (GnRHa), triptorelin, in adult, female rats (Rattus norvegicus sp.). The effects of the X-irradiation on the oocytes of ovarian primordial follicles, with and without GnRHa treatment, were compared, directly in the female rats (F{sub 0}) with reproductive parameters, and in the somatic cells of the resulting foetuses (F{sub 1}) with cytogenetical parameters. In order to do this, the ovaries and uteri from 82 females were extracted for the reproductive analysis and 236 foetuses were obtained for cytogenetical analysis. The cytogenetical study was based on the data from 22,151 metaphases analysed. The cytogenetical parameters analysed to assess the existence of chromosomal instability were the number of aberrant metaphases (2234) and the number (2854) and type of structural chromosomal aberrations, including gaps and breaks. Concerning the reproductive analysis of the ovaries and the uteri, the parameters analysed were the number of corpora lutea, implantations, implantation losses and foetuses. Triptorelin confers radio-protection of the ovaries in front of chromosomal instability, which is different, with respect to the single and fractioned dose. The cytogenetical analysis shows a general decrease in most of the parameters of the triptorelin-treated groups, with respect to their controls, and some of these differences were considered to be statistically significant. The reproductive analysis indicates that there is also radio-protection by the agonist, although minor to the cytogenetical one. Only some of the analysed parameters show a statistically significant decrease in the triptorelin-treated groups.

  1. Changes in gonadotropin-releasing hormone and gonadotropin-releasing hormone receptor gene expression after an increase in carbon monoxide concentration in the cavernous sinus of male wild boar and pig crossbread.

    Science.gov (United States)

    Romerowicz-Misielak, M; Tabecka-Lonczynska, A; Koziol, K; Gilun, P; Stefanczyk-Krzymowska, S; Och, W; Koziorowski, M

    2016-06-01

    Previous studies indicate that there are at least a few regulatory systems involved in photoperiodic synchronisation of reproductive activity, which starts with the retina and ends at the gonadotropin-releasing hormone (GnRH) pulse generator. Recently we have shown indicated that the amount of carbon monoxide (CO) released from the eye into the ophthalmic venous blood depends on the intensity of sunlight. The aim of this study was to test whether changes in the concentration of carbon monoxide in the ophthalmic venous blood may modulate reproductive activity, as measured by changes in GnRH and GnRH receptor gene expression. The animal model used was mature male swine crossbred from wild boars and domestic sows (n = 48). We conducted in vivo experiments to determine the effect of increased CO concentrations in the cavernous sinus of the mammalian perihypophyseal vascular complex on gene expression of GnRH and GnRH receptors as well as serum luteinizing hormone (LH) levels. The experiments were performed during long photoperiod days near the summer solstice (second half of June) and short photoperiod days near the winter solstice (second half of December). These crossbred swine demonstrated a seasonally-dependent marked variation in GnRH and GnRH receptor gene expression and systemic LH levels in response to changes in CO concentration in ophthalmic venous blood. These results seem to confirm the hypothesis of humoral phototransduction as a mechanism for some of bright light's effects in animal chronobiology and the effect of CO on GnRH and GnRH receptor gene expression.

  2. Lactobacillus rhamnosus accelerates zebrafish backbone calcification and gonadal differentiation through effects on the GnRH and IGF systems.

    Directory of Open Access Journals (Sweden)

    Matteo A Avella

    Full Text Available Endogenous microbiota play essential roles in the host's immune system, physiology, reproduction and nutrient metabolism. We hypothesized that a continuous administration of an exogenous probiotic might also influence the host's development. Thus, we treated zebrafish from birth to sexual maturation (2-months treatment with Lactobacillus rhamnosus, a probiotic species intended for human use. We monitored for the presence of L. rhamnosus during the entire treatment. Zebrafish at 6 days post fertilization (dpf exhibited elevated gene expression levels for Insulin-like growth factors -I and -II, Peroxisome proliferator activated receptors -α and -β, VDR-α and RAR-γ when compared to untreated-10 days old zebrafish. Using a gonadotropin-releasing hormone 3 GFP transgenic zebrafish (GnRH3-GFP, higher GnRH3 expression was found at 6, 8 and 10 dpf upon L. rhamnosus treatment. The same larvae exhibited earlier backbone calcification and gonad maturation. Noteworthy in the gonad development was the presence of first testes differentiation at 3 weeks post fertilization in the treated zebrafish population -which normally occurs at 8 weeks- and a dramatic sex ratio modulation (93% females, 7% males in control vs. 55% females, 45% males in the treated group. We infer that administration of L. rhamnosus stimulated the IGF system, leading to a faster backbone calcification. Moreover we hypothesize a role for administration of L. rhamnosus on GnRH3 modulation during early larval development, which in turn affects gonadal development and sex differentiation. These findings suggest a significant role of the microbiota composition on the host organism development profile and open new perspectives in the study of probiotics usage and application.

  3. Identification of the GnRH-(1-5) Receptor and Signaling Pathway

    Science.gov (United States)

    2013-03-22

    expression in immortalized GnRH neurons and to facilitate lordosis behavior in female rats. Interestingly, EP24.15 colocalizes with vii...expression in immortalized GnRH neurons (73) and facilitates lordosis behavior in female rats (72). Interestingly, EP24.15 is expressed along the...biologically active by facilitating lordosis behavior in ovariectomized estrogen-primed rats (72); and can increase the mRNA expression of GnRH in immortalized

  4. Negative feedback governs gonadotrope frequency-decoding of gonadotropin releasing hormone pulse-frequency.

    Directory of Open Access Journals (Sweden)

    Stefan Lim

    Full Text Available The synthesis of the gonadotropin subunits is directed by pulsatile gonadotropin-releasing hormone (GnRH from the hypothalamus, with the frequency of GnRH pulses governing the differential expression of the common alpha-subunit, luteinizing hormone beta-subunit (LHbeta and follicle-stimulating hormone beta-subunit (FSHbeta. Three mitogen-activated protein kinases, (MAPKs, ERK1/2, JNK and p38, contribute uniquely and combinatorially to the expression of each of these subunit genes. In this study, using both experimental and computational methods, we found that dual specificity phosphatase regulation of the activity of the three MAPKs through negative feedback is required, and forms the basis for decoding the frequency of pulsatile GnRH. A fourth MAPK, ERK5, was shown also to be activated by GnRH. ERK5 was found to stimulate FSHbeta promoter activity and to increase FSHbeta mRNA levels, as well as enhancing its preference for low GnRH pulse frequencies. The latter is achieved through boosting the ultrasensitive behavior of FSHbeta gene expression by increasing the number of MAPK dependencies, and through modulating the feedforward effects of JNK activation on the GnRH receptor (GnRH-R. Our findings contribute to understanding the role of changing GnRH pulse-frequency in controlling transcription of the pituitary gonadotropins, which comprises a crucial aspect in regulating reproduction. Pulsatile stimuli and oscillating signals are integral to many biological processes, and elucidation of the mechanisms through which the pulsatility is decoded explains how the same stimulant can lead to various outcomes in a single cell.

  5. Expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in control of GnRH secretion.

    Science.gov (United States)

    Yang, Ying; Zhou, Li-bin; Liu, Shang-quan; Tang, Jing-feng; Li, Feng-yin; Li, Rong-ying; Song, Huai-dong; Chen, Ming-dao

    2005-08-01

    To investigate the expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in the control of GnRH secretion. Receptors of bombesin3, cholecystokinin (CCK)-A, CCK-B, glucagon-like peptide (GLP)1, melanin-concentrating hormone (MCH)1, orexin1, orexin2, neuromedin-B, neuropeptide Y (NPY)1 and NPY5, neurotensin (NT)1, NT2, NT3, and leptin receptor long form mRNA in GT1-7 cells were detected by reversed transcriptase-polymerase chain reaction. GT1-7 cells were treated with leptin, orexin A and orexin B at a cohort of concentrations for different lengths of time, and GnRH in medium was determined by radioimmunoassay (RIA). Receptors of bombesin 3, CCK-B, GLP1, MCH1, orexin1, neuromedin-B, NPY1, NPY5, NT1, NT3, and leptin receptor long form mRNA were expressed in GT1-7 cells, of which, receptors of GLP1, neuromedin-B, NPY1, and NT3 were highly expressed. No amplified fragments of orexin2, NT2, and CCK-A receptor cDNA were generated with GT1-7 RNA, indicating that the GT1-7 cells did not express mRNA of them. Leptin induced a significant stimulation of GnRH release, the results being most significant at 0.1 nmol/L for 15 min. In contrast to other studies in hypothalamic explants, neither orexin A nor orexin B affected basal GnRH secretion over a wide range of concentrations ranging from 1 nmol/L to 500 nmol/Lat 15, 30, and 60 min. Feeding and reproductive function are closely linked. Many orexigenic and anorexigenic signals may control feeding behavior as well as alter GnRH secretion through their receptors on GnRH neurons.

  6. Targeted Mutagenesis of the Hypophysiotropic Gnrh3 in Zebrafish (Danio rerio Reveals No Effects on Reproductive Performance.

    Directory of Open Access Journals (Sweden)

    Olivia Smith Spicer

    Full Text Available Gnrh is the major neuropeptide regulator of vertebrate reproduction, triggering a cascade of events in the pituitary-gonadal axis that result in reproductive competence. Previous research in mice and humans has demonstrated that Gnrh/GNRH null mutations result in hypogonadotropic hypogonadism and infertility. The goal of this study was to eliminate gnrh3 (the hypophysiotropic Gnrh form function in zebrafish (Danio rerio to determine how ontogeny and reproductive performance are affected, as well as factors downstream of Gnrh3 along the reproductive axis. Using the TALEN technology, we developed a gnrh3-/- zebrafish line that harbors a 62 bp deletion in the gnrh3 gene. Our gnrh3-/- zebrafish line represents the first targeted and heritable mutation of a Gnrh isoform in any organism. Using immunohistochemistry, we verified that gnrh3-/- fish do not possess Gnrh3 peptide in any regions of the brain. However, other than changes in mRNA levels of pituitary gonadotropin genes (fshb, lhb, and cga during early development, which are corrected by adulthood, there were no changes in ontogeny and reproduction in gnrh3-/- fish. The gnrh3-/- zebrafish are fertile, displaying normal gametogenesis and reproductive performance in males and females. Together with our previous results that Gnrh3 cell ablation causes infertility, these results indicate that a compensatory mechanism is being activated, which is probably primed early on upon Gnrh3 neuron differentiation and possibly confined to Gnrh3 neurons. Potential compensation factors and sensitive windows of time for compensation during development and puberty should be explored.

  7. Adult height after spontaneous pubertal growth or GnRH analog treatment in girls with early puberty: a meta-analysis.

    Science.gov (United States)

    Bertelloni, Silvano; Massart, Francesco; Miccoli, Mario; Baroncelli, Giampiero I

    2017-06-01

    Early puberty (EP) has been defined as the onset of puberty in the low-normal range; it may be a cause for concern regarding a possible impairment of adult height (AH). This paper meta-analysed data on AH after spontaneous growth or after gonadotropin-releasing hormone (GnRH) analog treatment in girls with EP. A computerized literature search was conducted from 1980 to June 30, 2016. Only published studies in English were considered. Eight papers were selected (483 cases). In untreated girls (n = 300), predicted adult height (PAH) at start of follow-up (-0.559 SDS (95%CI -1.110 to 0.001); P = 0.050) was close to mid-parental height (MPH) (-0.557 SDS (95%CI -0.736 to -0.419); P adult height. What is New: • Untreated and GnRH analog treated girls with early puberty reached similar adult height. • Adult height was consistent with mid-parental height in both untreated and GnRH analog treated girls with early puberty.

  8. The olfactory gonadotropin-releasing hormone immunoreactive system in mouse.

    Science.gov (United States)

    Jennes, L

    1986-10-29

    The olfactory gonadotropin-releasing hormone (GnRH) system in mice was studied with immunofluorescence in combination with lesions of the olfactory bulb and retrograde transport of horseradish peroxidase (HRP) which was administered intravascularly, intranasally or into the subarachnoid space. GnRH-positive neurons were located in the two major branches forming the septal roots of the nervus terminalis, in the ganglion terminale, within the fascicles of the nervus terminalis throughout its extent, in a conspicuous band which connects the ventral neck of the caudal olfactory bulb with the accessory olfactory bulb and in the nasal mucosa. GnRH-positive fibers were seen in all areas in which neurons were found, i.e. in the rostral septum, the ganglion and nervus terminalis and in the nasal subepithelium. In addition, a broad bundle of fibers was observed to surround the entire caudal olfactory bulb, connecting the rostral sulcus rhinalis with the ventrocaudal olfactory bulb. Fibers were seen in close association with the main and accessory olfactory bulb, with the fila olfactoria and with the nasal mucosa. Throughout the olfactory bulb and the nasal epithelium, an association of GnRH fibers with blood vessels was apparent. Intravascular and intranasal injection of HRP resulted in labeling of certain GnRH neurons in the septal roots of the nervus terminalis, the ganglion terminale, the nervus terminalis, the caudal ventrodorsal connection and in the accessory olfactory bulb. After placement of HRP into the subarachnoid space dorsal to the accessory olfactory bulb, about 50% of the GnRH neurons in the accessory olfactory bulb and in the ventrodorsal connection were labeled with HRP. Also, a few GnRH neurons in the rostral septum, the ganglion terminale and in the fascicles of the nervus terminalis had taken up the enzyme. Lesions of the nervus terminalis caudal to the ganglion terminale resulted in sprouting of GnRH fibers at both sites of the knife cut. Lesions rostral

  9. alpha-difluoromethylornithine modifies gonadotropin-releasing hormone release and follicle-stimulating hormone secretion in the immature female rat.

    Science.gov (United States)

    Thyssen, S M; Becú-Villalobos, D; Lacau-Mengido, I M; Libertun, C

    1997-06-01

    Polyamines play an essential role in tissue growth and differentiation, in body weight increment, in brain organization, and in the molecular mechanisms of hormonal action, intracellular signaling, and cell-to-cell communication. In a previous study, inhibition of their synthesis by alpha-difluoromethylornithine (DFMO), a specific and irreversible inhibitor of ornithine decarboxylase, during development in female rats, was followed by prolonged high follicle-stimulating hormone (FSH) serum level and a delayed puberty onset. Those changes were relatively independent of body mass and did not impair posterior fertility. The present work studies the mechanisms and site of action of polyamine participation in FSH secretion during development. DFMO was injected in female rats between Days 1 and 9 on alternate days. At 10 days of age, hypothalami from control and DFMO rats were perifused in vitro, and basal and potassium-induced gonadotropin-releasing hormone (GnRH) release were measured. The response to membrane depolarization was altered in DFMO hypothalami. Increased GnRH release in response to a low K+ concentration was evidenced. Adenohypophyses of the same treated prepubertal rats were perifused in vitro and the response to GnRH pulses was checked. In DFMO-treated rats, higher FSH release was observed, with no changes in LH or PRL secretion. Finally, pituitary GnRH receptor number in adenohypophyseal membranes from treated and control groups was quantified. A significant reduction in specific binding was evident in hypophyses from DFMO-treated rats when compared with binding in the control group. In summary, DFMO treatment in a critical developmental period in the female rat impacts the immature GnRH neuronal network and immature gonadotropes. A delay in maturation is evidenced by a higher sensitivity to secretagogs in both pituitary glands and hypothalamic explants. These events could explain the prolonged high FSH serum levels and delayed puberty onset seen in

  10. Serum inhibin A and inhibin B in central precocious puberty before and during treatment with GnRH agonists

    DEFF Research Database (Denmark)

    Sehested, A; Andersson, A M; Müller, J

    2000-01-01

    both gonadotropins and estradiol levels become suppressed. We therefore investigated serum levels of inhibin A and inhibin B in girls with CPP at diagnosis and during treatment in order to test the hypothesis that inhibin secretion would increase and decrease in parallel with the activation......Serum levels of the gonadal hormones inhibin A and inhibin B are undetectable or low in prepubertal girls, and rise during puberty. In girls with central precocious puberty (CPP) the hypothalamic-pituitary-gonadal axis is prematurely activated, if the girl is thereafter treated with GnRH agonists...... and suppression of the hypothalamic-pituitary-gonadal axis. Serum levels of inhibin A and inhibin B were significantly (p 0.0005) elevated in 42 girls at diagnosis of CPP (inhibin A: 7 pg/ml (...

  11. Do GnRH analogues directly affect human endometrial epithelial cell gene expression?

    KAUST Repository

    Zhang, Xiaomei; Bocca, Silvina Maria; Franchi, Anahí ; Anderson, Sandra; Kaur, Mandeep; Bajic, Vladimir B.; Oehninger, Sergio Carlos

    2010-01-01

    were: (i) to study the modulatory effect of GnRH analogues by RT-PCR [in the absence and presence of E2 and P4, and cyclic adenosine monophos-phate (cAMP)] on mRNA expression of genes modulated during the window of implantation in GnRH analogues

  12. Low-dose add-back therapy during postoperative GnRH agonist treatment

    Directory of Open Access Journals (Sweden)

    Hsiao-Wen Tsai

    2016-02-01

    Conclusion: Low dose add-back therapy could effectively ameliorate hypoestrogenic side effects and simultaneously maintain the therapeutic response of GnRH agonist treatment. The treatment dropout was lower compared with a regular dose. Therefore, low dose add-back therapy can be considered a treatment choice during postoperative GnRH agonist treatment.

  13. Prenatal exposure to vinclozolin disrupts selective aspects of the gonadotrophin-releasing hormone neuronal system of the rabbit.

    Science.gov (United States)

    Wadas, B C; Hartshorn, C A; Aurand, E R; Palmer, J S; Roselli, C E; Noel, M L; Gore, A C; Veeramachaneni, D N R; Tobet, S A

    2010-06-01

    Developmental exposure to the agricultural fungicide vinclozolin can impair reproductive function in male rabbits and was previously found to decrease the number of immunoreactive-gonadotrophin-releasing hormone (GnRH) neurones in the region of the organum vasculosum of the lamina terminalis and rostral preoptic area by postnatal week (PNW) 6. In the present study, in an aim to further examine the disruption of GnRH neurones by foetal vinclozolin exposure, pregnant rabbits were dosed orally with vinclozolin, flutamide or carrot paste vehicle for the last 2 weeks of gestation. Offspring were euthanised at birth (males and females), PNW 6 (females), PNW 26 (adult males) or PNW 30 (adult females) of age. At birth and in adults, brains were sectioned and processed for immunoreactive GnRH. The numbers of immunoreactive GnRH neuronal perikarya were significantly decreased in vinclozolin-treated rabbits at birth and in adult littermates. By contrast, there was an increase in GnRH immunoreactivity in the terminals in the region of the median eminence. Analysis of PNW 6 female brains by radioimmunoassay revealed a two-fold increase in GnRH peptide content in the mediobasal hypothalamus in vinclozolin-treated rabbits. This finding was complemented by immunofluorescence analyses, which revealed a 2.8-fold increase in GnRH immunoreactivity in the median eminence of vinclozolin compared to vehicle-treated females at PNW 30. However, there was no difference between treatment groups in the measures of reproduction that were evaluated: ejaculation latency, conception rates or litter size. These results indicate that sub-acute, prenatal vinclozolin treatment is sufficient to create perdurable alterations in the GnRH neuronal network that forms an important input into the reproductive axis. Finally, the effect of vinclozolin on the GnRH neuronal network was not comparable to that of flutamide, suggesting that vinclozolin was not acting through anti-androgenic mechanisms.

  14. Live birth in a 46-year-old woman using microdose GnRH agonist flare-up protocol combined with GnRH antagonist: a case report.

    Science.gov (United States)

    Zhang, Hong; Liu, Ya-Qiong; Lu, Guang-Xiu; Gong, Fei

    2016-12-01

    Few successful pregnancies after age 45 years with low ovarian reserve have been reported. We report a 46-year-old woman with basal FSH 20.36 mIU/mL and an antral follicle count of four obtained two embryos and delivered a healthy infant with IVF using a microdose GnRH-a flare-up protocol combined with GnRH-ant.

  15. Effect of cortisol on gonadotropin inhibitory hormone (GnIH) in the cinnamon clownfish, Amphiprion melanopus.

    Science.gov (United States)

    Choi, Young Jae; Habibi, Hamid R; Kil, Gyung-Suk; Jung, Min-Min; Choi, Cheol Young

    2017-04-01

    Hypothalamic peptides, gonadotropin-releasing hormone (GnRH) and gonadotropin inhibitory hormone (GnIH), play pivotal roles in the control of reproduction and gonadal maturation in fish. In the present study we tested the possibility that stress-mediated reproductive dysfunction in teleost may involve changes in GnRH and GnIH activity. We studied expression of brain GnIH, GnIH-R, seabream GnRH (sbGnRH), as well as circulating levels of follicle stimulating hormone (FSH), and luteinizing hormone (LH) in the cinnamon clownfish, Amphiprion melanopus. Treatment with cortisol increased GnIH mRNA level, but reduced sbGnRH mRNA and circulating levels of LH and FSH in cinnamon clownfish. Using double immunofluorescence staining, we found expression of both GnIH and GnRH in the diencephalon region of cinnamon clownfish brain. These findings support the hypothesis that cortisol, an indicator of stress, affects reproduction, in part, by increasing GnIH in cinnamon clownfish which contributes to hypothalamic suppression of reproductive function in A. melanopus, a protandrous hermaphroditic fish. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. LH response to GnRH blood test

    Science.gov (United States)

    ... as release of too much hormone ( hyperprolactinemia ) Large pituitary tumors Decrease in hormones made by the endocrine glands Too much iron in the body ( hemochromatosis ) Eating disorders, such as anorexia Recent significant weight loss, such ...

  17. A nonpeptidyl growth hormone secretagogue.

    Science.gov (United States)

    Smith, R G; Cheng, K; Schoen, W R; Pong, S S; Hickey, G; Jacks, T; Butler, B; Chan, W W; Chaung, L Y; Judith, F

    1993-06-11

    A nonpeptidyl secretagogue for growth hormone of the structure 3-amino-3-methyl-N-(2,3,4,5-tetrahydro-2-oxo-1-([2'-(1H-tetrazol-5 -yl) (1,1'-biphenyl)-4-yl]methyl)-1H-1-benzazepin-3(R)-yl)-butanamid e (L-692,429) has been identified. L-692,429 synergizes with the natural growth hormone secretagogue growth hormone-releasing hormone and acts through an alternative signal transduction pathway. The mechanism of action of L-692,429 and studies with peptidyl and nonpeptidyl antagonists suggest that this molecule is a mimic of the growth hormone-releasing hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6). L-692,429 is an example of a nonpeptidyl specific secretagogue for growth hormone.

  18. Effects of a gonadotropin-releasing hormone vaccine on ovarian cyclicity and uterine morphology of an Asian elephant (Elephas maximus).

    Science.gov (United States)

    Boedeker, Nancy C; Hayek, Lee-Ann C; Murray, Suzan; de Avila, David M; Brown, Janine L

    2012-09-01

    This report describes the successful use of a gonadotropin-releasing hormone (GnRH) vaccine to suppress ovarian steroidogenic activity and to treat hemorrhage and anemia associated with reproductive tract pathology in a 59-year-old Asian elephant (Elephas maximus). The Repro-BLOC GnRH vaccine was administered subcutaneously as a series of 4 boosters of increasing dose from 3 to 30 mg of recombinant ovalbumin-GnRH fusion protein given at variable intervals after initial vaccination with 3 mg protein. Efficacy was confirmed over a year after initial vaccination based on complete ovarian cycle suppression determined by serum progestagen analyses. Estrous cycle suppression was associated with a significant increase in GnRH antibody binding and subsequent decrease in serum luteinizing hormone and follicle-stimulating hormone concentrations. Ultrasonographic examinations of the reproductive tract documented a reduction in uterine size and vascularity after immunization. The hematocrit level normalized soon after the initial intrauterine hemorrhage, and no recurrence of anemia has been detected. No substantive adverse effects were associated with GnRH vaccination. The results indicate that GnRH vaccination in elephants shows potential for contraception and management of uterine pathology in older elephants.

  19. Evaluation of basal sex hormone levels for activation of the hypothalamic-pituitary-gonadal axis.

    Science.gov (United States)

    Ding, Yu; Li, Juan; Yu, Yongguo; Yang, Peirong; Li, Huaiyuan; Shen, Yongnian; Huang, Xiaodong; Liu, Shijian

    2018-03-28

    This study aimed to identify the predictive value of basal sex hormone levels for activation of the hypothalamic-pituitary-gonadal (HPG) axis in girls. Gonadotropin-releasing hormone (GnRH) stimulation tests were performed and evaluated in a total of 1750 girls with development of secondary sex characteristics. Correlation analyses were conducted between basal sex hormones and peak luteinizing hormone (LH) levels ≥5 IU/L during the GnRH stimulation test. Receiver operating characteristic (ROC) curves for basal levels of LH, follicle-stimulating hormone (FSH), LH/FSH, and estradiol (E2) before the GnRH stimulation test were plotted. The area under the curve (AUC) and 95% confidence intervals (CIs) were measured for each curve. The maximum AUC value was observed for basal LH levels (0.77, 95% CI: 0.74-0.79), followed by basal FSH levels (0.73, 95% CI: 0.70-0.75), the basal LH/FSH ratio (0.68, 95% CI: 0.65-0.71), and basal E2 levels (0.61, 95% CI: 0.59-0.64). The appropriate cutoff value of basal LH levels associated with a positive response of the GnRH stimulation test was 0.35 IU/L, with a sensitivity of 63.96% and specificity of 76.3% from the ROC curves when Youden's index showed the maximum value. When 100% of patients had peak LH levels ≥5 IU/L, basal LH values were >2.72 IU/L, but the specificity was only 5.45%. Increased basal LH levels are a significant predictor of a positive response during the GnRH stimulation test for assessing activation of the HPG axis in most girls with early pubertal signs.

  20. Luteinizing hormone pulsatility in females following radiation therapy for central nervous system malignancies

    International Nuclear Information System (INIS)

    Brasacchio, R.A.; Constine, L.S.; Woolf, P.; Raubertas, R.F.; Veldhuis, J.D.; Muhs, A.G.

    1997-01-01

    Purpose: Females incidentally irradiated to the hypothalamic-pituitary axis (H/P-A) during radiation therapy (RT) for brain tumors may become oligoamenorrheic. We previously demonstrated that these women are hypoestrogenemic but frequently have near normal or only moderately decreased basal luteinizing hormone (LH) levels and maintain appropriate peak pituitary responses to exogenous gonadotropin releasing hormone (GnRH). We postulated that hypothalamic injury resulting in abnormal LH pulsatility could explain this complex of findings. This investigation intended to characterize this hypothalamic injury and test two potentially corrective pharmacologic interventions. Catecholamines (specifically dopamine) and opiates are known to suppress pituitary LH release through inhibition of the pituitary gonadotropes or of the GnRH neuronal terminals in the hypothalamus. Radiation-induced dysfunction of the catecholaminergic or opiate control mechanisms might translate into an increase in dopamine or opiate release or receptor responsiveness, which in turn would inhibit pulsatile gonadotropin secretion, leading to reduced LH pulsatility and to gonadal dysfunction. We therefore determined the pattern of LH release in normal controls and in patients, at baseline as well as after administration of the dopamine receptor antagonist metoclopramide (MCP), and the opiate-receptor antagonist naloxone (NAL). Methods: Patient eligibility criteria included RT to the H/P-A for a non-H/P-A CNS tumor, usually astrocytoma, with subsequent hypoestrogenemia and oligo-amenorrhea. Patients and normal volunteers were studied first under control conditions and then using MCP and NAL in a randomized cross-over manner at monthly intervals. Serum samples for LH determination were taken every 10 minutes for 12 hours during an overnight hospital stay. MCP (10 mg) was administered as an IV bolus every 4.5 hours, and NAL was administered as a continuous infusion (1.6 mg/hour). The following morning each

  1. Gonadotrophin-Releasing Hormone Agonists and Other Contraceptive Medications in Exotic Companion Animals.

    Science.gov (United States)

    Schoemaker, Nico J

    2018-05-01

    The use of a gonadotrophin-releasing hormone agonist slow-release implant (GnRH A-SRI) has become increasingly popular as an alternative for surgical contraception in many species. Although these implants have proven to be very effective in some species (eg, ferrets, rats, chicken, psittacines, and iguanas), they have been found less effective in other species (eg, male guinea pigs and rabbits, veiled chameleons, slider turtles, and leopard geckos). This review provides an overview of the available literature on the effects of GnRH A-SRIs in companion exotic animals. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Calcium-independent phosphatidylinositol response in gonadotropin-releasing-hormone-stimulated pituitary cells.

    OpenAIRE

    Naor, Z; Molcho, J; Zakut, H; Yavin, E

    1985-01-01

    This paper describes the effect of gonadotropin-releasing hormone (GnRH, gonadoliberin) on phospholipid metabolism in cultured rat pituitary cells. The cells were incubated with [32P]Pi to label endogenous phospholipids (10-60 min) and then stimulated with GnRH for up to 60 min. Cellular phospholipids were separated by two-dimensional t.l.c. and the radioactivity was determined. Phosphatidylinositol (PI), a minor constituent of cellular phospholipids (7.7%), was the major labelled phospholipi...

  3. The chicken type III GnRH receptor homologue is predominantly expressed in the pituitary, and exhibits similar ligand selectivity to the type I receptor

    Science.gov (United States)

    Joseph, Nerine T; Morgan, Kevin; Sellar, Robin; McBride, Derek; Millar, Robert P; Dunn, Ian C

    2009-01-01

    Two GnRH isoforms (cGnRH-I and GnRH-II) and two GnRH receptor subtypes (cGnRH-R-I and cGnRH-R-III) occur in chickens. Differential roles for these molecules in regulating gonadotrophin secretion or other functions are unclear. To investigate this we cloned cGnRH-R-III from a broiler chicken and compared its structure, expression and pharmacological properties with cGnRH-R-I. The broiler cGnRH-R-III cDNA was 100% identical to the sequence reported in the red jungle fowl and white leghorn breed. Pituitary cGnRH-R-III mRNA was ∼1400-fold more abundant than cGnRH-R-I mRNA. Northern analysis indicated a single cGnRH-R-III transcript. A pronounced sex and age difference existed, with higher pituitary transcript levels in sexually mature females versus juvenile females. In contrast, higher expression levels occurred in juvenile males versus sexually mature males. Functional studies in COS-7 cells indicated that cGnRH-R-III has a higher binding affinity for GnRH-II than cGnRH-I (Kd: 0·57 vs 19·8 nM) with more potent stimulation of inositol phosphate production (ED50: 0·8 vs 4·38 nM). Similar results were found for cGnRH-R-I, (Kd: 0·51 vs 10·8 nM) and (ED50: 0·7 vs 2·8 nM). The initial rate of internalisation was faster for cGnRH-R-III than cGnRH-R-I (26 vs 15·8%/min). Effects of GnRH antagonists were compared at the two receptors. Antagonist #27 distinguished between cGnRH-R-I and cGnRH-R-III (IC50: 2·3 vs 351 nM). These results suggest that cGnRH-R-III is probably the major mediator of pituitary gonadotroph function, that antagonist #27 may allow delineation of receptor subtype function in vitro and in vivo and that tissue-specific recruitment of cGnRH-R isoforms has occurred during evolution. PMID:19380456

  4. Growth inhibition of tumor cells in vitro by using monoclonal antibodies against gonadotropin-releasing hormone receptor.

    Science.gov (United States)

    Lee, Gregory; Ge, Bixia

    2010-07-01

    As the continuation of a previous study, synthetic peptides corresponding to the extracellular domains of human gonadotropin-releasing hormone (GnRH) receptor were used to generate additional monoclonal antibodies which were further characterized biochemically and immunologically. Among those identified to recognize GnRH receptor, monoclonal antibodies designated as GHR-103, GHR-106 and GHR-114 were found to exhibit high affinity (Kd L37), when cancer cells were incubated with GnRH or GHR-106. The widespread expressions of GnRH receptor in almost all of the studied human cancer cell lines were also demonstrated by RT-PCR and Western blot assay, as well as indirect immunofluorescence assay with either of these monoclonal antibodies as the primary antibody. In view of the longer half life of antibodies as compared to that of GnRH or its analogs, anti-GnRH receptor monoclonal antibodies in humanized forms could function as GnRH analogs and serve as an ideal candidate of anti-cancer drugs for therapeutic treatments of various cancers in humans as well as for fertility regulations.

  5. GnRH receptor activation competes at a low level with growth signaling in stably transfected human breast cell lines

    International Nuclear Information System (INIS)

    Morgan, Kevin; Meyer, Colette; Miller, Nicola; Sims, Andrew H; Cagnan, Ilgin; Faratian, Dana; Harrison, David J; Millar, Robert P; Langdon, Simon P

    2011-01-01

    Gonadotrophin releasing hormone (GnRH) analogs lower estrogen levels in pre-menopausal breast cancer patients. GnRH receptor (GnRH-R) activation also directly inhibits the growth of certain cells. The applicability of GnRH anti-proliferation to breast cancer was therefore analyzed. GnRH-R expression in 298 primary breast cancer samples was measured by quantitative immunofluorescence. Levels of functional GnRH-R in breast-derived cell lines were assessed using 125 I-ligand binding and stimulation of 3 H-inositol phosphate production. Elevated levels of GnRH-R were stably expressed in cells by transfection. Effects of receptor activation on in vitro cell growth were investigated in comparison with IGF-I and EGF receptor inhibition, and correlated with intracellular signaling using western blotting. GnRH-R immunoscoring was highest in hormone receptor (triple) negative and grade 3 breast tumors. However prior to transfection, functional endogenous GnRH-R were undetectable in four commonly studied breast cancer cell lines (MCF-7, ZR-75-1, T47D and MDA-MB-231). After transfection with GnRH-R, high levels of cell surface GnRH-R were detected in SVCT and MDA-MB-231 clones while low-moderate levels of GnRH-R occurred in MCF-7 clones and ZR-75-1 clones. MCF-7 sub-clones with high levels of GnRH-R were isolated following hygromycin phosphotransferase transfection. High level cell surface GnRH-R enabled induction of high levels of 3 H-inositol phosphate and modest growth-inhibition in SVCT cells. In contrast, growth of MCF-7, ZR-75-1 or MDA-MB-231 clones was unaffected by GnRH-R activation. Cell growth was inhibited by IGF-I or EGF receptor inhibitors. IGF-I receptor inhibitor lowered levels of p-ERK1/2 in MCF-7 clones. Washout of IGF-I receptor inhibitor resulted in transient hyper-elevation of p-ERK1/2, but co-addition of GnRH-R agonist did not alter the dynamics of ERK1/2 re-phosphorylation. Breast cancers exhibit a range of GnRH-R immunostaining, with higher levels of

  6. Enhancement of a robust arcuate GABAergic input to gonadotropin-releasing hormone neurons in a model of polycystic ovarian syndrome.

    Science.gov (United States)

    Moore, Aleisha M; Prescott, Mel; Marshall, Christopher J; Yip, Siew Hoong; Campbell, Rebecca E

    2015-01-13

    Polycystic ovarian syndrome (PCOS), the leading cause of female infertility, is associated with an increase in luteinizing hormone (LH) pulse frequency, implicating abnormal steroid hormone feedback to gonadotropin-releasing hormone (GnRH) neurons. This study investigated whether modifications in the synaptically connected neuronal network of GnRH neurons could account for this pathology. The PCOS phenotype was induced in mice following prenatal androgen (PNA) exposure. Serial blood sampling confirmed that PNA elicits increased LH pulse frequency and impaired progesterone negative feedback in adult females, mimicking the neuroendocrine abnormalities of the clinical syndrome. Imaging of GnRH neurons revealed greater dendritic spine density that correlated with increased putative GABAergic but not glutamatergic inputs in PNA mice. Mapping of steroid hormone receptor expression revealed that PNA mice had 59% fewer progesterone receptor-expressing cells in the arcuate nucleus of the hypothalamus (ARN). To address whether increased GABA innervation to GnRH neurons originates in the ARN, a viral-mediated Cre-lox approach was taken to trace the projections of ARN GABA neurons in vivo. Remarkably, projections from ARN GABAergic neurons heavily contacted and even bundled with GnRH neuron dendrites, and the density of fibers apposing GnRH neurons was even greater in PNA mice (56%). Additionally, this ARN GABA population showed significantly less colocalization with progesterone receptor in PNA animals compared with controls. Together, these data describe a robust GABAergic circuit originating in the ARN that is enhanced in a model of PCOS and may underpin the neuroendocrine pathophysiology of the syndrome.

  7. Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion.

    Science.gov (United States)

    Lacau-Mengido, I M; González Iglesias, A; Díaz-Torga, G; Thyssen-Cano, S; Libertun, C; Becú-Villalobos, D

    1998-04-01

    Marked sexual and ontogenic differences have been described in gonadotropin regulation in the rat. These could arise from events occurring both at the hypothalamic or hypophyseal levels. The present experiments were designed to evaluate the capacity of the hypothalamus in releasing GnRH in vitro, basally and in response to depolarization with KCl, during ontogeny in the rat. To that end we chose two well-defined developmental ages that differ markedly in sexual and ontogenic characteristics of gonadotropin regulation, 15 and 30 days. We compared GnRH release from hypothalami of females, neonatal androgenized females and males. Mediobasal hypothalami were perifused in vitro, and GnRH measured in the effluent. Basal secretion of the decapeptide increased with age in the three groups with no sexual differences encountered. When studying GnRH release induced by membrane depolarization, no differences within sex or age were encountered. On the other hand FSH serum levels decreased with age in females and increased in males, and in neonatal androgenized females followed a similar pattern to that of females. LH levels were higher in infantile females than in age-matched males or androgenized females. Such patterns of gonadotropin release were therefore not correlated to either basal or K+-induced GnRH release from the hypothalamus. We conclude that sexual and ontogenic differences in gonadotropin secretion in the developing rat are not dependent on the intrinsic capability of the hypothalamus to release GnRH in response to membrane depolarization. The hormonal differences observed during development and between sexes are probably related to differences in the sensitivity of the GnRH neuron to specific secretagogue and neurotransmitter regulation, and/or to differences in hypophyseal GnRH receptors and gonadotrope sensitivity.

  8. Maternal Dexamethasone Exposure Alters Synaptic Inputs to Gonadotropin-Releasing Hormone Neurons in the Early Postnatal Rat

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    Wei Ling Lim

    2016-08-01

    Full Text Available Maternal dexamethasone (DEX; a glucocorticoid receptor agonist exposure delays pubertal onset and alters reproductive behaviour in the adult offspring. However, little is known whether maternal DEX exposure affects the offspring’s reproductive function by disrupting the gonadotropin-releasing hormone (GnRH neuronal function in the brain. Therefore, this study determined the exposure of maternal DEX on the GnRH neuronal spine development and synaptic cluster inputs to GnRH neurons using transgenic rats expressing enhanced green fluorescent protein (EGFP under the control of GnRH promoter. Pregnant females were administered with DEX (0.1mg/kg or vehicle (VEH, water daily during gestation day 13-20. Confocal imaging was used to examine the spine density of EGFP-GnRH neurons by three-dimensional rendering and synaptic cluster inputs to EGFP-GnRH neurons by synapsin I immunohistochemistry on postnatal day 0 (P0 males. The spine morphology and number on GnRH neurons did not change between the P0 males following maternal DEX and VEH treatment. The number of synaptic clusters within the organum vasculosum of the lamina terminalis (OVLT was decreased by maternal DEX exposure in P0 males. Furthermore, the number and levels of synaptic cluster inputs in close apposition with GnRH neurons was decreased following maternal DEX exposure in the OVLT region of P0 males. In addition, the post synaptic marker molecule, post-synaptic density 95 was observed in GnRH neurons following both DEX and VEH treatment. These results suggest that maternal DEX exposure alters neural afferent inputs to GnRH neurons during early postnatal stage, which could lead to reproductive dysfunction during adulthood.

  9. Prenatal exposure to vinclozolin disrupts selective aspects of the gonadotropin-releasing hormone neuronal system of the rabbit

    Science.gov (United States)

    Wadas, B.C.; Hartshorn, C.A.; Aurand, E.R.; Palmer, J.S.; Roselli, C.E.; Noel, M.L.; Gore, A.C.; Veeramachaneni, D.N.R.; Tobet, S.A.

    2010-01-01

    Developmental exposure to the agricultural fungicide vinclozolin can impair reproductive function in male rabbits and was previously found to decrease the number of immunoreactive-gonadotropin-releasing hormone (ir-GnRH) neurons in the region of the organum vasculosum of the lamina terminalis (OVLT) and rostral preoptic area (rPOA) by postnatal week (PNW) 6. To further examine the disruption of GnRH neurons by fetal vinclozolin exposure, in the current study, pregnant rabbits were dosed orally with vinclozolin, flutamide, or carrot paste vehicle for the last two weeks of gestation. Offspring were euthanized at birth (males and females), PNW6 (females), PNW26 (adult males), or PNW30 (adult females) of age. At birth and in adults, brains were sectioned and processed for immunoreactive GnRH. The numbers of immunoreactive GnRH neuronal perikarya were significantly decreased in vinclozolin-treated rabbits at birth and in adult littermates. By contrast, there was an increase in GnRH immunoreactivity in the terminals in the region of the median eminence. Analysis of PNW6 female brains by radioimmunoassay (RIA) revealed a two-fold increase in GnRH peptide content in the mediobasal hypothalamus in vinclozolin-treated rabbits. This finding was complemented by immunofluorescence analyses that showed a 2.8-fold increase in GnRH immunoreactivity in the median eminence of vinclozolin compared to vehicle-treated females at PNW30. However, there was no difference between treatment groups in the measures of reproduction that were evaluated: ejaculation latency, conception rates or litter size. These results indicate that subacute, prenatal vinclozolin treatment is sufficient to create perdurable alterations in the GnRH neuronal network that forms an important input into the reproductive axis. Finally, the effect of vinclozolin on the GnRH neuronal network was not comparable to that of flutamide, suggesting that vinclozolin was not acting through anti-androgenic mechanisms. PMID

  10. Differential Gene Expression in Gonadotropin-Releasing Hormone Neurons of Male and Metestrous Female Mice.

    Science.gov (United States)

    Vastagh, Csaba; Rodolosse, Annie; Solymosi, Norbert; Farkas, Imre; Auer, Herbert; Sárvári, Miklós; Liposits, Zsolt

    2015-01-01

    Gonadotropin-releasing hormone (GnRH) neurons play a pivotal role in the regulation of the hypothalamic-pituitary gonadal axis in a sex-specific manner. We hypothesized that the differences seen in reproductive functions of males and females are associated with a sexually dimorphic gene expression profile of GnRH neurons. We compared the transcriptome of GnRH neurons obtained from intact metestrous female and male GnRH-green fluorescent protein transgenic mice. About 1,500 individual GnRH neurons from each sex were sampled with laser capture microdissection followed by whole-transcriptome amplification for gene expression profiling. Under stringent selection criteria (fold change >1.6, adjusted p value 0.01), Affymetrix Mouse Genome 430 PM array analysis identified 543 differentially expressed genes. Sexual dimorphism was most apparent in gene clusters associated with synaptic communication, signal transduction, cell adhesion, vesicular transport and cell metabolism. To validate microarray results, 57 genes were selected, and 91% of their differential expression was confirmed by real-time PCR. Similarly, 88% of microarray results were confirmed with PCR from independent samples obtained by patch pipette harvesting and pooling of 30 GnRH neurons from each sex. We found significant differences in the expression of genes involved in vesicle priming and docking (Syt1, Cplx1), GABAergic (Gabra3, Gabrb3, Gabrg2) and glutamatergic (Gria1, Grin1, Slc17a6) neurotransmission, peptide signaling (Sstr3, Npr2, Cxcr4) and the regulation of intracellular ion homeostasis (Cacna1, Cacnb1, Cacng5, Kcnq2, Kcnc1). The striking sexual dimorphism of the GnRH neuron transcriptome we report here contributes to a better understanding of the differences in cellular mechanisms of GnRH neurons in the two sexes. © 2015 S. Karger AG, Basel.

  11. [Spermatogenesis of pulsatile gonadotropin-releasing hormone infusion versus gonadotropin therapy in male idiopathic hypogonadotropic hypogonadism].

    Science.gov (United States)

    Huang, Bingkun; Mao, Jiangfeng; Xu, Hongli; Wang, Xi; Liu, Zhaoxiang; Nie, Min; Wu, Xueyan

    2015-05-26

    To compare the efficacies of pulsatile gonadotropin-releasing hormone (GnRH) versus human chorionic gonadotropin/human menopausal gonadotropin (HCG/HMG) for spermatogenesis in male idiopathic hypogonadotropic hypogonadism (IHH). For this retrospective study, a total of 92 male IHH outpatients from May 2010 to October 2014 were recruited and categorized into GnRH (n = 40) and HCG/HMG (n = 52) groups. Each subject selected one specific therapy voluntarily. The gonadotropin levels were measured in the first week and monthly post-treatment in GnRH group. And serum total testosterone (TT), testicular volume (TV) and rate of spermatogenesis were observed monthly post-treatment in two groups. Spermatogenesis, TT and TV were compared between two groups. All IHH patients were treated for over 3 months. The median follow-up periods in GnRH and HCG/HMG groups was 8.2 (3.0-18.4) and 9.2 (3.0-18.6) months respectively (P = 0.413). In GnRH group, LH ((0.5 ± 0.6) vs (3.4 ± 2.4) U/L, P treatment. In GnRH group, at the end of follow-up, TT ((1.0 ± 1.0) vs (7.4 ± 5.2) nmol/L, P treatment time for initial sperm appearance than HCG/HMG group ((6.5 ± 3.1) vs (10.8 ± 3.7) months, P = 0.001). Pulsatile GnRH requires a shorter time for initiation of spermatogenesis than gonadotropin therapy in IHH male patients.

  12. Combination growth hormone and gonadotropin releasing hormone analog therapy in 11beta-hydroxylase deficiency.

    Science.gov (United States)

    Bajpai, Anurag; Kabra, Madhulika; Menon, P S N

    2006-06-01

    Diagnosis of 11beta-hydroxylase deficiency was made in a boy at the age of 2 1/2 years on the basis of peripheral precocious puberty, growth acceleration (height standard deviation score +4.4) with advanced skeletal maturation (bone age 8.4 years) and elevated deoxycortisol levels. Glucocorticoid supplementation led to normalization of blood pressure but was associated with progression to central precocious puberty and increase in bone age resulting in decrease in predicted adult height to 133.7 cm (target height 163 cm). The child was started on GnRH analog (triptorelin 3.75 mg every 28 days), which led to improvement in predicted adult height by 3.1 cm over 15 months. Addition of growth hormone (0.1 IU/kg/day) resulted in improvement in predicted adult height (151 cm) and height deficit (12 cm) over the next 3.6 years. Final height (151 cm) exceeded predicted height at the initiation of GnRH analog treatment by 17.3 cm. This report suggests that combination GH and GnRH analog treatment may be useful in improving height outcome in children with 11beta-hydroxylase deficiency and compromised final height.

  13. Receptors of Hypothalamic-Pituitary-Ovarian-Axis Hormone in Uterine Myomas

    Directory of Open Access Journals (Sweden)

    Danuta Plewka

    2014-01-01

    Full Text Available In this study the expression of GnRH, FSH, LH, ER-α, ER-β, and PR receptors was examined in uterine myomas of women in reproductive and perimenopausal age. In cases of GnRH and tropic hormones a membranous and cytoplasmic immunohistochemical reaction was detected, in cases of ER-α and PR the reaction was located in cell nucleus, and in the case of ER-β it manifested also a cytoplasmic location. In some of the examined cases the expression was detected in endometrium, myocytes, and endothelium of blood vessels, in uterine glands and myoma cells. In myometrium the level of GnRH and LH receptors increases with age, whereas the level of progesterone and both estrogen receptors decreases. In myomas of women in reproductive age, independently of their size, expression of GnRH, FSH, and LH receptors was more pronounced than in myometrium. In women of perimenopausal age, independently of myoma size, expression of LH and estrogen α receptors was higher while expression of GnRH receptors was lower than in myometrium. FSH receptor expression was not observed. Expression of estrogen receptor β was not affected by age of the woman or size of myoma. Analysis of obtained results indicates on existing in small myomas local feedback axis between GnRH-LH-progesterone.

  14. Gonadotropin-releasing hormone immunoreactivity in the adult and fetal human olfactory system.

    Science.gov (United States)

    Kim, K H; Patel, L; Tobet, S A; King, J C; Rubin, B S; Stopa, E G

    1999-05-01

    Studies in fetal brain tissue of rodents, nonhuman primates and birds have demonstrated that cells containing gonadotropin-releasing hormone (GnRH) migrate from the olfactory placode across the nasal septum into the forebrain. The purpose of this study was to examine GnRH neurons in components of the adult and fetal human olfactory system. In the adult human brain (n=4), immunoreactive GnRH was evident within diffusely scattered cell bodies and processes in the olfactory bulb, olfactory nerve, olfactory cortex, and nervus terminalis located on the anterior surface of the gyrus rectus. GnRH-immunoreactive structures showed a similar distribution in 20-week human fetal brains (n=2), indicating that the migration of GnRH neurons is complete at this time. In 10-11-week fetal brains (n=2), more cells were noted in the nasal cavity than in the brain. Our data are consistent with observations made in other species, confirming olfactory derivation and migration of GnRH neurons into the brain from the olfactory placode. Copyright 1999 Elsevier Science B.V.

  15. Hormone assay

    International Nuclear Information System (INIS)

    Eisentraut, A.M.

    1977-01-01

    An improved radioimmunoassay is described for measuring total triiodothyronine or total thyroxine levels in a sample of serum containing free endogenous thyroid hormone and endogenous thyroid hormone bound to thyroid hormone binding protein. The thyroid hormone is released from the protein by adding hydrochloric acid to the serum. The pH of the separated thyroid hormone and thyroid hormone binding protein is raised in the absence of a blocking agent without interference from the endogenous protein. 125 I-labelled thyroid hormone and thyroid hormone antibodies are added to the mixture, allowing the labelled and unlabelled thyroid hormone and the thyroid hormone antibody to bind competitively. This results in free thyroid hormone being separated from antibody bound thyroid hormone and thus the unknown quantity of thyroid hormone may be determined. A thyroid hormone test assay kit is described for this radioimmunoassay. It provides a 'single tube' assay which does not require blocking agents for endogenous protein interference nor an external solid phase sorption step for the separation of bound and free hormone after the competitive binding step; it also requires a minimum number of manipulative steps. Examples of the assay are given to illustrate the reproducibility, linearity and specificity of the assay. (UK)

  16. Elevated mRNA-levels of gonadotropin-releasing hormone and its receptor in plaque-bearing Alzheimer's disease transgenic mice.

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    Syed Nuruddin

    Full Text Available Research on Alzheimer's disease (AD has indicated an association between hormones of the hypothalamic-pituitary-gonadal (HPG axis and cognitive senescence, indicating that post meno-/andropausal changes in HPG axis hormones are implicated in the neuropathology of AD. Studies of transgenic mice with AD pathologies have led to improved understanding of the pathophysiological processes underlying AD. The aims of this study were to explore whether mRNA-levels of gonadotropin-releasing hormone (Gnrh and its receptor (Gnrhr were changed in plaque-bearing Alzheimer's disease transgenic mice and to investigate whether these levels and amyloid plaque deposition were downregulated by treatment with a gonadotropin-releasing hormone analog (Gnrh-a; Leuprorelin acetate. The study was performed on mice carrying the Arctic and Swedish amyloid-β precursor protein (AβPP mutations (tgArcSwe. At 12 months of age, female tgArcSwe mice showed a twofold higher level of Gnrh mRNA and more than 1.5 higher level of Gnrhr mRNA than age matched controls. Male tgArcSwe mice showed the same pattern of changes, albeit more pronounced. In both sexes, Gnrh-a treatment caused significant down-regulation of Gnrh and Gnrhr mRNA expression. Immunohistochemistry combined with quantitative image analysis revealed no significant changes in the plaque load after Gnrh-a treatment in hippocampus and thalamus. However, plaque load in the cerebral cortex of treated females tended to be lower than in female vehicle-treated mice. The present study points to the involvement of hormonal changes in AD mice models and demonstrates that these changes can be effectively counteracted by pharmacological treatment. Although known to increase in normal aging, our study shows that Gnrh/Gnrhr mRNA expression increases much more dramatically in tgArcSwe mice. Treatment with Leuprorelin acetate successfully abolished the transgene specific effects on Gnrh/Gnrhr mRNA expression. The present experimental

  17. Anti-Mullerian hormone-tailored stimulation protocols improve outcomes whilst reducing adverse effects and costs of IVF.

    Science.gov (United States)

    Yates, A P; Rustamov, O; Roberts, S A; Lim, H Y N; Pemberton, P W; Smith, A; Nardo, L G

    2011-09-01

    Anti-Müllerian hormone (AMH) is increasingly used to quantify ovarian reserve, but it has not yet realized its full clinical potential in assisted reproduction technology. We investigated the possible benefits of using novel, stratified ovarian hyperstimulation protocols, tailored to individual AMH levels, compared with conventional stimulation. Retrospective data were collected from 769 women (first cycle of IVF, using fresh embryos), in a UK tertiary care unit: 346 women using conventional stimulation protocols; 423 women treated under new AMH-tailored protocols. Embryo transfer rates increased significantly (79-87%: P= 0.002) after the introduction of AMH-tailored stimulation protocols. Pregnancy rate per cycle started and live birth rate also increased significantly compared with conventionally treated women (17.9-27.7%, P= 0.002 and 15.9-23.9%, P = 0.007, respectively). Moreover, in the AMH group, the incidence of the ovarian hyperstimulation syndrome (OHSS) fell significantly (6.9-2.3%, P = 0.002) and failed fertilization fell from 7.8 to 4.5%. The cost of fertility drug treatment fell by 29% per patient and the overall cost of clinical management of OHSS fell by 43% in the AMH group. GnRH antagonist protocols, introduced as part of AMH-tailored treatment, may have contributed to the observed improvements: however, within the AMH-tailored group, the live birth rate was not significantly different between agonist and antagonist-treated groups. Although large, prospective, multicentre studies are indicated, we have clearly demonstrated that individualized, AMH-guided, controlled ovarian hyperstimulation protocols significantly improved positive clinical outcomes, reduced the incidence of complications and reduced the financial burden associated with assisted reproduction.

  18. Intracerebroventricular Infusion of Vasoactive Intestinal Peptide (VIP Rescues the Luteinizing Hormone Surge in Middle-Aged Female Rats

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    Yan eSun

    2012-02-01

    Full Text Available Reproductive aging is characterized by delayed and attenuated luteinizing hormone (LH surges apparent in middle-aged rats. The suprachiasmatic nucleus (SCN contains the circadian clock that is responsible for the timing of diverse neuroendocrine rhythms. Electrophysiological studies suggest vasoactive intestinal peptide (VIP originating from the SCN excites gonadotropin-releasing hormone (GnRH neurons and affects daily patterns of GnRH-LH release. Age-related LH surge dysfunction correlates with reduced VIP mRNA expression in the SCN and fewer GnRH neurons with VIP contacts expressing c-fos, a marker of neuronal activation, on the day of the LH surge. To determine if age-related LH surge dysfunction reflects reduced VIP availability or altered VIP responsiveness under estradiol positive feedback conditions, we assessed the effect of intracerebroventricular (icv VIP infusion on c-fos expression in GnRH neurons and on LH release in ovariohysterectomized, hormone-primed young and middle-aged rats. Icv infusion of VIP between 1300 and 1600 h significantly advanced the time of peak LH release, increased total and peak LH release, and increased the number of GnRH neurons expressing c-fos on the day of the LH surge in middle-aged rats. Surprisingly, icv infusion of VIP in young females significantly reduced the number of GnRH neurons expressing c-fos and delayed and reduced the LH surge. These observations suggest that a critical balance of VIP signaling is required to activate GnRH neurons for an appropriately timed and robust LH surge in young and middle-aged females. Age-related LH surge changes may, in part, result from decreased availability and reduced VIP-mediated neurotransmission under estradiol positive feedback conditions.

  19. Gonadotropin-Releasing Hormone Regulates Expression of the DNA Damage Repair Gene, Fanconi anemia A, in Pituitary Gonadotroph Cells1

    Science.gov (United States)

    Larder, Rachel; Chang, Lynda; Clinton, Michael; Brown, Pamela

    2007-01-01

    Gonadal function is critically dependant on regulated secretion of the gonadotropin hormones from anterior pituitary gonadotroph cells. Gonadotropin biosynthesis and release is triggered by the binding of hypothalamic GnRH to GnRH receptor expressed on the gonadotroph cell surface. The repertoire of regulatory molecules involved in this process are still being defined. We used the mouse LβT2 gonadotroph cell line, which expresses both gonadotropin hormones, as a model to investigate GnRH regulation of gene expression and differential display reverse transcription-polymerase chain reaction (RT-PCR) to identify and isolate hormonally induced changes. This approach identified Fanconi anemia a (Fanca), a gene implicated in DNA damage repair, as a differentially expressed transcript. Mutations in Fanca account for the majority of cases of Fanconi anemia (FA), a recessively inherited disease identified by congenital defects, bone marrow failure, infertility, and cancer susceptibility. We confirmed expression and hormonal regulation of Fanca mRNA by quantitative RT-PCR, which showed that GnRH induced a rapid, transient increase in Fanca mRNA. Fanca protein was also acutely upregulated after GnRH treatment of LβT2 cells. In addition, Fanca gene expression was confined to mature pituitary gonadotrophs and adult mouse pituitary and was not expressed in the immature αT3-1 gonadotroph cell line. Thus, this study extends the expression profile of Fanca into a highly specialized endocrine cell and demonstrates hormonal regulation of expression of the Fanca locus. We suggest that this regulatory mechanism may have a crucial role in the GnRH-response mechanism of mature gonadotrophs and perhaps the etiology of FA. PMID:15128600

  20. Gonadotropin-releasing hormone regulates expression of the DNA damage repair gene, Fanconi anemia A, in pituitary gonadotroph cells.

    Science.gov (United States)

    Larder, Rachel; Chang, Lynda; Clinton, Michael; Brown, Pamela

    2004-09-01

    Gonadal function is critically dependant on regulated secretion of the gonadotropin hormones from anterior pituitary gonadotroph cells. Gonadotropin biosynthesis and release is triggered by the binding of hypothalamic GnRH to GnRH receptor expressed on the gonadotroph cell surface. The repertoire of regulatory molecules involved in this process are still being defined. We used the mouse L beta T2 gonadotroph cell line, which expresses both gonadotropin hormones, as a model to investigate GnRH regulation of gene expression and differential display reverse transcription-polymerase chain reaction (RT-PCR) to identify and isolate hormonally induced changes. This approach identified Fanconi anemia a (Fanca), a gene implicated in DNA damage repair, as a differentially expressed transcript. Mutations in Fanca account for the majority of cases of Fanconi anemia (FA), a recessively inherited disease identified by congenital defects, bone marrow failure, infertility, and cancer susceptibility. We confirmed expression and hormonal regulation of Fanca mRNA by quantitative RT-PCR, which showed that GnRH induced a rapid, transient increase in Fanca mRNA. Fanca protein was also acutely upregulated after GnRH treatment of L beta T2 cells. In addition, Fanca gene expression was confined to mature pituitary gonadotrophs and adult mouse pituitary and was not expressed in the immature alpha T3-1 gonadotroph cell line. Thus, this study extends the expression profile of Fanca into a highly specialized endocrine cell and demonstrates hormonal regulation of expression of the Fanca locus. We suggest that this regulatory mechanism may have a crucial role in the GnRH-response mechanism of mature gonadotrophs and perhaps the etiology of FA.

  1. Growth Hormone-Releasing Hormone in Diabetes

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    Leonid Evsey Fridlyand

    2016-10-01

    Full Text Available Growth hormone-releasing hormone (GHRH is produced by the hypothalamus and stimulates growth hormone synthesis and release in the anterior pituitary gland. In addition GHRH is an important regulator of cellular functions in many cells and organs. Expression of GHRH G-Protein Coupled Receptor (GHRHR has been demonstrated in different peripheral tissues and cell types including pancreatic islets. Among the peripheral activities, recent studies demonstrate a novel ability of GHRH analogs to increase and preserve insulin secretion by beta-cells in isolated pancreatic islets, which makes them potentially useful for diabetes treatment. This review considers the role of GHRHR in the beta-cell and addresses the unique engineered GHRH agonists and antagonists for treatment of Type 2 diabetes mellitus. We discuss the similarity of signaling pathways activated by GHRHR in pituitary somatotrophs and in pancreatic beta-cells and possible ways as to how the GHRHR pathway can interact with glucose and other secretagogues to stimulate insulin secretion. We also consider the hypothesis that novel GHRHR agonists can improve glucose metabolism in Type 2 diabetes by preserving the function and survival of pancreatic beta-cells. Wound healing and cardioprotective action with new GHRH agonists suggesting that they may prove useful in ameliorating certain diabetic complications. These findings highlight the future potential therapeutic effectiveness of modulators of GHRHR activity for the development of new therapeutic approaches in diabetes and its complications.

  2. Kisspeptin Antagonists Reveal Kisspeptin 1 and Kisspeptin 2 Differential Regulation of Reproduction in the Teleost, Morone saxatilis.

    Science.gov (United States)

    Zmora, Nilli; Stubblefield, John David; Wong, Ten-Tsao; Levavi-Sivan, Berta; Millar, Robert Peter; Zohar, Yonathan

    2015-09-01

    The importance of kisspeptin in regulating vertebrate reproduction has been well established, but the exact mechanism continues to unfold. Unlike mammals, many lower vertebrates possess a dual kisspeptin system, Kiss1 and Kiss2. To decipher the roles of the kisspeptins in fish, we identified two potential kisspeptin antagonists, pep 234 and pep 359, by screening analogs for their ability to inactivate striped bass Kiss1 and Kiss2 receptors expressed in COS7 cells. Pep 234 (a mammalian KISS1 antagonist) antagonizes Kiss1r signaling activated by Kiss1 and Kiss2, and pep 359 (a novel analog) antagonizes Kiss2 activation of both receptors. In vitro studies using brain slices demonstrated that only Kiss2 can upregulate the expression of the hypophysiotropic gnrh1, which was subsequently diminished by pep 234 and pep 359. In primary pituitary cell cultures, the two antagonists revealed a complex network of putative endogenous and exogenous regulation by kisspeptin. While both kisspeptins stimulate Fsh expression and secretion, Kiss2 predominately induces Lh secretion. Pep 234 and 359 treatment of spawning males hindered sperm production. This effect was accompanied with decreased brain gnrh1 and gnrh2 mRNA levels and peptide content in the pituitary, and increased levels of pituitary Lh, probably due to attenuation of Lh release. Strikingly, the mRNA levels of arginine-vasotocin, the neurons of which in the preoptic area coexpress kiss2r, were dramatically reduced by the antagonists. Our results demonstrate differential actions of Kiss1 and Kiss2 systems along the hypothalamic-pituitary axis and interactions with other neuropeptides, and further reinforce the importance of kisspeptin in the execution of spawning. © 2015 by the Society for the Study of Reproduction, Inc.

  3. Haploinsufficiency of Dmxl2, encoding a synaptic protein, causes infertility associated with a loss of GnRH neurons in mouse.

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    Brooke Tata

    2014-09-01

    Full Text Available Characterization of the genetic defects causing gonadotropic deficiency has made a major contribution to elucidation of the fundamental role of Kisspeptins and Neurokinin B in puberty onset and reproduction. The absence of puberty may also reveal neurodevelopmental disorders caused by molecular defects in various cellular pathways. Investigations of these neurodevelopmental disorders may provide information about the neuronal processes controlling puberty onset and reproductive capacity. We describe here a new syndrome observed in three brothers, which involves gonadotropic axis deficiency, central hypothyroidism, peripheral demyelinating sensorimotor polyneuropathy, mental retardation, and profound hypoglycemia, progressing to nonautoimmune insulin-dependent diabetes mellitus. High-throughput sequencing revealed a homozygous in-frame deletion of 15 nucleotides in DMXL2 in all three affected patients. This homozygous deletion was associated with lower DMXL2 mRNA levels in the blood lymphocytes of the patients. DMXL2 encodes the synaptic protein rabconnectin-3α, which has been identified as a putative scaffold protein for Rab3-GAP and Rab3-GEP, two regulators of the GTPase Rab3a. We found that rabconnectin-3α was expressed in exocytosis vesicles in gonadotropin-releasing hormone (GnRH axonal extremities in the median eminence of the hypothalamus. It was also specifically expressed in cells expressing luteinizing hormone (LH and follicle-stimulating hormone (FSH within the pituitary. The conditional heterozygous deletion of Dmxl2 from mouse neurons delayed puberty and resulted in very low fertility. This reproductive phenotype was associated with a lower number of GnRH neurons in the hypothalamus of adult mice. Finally, Dmxl2 knockdown in an insulin-secreting cell line showed that rabconnectin-3α controlled the constitutive and glucose-induced secretion of insulin. In conclusion, this study shows that low levels of DMXL2 expression cause a

  4. Effects of hormones on platelet aggregation.

    Science.gov (United States)

    Farré, Antonio López; Modrego, Javier; Zamorano-León, José J

    2014-04-01

    Platelets and their activation/inhibition mechanisms play a central role in haemostasis. It is well known agonists and antagonists of platelet activation; however, during the last years novel evidences of hormone effects on platelet activation have been reported. Platelet functionality may be modulated by the interaction between different hormones and their platelet receptors, contributing to sex differences in platelet function and even in platelet-mediated vascular damage. It has suggested aspects that apparently are well established should be reviewed. Hormones effects on platelet activity are included among them. This article tries to review knowledge about the involvement of hormones in platelet biology and activity.

  5. Simultaneous measurement of hormone release and secretagogue binding by individual pituitary cells

    International Nuclear Information System (INIS)

    Smith, P.F.; Neill, J.D.

    1987-01-01

    The quantitative relationship between receptor binding and hormone secretion at the single-cell level was investigated in the present study by combining a reverse hemolytic plaque assay for measurement of luteinizing hormone (LH) secretion from individual pituitary cells with an autoradiographic assay of 125 I-labeled gonadontropin-releasing hormone (GnRH) agonist binding to the same cells. In the plaque assay, LH secretion induces complement-mediated lysis of the LH-antibody-coated erythrocytes around the gonadotropes, resulting in areas of lysis (plaques). LH release from individual gonadotropes was quantified by comparing radioimmunoassayable LH release to hemolytic area in similarly treated cohort groups of cells; plaque area was linearly related to the amount of LH secreted. Receptor autoradiography was performed using 125 I-labeled GnRH-A (a superagonist analog of GnRH) both as the ligand and as the stimulant for LH release in the plaque assay. The grains appeared to represent specific and high-affinity receptors for GnRH because (i) no pituitary cells other than gonadotropes bound the labeled ligand and (ii) grain development was progressively inhibited by coincubation with increasing doses of unlabeled GnRH-A. The authors conclude that GnRH receptor number for any individual gonadotrope is a weak determinant of the amount of LH it can secrete; nevertheless, full occupancy of all its GnRH receptors is required for any gonadotrope to reach its full LH-secretory capacity. Apparently the levels of other factors comprising the steps along the secretory pathway determine the secretory capacity of an individual cell

  6. Kisspeptin Signaling Is Required for the Luteinizing Hormone Response in Anestrous Ewes following the Introduction of Males

    Science.gov (United States)

    De Bond, Julie-Ann P.; Li, Qun; Millar, Robert P.; Clarke, Iain J.; Smith, Jeremy T.

    2013-01-01

    The introduction of a novel male stimulates the hypothalamic-pituitary-gonadal axis of female sheep during seasonal anestrus, leading to the resumption of follicle maturation and ovulation. How this pheromone cue activates pulsatile secretion of gonadotropin releasing hormone (GnRH)/luteinizing hormone (LH) is unknown. We hypothesised that pheromones activate kisspeptin neurons, the product of which is critical for the stimulation of GnRH neurons and fertility. During the non-breeding season, female sheep were exposed to novel males and blood samples collected for analysis of plasma LH profiles. Females without exposure to males served as controls. In addition, one hour before male exposure, a kisspeptin antagonist (P-271) or vehicle was infused into the lateral ventricle and continued for the entire period of male exposure. Introduction of a male led to elevated mean LH levels, due to increased LH pulse amplitude and pulse frequency in females, when compared to females not exposed to a male. Infusion of P-271 abolished this effect of male exposure. Brains were collected after the male effect stimulus and we observed an increase in the percentage of kisspeptin neurons co-expressing Fos, by immunohistochemistry. In addition, the per-cell expression of Kiss1 mRNA was increased in the rostral and mid (but not the caudal) arcuate nucleus (ARC) after male exposure in both aCSF and P-271 treated ewes, but the per-cell content of neurokinin B mRNA was decreased. There was also a generalized increase in Fos positive cells in the rostral and mid ARC as well as the ventromedial hypothalamus of females exposed to males. We conclude that introduction of male sheep to seasonally anestrous female sheep activates kisspeptin neurons and other cells in the hypothalamus, leading to increased GnRH/LH secretion. PMID:23469121

  7. Behavior of feral horses in response to culling and GnRH immunocontraception

    Science.gov (United States)

    Ransom, Jason I.; Powers, Jenny G.; Garbe, Heidi M.; Oehler, Michael W.; Nett, Terry M.; Baker, Dan L.

    2014-01-01

    Wildlife management actions can alter fundamental behaviors of individuals and groups,which may directly impact their life history parameters in unforeseen ways. This is especially true for highly social animals because changes in one individual’s behavior can cascade throughout its social network. When resources to support populations of social animals are limited and populations become locally overabundant, managers are faced with the daunting challenge of decreasing population size without disrupting core behavioral processes. Increasingly, managers are turning to fertility control technologies to supplement culling in efforts to suppress population growth, but little is quantitatively known about how either of these management tools affects behavior. Gonadotropin releasing hormone (GnRH) is a small neuropeptide that performs an obligatory role in mammalian reproduction and has been formulated into the immunocontraceptive GonaCon-BTM. We investigated the influences of this vaccine on behavior of feral horses (Equus caballus) at Theodore Roosevelt National Park, North Dakota, USA, for a year preceding and a year following nonlethal culling and GnRH-vaccine treatment. We observed horses during the breeding season and found only minimal differences in time budget behaviors of free-ranging female feral horses treated with GnRH and those treated with saline. The differences observed were consistent with the metabolic demands of pregnancy and lactation. We observed similar social behaviors between treatment groups, reflecting limited reproductive behavior among control females due to high rates of pregnancy and suppressed reproductive behavior among treated females due to GnRH-inhibited ovarian activity. In the treatment year, band stallion age was the only supported factor influencing herding behavior (P < 0.001), harem-tending behavior (P < 0.001), and agonistic behavior (P = 0.02). There was no difference between the mean body condition of control females (4

  8. GnRH在性成熟高白鲑神经系统及性腺中的分布定位%An Immunocytochemical Localization of GnRH in the Nerve System and Gonad of Mature Coregonus peled

    Institute of Scientific and Technical Information of China (English)

    曹玉洁; 贾斌; 柳建新; 李志远; 张莉

    2011-01-01

    摘要:应用免疫组织化学方法,系统观察性成熟期高白鲑(Coregonus peled)神经系统及性腺中的促性腺激素释放激素( GnRH)的分布情况。结果表明,GnRH在大脑、小脑、中脑、脊髓、延髓中免疫阳性反应明显,且主要分布在神经元内。GnRH免疫阳性细胞在卵巢和精巢中均有分布,而且其阳性部位在卵巢主要分布于小生长期卵母细胞;在精巢中主要分布于间质细胞和精原细胞中。本文讨论了GnRH直接或间接参与高白鲑性腺发育成熟调节的可能性。%Immunocytochemical staining technique was used to study the expression of gonadotropin-releasing hormone (GnRH) in the nervous system and gonad of Coregonus peled. The results showed that there were GnRH immunoreactive endocrine cells in the cerebrum,cerebellum,diencephalon,medulla oblongata,and spinal cord. There were GnRH immunoreactive endocrine cells in the ovary and testis. The positive staining was observed mainly in the small growing oocyte, and in the interstitial cells and spermatogonia. The possible physiological function and morphological evidence of GnRH regulation on the development of gonad in C. Peled were discussed.

  9. COMPARISON BETWEEN ESTRADIOL CYPIONATE AND GONADOTROPIN RELEASING HORMONE AS OVULATION SYNCHRONIZATION TREATMENTS FOR FIXED-TIME ARTIFICIAL INSEMINATION PROGRAMS IN BRAHMAN-CROSS HEIFERS IN A SUBTROPICAL REGION OF NORTHEASTERN MEXICO

    Directory of Open Access Journals (Sweden)

    Miguel Angel Dominguez

    2012-12-01

    Full Text Available Synchronization protocols with intravaginal progesterone releasing devices (CIDR and PGF2α were evaluated, with GnRH or estradiol cypionate (ECP added for fixed-time artificial insemination (FTAI in five counties in Tamaulipas, Mexico. Brahman-cross heifers (≥15 months old were selected based on body condition (≥3 on a 5-point scale and confirmed ovarian activity. The six treatments (n = 320 each were: T1 (9-d CIDR, ECP on insertion, PGF2α on day 9, ECP on day 10, FTAI 54 h after removal; T2 (7-d CIDR, ECP on insertion, PGF2α on day 7, ECP on day 8, FTAI 54 h after removal; T3 (7-d CIDR, GnRH on insertion, PGF2α on day 7, FTAI and GnRH 48 h after removal; T4 (7-d CIDR, GnRH on insertion, PGF2α on day 6, FTAI and GnRH 48 h after removal; T5 (7-d CIDR, GnRH on insertion, PGF2α on day 7, FTAI and GnRH 60 h after removal; and T6 (7-d CIDR, GnRH on insertion, PGF2α on day 7, FTAI alone 48 h after removal. Pregnancy was diagnosed ultrasonically 45 days after FTAI. Analyses included pregnancy rates and treatment costs (hormones and handling. Pregnancy rates ranged from 31.6 ± 3.9 to 48.0 ± 10.6%; neither treatment nor county affected these rates (p > 0.05. In conclusion, the inclusion of treatment costs showed two more economical treatments (T2 using estradiol or T3 using GnRH under the nutritional, weather and handling conditions present in the tropical region of southeastern Tamaulipas.

  10. Hormonal alterations in PCOS and its influence on bone metabolism.

    Science.gov (United States)

    Krishnan, Abhaya; Muthusami, Sridhar

    2017-02-01

    According to the World Health Organization (WHO) polycystic ovary syndrome (PCOS) occurs in 4-8% of women worldwide. The prevalence of PCOS in Indian adolescents is 12.2% according to the Indian Council of Medical Research (ICMR). The National Institute of Health has documented that it affects approximately 5 million women of reproductive age in the United States. Hormonal imbalance is the characteristic of many women with polycystic ovarian syndrome (PCOS). The influence of various endocrine changes in PCOS women and their relevance to bone remains to be documented. Hormones, which include gonadotrophin-releasing hormone (GnRH), insulin, the leutinizing/follicle-stimulating hormone (LH/FSH) ratio, androgens, estrogens, growth hormones (GH), cortisol, parathyroid hormone (PTH) and calcitonin are disturbed in PCOS women. These hormones influence bone metabolism in human subjects directly as well as indirectly. The imbalance in these hormones results in increased prevalence of osteoporosis in PCOS women. Limited evidence suggests that the drugs taken during the treatment of PCOS increase the risk of bone fracture in PCOS patients through endocrine disruption. This review is aimed at the identification of the relationship between bone mineral density and hormonal changes in PCOS subjects and identifies potential areas to study bone-related disorders in PCOS women. © 2017 Society for Endocrinology.

  11. Effect of Valsartan on the hormones of Pituitary-gonadal axis Performance in mature female Wistar Rats

    Directory of Open Access Journals (Sweden)

    Ebrahim Hosseini

    2013-02-01

    Conclusion: Valsartan , as a receptor antagonist of Ang II inhibits the secretion of gonadotropin hormones and accelerates their effect on blocking the follicular cells of the female sex ,causing the reduction of female hormones.

  12. Molecular Cloning, Genomic Organization and Developmental Regulation of a Novel Receptor from Drosophila melanogaster Structurally Related to Gonadotropin-Releasing Hormone Receptors from Vertebrates

    DEFF Research Database (Denmark)

    Hauser, Frank; Søndergaard, Leif; Grimmelikhuijzen, Cornelis J.P.

    1998-01-01

    After screening the data base of the BerkeleyDrosophilaGenome Project with a sequence coding for the transmembrane region of a G protein-coupled receptor, we found thatDrosophilamight contain a gene coding for a receptor that is structurally related to the Gonadotropin-Releasing Hormone (GnRH) re...

  13. Influence of gonadotropin-releasing hormone and timing of insemination relative to estrus on pregnancy rates of dairy cattle at first service.

    Science.gov (United States)

    Mee, M O; Stevenson, J S; Scoby, R K; Folman, Y

    1990-06-01

    The objective was to determine the influence of gonadotropin-releasing hormone on pregnancy rates of dairy cattle at first services, when both the timing of hormone injection and insemination were altered relative to the onset of estrus. Cows (n = 325) were assigned randomly to six groups making up a 2 X 2 X 2 incomplete factorial experiment; dose of GnRH (100 micrograms versus saline), timing [1 h (early) or 12 to 16 h (late) after first detected estrus] of AI, and timing of hormone injection (early versus late) were the three main effects. Cows were observed for estrus 4 times daily. Treatments and resulting pregnancy rates were: 1) hormone injection early plus AI early (35%), 2) hormone injection late plus AI early (34%), 3) saline injection early plus AI early (30%), 4) hormone injection late plus AI late (30%), 5) hormone injection early plus AI late (46%), and 6) saline injection late plus AI late (43%). Pregnancy rate in the first four groups (32%) was less than that in the latter two groups (44%). Concentrations of LH in serum were greater for cows given hormone or saline injections in early estrus than for cows injected with either hormone of saline during late estrus. Concentrations of LH in serum 2 h after GnRH were elevated above those of controls, whether GnRH was injected during early or late estrus. Neither concentrations of LH during estrus nor concentrations of progesterone 8 to 14 d after estrus explained the possible antifertility effect of GnRH given during late estrus.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Pharmacokinetics and Bioavailability of the GnRH Analogs in the Form of Solution and Zn2+-Suspension After Single Subcutaneous Injection in Female Rats.

    Science.gov (United States)

    Suszka-Świtek, Aleksandra; Ryszka, Florian; Dolińska, Barbara; Dec, Renata; Danch, Alojzy; Filipczyk, Łukasz; Wiaderkiewicz, Ryszard

    2017-04-01

    Although many synthetic gonadoliberin analogs have been developed, only a few of them, including buserelin, were introduced into clinical practice. Dalarelin, which differs from buserelin by just one aminoacid in the position 6 (D-Ala), is not widely used so far. Gonadotropin-releasing hormone (GnRH) analogs are used to treat many different illnesses and are available in different forms like solution for injection, nasal spray, microspheres, etc. Unfortunately, none of the above drug formulations can release the hormones for 24 h. We assumed that classical suspension could solve this problem. Two sets of experiments were performed. In the first one, buserelin and dalarelin were injected into mature female rats in two forms: suspension, in which the analogs are bounded by Zn 2+ ions and solution. The pharmacokinetic parameters and bioavailability of the analogs were calculated, based on their concentration in the plasma measured by high-performance liquid chromatography method (HPLC). In the second experiment, the hormones in two different forms were injected into superovulated immature female rats and then the concentration of Luteinizing hormone (LH), Follicle-stimulating hormone (FSH) and 17β-estradiol in the serum was measured by radioimmunological method. The Extent of Biological Availability (EBA), calculated on the base of AUC 0-∞ , showed that in the form of solution buserelin and dalarelin display, respectively, only 13 and 8 % of biological availability of their suspension counterparts. Comparing both analogs, the EBA of dalarelin was half (53 %) that of buserelin delivered in the form of solution and 83 % when they were delivered in the form of suspension. The injection of buserelin or dalarelin, in the form of solution or suspension, into superovulated female rats increased LH, FSH and estradiol concentration in the serum. However, after injection of the analogs in the form of suspension, the high concentration of LH and FSH in the serum persisted

  15. Prospective assessment of pituitary size and shape on MR imaging after suppressive hormonal therapy in central precocious puberty

    Energy Technology Data Exchange (ETDEWEB)

    Beek, J.T. van; Sharafuddin, M.J.A.; Kao, S.C.S. [Department of Radiology-JPP 3889, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52246 (United States); Luisiri, A. [Cardinal Glennon Children' s Hospital, St. Louis, Missouri (United States); Garibaldi, L.R. [Children' s Hospital of New Jersey, Newark Beth Israel Medical Center, Newark, New Jersey (United States); St. Barnabas Medical Center, Livingston, New Jersey (United States)

    2000-07-01

    Objective. The diagnostic significance of an enlarged pituitary gland regarding both shape and size parameters on MR imaging has previously been demonstrated in children with central precocious puberty. This study was designed to assess changes in these parameters following successful suppressive therapy of central precocious puberty with the gonadotropin-releasing hormone (GnRH) analogue. Materials and methods. Twelve girls (mean age 7.3 years) with central precocious puberty were prospectively enrolled in our study protocol. Sagittal and coronal MR images of the pituitary region were obtained in all patients before treatment and after at least 6 months of GnRH analogue therapy (mean 18.0 months). Parameters measured included pituitary gland height, length, width, sagittal cross-sectional area, and volume. Results. All patients had excellent clinical response to treatment with arrest of secondary sexual development, normalization of serum estradiol levels, and complete obliteration of the LH response to diagnostic GnRH stimulation. No significant change occurred in any pituitary size or shape parameter following GnRH analogue therapy. Conclusion. Favorable clinical response to GnRH analogue therapy in central precocious puberty is not accompanied by significant a change in pituitary gland size and shape. (orig.)

  16. Prospective assessment of pituitary size and shape on MR imaging after suppressive hormonal therapy in central precocious puberty

    International Nuclear Information System (INIS)

    Beek, J.T. van; Sharafuddin, M.J.A.; Kao, S.C.S.; Luisiri, A.; Garibaldi, L.R.

    2000-01-01

    Objective. The diagnostic significance of an enlarged pituitary gland regarding both shape and size parameters on MR imaging has previously been demonstrated in children with central precocious puberty. This study was designed to assess changes in these parameters following successful suppressive therapy of central precocious puberty with the gonadotropin-releasing hormone (GnRH) analogue. Materials and methods. Twelve girls (mean age 7.3 years) with central precocious puberty were prospectively enrolled in our study protocol. Sagittal and coronal MR images of the pituitary region were obtained in all patients before treatment and after at least 6 months of GnRH analogue therapy (mean 18.0 months). Parameters measured included pituitary gland height, length, width, sagittal cross-sectional area, and volume. Results. All patients had excellent clinical response to treatment with arrest of secondary sexual development, normalization of serum estradiol levels, and complete obliteration of the LH response to diagnostic GnRH stimulation. No significant change occurred in any pituitary size or shape parameter following GnRH analogue therapy. Conclusion. Favorable clinical response to GnRH analogue therapy in central precocious puberty is not accompanied by significant a change in pituitary gland size and shape. (orig.)

  17. Dual antagonists of integrins.

    Science.gov (United States)

    Nadrah, K; Dolenc, M Sollner

    2005-01-01

    The roles of integrins in pathologies have been studied intensively and only partially explained. This has resulted in the development of several nanomolar antagonists to certain integrins. In most cases, the aim was to produce compounds which are highly selective towards specific integrins. This paradigm has recently shifted a little. Targeting two or more integrins with one compound has become a very attractive concept, especially since it has become clear that several severe disorders, such as pathological angiogenesis, cannot be treated just with highly specific integrin antagonists. This review is aimed to elucidate some aspects regarding the design of drugs with dual activity towards integrins. Integrin structure and tissue distribution will first be described, in order to provide the basis for their functions in various pathologies which will follow. Inhibitors of several pairs of integrins will be described.

  18. Double insemination and gonadotropin-releasing hormone treatment of repeat-breeding dairy cattle.

    Science.gov (United States)

    Stevenson, J S; Call, E P; Scoby, R K; Phatak, A P

    1990-07-01

    Our objective was to determine if double inseminations during the same estrous period of dairy cattle eligible for their third or fourth service (repeat breeders) would improve pregnancy rates equivalent to injections of GnRH given at the time of AI. Repeat-breeding, lactating cows from six herds (five herds in the San Joaquin Valley of central California and one herd in northeast Kansas) were assigned randomly to four treatment groups when detected in estrus: 1) single AI plus no injection, 2) single AI plus 100 micrograms GnRH at AI, 3) double AI plus no injection, or 4) double AI plus 100 micrograms of GnRH at AI. Inseminations were performed according to the a.m.-p.m. rule. The second AI for the double AI treatment was given 12 to 16 h after the first AI. Injections of GnRH were given intramuscularly immediately following the single AI or the first AI of the double AI. Pregnancy rates of cows given a single AI and hormone injection were numerically higher in all six herds than those of their herdmates given only a single AI. In five of six herds, the pregnancy rates of cows given a double AI and hormone injection were numerically higher than pregnancy rates of their herdmates given only a double AI. Overall pregnancy rates for the four treatments were 1) 112/353 (32.1%), 2) 165/406 (41.6%), 3) 119/364 (33.5%), and 4) 135/359 (37.5%). Gonadotropin-releasing hormone increased pregnancy rates of repeat breeders compared with controls given only a single AI. No further benefit beyond the single AI was accrued from the double AI treatment, with or without concurrent hormone administration.

  19. Hormone action. Part I. Peptide hormones

    International Nuclear Information System (INIS)

    Birnbaumer, L.; O'Malley, B.W.

    1985-01-01

    The major sections of this book on the hormonal action of peptide hormones cover receptor assays, identification of receptor proteins, methods for identification of internalized hormones and hormone receptors, preparation of hormonally responsive cells and cell hybrids, purification of membrane receptors and related techniques, assays of hormonal effects and related functions, and antibodies in hormone action

  20. Comparison of estradiol and progesterone priming/antagonist/letrozole and microdose flare-up protocols for poor responders undergoing intracytoplasmic sperm injection.

    Science.gov (United States)

    Yucel, Oguz; Ekin, Murat; Cengiz, Hüseyin; Zebitay, Ali Galip; Yalcinkaya, Sener; Karahuseyinoglu, Sercin

    2014-09-01

    To compare the effect of the GnRH antagonist/letrozole/gonadotropin protocol with the microdose GnRH agonist flare-up protocol in poor ovarian responders for intracytoplasmic sperm injection. One hundred twenty-one consecutive patients suspected of having or with a history of poor ovarian response between January 2009 and June 2010, who were undergoing ICSI were enrolled. The microdose flareup (MF) protocol was used in 79 patients and the estradiol + progesterone/letrozole + gonadotropin and GnRH antagonist (EP/ALG) protocol was used in 42 patients. Age of the patients, duration of infertility, basal FSH, the total gonadotropin consumption, duration of stimulation, E2 level on the day of hCG administration, the number of embryo transferred, the fertilization rate, implantation rate, clinical pregnancy rate and the live birth rate were not statistically different (p > 0.05). Only the number of oocytes retrieved was significantly higher in the EP/LGA group (1.7 ± 0.7 versus 2.6 ± 0.6). The EP/LGA protocol has no significant improvement against the microdose flare-up protocol in poor responder patients.

  1. Highly immunogenic and fully synthetic peptide-carrier constructs targetting GnRH

    DEFF Research Database (Denmark)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Turkstra, J.A.

    1999-01-01

    To use peptides as synthetic vaccines, they have to be coupled to a carrier protein to make them more immunogenic. Coupling efficiency between a carrier protein and a peptide, however, is difficult to control with respect to loading density of the peptide, This makes these carrier proteins poorly...... for the induction of antibodies against GnRH and immunocastration of pigs....

  2. Social Crowding during Development Causes Changes in GnRH1 DNA Methylation.

    Science.gov (United States)

    Alvarado, Sebastian G; Lenkov, Kapa; Williams, Blake; Fernald, Russell D

    2015-01-01

    Gestational and developmental cues have important consequences for long-term health, behavior and adaptation to the environment. In addition, social stressors cause plastic molecular changes in the brain that underlie unique behavioral phenotypes that also modulate fitness. In the adult African cichlid, Astatotilapia burtoni, growth and social status of males are both directly regulated by social interactions in a dynamic social environment, which causes a suite of plastic changes in circuits, cells and gene transcription in the brain. We hypothesized that a possible mechanism underlying some molecular changes might be DNA methylation, a reversible modification made to cytosine nucleotides that is known to regulate gene function. Here we asked whether changes in DNA methylation of the GnRH1 gene, the central regulator of the reproductive axis, were altered during development of A. burtoni. We measured changes in methylation state of the GnRH1 gene during normal development and following the gestational and developmental stress of social crowding. We found differential DNA methylation within developing juveniles between 14-, 28- and 42-day-old. Following gestational crowding of mouth brooding mothers, we saw differential methylation and transcription of GnRH1 in their offspring. Taken together, our data provides evidence for social control of GnRH1 developmental responses to gestational cues through DNA methylation.

  3. Conservation of Three-Dimensional Helix-Loop-Helix Structure through the Vertebrate Lineage Reopens the Cold Case of Gonadotropin-Releasing Hormone-Associated Peptide

    OpenAIRE

    Daniela I. Pérez Sirkin; Daniela I. Pérez Sirkin; Anne-Gaëlle Lafont; Nédia Kamech; Gustavo M. Somoza; Paula G. Vissio; Paula G. Vissio; Sylvie Dufour

    2017-01-01

    GnRH-associated peptide (GAP) is the C-terminal portion of the gonadotropin-releasing hormone (GnRH) preprohormone. Although it was reported in mammals that GAP may act as a prolactin-inhibiting factor and can be co-secreted with GnRH into the hypophyseal portal blood, GAP has been practically out of the research circuit for about 20 years. Comparative studies highlighted the low conservation of GAP primary amino acid sequences among vertebrates, contributing to consider that this peptide onl...

  4. Development of Gonadotropin-Releasing Hormone-Secreting Neurons from Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Carina Lund

    2016-08-01

    Full Text Available Gonadotropin-releasing hormone (GnRH neurons regulate human puberty and reproduction. Modeling their development and function in vitro would be of interest for both basic research and clinical translation. Here, we report a three-step protocol to differentiate human pluripotent stem cells (hPSCs into GnRH-secreting neurons. Firstly, hPSCs were differentiated to FOXG1, EMX2, and PAX6 expressing anterior neural progenitor cells (NPCs by dual SMAD inhibition. Secondly, NPCs were treated for 10 days with FGF8, which is a key ligand implicated in GnRH neuron ontogeny, and finally, the cells were matured with Notch inhibitor to bipolar TUJ1-positive neurons that robustly expressed GNRH1 and secreted GnRH decapeptide into the culture medium. The protocol was reproducible both in human embryonic stem cells and induced pluripotent stem cells, and thus provides a translational tool for investigating the mechanisms of human puberty and its disorders.

  5. Gonadotropin-Releasing Hormone Modulates Vomeronasal Neuron Response to Male Salamander Pheromone

    Directory of Open Access Journals (Sweden)

    Celeste R. Wirsig-Wiechmann

    2012-01-01

    Full Text Available Electrophysiological studies have shown that gonadotropin-releasing hormone (GnRH modifies chemosensory neurons responses to odors. We have previously demonstrated that male Plethodon shermani pheromone stimulates vomeronasal neurons in the female conspecific. In the present study we used agmatine uptake as a relative measure of the effects of GnRH on this pheromone-induced neural activation of vomeronasal neurons. Whole male pheromone extract containing 3 millimolar agmatine with or without 10 micromolar GnRH was applied to the nasolabial groove of female salamanders for 45 minutes. Immunocytochemical procedures were conducted to visualize and quantify relative agmatine uptake as measured by labeling density of activated vomeronasal neurons. The relative number of labeled neurons did not differ between the two groups: pheromone alone or pheromone-GnRH. However, vomeronasal neurons exposed to pheromone-GnRH collectively demonstrated higher labeling intensity, as a percentage above background (75% as compared with neurons exposed to pheromone alone (63%, P < 0.018. Since the labeling intensity of agmatine within neurons signifies the relative activity levels of the neurons, these results suggest that GnRH increases the response of female vomeronasal neurons to male pheromone.

  6. Morphological Characterization of the Action Potential Initiation Segment in GnRH Neuron Dendrites and Axons of Male Mice.

    Science.gov (United States)

    Herde, Michel K; Herbison, Allan E

    2015-11-01

    GnRH neurons are the final output neurons of the hypothalamic network controlling fertility in mammals. In the present study, we used ankyrin G immunohistochemistry and neurobiotin filling of live GnRH neurons in brain slices from GnRH-green fluorescent protein transgenic male mice to examine in detail the location of action potential initiation in GnRH neurons with somata residing at different locations in the basal forebrain. We found that the vast majority of GnRH neurons are bipolar in morphology, elaborating a thick (primary) and thinner (secondary) dendrite from opposite poles of the soma. In addition, an axon-like process arising predominantly from a proximal dendrite was observed in a subpopulation of GnRH neurons. Ankyrin G immunohistochemistry revealed the presence of a single action potential initiation zone ∼27 μm in length primarily in the secondary dendrite of GnRH neurons and located 30 to 140 μm distant from the cell soma, depending on the type of process and location of the cell body. In addition to dendrites, the GnRH neurons with cell bodies located close to hypothalamic circumventricular organs often elaborated ankyrin G-positive axon-like structures. Almost all GnRH neurons (>90%) had their action potential initiation site in a process that initially, or ultimately after a hairpin loop, was coursing in the direction of the median eminence. These studies indicate that action potentials are initiated in different dendritic and axonal compartments of the GnRH neuron in a manner that is dependent partly on the neuroanatomical location of the cell body.

  7. A Pharmacokinetic/Pharmacodynamic Study of the Glucocorticoid Receptor Antagonist Mifepristone Combined with Enzalutamide in Castrate Resistant Prostate Cancer

    Science.gov (United States)

    2015-12-01

    AWARD NUMBER: W81XWH-14-1-0021 TITLE: A Pharmacokinetic/Pharmacodynamic Study of the Glucocorticoid Receptor Antagonist Mifepristone Combined...4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER A Pharmacokinetic/Pharmacodynamic Study of the Glucocorticoid Receptor Antagonist Mifepristone Combined...way it adapts is by upregulating another hormone receptor, the glucocorticoid receptor (GR), which may compensate for diminished AR activity. The

  8. Women with oligo-/amenorrhoea and polycystic ovaries have identical responses to GnRH stimulation regardless of their androgen status: comparison of the Rotterdam and Androgen Excess Society diagnostic criteria.

    Science.gov (United States)

    Lewandowski, Krzysztof C; Cajdler-Luba, Agata; Bieńkiewicz, Małgorzata; Lewiński, Andrzej

    2011-01-01

    As increased frequency of gonadotrophin-releasing hormone (GnRH) pulses is characteristic for polycystic ovary syndrome (PCOS), we assessed gonadotrophin response to GnRH in women with PCOS with normal and raised androgens and in regularly menstruating controls. The study involved 155 subjects: PCOS, n=121, age (mean±SD) 24.8±5.4 yrs, BMI 24.5±6.0 kg/m2, all with oligo-/amenorrhoea and PCO morphology, and 34 controls. Gonadotrophins were measured in early follicular phase after GnRH stimulation (0, 30 and 60 minutes). Fifty four (41.9%) women with PCOS had androgens (testosterone, androstendione, dihydroepiandrosterone sulphate) within the reference range, and would fulfil the "Rotterdam", but not the Androgen Excess Society PCOS criteria. Baseline and stimulated LH concentrations were higher in PCOS (9.09±5.56 vs 4.83±1.71 IU/l, 35.48±31.4 vs 16.30±6.68 IU/l, 33.86±31.8 vs 13.45±5.2 IU/l, at 0, 30 and 60 min post GnRH, respectively, pPCOS increased further after GnRH stimulation. ROC analysis revealed that LH30min/FSH30min >2.11 or LH60min/FSH60min >1.72 had 78.3% and 87.5% sensitivity and 81.7% and 81.3% specificity for diagnosis of PCOS. Both baseline and GnRH-stimulated LH and FSH concentrations were similar in women with PCOS and raised androgens and with androgens within the reference range (p=0.71 and p=0.20 for LH and FSH, respectively). Regardless of their androgen status, women with PCO morphology and oligo-/amenorrhoea have higher baseline and GnRH-stimulated LH concentrations and higher GnRH-stimulated LH/FSH ratio than controls, suggestive of similar underlying mechanism accounting for menstrual irregularities. These observations support validity of PCOS diagnostic criteria based on the Rotterdam consensus.

  9. Effects of GnRH administration on ovulation and fertility in ewes subjected to estrous synchronization

    Directory of Open Access Journals (Sweden)

    Amanda dos Santos Cavalcanti

    2012-06-01

    Full Text Available The objective of this study was to verify the effects of GnRH on ovulation and pregnancy of ewes subjected to a short-term synchronization of estrus. Santa Inês and crossbred Santa Inês/Dorper ewes received 60 mg MAP sponges during 6 days plus 300 IU eCG and 30 µg d-cloprostenol 24 h prior to sponge withdrawal (SW. Ewes were assigned to receive 0.9% NaCl solution (Tcontrol; n = 32 or 25 µg GnRH (licerelin, T GnRH; n = 34 24 hours after SW. Each group was assigned to intrauterine insemination by laparoscopy (n = 25 or to natural mating (n = 41. Artificial insemination was performed with a single dose of fresh semen. For controlled mating, females were exposed to males 12, 24, 36 and 48 hours after SW. Ten females per treatment were subjected to transrectal ultrasound examination at 12-hour intervals (SW to 60 hours after. Estrous response (100.0% vs 95.2%, interval from SW to estrus (32.9±7.4 vs 29.8±6.9 hours, estrous length (37.4±9.0 vs 31.5±10.4 hours, pregnancy rates (57.0% vs 41.0%, ovulation rate (100.0% vs 90.0%, number of ovulations/ewe (1.1±0.3 vs 1.2±0.4, maximum follicular diameter (6.4±0.7 vs 6.1±0.6 mm, interval from SW to ovulation (59.1±3.5 vs 58.4±3.5 hours did not differ between Tcontrol and T GnRH, respectively. Administration of GnRH 24 hours after SW does not improve ovulation or pregnancy rate in estrous synchronization in ewes.

  10. Effects of Thyroid Dysfunction on Reproductive Hormones in Female Rats.

    Science.gov (United States)

    Liu, Juan; Guo, Meng; Hu, Xusong; Weng, Xuechun; Tian, Ye; Xu, Kaili; Heng, Dai; Liu, Wenbo; Ding, Yu; Yang, Yanzhou; Zhang, Cheng

    2018-05-10

    Thyroid hormones (THs) play a critical role in the development of ovarian cells. Although the effects of THs on female reproduction are of great interest, the mechanism remains unclear. We investigated the effects of TH dysregulation on reproductive hormones in rats. Propylthiouracil (PTU) and L-thyroxine were administered to rats to induce hypo- and hyper-thyroidism, respectively, and the reproductive hormone profiles were analyzed by radioimmunoassay. Ovarian histology was evaluated with H&E staining, and gene protein level or mRNA content was analyzed by western blotting or RT-PCR. The serum levels of gonadotropin releasing hormone (GnRH) and follicle stimulating hormone (FSH) in both rat models were significantly decreased on day 21, although there were no significant changes at earlier time points. There were no significant differences in luteinizing hormone (LH) or progesterone levels between the treatment and the control groups. Both PTU and L-thyroxine treatments downregulated estradiol concentrations; however, the serum testosterone level was increased only in hypothyroid rats at day 21. In addition, the expression levels of FSH receptor, cholesterol side-chain cleavage enzyme (P450scc), and steroidogenic acute regulatory protein were decreased in both rat models. Moreover, the onset of puberty was significantly delayed in the hypothyroid group. These results provide evidence that TH dysregulation alters reproductive hormone profiles, and that the initiation of the estrous cycle is postponed in hypothyroidism.

  11. Characterization of gonadotrophin-releasing hormone precursor cDNA in the Old World mole-rat Cryptomys hottentotus pretoriae: high degree of identity with the New World guinea pig sequence.

    Science.gov (United States)

    Kalamatianos, T; du Toit, L; Hrabovszky, E; Kalló, I; Marsh, P J; Bennett, N C; Coen, C W

    2005-05-01

    Regulation of pituitary gonadotrophins by the decapeptide gonadotrophin-releasing hormone 1 (GnRH1) is crucial for the development and maintenance of reproductive functions. A common amino acid sequence for this decapeptide, designated as 'mammalian' GnRH, has been identified in all mammals thus far investigated with the exception of the guinea pig, in which there are two amino acid substitutions. Among hystricognath rodents, the members of the family Bathyergidae regulate reproduction in response to diverse cues. Thus, highveld mole-rats (Cryptomys hottentotus pretoriae) are social bathyergids in which breeding is restricted to a particular season in the dominant female, but continuously suppressed in subordinate colony members. Elucidation of reproductive control in these animals will be facilitated by characterization of their GnRH1 gene. A partial sequence of GnRH1 precursor cDNA was isolated and characterized. Comparative analysis revealed the highest degree of identity (86%) to guinea pig GnRH1 precursor mRNA. Nevertheless, the deduced amino acid sequence of the mole-rat decapeptide is identical to the 'mammalian' sequence rather than that of guinea pigs. Successful detection of GnRH1-synthesizing neurones using either a guinea pig GnRH1 riboprobe or an antibody against the 'mammalian' decapeptide is consistent with the guinea pig-like sequence for the precursor and the classic 'mammalian' form for the decapeptide. The high degree of identity in the GnRH1 precursor sequence between this Old World mole-rat and the New World guinea pig is consistent with the theory that caviomorphs and phiomorphs originated from a common ancestral line in the Palaeocene to mid Eocene, some 63-45 million years ago.

  12. Hormone Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hormones quantified from marine mammal and sea turtle tissue provide information about the status of each animal sampled, including its sex, reproductive status and...

  13. Hormone Therapy

    Science.gov (United States)

    ... it also can be a sign of endometrial cancer. All bleeding after menopause should be evaluated. Other side effects reported by women who take hormone therapy include fluid retention and breast soreness. This soreness usually lasts for a short ...

  14. Pulsatile gonadotropin-releasing hormone therapy is associated with earlier spermatogenesis compared to combined gonadotropin therapy in patients with congenital hypogonadotropic hypogonadism

    Directory of Open Access Journals (Sweden)

    Jiang-Feng Mao

    2017-01-01

    Full Text Available Both pulsatile gonadotropin-releasing hormone (GnRH infusion and combined gonadotropin therapy (human chorionic gonadotropin and human menopausal gonadotropin [HCG/HMG] are effective to induce spermatogenesis in male patients with congenital hypogonadotropic hypogonadism (CHH. However, evidence is lacking as to which treatment strategy is better. This retrospective cohort study included 202 patients with CHH: twenty had received pulsatile GnRH and 182 had received HCG/HMG. Patients had received therapy for at least 12 months. The total follow-up time was 15.6 ± 5.0 months (range: 12-27 months for the GnRH group and 28.7 ± 13.0 months (range: 12-66 months for the HCG/HMG group. The median time to first sperm appearance was 6 months (95% confidence interval [CI]: 1.6-10.4 in the GnRH group versus 18 months (95% CI: 16.4-20.0 in the HCG/HMG group (P 1 × 10 6 ml−1 was 43.7% ± 20.4% (16 samples in the GnRH group versus 43.2% ± 18.1% (153 samples in the HCG/HMG group (P = 0.921. Notably, during follow-up, the GnRH group had lower serum testosterone levels than the HCG/HMG group (8.3 ± 4.6 vs 16.2 ± 8.2 nmol l−1 , P < 0.001. Our study found that pulsatile GnRH therapy was associated with earlier spermatogenesis and larger testicular size compared to combined gonadotropin therapy. Additional prospective randomized studies would be required to confirm these findings.

  15. Degarelix 240/80 mg: a new treatment option for patients with advanced prostate cancer

    DEFF Research Database (Denmark)

    Boccon-Gibod, L.; Iversen, P.; Persson, B.E.

    2009-01-01

    Gonadotrophin-releasing hormone (GnRH) receptor blockers (antagonists) are the latest addition to the hormonal therapy armamentarium for patients with prostate cancer. In contrast to the GnRH agonists, GnRH blockers have an immediate onset of action and do not cause an initial surge in testosterone...... levels that can lead to clinical flare in patients with advanced disease. Degarelix (Firmagon is a new GnRH blocker that has recently been approved by the EMEA and US FDA for the treatment of men with hormone-sensitive advanced prostate cancer. In this article, we briefly review the Phase III trial data...

  16. Expression of the GnRH and GnRH receptor (GnRH-R) genes in the hypothalamus and of the GnRH-R gene in the anterior pituitary gland of anestrous and luteal phase ewes.

    Science.gov (United States)

    Ciechanowska, Magdalena; Lapot, Magdalena; Malewski, Tadeusz; Mateusiak, Krystyna; Misztal, Tomasz; Przekop, Franciszek

    2008-11-01

    Data exists showing that seasonal changes in the innervations of GnRH cells in the hypothalamus and functions of some neural systems affecting GnRH neurons are associated with GnRH release in ewes. Consequently, we put the question as to how the expression of GnRH gene and GnRH-R gene in the hypothalamus and GnRH-R gene in the anterior pituitary gland is reflected with LH secretion in anestrous and luteal phase ewes. Analysis of GnRH gene expression by RT-PCR in anestrous ewes indicated comparable levels of GnRH mRNA in the preoptic area, anterior and ventromedial hypothalamus. GnRH-R mRNA at different concentrations was found throughout the preoptic area, anterior and ventromedial hypothalamus, stalk/median eminence and in the anterior pituitary gland. The highest GnRH-R mRNA levels were detected in the stalk/median eminence and in the anterior pituitary gland. During the luteal phase of the estrous cycle in ewes, the levels of GnRH mRNA and GnRH-R mRNA in all structures were significantly higher than in anestrous ewes. Also LH concentrations in blood plasma of luteal phase ewes were significantly higher than those of anestrous ewes. In conclusion, results from this study suggest that low expression of the GnRH and GnRH-R genes in the hypothalamus and of the GnRH-R gene in the anterior pituitary gland, amongst others, may be responsible for a decrease in LH secretion and the anovulatory state in ewes during the long photoperiod.

  17. Incidence of premature estrus in lactating dairy cows and conception rates to standing estrus or fixed-time inseminations after synchronization using GnRH and PGF(2alpha).

    Science.gov (United States)

    DeJarnette, J M; Salverson, R R; Marshall, C E

    2001-07-03

    Fixed-time AI (TAI) after GnRH-PGF(2alpha)-GnRH treatment is a method to achieve pregnancies in dairy herds without estrous detection. However, cows that fail to respond to the initial GnRH may have compromised TAI conception rates due to asynchronous ovarian response. This study documented the percentage of GnRH-treated Holstein cows (n=345) in two herds that displayed estrus at an inopportune time for optimum TAI conception rate (conception rates of two TAI protocols in cows that did not display PE. At biweekly herd health exams, cows diagnosed as not pregnant to a previous AI and cows >80 days postpartum with no AI were treated with 100 microg GnRH (day -7) and 25mg PGF(2alpha) (day 0). Cows detected in PE by twice-daily visual observation from day -7 to day 2 were bred by AI 8-12h later. Cows not detected in PE were randomly assigned by parity, body condition score, and postpartum interval to receive either: (1) 100microg GnRH at 48h after PGF(2alpha) and TAI 16 to 18h later (Ovsynch); or (2) TAI at 72h post-PGF(2alpha) and a concurrent 100 microg GnRH injection to those cows not detected in estrus between 48 and 72h post-PGF(2alpha) (modified Ovsynch (MOV)). All hormone injections were im. Twenty percent (68/345) of the cows were detected in estrus before 48 after PGF(2alpha), of which 5% (17/345) were detected in estrus before PGF(2alpha) (Conception rates were not affected by treatment (PE versus Ovsynch versus MOV; 32% (21/65) versus 30% (37/125) versus 32% (47/145); P>0.10). However, within MOV-treated cows, conception rates were greater (Prates are to be achieved. Although additional estrous detection is required compared to Ovsynch, reduced cow handling and hormone usage, efficient use of expensive semen through greater conception rates in cows detected in estrus, and comparable TAI conception rates, suggests the MOV protocol may be a cost effective alternative to Ovsynch in many dairy herd reproductive management programs.

  18. [Revelation of a polymicrocystic ovary syndrome after one month's treatment by pulsatile GnRH in a patient presenting with functional hypothalamic amenorrhea].

    Science.gov (United States)

    Reyss, A C; Merlen, E; Demerle, C; Dewailly, D

    2003-12-01

    Polycystic ovary syndrome (PCOS) and hypothalamic amenorrhea (HA) are the most frequent causes of endocrine infertility, but their association is an uncommon occurrence. We report the case of a 28-year old woman suffering from infertility and amenorrhea. Her weight was normal (BMI = 19) and she had no hirsutism. She self-reported food restriction and a 10 kg weight loss 5 years ago, concomitant with the onset of amenorrhea. At the initial evaluation, the patient was considered as having HA due to food restriction. At ultrasonography, ovaries were small and multifollicular (right and left area: 2.2 and 2.5 cm(2), respectively; number of cysts 2-9 mm in diameter: 15 and 12, respectively), and no stromal hypertrophy was noted. She has been treated for 1 month by intravenous pulsatile GnRH administration. Although the doses were increased from 5 to 15 microg/pulse every 90 min, no E2 response and no follicular development were observed. Hormonal re-evaluation revealed normal levels of serum LH, FSH and androgens, and a normal LH/FSH ratio. However, a typical aspect of PCO was found at ultrasound (right and left area: 6.5 and 5.5 cm(2), respectively, and more than 15 small cysts arranged peripherally around an increased central stroma in each ovary). The treatment has been then switched to hMG, using the low dose step-up regimen and starting with 75 U/day. In the absence of response after 2 weeks, the dose was increased to 112.5 U/day and a multifollicular reaction occurred, leading to cancellation. In conclusion, we hypothesize that this patient had a "hidden" PCOS when she was hypogonadotrophic and that it developed very rapidly after restitution of a normal gonadotropin level under exogenous GnRH. This occurred despite a low insulin level, showing that hyperinsulinism is not a prerequisite for the development of PCOS in every case.

  19. Responsiveness to a Physiological Regimen of GnRH Therapy and Relation to Genotype in Women With Isolated Hypogonadotropic Hypogonadism

    Science.gov (United States)

    Abel, Brent S.; Shaw, Natalie D.; Brown, Jenifer M.; Adams, Judith M.; Alati, Teresa; Martin, Kathryn A.; Pitteloud, Nelly; Seminara, Stephanie B.; Plummer, Lacey; Pignatelli, Duarte; Crowley, William F.; Welt, Corrine K.

    2013-01-01

    Context: Isolated hypogonadotropic hypogonadism (IHH) is caused by defective GnRH secretion or action resulting in absent or incomplete pubertal development and infertility. Most women with IHH ovulate with physiological GnRH replacement, implicating GnRH deficiency as the etiology. However, a subset does not respond normally, suggesting the presence of defects at the pituitary or ovary. Objectives: The objective of the study was to unmask pituitary or ovarian defects in IHH women using a physiological regimen of GnRH replacement, relating these responses to genes known to cause IHH. Design, Setting, and Subjects: This study is a retrospective analysis of 37 IHH women treated with iv pulsatile GnRH (75 ng/kg per bolus). Main Outcome Measures: Serum gonadotropin and sex steroid levels were measured, and 14 genes implicated in IHH were sequenced. Results: During their first cycle of GnRH replacement, normal cycles were recreated in 60% (22 of 37) of IHH women. Thirty percent of women (12 of 37) demonstrated an attenuated gonadotropin response, indicating pituitary resistance, and 10% (3 of 37) exhibited an exaggerated FSH response, consistent with ovarian resistance. Mutations in CHD7, FGFR1, KAL1, TAC3, and TACR3 were documented in IHH women with normal cycles, whereas mutations were identified in GNRHR, PROKR2, and FGFR1 in those with pituitary resistance. Women with ovarian resistance were mutation negative. Conclusions: Although physiological replacement with GnRH recreates normal menstrual cycle dynamics in most IHH women, hypogonadotropic responses in the first week of treatment identify a subset of women with pituitary dysfunction, only some of whom have mutations in GNRHR. IHH women with hypergonadotropic responses to GnRH replacement, consistent with an additional ovarian defect, did not have mutations in genes known to cause IHH, similar to our findings in a subset of IHH men with evidence of an additional testicular defect. PMID:23341491

  20. The Effect of a GnRH Agonist Injection or Progesterone Implant at Diestrus in Cryopreserved Embryo Transferred Cows

    OpenAIRE

    KIRBAŞ, Mesut; BÜLBÜL, Bülent; KÖSE, Mehmet; DURSUN, Şükrü; ÇOLAK, Mehmet

    2014-01-01

    In this study, the effect of a single dose of GnRH on d 13 or progesterone implant for 7 days between d 13 and 20 on plasma progesterone levels and pregnancy rates on cryopreserved embryo transferred cows were investigated. Synchronized 48 Brown Swiss recipient cows were used as animal material. Seven days after estrus detection, cryopreserved cattle embryos were transferred into recipients and cows were assigned randomly into three groups. In GnRH group (n=16), cows were intramuscularly inje...

  1. Naloxone : actions of an antagonist

    NARCIS (Netherlands)

    Dorp, Eveline Louise Arianna van

    2009-01-01

    The opioid antagonist naloxone has a special place in pharmacology – it has no intrinsic action of its own, but it is able to save lives in the case of life threatening side-effects caused by other drugs. Naloxone is an antagonist for all opioid receptors, but most specifically for the μ-opioid

  2. GnRH dysregulation in polycystic ovarian syndrome (PCOS) is a manifestation of an altered neurotransmitter profile.

    Science.gov (United States)

    Chaudhari, Nirja; Dawalbhakta, Mitali; Nampoothiri, Laxmipriya

    2018-04-11

    GnRH is the master molecule of reproduction that is influenced by several intrinsic and extrinsic factors such as neurotransmitters and neuropeptides. Any alteration in these regulatory loops may result in reproductive-endocrine dysfunction such as the polycystic ovarian syndrome (PCOS). Although low dopaminergic tone has been associated with PCOS, the role of neurotransmitters in PCOS remains unknown. The present study was therefore aimed at understanding the status of GnRH regulatory neurotransmitters to decipher the neuroendocrine pathology in PCOS. PCOS was induced in rats by oral administration of letrozole (aromatase inhibitor). Following PCOS validation, animals were assessed for gonadotropin levels and their mRNA expression. Neurotrasnmitter status was evaluated by estimating their levels, their metabolism and their receptor expression in hypothalamus, pituitary, hippocampus and frontal cortex of PCOS rat model. We demonstrate that GnRH and LH inhibitory neurotransmitters - serotonin, dopamine, GABA and acetylcholine - are reduced while glutamate, a major stimulator of GnRH and LH release, is increased in the PCOS condition. Concomitant changes were observed for neurotransmitter metabolising enzymes and their receptors as well. Our results reveal that increased GnRH and LH pulsatility in PCOS condition likely result from the cumulative effect of altered GnRH stimulatory and inhibitory neurotransmitters in hypothalamic-pituitary centre. This, we hypothesise, is responsible for the depression and anxiety-like mood disorders commonly seen in PCOS women.

  3. Long-term effects of GnRH agonists on fertility and behaviour

    DEFF Research Database (Denmark)

    Goericke-Pesch, Sandra Kathrin

    2017-01-01

    ; a significant positive effect in reducing sexual behaviour and libido, hypersexuality, intermale dominance and excessive territorial urine marking has been described. Rates of improvement of the respective behaviour are comparable to those after surgical castration, making GnRH A-SRI a valuable option...... and behaviour have by now been shown to be fully reversible. Knowledge in females is more limited, and particularly, the initial induction of a possibly fertile oestrus and individual variation in duration of efficacy remain problems in bitches and queens treated for suppression of fertility. However, long......-term suppression of oestrous cycle and fertility seems to be possible with induced effects shown to be reversible including restoration of normal fertility after the end of efficacy/GNRH A-SRI removal....

  4. Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris).

    Science.gov (United States)

    Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

    2006-04-01

    GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homologue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnRHR and the chordate GnRHR genes. The oct-GnRHR expressed in Xenopus (South African clawed frog) oocytes was responsive to oct-GnRH, but not to any other HPLC fractions of the Octopus brain extract. These results show that oct-GnRHR is an authentic receptor for oct-GnRH. Southern blotting of reverse-transcription PCR products revealed that the oct-GnRHR mRNA was widely distributed in the central and peripheral nervous systems and in several peripheral tissues. In situ hybridization showed that oct-GnRHR mRNA was expressed in some regions involved in autonomic functions, feeding, memory and movement. Oct-GnRH was shown to induce steroidogenesis of testosterone, progesterone and 17beta-oestradiol in Octopus ovary and testis, where oct-GnRHR was abundantly expressed. These results suggest that oct-GnRH, like its vertebrate counterparts, acts as a multifunctional neurotransmitter, neuromodulator and hormone-like factor, both in Octopus central nervous system and peripheral tissues, and that both structure and functions of the GnRH family are, at least partially, evolutionarily conserved between octopuses and chordates.

  5. Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris)

    Science.gov (United States)

    Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

    2005-01-01

    GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homo-logue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnRHR and the chordate GnRHR genes. The oct-GnRHR expressed in Xenopus (South African clawed frog) oocytes was responsive to oct-GnRH, but not to any other HPLC fractions of the Octopus brain extract. These results show that oct-GnRHR is an authentic receptor for oct-GnRH. Southern blotting of reverse-transcription PCR products revealed that the oct-GnRHR mRNA was widely distributed in the central and peripheral nervous systems and in several peripheral tissues. In situ hybridiz-ation showed that oct-GnRHR mRNA was expressed in some regions involved in autonomic functions, feeding, memory and movement. Oct-GnRH was shown to induce steroidogenesis of testosterone, progesterone and 17β-oestradiol in Octopus ovary and testis, where oct-GnRHR was abundantly expressed. These results suggest that oct-GnRH, like its vertebrate counterparts, acts as a multifunctional neurotransmitter, neuromodulator and hormone-like factor, both in Octopus central nervous system and peripheral tissues, and that both structure and functions of the GnRH family are, at least partially, evolutionarily conserved between octopuses and chordates. PMID:16367741

  6. Resumption of menstruation and pituitary response to gonadotropin-releasing hormone in functional hypothalamic amenorrhea subjects undertaking estrogen replacement therapy.

    Science.gov (United States)

    Shen, Z Q; Xu, J J; Lin, J F

    2013-11-01

    Functional hypothalamic amenorrhea (FHA) refers to a functional menstrual disorder with various causes and presentations. Recovery of menstrual cyclicity is common in long-term follow-up but the affecting factors remain unknown. To explore factors affecting the menstrual resumption and to evaluate the pituitary response to gonadotropin-releasing hormone (GnRH) in FHA. Thirty cases with FHA were recruited. All subjects were put on continuous 1 mg/day estradiol valerate orally and followed up monthly. Recovery was defined as the occurrence of at least three consecutive regular cycles. Responder referred to those who recovered within two years of therapy. Gonadotropin response to the 50 μg GnRH challenge was tested every three months. Nineteen (63.3%) subjects recovered with a mean time to recovery of 26.8 months. Time to recovery was negatively correlated with body mass index (BMI) before and by amenorrhea. Twentyone cases had undertaken therapy for more than two years and 10 of them recovered. BMI before and by amenorrhea were negatively correlated with the recovery. Significant increase of serum luteinizing hormone (LH) and LH response to GnRH were noted after recovery. Menstrual resumption was common in FHA undertaking estrogen replacement therapy (ERT). The likelihood of recovery was affected by their BMI before and by amenorrhea but not by the weight gain during therapy. Low serum LH and attenuated LH response to GnRH were the main features of pituitary deficiency in FHA. The menstrual resumption in FHA was accompanied by the recovery of serum LH and the LH response to GnRH.

  7. Prenatal exposure to vinclozolin disrupts selective aspects of the gonadotropin-releasing hormone neuronal system of the rabbit

    OpenAIRE

    Wadas, B.C.; Hartshorn, C.A.; Aurand, E.R.; Palmer, J.S.; Roselli, C.E.; Noel, M.L.; Gore, A.C.; Veeramachaneni, D.N.R.; Tobet, S.A.

    2010-01-01

    Developmental exposure to the agricultural fungicide vinclozolin can impair reproductive function in male rabbits and was previously found to decrease the number of immunoreactive-gonadotropin-releasing hormone (ir-GnRH) neurons in the region of the organum vasculosum of the lamina terminalis (OVLT) and rostral preoptic area (rPOA) by postnatal week (PNW) 6. To further examine the disruption of GnRH neurons by fetal vinclozolin exposure, in the current study, pregnant rabbits were dosed orall...

  8. Prenatal testosterone treatment alters LH and testosterone responsiveness to GnRH agonist in male sheep

    Directory of Open Access Journals (Sweden)

    SERGIO E RECABARREN

    2007-01-01

    Full Text Available Although evidence is accumulating that prenatal testosterone (T compromises reproductive function in the female, the effects of excess T in utero on the postnatal development of male reproductive function has not been studied. The aim of this study was to assess the influence of prenatal T excess on age-related changes in pituitary and gonadal responsiveness to GnRH in the male sheep. We used the GnRH agonist, leuprolide (10 µg/kg, as a pharmacologic challenge at 5, 10, 20 and 30 weeks of age. These time points correspond to early and late juvenile periods and the prepubertal and postpubertal periods of sexual development, respectively. LH and T were measured in blood samples collected before and after GnRH agonist administration. The area under the response curve (AUC of LH increased progressively in both controls and prenatal T-treated males from 5 to 20 weeks of age (P<0.01. The LH responses in prenatal T-treated males were lower at 20 and 30 weeks of age compared to controls (P<0.05. AUC-T increased progressively in control males from 5 through 30 weeks of age and prenatal T-treated males from 5 to 20 weeks of age. The T response in prenatal T-treated males was higher at 20 weeks compared to controls of same age but similar to controls and prenatal T-treated males at 30 weeks of age (P <0.05. Our findings suggest that prenatal T treatment advances the developmental trajectory of gonadal responsiveness to GnRH in male offspring

  9. Carbon adaptation influence the antagonistic ability of ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... INTRODUCTION. The use of antagonistic bacteria to control soil-borne ... plant was used to evaluate the antifungal activities of antagonistic bacteria. ..... antagonistic bacteria and cloning of its phenazine carboxylic acid genes.

  10. Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone

    International Nuclear Information System (INIS)

    Bajusz, S.; Janaky, T.; Csernus, V.J.; Bokser, L.; Fekete, M.; Srkalovic, G.; Redding, T.W.; Schally, A.V.

    1989-01-01

    Metal complexes related to the cytotoxic complexes cisplatin [cis-diamminedichloroplatinum(II)] and transbis(salicylaldoximato)copper(II) were incorporated into suitably modified luteinizing hormone-releasing hormone (LH-RH) analogues containing D-lysine at position 6. Some of the metallopeptides thus obtained proved to be highly active LH-RH agonists or antagonists. Most metallopeptide analogues of LH-RH showed high affinities for the membrane receptors of rat pituitary and human breast cancer cells. Some of these metallopeptides had cytotoxic activity against human breast cancer and prostate cancer and prostate cancer cell lines in vitro. Such cytostatic metallopeptides could be envisioned as targeted chemotherapeutic agents in cancers that contain receptors for LH-RH-like peptides

  11. Hormones and tumour therapy: current clinical status and future developments in endocrine therapy of breast cancer

    International Nuclear Information System (INIS)

    Szepesi, T.; Schratter-Sehn, A.U.

    1982-01-01

    Postoperative adjuvant hormone therapy and hormone therapy in disseminated breast cancer will be discussed systematically. The classical ablative and additive endocrine therapeutic measures - with the exception of ovarectomy and gestagen therapy - are increasinlgy being replaced by antagonists. Individual chapters discuss recent experience with combined hormone-radiotherapy or hormone-chemotherapy. In addition, a successful therapy scheme for the treatment of disseminated breast cancer will be presented. (Author)

  12. Population pharmacokinetic/pharmacodynamic (PK/PD) modelling of the hypothalamic-pituitary-gonadal axis following treatment with GnRH analogues

    DEFF Research Database (Denmark)

    Tornøe, Christoffer Wenzel; Agersø, Henrik; Senderovitz, Thomas

    2007-01-01

    and the GnRH receptor blocker degarelix. Methods Fifty-eight healthy subjects received single subcutaneous or intramuscular injections of 3.75 mg of triptorelin and 170 prostate cancer patients received multiple subcutaneous doses of degarelix of between 120 and 320 mg. All subjects were pooled...... for the different dynamic responses observed after administration of both GnRH agonists and GnRH receptor blockers, suggesting that the model adequately characterizes the underlying physiology of the endocrine system....

  13. Basal testosterone concentrations after the application of a slow-release GnRH agonist implant are associated with a loss of response to buserelin, a short-term GnRH agonist, in the tom cat.

    Science.gov (United States)

    Goericke-Pesch, Sandra; Georgiev, Plamen; Fasulkov, Ivan; Vodenicharov, Angel; Wehrend, Axel

    2013-07-01

    Slow-release GnRH agonist implants are considered an effective, reversible alternative to surgical castration in male tom cats. Individual differences exist regarding the onset of efficacy and might be delayed in some animals. Single measurements of testosterone (T) might result in basal concentrations also in intact male cats. Consequently, GnRH stimulation tests are performed to measure T increase in intact animals and to differentiate castrated from intact male cats. In this study, five tom cats were treated with a 4.7-mg deslorelin implant and GnRH stimulation tests using buserelin were performed before treatment and at 4-week intervals afterward until Week 20. After the last test in Week 20 all animals were castrated. Four of five animals had basal T after 4 weeks and-in contrast to pretreatment-application of buserelin did not result in any further T increase. In one animal, T was low after implant insertion, but not basal; however, a GnRH stimulation test induced a slight increase of T in Week 8 and 16 only and no response in Weeks 4, 12, and 20. Testicular volume was significantly decreased and penile spines disappeared in all cats. Testicular histology showed mixed atrophy, but also fully elongated spermatids in three of five male cats making infertility questionable. Because of the loss of the stimulatory effect of short-term GnRH application (buserelin), it can be assumed that long-term GnRH agonists also act by some mechanisms of downregulation of pituitary GnRH receptors in the tom cat. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Recurrent venous thromboembolism and abnormal uterine bleeding with anticoagulant and hormone therapy use

    NARCIS (Netherlands)

    Martinelli, Ida; Lensing, Anthonie W. A.; Middeldorp, Saskia; Levi, Marcel; Beyer-Westendorf, Jan; van Bellen, Bonno; Bounameaux, Henri; Brighton, Timothy A.; Cohen, Alexander T.; Trajanovic, Mila; Gebel, Martin; Lam, Phuong; Wells, Philip S.; Prins, Martin H.

    2016-01-01

    Women receiving vitamin K antagonists (VKAs) require adequate contraception because of the potential for fetal complications. It is unknown whether the use of hormonal therapy, especially those containing estrogens, is associated with recurrent venous thromboembolism (VTE) during anticoagulation.

  15. ANTAGONISTIC POTENTIAL OF FLUORESCENT Pseudomonas ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    GROWTH OF TOMATO CHALLENGED WITH PHTOPATHOGENS ... This study focused on the antagonistic potential of fluorescent Pseudomonas in vitro, and its inoculation effect on growth .... the 5 days old culture in starch agar with Lugol's.

  16. Bioidentical Hormones and Menopause

    Science.gov (United States)

    ... Endocrinologist Search Featured Resource Menopause Map™ View Bioidentical Hormones January 2012 Download PDFs English Espanol Editors Howard ... take HT for symptom relief. What are bioidentical hormones? Bioidentical hormones are identical to the hormones that ...

  17. Induction of ovarian activity and ovulation in an induced ovulator, the maned wolf (Chrysocyon brachyurus), using GnRH agonist and recombinant LH.

    Science.gov (United States)

    Johnson, Amy E M; Freeman, Elizabeth W; Colgin, Mark; McDonough, Caitlin; Songsasen, Nucharin

    2014-07-01

    Assisted reproductive techniques, such as ovarian manipulation and artificial insemination, are useful for enhancing genetic management of threatened wildlife maintained ex situ. In this study, we used noninvasive fecal hormone monitoring to investigate (1) the influence of pairing with a male on endocrine responses of female maned wolves (Chrysocyon brachyurus) to a GnRH agonist (deslorelin) and (2) the efficiency of recombinant LH (reLH) on ovulation induction in females housed alone. Deslorelin (2.1 mg Ovuplant) was given to females that were either paired with a male (n = 4) or housed alone (n = 7); the implant was removed 7 to 11 days postimplantation. Three of seven singleton females were injected with reLH (0.0375 mg) on the day of implant removal, whereas the remaining females (n = 4) did not receive the additional treatment. Fecal samples were collected 5 to 7 days/wk from all females starting 11 days prior to hormone insertion until at least 70 days post implant removal for a total of 11 hormone treatment cycles. Fecal estrogen and progestagen metabolites were extracted and analyzed by enzyme immunoassay. Evidence of ovulation, demonstrated by a surge of estrogen followed by a significant rise in progestagen, occurred in all paired females. Three of the four singleton females that did not receive reLH treatment exhibited no rise in progestagen after an estrogen surge. All singleton females treated with reLH exhibited a rise in fecal progestagen after injection, indicating ovulation. In conclusion, deslorelin is effective at inducing ovarian activity and ovulation in paired female maned wolves; however, exogenous reLH is needed to induce ovulation in females housed alone. The findings obtained from this study serve as a foundation for future application of artificial insemination to enhance genetic management of this threatened species ex situ. Published by Elsevier Inc.

  18. Identification of Smad Response Elements in the Promoter of Goldfish FSHβ Gene and Evidence for Their Mediation of Activin and GnRH Stimulation of FSHβ Expression

    Directory of Open Access Journals (Sweden)

    Man-Tat eLau

    2012-03-01

    Full Text Available As an essential hormone regulating gonads in vertebrates, the biosynthesis and secretion of follicle-stimulating hormone (FSH is controlled by a variety of endocrine and paracrine factors in both mammalian and non-mammalian vertebrates. Activin was initially discovered in the ovary for its specific stimulation of FSH secretion by the pituitary cells. Our earlier studies in fish have shown that activin stimulates FSHβ but suppresses LHβ expression in both the goldfish and zebrafish. Further experiments showed that the regulation of FSHβ in fish occurred at the promoter level involving Smads, in particular Smad3. To further understand the mechanisms by which activin/Smad regulates FSHβ transcription, the present study was undertaken to analyze the promoter of goldfish FSHβ gene (fshb with the aim to identify potential cis-regulatory elements responsible for activin/Smad stimulation. Both serial deletion and site-directed mutagenesis were used, and the promoter activity was tested in the LβT2 cells, a murine gonadotroph cell line. The reporter constructs of goldfish FSHβ promoter-SEAP (secreted alkaline phosphatase were co-transfected with an expression plasmid for Smads (2 or 3 followed by measurement of SEAP activity in the medium. Two putative Smad responsive elements (SRE were identified in the promoter at distal and proximal regions, respectively. The distal site contained a consensus Smad binding element (SBE; AGAC, -1675/-1672 whereas the proximal site (GACCTTGA, -212/-205 was identical to an SF-1 binding site reported in humans, which was preceded by a sequence (AACACTGA highly conserved between fish and mammals. The proximal site also seemed to be involved in mediating stimulation of FSHβ expression by gonadotropin-releasing hormone (GnRH and its potential interaction with activin. In conclusion, we have identified two potential cis-regulatory elements in the promoter of goldfish FSHβ that are responsible for activin

  19. In vitro evidence of glucose-induced toxicity in GnRH secreting neurons: high glucose concentrations influence GnRH secretion, impair cell viability, and induce apoptosis in the GT1-1 neuronal cell line.

    Science.gov (United States)

    Pal, Lubna; Chu, Hsiao-Pai; Shu, Jun; Topalli, Ilir; Santoro, Nanette; Karkanias, George

    2007-10-01

    To evaluate for direct toxic effects of high glucose concentrations on cellular physiology in GnRH secreting immortalized GT1-1 neurons. Prospective experimental design. In vitro experimental model using a cell culture system. GT1-1 cells were cultured in replicates in media with two different glucose concentrations (450 mg/dL and 100 mg/dL, respectively) for varying time intervals (24, 48, and 72 hours). Effects of glucose concentrations on GnRH secretion by the GT1-1 neurons were evaluated using a static culture model. Cell viability, cellular apoptosis, and cell cycle events in GT1-1 neurons maintained in two different glucose concentrations were assessed by flow cytometry (fluorescence-activated cell sorter) using Annexin V-PI staining. Adverse influences of high glucose concentrations on GnRH secretion and cell viability were noted in cultures maintained in high glucose concentration (450 mg/dL) culture medium for varying time intervals. A significantly higher percentage of cells maintained in high glucose concentration medium demonstrated evidence of apoptosis by a fluorescence-activated cell sorter. We provide in vitro evidence of glucose-induced cellular toxicity in GnRH secreting GT1-1 neurons. Significant alterations in GnRH secretion, reduced cell viability, and a higher percentage of apoptotic cells were observed in GT1-1 cells maintained in high (450 mg/dL) compared with low (100 mg/dL) glucose concentration culture medium.

  20. Efeito da aplicação de hCG ou GnRH sobre a concentração sérica de progesterona e eficiência reprodutiva em porcas Effect of injection of hCG or GnRH on progesterone serum concentration and reproductive efficiency of sows

    Directory of Open Access Journals (Sweden)

    L.F.R. Carvalho

    2003-12-01

    Full Text Available Avaliou-se o efeito da aplicação de diferentes hormônios no quinto dia após a primeira inseminação sobre a concentração sérica de progesterona e sobre as características reprodutivas, em 103 porcas entre o terceirro e sexto parto. As matrizes foram divididas em: grupo-controle (n=35, não tratado, grupo GnRH (n=34, animais submetidos à aplicação intramuscular (IM de 50mcg de um análogo-GnRH no quinto dia após a primeira inseminação, e grupo hCG (n=34, animais submetidos à aplicação IM de 500UI de hCG no quinto dia após a primeira inseminação. A aplicação dos hormônios não influenciou as características reprodutivas taxa de parto, número total de nascidos, número de nascidos vivos e peso da leitegada (P>0,05. Cinco animais de cada grupo foram submetidos a coletas de sangue da veia cava nos dias 3, 5, 8, 12, 21 e 28 após a primeira inseminação para avaliação da concentração sérica de progesterona (ng/ml, utilizando a técnica de radioimunoensaio. Não houve diferença significativa quanto à concentração sérica de progesterona entre os grupos.Two different hormones were administered on the fifth day after the first insemination to evaluate their influence on serum progesterone concentrations and on reproductive efficiency, in multiparous sows between the third and the sixth parturition. The reproductive performance was evaluated in 103 sows distributed into three groups: 1-Control (n=35; 2-GnRH, 50m g of GnRH-analogue, administered IM on the fifth day after the first insemination (n=34; and 3-hCG, 500 IU of hCG administered IM in the fifth day after the first insemination (n=34. No effect (P>0.05 of hormone treatments on farrowing rate, litter size, live born and litter weight was observed. Five sows of each group were blood sampled on days 3, 5, 8, 12, 21, 28, after the first insemination, to evaluate serum progesterone concentrations (ng/ml. Serum progesterone concentrations were not affected (P>0.05 by

  1. Polycystic ovarian disease unmasked by pulsatile GnRH therapy in a subgroup of women with hypothalamic amenorrhea.

    Science.gov (United States)

    Mattle, Verena; Bilgyicildirim, Aysen; Hadziomerovic, Dijana; Ott, Helmut W; Zervomanolakis, Ioannis; Leyendecker, Gerhard; Wildt, Ludwig

    2008-02-01

    To present the observation in six out of 120 women treated with pulsatile GnRH for ovulation induction, who developed hyperandrogenemia and polycystic ovaries during treatment. Clinical observation. Department of Gynecologic Endocrinology and Reproductive Medicine, Medical University of Innsbruck, Austria. A total of 120 women initially diagnosed as suffering from primary or secondary hypothalamic amenorrhea were treated for ovulation induction with pulsatile administration of GnRH for up to 140 days. There was no indication of the presence of polycystic ovaries or hyperandrogenemia before therapy. Pulsatile GnRH therapy using the Zyklomat pump. Ovulatory menstrual cycles. Initially, all patients responded to pulsatile GnRH administration with ovulation and corpus luteum formation. During continuation of treatment, 6 patients developed an increase in LH and LH/FSH ratio as well as a progressive rise in serum T levels resulting in hyperandrogenemia. This was accompanied by the development of polycystic ovaries and cessation of follicular maturation. We conclude from these observations that restoration of normal GnRH stimulation of the pituitary gland can result in the development of hyperandrogenemia and polycystic ovaries, suggesting a pituitary or ovarian defect underlying the pathogenesis of this disorder.

  2. Hot issues in female and male hormonal contraception.

    Science.gov (United States)

    Gava, Giulia; Lantadilla, Claudia; Martelli, Valentina; Fattorini, Anna; Seracchioli, Renato; Meriggiola, Maria C

    2016-02-01

    In recent years a number of significant developments in the field of female hormonal contraception have been made which have produced new formulations and delivery systems providing high efficacy, safety and important non-contraceptive benefits. In particular long-acting reversible contraception (LARC) formulations have been demonstrated to ensure extremely high efficacy in typical use, minimal contraindications, optimal safety in all women thereby representing the best option for most women of all ages. Their effectiveness is not reliant upon user adherence and their ability to reduce unintended pregnancies and abortions has been proven. Unfortunately the same considerations cannot be made for male hormonal contraception. Although a large number of men are interested and would welcome the opportunity to use male contraceptive methods, no safe, effective and reversible methods are available on the market. Current methods available for men are limited to condoms and vasectomy. Highly effective prototype regimens have been developed but the pharmaceutical industry is unwilling to pursue further development and market these products. Of all new approaches to male contraception, hormonal methods are the closest to clinical application. These are based on the reversible suppression of luteinizing hormone and follicle stimulating hormone with subsequent reversible inhibition of spermatogenesis and consequent replacement to maintain androgen dependent physiological functions. Most approaches tested combination regimens such as testosterone and a progestin or testosterone and a GnRH analog.

  3. Factors that predict a positive response on gonadotropin-releasing hormone stimulation test for diagnosing central precocious puberty in girls

    Directory of Open Access Journals (Sweden)

    Junghwan Suh

    2013-12-01

    Full Text Available PurposeThe rapid increase in the incidence of precocious puberty in Korea has clinical and social significance. Gonadotropin-releasing hormone (GnRH stimulation test is required to diagnose central precocious puberty (CPP, however this test is expensive and time-consuming. This study aimed to identify factors that can predict a positive response to the GnRH stimulation test.MethodsClinical and laboratory parameters, including basal serum luteinizing hormone (LH, follicle-stimulating hormone (FSH, and estradiol (E2, were measured in 540 girls with clinical signs of CPP.ResultsTwo hundred twenty-nine of 540 girls with suspected CPP had a peak serum LH level higher than 5 IU/L (the CPP group. The CPP group had advanced bone age (P<0.001, accelerated yearly growth rate (P<0.001, increased basal levels of LH (P=0.02, FSH (P<0.001, E2 (P=0.001, and insulin-like growth factor-I levels (P<0.001 compared to the non-CPP group. In contrast, body weight (P<0.001 and body mass index (P<0.001 were lower in the CPP group. Although basal LH was significantly elevated in the CPP group compared to the non-CPP group, there was considerable overlap between the 2 groups. Cutoff values of basal LH (0.22 IU/L detected CPP with 87.8% sensitivity and 20.9% specificity.ConclusionNo single parameter can predict a positive response on the GnRH stimulation test with both high sensitivity and specificity. Therefore, multiple factors should be considered in evaluation of sexual precocity when deciding the timing of the GnRH stimulation test.

  4. Peptide hormones and lung cancer.

    Science.gov (United States)

    Moody, T W

    2006-03-01

    Several peptide hormones have been identified which alter the proliferation of lung cancer. Small cell lung cancer (SCLC), which is a neuroendocrine cancer, produces and secretes gastrin releasing peptide (GRP), neurotensin (NT) and adrenomedullin (AM) as autocrine growth factors. GRP, NT and AM bind to G-protein coupled receptors causing phosphatidylinositol turnover or elevated cAMP in SCLC cells. Addition of GRP, NT or AM to SCLC cells causes altered expression of nuclear oncogenes, such as c-fos, and stimulation of growth. Antagonists have been developed for GRP, NT and AM receptors which function as cytostatic agents and inhibit SCLC growth. Growth factor antagonists, such as the NT1 receptor antagonist SR48692, facilitate the ability of chemotherapeutic drugs to kill lung cancer cells. It remains to be determined if GRP, NT and AM receptors will served as molecular targets, for development of new therapies for the treatment of SCLC patients. Non-small cell lung cancer (NSCLC) cells also have a high density of GRP, NT, AM and epidermal growth factor (EGF) receptors. Several NSCLC patients with EGF receptor mutations respond to gefitinib, a tyrosine kinase inhibitor. Gefitinib relieves NSCLC symptoms, maintaining stable disease in patients who are not eligible for systemic chemotherapy. It is important to develop new therapeutic approaches using translational research techniques for the treatment of lung cancer patients.

  5. Gonadotropin-releasing hormone analogues inhibit leiomyoma extracellular matrix despite presence of gonadal hormones.

    Science.gov (United States)

    Malik, Minnie; Britten, Joy; Cox, Jeris; Patel, Amrita; Catherino, William H

    2016-01-01

    To determine the effect of GnRH analogues (GnRH-a) leuprolide acetate (LA) and cetrorelix acetate on gonadal hormone-regulated expression of extracellular matrix in uterine leiomyoma three-dimensional (3D) cultures. Laboratory study. University research laboratory. Women undergoing hysterectomy for symptomatic leiomyomas. The 3D cell cultures, protein analysis, Western blot, immunohistochemistry. Expression of extracellular matrix proteins, collagen 1, fibronectin, and versican in leiomyoma cells 3D cultures exposed to E2, P, LA, cetrorelix acetate, and combinations for 24- and 72-hour time points. The 3D leiomyoma cultures exposed to E2 for 24 hours demonstrated an increased expression of collagen-1 and fibronectin, which was maintained for up to 72 hours, a time point at which versican was up-regulated significantly. Although P up-regulated collagen-1 protein (1.29 ± 0.04) within 24 hours of exposure, significant increase in all extracellular matrix (ECM) proteins was observed when the gonadal hormones were used concomitantly. Significant decrease in the amount of ECM proteins was observed on use of GnRH-a, LA and cetrorelix, with 24-hour exposure. Both the compounds also significantly decreased ECM protein concentration despite the presence of E2 or both gonadal hormones. This study demonstrates that GnRH-a directly affect the gonadal hormone-regulated collagen-1, fibronectin, and versican production in their presence. These findings suggest that localized therapy with GnRH-a may inhibit leiomyoma growth even in the presence of endogenous gonadal hormone exposure, thereby providing a mechanism to eliminate the hypoestrogenic side effects associated with GnRH-a therapy. Published by Elsevier Inc.

  6. [Ovulation induction by pulsatile GnRH therapy in 2014: literature review and synthesis of current practice].

    Science.gov (United States)

    Gronier, H; Peigné, M; Catteau-Jonard, S; Dewailly, D; Robin, G

    2014-10-01

    The hypogonadotropic hypogonadism is an easily treatable form of female infertility. The most common cause of hypogonadotropic hypogonadism is functional hypothalamic amenorrhea. The GnRH pump is a simple and effective treatment to restore fertility of patients with hypothalamic amenorrhea: cumulative pregnancy rate is estimated between 70 and 100% after 6 cycles, compared to a low rate of complications and multiple pregnancies. While only 2.8 cycles are on average required to achieve a pregnancy with a pump, this induction of ovulation stays underused in France. The objective of this paper is to propose a practical manual of pulsatile GnRH, in order to improve the accessibility of pulsatile GnRH for patients with hypogonadotropic hypogonadism. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. Effects of aqueous extract from Asparagus officinalis L. roots on hypothalamic-pituitary-gonadal axis hormone levels and the number of ovarian follicles in adult rats

    Directory of Open Access Journals (Sweden)

    Hojatollah Karimi Jashni

    2016-02-01

    Full Text Available Background: Asparagus is a plant with high nutritional, pharmaceutical, and industrial values. Objective: The present study aimed to evaluate the effect of aqueous extract of asparagus roots on the hypothalamic-pituitary-gonadal axis hormones and oogenesis in female rats. Materials and Methods: In this experimental study, 40 adult female Wistar rats were divided into five groups, which consist 8 rats. Groups included control, sham and three experimental groups receiving different doses (100, 200, 400 mg/kg/bw of aqueous extract of asparagus roots. All dosages were administered orally for 28 days. Blood samples were taken from rats to evaluate serum levels of Gonadotropin releasing hormone (GnRH, follicular stimulating hormone (FSH, Luteinal hormone (LH, estrogen, and progesterone hormones. The ovaries were removed, weighted, sectioned, and studied by light microscope. Results: Dose-dependent aqueous extract of asparagus roots significantly increased serum levels of GnRH, FSH, LH, estrogen, and progestin hormones compared to control and sham groups. Increase in number of ovarian follicles and corpus luteum in groups treated with asparagus root extract was also observed (p<0.05. Conclusion: Asparagus roots extract stimulates secretion of hypothalamic- pituitary- gonadal axis hormones. This also positively affects oogenesis in female rats.

  8. Differential roles of PKC isoforms (PKCs) in GnRH stimulation of MAPK phosphorylation in gonadotrope derived cells.

    Science.gov (United States)

    Mugami, Shany; Dobkin-Bekman, Masha; Rahamim-Ben Navi, Liat; Naor, Zvi

    2018-03-05

    The role of protein kinase C (PKC) isoforms (PKCs) in GnRH-stimulated MAPK [ERK1/2, JNK1/2 and p38) phosphorylation was examined in gonadotrope derived cells. GnRH induced a protracted activation of ERK1/2 and a slower and more transient activation of JNK1/2 and p38MAPK. Gonadotropes express conventional PKCα and PKCβII, novel PKCδ, PKCε and PKCθ, and atypical PKC-ι/λ. The use of green fluorescent protein (GFP)-PKCs constructs revealed that GnRH induced rapid translocation of PKCα and PKCβII to the plasma membrane, followed by their redistribution to the cytosol. PKCδ and PKCε localized to the cytoplasm and Golgi, followed by the rapid redistribution by GnRH of PKCδ to the perinuclear zone and of PKCε to the plasma membrane. The use of dominant negatives for PKCs and peptide inhibitors for the receptors for activated C kinase (RACKs) has revealed differential role for PKCα, PKCβII, PKCδ and PKCε in ERK1/2, JNK1/2 and p38MAPK phosphorylation in a ligand-and cell context-dependent manner. The paradoxical findings that PKCs activated by GnRH and PMA play a differential role in MAPKs phosphorylation may be explained by persistent vs. transient redistribution of selected PKCs or redistribution of a given PKC to the perinuclear zone vs. the plasma membrane. Thus, we have identified the PKCs involved in GnRH stimulated MAPKs phosphorylation in gonadotrope derived cells. Once activated, the MAPKs will mediate the transcription of the gonadotropin subunits and GnRH receptor genes. Copyright © 2017. Published by Elsevier B.V.

  9. Hormone treatment of gender identity disorder in a cohort of children and adolescents.

    Science.gov (United States)

    Hewitt, Jacqueline K; Paul, Campbell; Kasiannan, Porpavai; Grover, Sonia R; Newman, Louise K; Warne, Garry L

    2012-05-21

    To describe the experience of hormone treatment of gender identity disorder (GID) in children and adolescents within a specialist clinic. Cohort study by medical record review of children aged 0-17 years referred during 2003-2011 for management at the GID clinic in a tertiary paediatric referral centre - the Royal Children's Hospital, Melbourne, Victoria. Clinical characteristics of the patient population, hormone treatment provided, frequency of referrals with time. Thirty-nine children and adolescents were referred for gender dysphoria. Seventeen individuals were pubertal with persistent GID, and were considered eligible for hormone treatment. Seven patients, comprising three biological males and four biological females, had legally endorsed hormone treatment. In this group, gender dysphoria was first noted at 3-6 years of age. Hormone treatment with GnRH analogue to suppress pubertal progression (phase 1) was given at 10-16 years of age. Treatment with cross-sex hormones (phase 2) was given at 15.6-16 years. One patient purchased cross-sex hormone treatment overseas. One patient received oestrogen and progesterone for menstrual suppression before phase 1. The annual frequency of new referrals increased continuously over the study period. Hormone treatment for pubertal suppression and subsequent gender transition needs to be individualised within stringent protocols in multidisciplinary specialist units.

  10. Histological organization of the central nervous system and distribution of a gonadotropin-releasing hormone-like peptide in the blue crab, Portunus pelagicus.

    Science.gov (United States)

    Saetan, Jirawat; Senarai, Thanyaporn; Tamtin, Montakan; Weerachatyanukul, Wattana; Chavadej, Jittipan; Hanna, Peter J; Parhar, Ishwar; Sobhon, Prasert; Sretarugsa, Prapee

    2013-09-01

    We present a detailed histological description of the central nervous system (CNS: brain, subesophageal ganglion, thoracic ganglia, abdominal ganglia) of the blue crab, Portunus pelagicus. Because the presence of gonadotropin-releasing hormone (GnRH) in crustaceans has been disputed, we examine the presence and localization of a GnRH-like peptide in the CNS of the blue crab by using antibodies against lamprey GnRH (lGnRH)-III, octopus GnRH (octGnRH) and tunicate GnRH (tGnRH)-I. These antibodies showed no cross-reactivity with red-pigment-concentrating hormone, adipokinetic hormone, or corazonin. In the brain, strong lGnRH-III immunoreactivity (-ir) was detected in small (7-17 μm diameter) neurons of clusters 8, 9 and 10, in medium-sized (21-36 μm diameter) neurons of clusters 6, 7 and 11 and in the anterior and posterior median protocerebral neuropils, olfactory neuropil, median and lateral antenna I neuropils, tegumentary neuropil and antenna II neuropil. In the subesophageal ganglion, lGnRH-III-ir was detected in medium-sized neurons and in the subesophageal neuropil. In the thoracic and abdominal ganglia, lGnRH-III-ir was detected in medium-sized and small neurons and in the neuropils. OctGnRH-ir was observed in neurons of the same clusters with moderate staining, particularly in the deutocerebrum, whereas tGnRH-I-ir was only detected in medium-sized neurons of cluster 11 in the brain. Thus, anti-lGnRH-III shows greater immunoreactivity in the crab CNS than anti-octGnRH and anti-tGnRH-I. Moreover, our functional bioassay demonstrates that only lGnRH-III has significant stimulatory effects on ovarian growth and maturation. We therefore conclude that, although the true identity of the crab GnRH eludes us, crabs possess a putative GnRH hormone similar to lGnRH-III. The identification and characterization of this molecule is part of our ongoing research.

  11. Development of a Ga-68 labeled triptorelin analog for GnRH receptor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zoghi, Masoumeh; Niazi, Ali [Islamic Azad Univ., Arak (Iran, Islamic Republic of). Dept. of Chemistry; Jalilian, Amir R.; Johari-daha, Fariba; Alirezapour, Behrouz [Nuclear Science and Technology Research Institute (NSTRI) (Iran, Islamic Republic of). Radiation Application Research School; Ramezanpour, Sorour [K.N. Toosi Univ. of Technology, Tehran (Iran, Islamic Republic of). Peptide Chemistry Research Center

    2016-08-01

    Optimized total synthesis, radiolabeling and quality control of [{sup 68}Ga]-DOTA-Hyd-TRP as an efficient and possible PET radiotracer for GnRH receptor imaging in various tumors is of great interest. DOTA-Hyd-TRP was synthesized using solid phase peptide synthesis followed by conjugation to DOTA using pSCN-Bn-DOTA. [{sup 68}Ga]-DOTA-Hyd-TRP was prepared using generator-based [{sup 68}Ga]GaCl{sub 3} and DOTA-Hyd-TRP under optimized conditions for time, temperature, ligand amount, gallium content and column cartridge purification followed by proper formulation. The biodistribution of the tracer in rats was studied using tissue counting up to 120 min. [{sup 68}Ga]-DOTA-Hyd-TRP was prepared at optimized conditions in 5-7 min at 95 C followed by separation using C{sub 18} cartridge (radiochemical purity ∼99 ± 0.88% ITLC, > 99% HPLC, specific activity: 300 ± 15 MBq/nM). The biodistribution of the tracer demonstrated high kidney uptake of the tracer in 10-20 min as well as significant testicular uptake consistent with reported GnRH receptor mappings. Block test studies by triptorelin pretreatment of the animals prior to tracer administration demonstrated significant specific uptake in receptor rich organs including testes and stomach.

  12. EFFECT TN EWES OF OESTROGEN PRIMING AND GnRH ON LH ...

    African Journals Online (AJOL)

    Cyclicvariationsintheincreasedresponsivenessof thepituitaryto luteinizing hormone-releasing hormone ( LH RH) induced by LHRH . Endocrinology 9l , 13. COPPINGS, R.J. & MALVEN, P.V.. 1976. Biphasic effect of oestradiol on LH release mechanisms.

  13. Serum dehydroepiandrosterone sulphate concentration is not a predictive factor in IVF outcomes before the first cycle of GnRH agonist administration in women with normal ovarian reserve.

    Directory of Open Access Journals (Sweden)

    Michał Kunicki

    Full Text Available The aim of our study was to determine whether serum dehydroepiandrosterone sulphate (DHEAS concentration and the models incorporating it could help clinicians to predict IVF outcomes in women with normal ovarian reserve undergoing their first long protocol.We performed a retrospective analysis of 459 women undergoing cycles of intracytoplasmic sperm injection (ICSI for the first time in a long GnRH agonist protocol.Embryo transfer was performed in 407 women (88.7%. The fertilisation rate was 78.6%. The clinical pregnancy rate was 44.8% per started cycle and 50.6% per embryo transfer. Our univariate model revealed that the best predictors of clinical pregnancy were the number of mature oocytes, the number of embryos transferred and the number of good quality embryos, account for the clinical parameters that reflect ovarian reserve the best being AMH level and AFC. DHEAS did not predict clinical pregnancy (OR 1.001, 95% CI, 0.999-1.004. After adjusting for the number of embryos transferred and class of embryos in a multivariate model, the best predictors were age (OR 0.918, 95% CI, 0.867-0.972 and AFC (OR 1.022, 95% CI, 0.992-1.053. Serum DHEAS levels were positively correlated with AFC (r = 0.098, P<0.039 and testosterone levels (r = 0.371, P<0.001, as well as the number of mature oocytes (r = 0.109, P<0.019; serum DHEAS levels were negatively correlated with age (r = -0.220, P<0.001, follicle-stimulating hormone (FSH, (r = -0.116, P<0.015 and sex hormone-binding globulin (SHBG, (r = -0.193, P<0.001.DHEAS concentration (in addition to the known factors of ovarian reserve does not predict clinical pregnancy in women with normal ovarian reserve who are undergoing ICSI.

  14. Excitatory amino acid receptor antagonists

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation......)-phenylethylamine salt of N-BOC-(R)-ATAA. Like ATAA, neither (R)- nor (S)-ATAA significantly affected (IC50 > 100 microM) the receptor binding of tritiated AMPA, kainic acid, or (RS)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid, the latter being a competitive NMDA antagonist. Electrophysiological experiments......, using the rat cortical wedge preparation, showed the NMDA antagonist effect as well as the AMPA antagonist effect of ATAA to reside exclusively in the (R)-enantiomer (Ki = 75 +/- 5 microM and 57 +/- 1 microM, respectively). Neither (R)- nor (S)-ATAA significantly reduced kainic acid-induced excitation...

  15. Kisspeptins modulate the biology of multiple populations of gonadotropin-releasing hormone neurons during embryogenesis and adulthood in zebrafish (Danio rerio).

    Science.gov (United States)

    Zhao, Yali; Lin, Meng-Chin A; Mock, Allan; Yang, Ming; Wayne, Nancy L

    2014-01-01

    Kisspeptin1 (product of the Kiss1 gene) is the key neuropeptide that gates puberty and maintains fertility by regulating the gonadotropin-releasing hormone (GnRH) neuronal system in mammals. Inactivating mutations in Kiss1 and the kisspeptin receptor (GPR54/Kiss1r) are associated with pubertal failure and infertility. Kiss2, a paralogous gene for kiss1, has been recently identified in several vertebrates including zebrafish. Using our transgenic zebrafish model system in which the GnRH3 promoter drives expression of emerald green fluorescent protein, we investigated the effects of kisspeptins on development of the GnRH neuronal system during embryogenesis and on electrical activity during adulthood. Quantitative PCR showed detectable levels of kiss1 and kiss2 mRNA by 1 day post fertilization, increasing throughout embryonic and larval development. Early treatment with Kiss1 or Kiss2 showed that both kisspeptins stimulated proliferation of trigeminal GnRH3 neurons located in the peripheral nervous system. However, only Kiss1, but not Kiss2, stimulated proliferation of terminal nerve and hypothalamic populations of GnRH3 neurons in the central nervous system. Immunohistochemical analysis of synaptic vesicle protein 2 suggested that Kiss1, but not Kiss2, increased synaptic contacts on the cell body and along the terminal nerve-GnRH3 neuronal processes during embryogenesis. In intact brain of adult zebrafish, whole-cell patch clamp recordings of GnRH3 neurons from the preoptic area and hypothalamus revealed opposite effects of Kiss1 and Kiss2 on spontaneous action potential firing frequency and membrane potential. Kiss1 increased spike frequency and depolarized membrane potential, whereas Kiss2 suppressed spike frequency and hyperpolarized membrane potential. We conclude that in zebrafish, Kiss1 is the primary stimulator of GnRH3 neuronal development in the embryo and an activator of stimulating hypophysiotropic neuron activities in the adult, while Kiss2 plays an

  16. Response of lactating dairy cows with or without purulent vaginal discharge to gonadotropin-releasing hormone and prostaglandin F2α.

    Science.gov (United States)

    Voelz, B E; Rocha, L; Scortegagna, F; Stevenson, J S; Mendonça, L G D

    2018-02-15

    Purulent vaginal discharge (PVD) is a common uterine disease in dairy cattle that has negative effects on reproductive performance. Reproductive management programs that synchronize ovulation use gonadotropin-releasing hormone (GnRH) to induce ovulation and prostaglandin F2α (PGF2α) to induce luteolysis. The objectives of this study were to evaluate ovarian response to treatment with GnRH and the odds of bearing a corpus luteum or being inseminated in dairy cows with or without PVD. Another objective was to determine the hazard of insemination after administration of PGF2α in dairy cows with or without PVD. Primiparous (n = 291) and multiparous (n = 402) cows were evaluated for PVD using a Metricheck device at 46 ± 3 and 35 ± 3 days in milk (DIM) (study day 0), respectively. On study day 14, primiparous (n = 107) and multiparous (n = 197) cows were treated with GnRH and subsequent ovulation was recorded. Primiparous (n = 178) and multiparous (n = 368) cows not inseminated by study day 21 were administered PGF2α and response to PGF2α treatment was determined by detection of estrus. Furthermore, cows were categorized by the presence of a CL or being inseminated by study days 14, 21, and 35. Overall prevalence of PVD was 28.5% and 13.4% for primiparous and multiparous cows, respectively. Projected 305-d milk yield was less (P PVD+ multiparous cows compared with PVD- multiparous cows, however, no (P = 0.26) difference was detected between primiparous PVD+ and PVD- cows. Ovulatory response to GnRH treatment was 51.8% and 47.8% for primiparous and multiparous cows, respectively. Primiparous PVD- cows tended (P = 0.06) to be less likely to ovulate to GnRH than primiparous PVD+ cows, whereas multiparous PVD+ cows were less (P = 0.04) likely to ovulate to GnRH than PVD- multiparous cows. The odds of bearing a corpus luteum or being inseminated by study days 14, 21, or 35 was not associated with PVD in primiparous cows. In contrast, the odds of bearing a corpus luteum

  17. Kisspeptins modulate the biology of multiple populations of gonadotropin-releasing hormone neurons during embryogenesis and adulthood in zebrafish (Danio rerio.

    Directory of Open Access Journals (Sweden)

    Yali Zhao

    Full Text Available Kisspeptin1 (product of the Kiss1 gene is the key neuropeptide that gates puberty and maintains fertility by regulating the gonadotropin-releasing hormone (GnRH neuronal system in mammals. Inactivating mutations in Kiss1 and the kisspeptin receptor (GPR54/Kiss1r are associated with pubertal failure and infertility. Kiss2, a paralogous gene for kiss1, has been recently identified in several vertebrates including zebrafish. Using our transgenic zebrafish model system in which the GnRH3 promoter drives expression of emerald green fluorescent protein, we investigated the effects of kisspeptins on development of the GnRH neuronal system during embryogenesis and on electrical activity during adulthood. Quantitative PCR showed detectable levels of kiss1 and kiss2 mRNA by 1 day post fertilization, increasing throughout embryonic and larval development. Early treatment with Kiss1 or Kiss2 showed that both kisspeptins stimulated proliferation of trigeminal GnRH3 neurons located in the peripheral nervous system. However, only Kiss1, but not Kiss2, stimulated proliferation of terminal nerve and hypothalamic populations of GnRH3 neurons in the central nervous system. Immunohistochemical analysis of synaptic vesicle protein 2 suggested that Kiss1, but not Kiss2, increased synaptic contacts on the cell body and along the terminal nerve-GnRH3 neuronal processes during embryogenesis. In intact brain of adult zebrafish, whole-cell patch clamp recordings of GnRH3 neurons from the preoptic area and hypothalamus revealed opposite effects of Kiss1 and Kiss2 on spontaneous action potential firing frequency and membrane potential. Kiss1 increased spike frequency and depolarized membrane potential, whereas Kiss2 suppressed spike frequency and hyperpolarized membrane potential. We conclude that in zebrafish, Kiss1 is the primary stimulator of GnRH3 neuronal development in the embryo and an activator of stimulating hypophysiotropic neuron activities in the adult, while

  18. Diagnosis of polycystic ovary disease in obese women with a 24-hour hormone profile after buserelin stimulation.

    Science.gov (United States)

    Hagag, P; Ben-Shlomo, A; Herzianu, I; Weiss, M

    2000-03-01

    To evaluate the 24-hour hormone response to GnRH agonist stimulation in the diagnosis of polycystic ovary disease (PCOD) in obese women. Forty-three obese PCOD patients and 23 controls were randomized to 1 mg buserelin (BSRL) stimulation (PCOD group P-1, n = 31; control group C-1, n = 12) or 0.1 mg (PCOD group P-0.1, n = 12; control group C-0.1, n = 11). Whereas following 1 mg BSRL administration, serum levels of 17 hydroxyprogesterone (17OHP), delta 4 androstenedione, estradiol (E2) and luteinizing hormone increment (delta LH) as well as the delta LH/delta follicle stimulating hormone ratio were all higher in group P-1 than in group C-1 (P PCOD. The hormone response to BSRL administration is related to obesity, not to insulin resistance.

  19. GnRH and prostaglandin-based synchronization protocols as alternatives to progestogen-based treatments in sheep.

    Science.gov (United States)

    Rekik, M; Haile, A; Abebe, A; Muluneh, D; Goshme, S; Ben Salem, I; Hilali, M El-Dine; Lassoued, N; Chanyalew, Y; Rischkowsky, B

    2016-12-01

    The study investigated, for cycling sheep, synchronizing protocols simultaneously to the standard "P" protocol using progestogens priming with intravaginal devices and gonadotropin. In November 2014, 90 adult Menz ewes were assigned to either the "P" protocol, "PGF" treatment where oestrus and ovulation were synchronized using two injections of prostaglandin 11 days apart or a "GnRH" treatment where the ewes had their oestrus and ovulation synchronized with GnRH (day 0)-prostaglandin (day 6)-GnRH (day 9) sequence. The ewes were naturally mated at the induced oestrus and the following 36 days. Plasma progesterone revealed that 92% of the ewes were ovulating before synchronization and all, except one, ovulated in response to the applied treatments. All "P" ewes exhibited oestrus during the 96-hr period after the end of the treatments in comparison with only 79.3% and 73.3% for "PGF" and "GnRH" ewes, respectively (p sheep after the rainy season when most animals are spontaneously cycling. © 2016 Blackwell Verlag GmbH.

  20. Final height in central precocious puberty after long term treatment with a slow release GnRH agonist

    NARCIS (Netherlands)

    Oostdijk, W; Rikken, B; Schreuder, S; Otten, Barto; Odink, R; Rouwe, C; Jansen, M; Gerver, WJ; Waelkens, J; Drop, S

    1996-01-01

    Objective-To study the resumption of puberty and the final height achieved in children with central precocious puberty (CPP) treated with the GnRH agonist triptorelin. Patients-31 girls and five boys with CPP who were treated with triptorelin 3.75 mg intramuscularly every four weeks. Girls were

  1. Hormones in the immune system and their possible role. A critical review.

    Science.gov (United States)

    Csaba, György

    2014-09-01

    Immune cells synthesize, store and secrete hormones, which are identical with the hormones of the endocrine glands. These are: the POMC hormones (ACTH, endorphin), the thyroid system hormones (TRH, TSH, T3), growth hormone (GH), prolactin, melatonin, histamine, serotonin, catecholamines, GnRH, LHRH, hCG, renin, VIP, ANG II. This means that the immune cells contain all of the hormones, which were searched at all and they also have receptors for these hormones. From this point of view the immune cells are similar to the unicells (Tetrahymena), so it can be supposed that these cells retained the properties characteristic at a low level of phylogeny while other cells during the evolution accumulated to form endocrine glands. In contrast to the glandular endocrine cells, immune cells are polyproducers and polyreceivers. As they are mobile cells, they are able to transport the stored hormone to different places (packed transport) or attracted by local factors, accumulate in the neighborhood of the target, synthesizing and secreting hormones locally. This is taking place, e.g. in the case of endorphin, where the accumulating immune cells calms pain caused by the inflammation. The targeted packed transport is more economical than the hormone-pouring to the blood circulation of glandular endocrines and the targeting also cares the other receptor-bearing cells timely not needed the effect. Mostly the immune-effects of immune-cell derived hormones were studied (except endorphin), however, it is not exactly cleared, while the system could have scarcely studied important roles in other cases. The evolutionary aspects and the known as well, as possible roles of immune-endocrine system and their hormones are listed and discussed.

  2. 1,500 IU human chorionic gonadotropin administered at oocyte retrieval rescues the luteal phase when gonadotropin-releasing hormone agonist is used for ovulation induction

    DEFF Research Database (Denmark)

    Humaidan, Peter; Bredkjær, Helle Ejdrup; Westergaard, Lars Grabow

    2009-01-01

    OBJECTIVE: To prospectively assess the reproductive outcome with a small bolus of hCG administered on the day of oocyte retrieval after ovulation induction with a GnRH agonist (GnRHa). DESIGN: Prospective, randomized trial. SETTING: Three hospital-based IVF clinics. PATIENT(S): Three hundred five...... IVF/intracytoplasmic sperm injection patients after a GnRH antagonist protocol. INTERVENTION(S): Ovulation induction was performed with either 10,000 IU hCG or 0.5 mg GnRHa (buserelin) supplemented with 1,500 IU hCG on the day of oocyte retrieval. MAIN OUTCOME MEASURE(S): Reproductive outcome...... bolus of hCG in the GnRHa group secured the luteal phase, resulting in a comparable reproductive outcome in the two groups. However, a nonsignificant difference of 7% in delivery rates justifies further studies to refine the use of GnRHa for ovulation induction....

  3. Extracellular signal-regulated kinase 1 and 2 are not required for GnRH neuron development and normal female reproductive axis function in mice.

    Science.gov (United States)

    Wierman, Margaret E; Xu, Mei; Pierce, A; Bliesner, B; Bliss, S P; Roberson, M S

    2012-01-01

    Selective deletion of extracellular signal-regulated kinase (ERK) 1 and ERK2 in the pituitary gonadotrope and ovarian granulosa cells disrupts female reproductive axis function. Thus, we asked if ERK1 and ERK2 are critical for GnRH neuron ontogeny or the central control of female reproductive function. GnRH-Cre-recombinase (Cre+) expressing mice were crossed with mice with a global deletion of ERK1 and a floxed ERK2 allele (Erk1-/Erk2fl/fl) to selectively delete ERK2 in GnRH neurons. Cre-recombinase mRNA was selectively expressed in the brain of Cre+ mice. GnRH neuron number and location were determined during embryogenesis and in the adult. GnRH neuron counts at E15 did not differ between experimental and control groups (1,198 ± 65 and 1,160 ± 80 respectively, p = NS). In adults, numbers of GnRH neurons in the GnRHCre+Erk1-/Erk2- mice (741 ± 157) were similar to those in controls (756 ± 7), without alteration in their distribution across the forebrain. ERK1 and 2 deficiency did not alter the timing of vaginal opening, age at first estrus, or estrous cyclicity. Although ERK1 and 2 are components of a dominant signaling pathway in GnRH neuronal cells that modulates survival and control of GnRH gene expression, other signaling pathways compensate for their deletion in vivo to allow GnRH neuron survival and targeting and normal onset of female sexual maturation and reproductive function. In contrast to effects at the pituitary and the ovary, ERK1 and ERK2 are dispensable at the level of the GnRH neuron. Copyright © 2011 S. Karger AG, Basel.

  4. Hormonal characteristics of free-ranging female lions (Panthera leo) of the Serengeti Plains and Ngorongoro Crater.

    Science.gov (United States)

    Brown, J L; Bush, M; Packer, C; Pusey, A E; Monfort, S L; O'Brien, S J; Janssen, D L; Wildt, D E

    1993-01-01

    Pituitary responses to gonadotrophin-releasing hormone (GnRH) and prolactin and steroid secretory profiles were examined in two populations of adult, female lions in the Serengeti (one outbred in the Serengeti Plains and one inbred in the Ngorongoro Crater) to determine whether reductions in genetic variability adversely affected endocrine function. GnRH-induced gonadotrophin secretion was also examined after adrenocorticotrophic hormone (ACTH) treatment to determine whether acute increases in serum cortisol altered pituitary function. Anaesthetized lions were administered (i) saline i.v. after 10 and 100 min of blood sampling, (ii) saline at 10 min and GnRH (1 micrograms kg-1 body weight) after 100 min; or (iii) ACTH (3 micrograms kg-1) at 10 min and GnRH after 100 min of sampling. Basal serum cortisol and basal and GnRH-induced gonadotrophin secretion were similar (P > 0.05) between females of the Ngorongoro Crater and Serengeti Plains. After ACTH, serum cortisol increased two- to threefold over baseline values and the response was unaffected (P > 0.05) by location. ACTH-induced increases in serum cortisol had no effect on subsequent basal or GnRH-stimulated luteinizing hormone (LH) or follicle-stimulating hormone (FSH) secretion. Overall mean serum progesterone concentrations ranged from 0.2 to 5.4 ng ml-1 with the exception of four females (two in the Serengeti and two in the Crater; progesterone range, 18.4-46.5 ng ml-1) that were presumed pregnant (three of these females were observed nursing cubs several weeks later).(ABSTRACT TRUNCATED AT 250 WORDS)

  5. PRELIMINARY STUDY OF DIFFERENT HORMONE TREATMENTS IN THE ARTIFICIAL PROPAGATION OF PIKEPERCH (Sander luciopreca REGARDING THE ASPECTS OF ANIMAL WELFARE

    Directory of Open Access Journals (Sweden)

    Á. NÉMETH

    2009-10-01

    Full Text Available The pikeperch (Sander lucioperca is very important and valuable freshwater fish in Hungary. The quality of lash is very high (white, tasty and boneless thus the gastronomically demand grows year by year. Besides the pikeperch is an attractive game fish and as a top predator, plays an important role in the maintenance of ecological balance in freshwater ecosystems. The success of pond culture of pikeperch depends on the propagation and nursing methods. Recently the technological development of artificial reproduction ensures the production of more fry and fingerlings. Present study investigates the different reproduction methods in consideration of the spawning behaviour of the pikeperch breeders. Between the hormone treatment and spawning there were observed six stagers in the behaviour of pike-perch couples- In addition to the observations on behaviour of spawning, various hormone products were examined in order to stimulate and synchronise the ovulation of pike perch breeders. Best results were recorded in case of using dried carp pituitary as a hormone treatment (170g eggs/stripped females, while the treatment with GnRH analogs resulted 145 g respectively. Moreover the price and biological advances of GnRH analogs require more research in their use in the field of artificial propagation of pikeperch. These hormones do not interfere violently the neuro-humoral regulation of the ovulation, thus contributes to maintain better conditions of animal welfare during the propagation procedure.

  6. Efficiency of fixed-time artificial insemination using a progesterone device combined with GnRH or estradiol benzoate in Nellore heifers

    Directory of Open Access Journals (Sweden)

    Vinícius Antônio Pelissari Poncio

    2015-10-01

    Full Text Available he use of estrogens in artificial insemination protocols for cattle is the least expensive and most efficient method currently available. However, the trend to prohibit the use of estrogens for this purpose has made it necessary to find alternatives that replace estrogens without compromising the reproductive performance of the animals. The objective of this study was to evaluate conception rates in Bos indicus beef heifers treated with a progesterone device (P4 combined with GnRH or an estradiol ester. On day 0, pubertal Nellore heifers (n = 100 received an intravaginal device containing 1 g P4 and were randomly divided into two groups. The GnRH group (n = 49 received an intramuscular injection of 100 µg GnRH, while the E2 group (n = 51 received 2 mg estradiol benzoate (EB. The P4 device was removed after 5 (GnRH group or 8 days (E2 group, followed by an injection of 125 µg of the PGF2α, analog cloprostenol. On that occasion, the E2 group received an additional injection of 300 IU eCG. Twenty-four hours later, the GnRH group received a second injection of 125 µg cloprostenol, while the E2 group received 1 mg EB. The heifers were inseminated 72 (GnRH group or 54 hours (E2 group after removal of the P4 device. At the time of insemination, the GnRH group received additionally an injection of 100 µg GnRH. Estrus was monitored during the period of cloprostenol injection until the time of artificial insemination and pregnancy was diagnosed 40 days after insemination by transrectal ultrasonography. The data were analyzed by Fisher’s exact test. The pregnancy rate was 38.8% and 31.4% in the GnRH and E2 groups, respectively (P>0.05. The ovarian condition of the heifers (estrus or anestrus tended to influence (P=0.07 pregnancy rates in the GnRH group, but not in the E2 group. At the time of artificial insemination, 33.3% of heifers in the GnRH group showed signs of estrus versus 88.2% in the E2 group (P<0.05. However, the time of estrus

  7. Dual Actions of Mammalian and Piscine Gonadotropin-Inhibitory Hormones, RFamide-Related Peptides and LPXRFamide Peptides, in the Hypothalamic–Pituitary–Gonadal Axis

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    Takayoshi Ubuka

    2018-01-01

    Full Text Available Gonadotropin-inhibitory hormone (GnIH is a hypothalamic neuropeptide that decreases gonadotropin synthesis and release by directly acting on the gonadotrope or by decreasing the activity of gonadotropin-releasing hormone (GnRH neurons. GnIH is also called RFamide-related peptide in mammals or LPXRFamide peptide in fishes due to its characteristic C-terminal structure. The primary receptor for GnIH is GPR147 that inhibits cAMP production in target cells. Although most of the studies in mammals, birds, and fish have shown the inhibitory action of GnIH in the hypothalamic–pituitary–gonadal (HPG axis, several in vivo studies in mammals and many in vivo and in vitro studies in fish have shown its stimulatory action. In mouse, although the firing rate of the majority of GnRH neurons is decreased, a small population of GnRH neurons is stimulated by GnIH. In hamsters, GnIH inhibits luteinizing hormone (LH release in the breeding season when their endogenous LH level is high but stimulates LH release in non-breeding season when their LH level is basal. Besides different effects of GnIH on the HPG axis depending on the reproductive stages in fish, higher concentration or longer duration of GnIH administration can stimulate their HPG axis. These results suggest that GnIH action in the HPG axis is modulated by sex-steroid concentration, the action of neuroestrogen synthesized by the activity of aromatase stimulated by GnIH, estrogen membrane receptor, heteromerization and internalization of GnIH, GnRH, and estrogen membrane receptors. The inhibitory and stimulatory action of GnIH in the HPG axis may have a physiological role to maintain reproductive homeostasis according to developmental and reproductive stages.

  8. Hormones and absence epilepsy

    NARCIS (Netherlands)

    Luijtelaar, E.L.J.M. van; Tolmacheva, E.A.; Budziszewska, B.; Stein, J.

    2017-01-01

    Hormones have an extremely large impact on seizures and epilepsy. Stress and stress hormones are known to reinforce seizure expression, and gonadal hormones affect the number of seizures and even the seizure type. Moreover, hormonal concentrations change drastically over an individual's lifetime,

  9. EFFECT OF GnRH AND PHOSPHORUS IN DELAYED PUBERTAL SURTI BUFFALO HEIFERS

    Directory of Open Access Journals (Sweden)

    H.B. Dhamsaniya

    2016-06-01

    Full Text Available The study was conducted on eighteen delayed pubertal Surti buffalo heifers, divided into three equal groups (6 in each to evaluate the efficacy of GnRH alone and in combination of phosphorus. The buffalo heifers in Group-I and Group-II were treated with Buserelin acetate (5 ml, IM. Buffalo heifers in Group-II also received additional injection of Toldimphos sodium (10 ml, IM at 3 day interval for 4 times, while buffalo heifers in Group-III served as control. The percentage of induced estrus was highest (83.33% in each treated groups as compared to control group (50%. The mean estrus induction intervals were significantly (P<0.05 shorter in Group-I (20.20 ± 2.18 days and Group-II (18.80 ± 2.32 days as compared to control group (30.24 ± 0.81 days. The conception rate at induced estrus was highest in Group-II (50% followed by Group-I (33.33%. The plasma progesterone levels being significantly lowest on the day of estrus (less than 0.5 ng/ml as compared to pre-treatment days in all groups. The mean total protein and triglycerides levels were differed significantly between the groups on the day of estrus and being significantly higher in Group-II as compared to Group-I and III on that day. A significantly higher level of cholesterol in both treatment groups as compared to the control group during different intervals and also being higher on the day of estrus as compared to pre-treatment days. The mean plasma glucose levels were differed nonsignificantly between and within the treatment and control groups. It is concluded that estrus can be successfully induced in delayed pubertal heifers with the use of GnRH alone and in combination with phosphorus.

  10. Circadian rhythm disruption by a novel running wheel: Roles of exercise and arousal in blockade of the luteinizing hormone surge

    Science.gov (United States)

    Duncan, Marilyn J.; Franklin, Kathleen M.; Peng, Xiaoli; Yun, Christopher; Legan, Sandra J.

    2014-01-01

    Exposure of proestrous Syrian hamsters to a new room, cage, and novel running wheel blocks the luteinizing hormone (LH) surge until the next day in ~75% of hamsters (Legan et al, 2010) [1]. The studies described here tested the hypotheses that 1) exercise and/or 2) orexinergic neurotransmission mediate novel wheel blockade of the LH surge and circadian phase advances. Female hamsters were exposed to a 14L:10D photoperiod and activity rhythms were monitored with infra-red detectors. In Expt. 1, to test the effect of exercise, hamsters received jugular cannulae and on the next day, proestrus (Day 1), shortly before zeitgeber time 5 (ZT 5, 7 hours before lights-off) the hamsters were transported to the laboratory. After obtaining a blood sample at ZT 5, the hamsters were transferred to a new cage with a novel wheel that was either freely rotating (unlocked), or locked until ZT 9, and exposed to constant darkness (DD). Blood samples were collected hourly for 2 days from ZT 5–11 under red light for determination of plasma LH levels by radioimmunoassay. Running rhythms were monitored continuously for the next 10–14 days. The locked wheels were as effective as unlocked wheels in blocking LH surges (no Day 1 LH surge in 6/9 versus 8/8 hamsters, P>0.05) and phase advances in the activity rhythms did not differ between the groups (P= 0.28), suggesting that intense exercise is not essential for novel wheel blockade and phase advance of the proestrous LH surge. Expt. 2 tested whether orexin neurotransmission is essential for these effects. Hamsters were treated the same as in Expt. 1 except they were injected (i.p.) at ZT 4.5 and 5 with either the orexin 1 receptor antagonist SB334867 (15 mg/kg per injection) or vehicle (25% DMSO in 2-hydroxypropyl-beta-cyclodextrin (HCD). SB-334867 inhibited novel wheel blockade of the LH surge (surges blocked in 2/6 SB334867-injected animals versus 16/18 vehicle-injected animals, Pwheel running and circadian phase shifts, indicating that

  11. Impact of Triclosan on Female Reproduction through Reducing Thyroid Hormones to Suppress Hypothalamic Kisspeptin Neurons in Mice

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    Xin-Yuan Cao

    2018-01-01

    Full Text Available Triclosan (TCS, a broad-spectrum antimicrobial agent, is widely used in clinical settings and various personal care products. The aim of this study was to evaluate the influence of TCS on reproductive endocrine and function. Here, we show that the exposure of adult female mice to 10 or 100 mg/kg/day TCS caused prolongation of diestrus, and decreases in antral follicles and corpora lutea within 2 weeks. TCS mice showed decreases in the levels of serum luteinizing hormone (LH, follicle-stimulating hormone (FSH and progesterone, and gonadotrophin-releasing hormone (GnRH mRNA with the lack of LH surge and elevation of prolactin (PRL. TCS mice had lower kisspeptin immunoreactivity and kiss1 mRNA in anteroventral periventricular nucleus (AVPV and arcuate nucleus (ARC. Moreover, the estrogen (E2-enhanced AVPV-kisspeptin expression was reduced in TCS mice. In addition, the serum thyroid hormones (triiodothyronine (T3 and thyroxine (T4 in TCS mice were reduced with increases in levels of thyroid stimulating hormone (TSH and thyroid releasing hormone (TRH. In TCS mice, the treatment with Levothyroxine (L-T4 corrected the increases in PRL, TSH and TRH; the administration of L-T4 or type-2 dopamine receptors agonist quinpirole inhibiting PRL release could rescue the decline of kisspeptin expression in AVPV and ARC; the treatment with L-T4, quinpirole or the GPR45 agonist kisspeptin-10 recovered the levels of serum LH and FSH and progesterone, and GnRH mRNA. Furthermore, TCS mice treated with L-T4 or quinpirole resumed regular estrous cycling, follicular development and ovulation. Together, these results indicate that exposing adult female mice to TCS (≥10 mg/kg reduces thyroid hormones causing hyperprolactinemia that then suppresses hypothalamic kisspeptin expression, leading to deficits in reproductive endocrine and function.

  12. Effect of reproductive methods and GnRH administration on long-term protocol in Santa Ines ewes.

    Science.gov (United States)

    Biehl, Marcos V; Ferraz Junior, Marcos V C; Ferreira, Evandro M; Polizel, Daniel M; Miszura, Alexandre A; Barroso, José P R; Oliveira, Gabriela B; Bertoloni, Analisa V; Pires, Alexandre V

    2017-08-01

    This study aimed to determine whether reproductive performance of ewes submitted to laparoscopic timed artificial insemination (TAI) would be similar to ante meridiem (AM)/post meridiem (PM) rule and assisted natural mating (NM), and whether GnRH may enhance the pregnancy rate in TAI. In experiment I, 191 non-lactating ewes were synchronized, then TAI was performed either 48 h after progesterone (P4) removal (TAI-48 h) or 12 h after estrus detection (AM/PM); moreover, some ewes were submitted to NM (NM) as control treatment. In experiment II, 247 non-lactating ewes were allocated in five treatments, a control (no-GnRH on protocol) and four treatments arranged in a factorial design 2 × 2. The factors were time and dose of GnRH: ewes that received either 10 μg (TAI-10 μg-36 h) or 25 μg of GnRH (TAI-25 μg-36 h) 36 h after P4 removal and ewes that received either 10 μg (TAI-10 μg-48 h) or 25 μg of GnRH (TAI-25 μg-48 h) at time of insemination, 48 h after P4 removal. In experiment I, pregnancy rate in TAI-48 h was lower (P = 0.03) than AM/PM and NM. Moreover, the probability of pregnancy in TAI-48 h was higher (P = 0.06) in ewes detected in estrus early. In experiment II, the use of GnRH in TAI protocols increased (P < 0.01) pregnancy rate at synchronization, and TAI-25 μ-48 h and TAI-10 μg-36 h treatments increased (P = 0.02) pregnancy rate compered to TAI-10 μg-48 h. We conclude that TAI decreased pregnancy rate compered to NM and AM/PM, which may be improved by GnRH use in TAI to synchronize ovulation.

  13. Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone.

    Science.gov (United States)

    Bajusz, S; Janaky, T; Csernus, V J; Bokser, L; Fekete, M; Srkalovic, G; Redding, T W; Schally, A V

    1989-08-01

    Metal complexes related to the cytotoxic complexes cisplatin [cis-diamminedichloroplatinum(II)] and transbis(salicylaldoximato)copper(II) were incorporated into suitably modified luteinizing hormone-releasing hormone (LH-RH) analogues containing D-lysine at position 6. Some of the metallopeptides thus obtained proved to be highly active LH-RH agonists or antagonists. For instance, SB-40, a PtCl2-containing metallopeptide in which platinum is coordinated to an N epsilon-(DL-2,3-diaminopropionyl)-D-lysine residue [D-Lys(DL-A2pr] at position 6, showed 50 times higher LH-releasing potency than the native hormone. SB-95, [Ac-D-Nal(2)1,D-Phe(pCl)2, D-Pal(3)2, Arg5,D-Lys[DL-A2pr(Sal2Cu)]6,D-Ala10]LH-RH, where Nal(2) is 3-(2-naphthyl)alanine, Pal(3) is 3-(3-pyridyl)alanine, and copper(II) is coordinated to the salicylideneimino moieties resulting from condensation of salicylaldehyde with D-Lys(DL-A2pr)6, caused 100% inhibition of ovulation at a dose of 3 micrograms in rats. Most metallopeptide analogues of LH-RH showed high affinities for the membrane receptors of rat pituitary and human breast cancer cells. Some of these metallopeptides had cytotoxic activity against human breast cancer and prostate cancer cell lines in vitro (this will be the subject of a separate paper on cytotoxicity evaluation). Such cytostatic metallopeptides could be envisioned as targeted chemotherapeutic agents in cancers that contain receptors for LH-RH-like peptides.

  14. Selective thyroid hormone receptor modulators

    Directory of Open Access Journals (Sweden)

    Girish Raparti

    2013-01-01

    Full Text Available Thyroid hormone (TH is known to have many beneficial effects on vital organs, but its extrapolation to be used therapeutically has been restricted by the fact that it does have concurrent adverse effects. Recent finding of various thyroid hormone receptors (TR isoforms and their differential pattern of tissue distribution has regained interest in possible use of TH analogues in therapeutics. These findings were followed by search of compounds with isoform-specific or tissue-specific action on TR. Studying the structure-activity relationship of TR led to the development of compounds like GC1 and KB141, which preferentially act on the β1 isoform of TR. More recently, eprotirome was developed and has been studied in humans. It has shown to be effective in dyslipidemia by the lipid-lowering action of TH in the liver and also in obesity. Another compound, 3,5-diiodothyropropionic acid (DITPA, binds to both α- and β-type TRs with relatively low affinity and has been shown to be effective in heart failure (HF. In postinfarction models of HF and in a pilot clinical study, DITPA increased cardiac performance without affecting the heart rate. TR antagonists like NH3 can be used in thyrotoxicosis and cardiac arrhythmias. However, further larger clinical trials on some of these promising compounds and development of newer compounds with increased selectivity is required to achieve higher precision of action and avoid adverse effects seen with TH.

  15. Muscarinic Receptor Agonists and Antagonists

    Directory of Open Access Journals (Sweden)

    David R. Kelly

    2001-02-01

    Full Text Available A comprehensive review of pharmacological and medical aspects of the muscarinic class of acetylcholine agonists and antagonists is presented. The therapeutic benefits of achieving receptor subtype selectivity are outlined and applications in the treatment of Alzheimer’s disease are discussed. A selection of chemical routes are described, which illustrate contemporary methodology for the synthesis of chiral medicinal compounds (asymmetric synthesis, chiral pool, enzymes. Routes to bicyclic intrannular amines and intramolecular Diels-Alder reactions are highlighted.

  16. The terminal nerve plays a prominent role in GnRH-1 neuronal migration independent from proper olfactory and vomeronasal connections to the olfactory bulbs

    Directory of Open Access Journals (Sweden)

    Ed Zandro M. Taroc

    2017-10-01

    Yoshihara et al., 2005. Our data prove that correct development of the OBs and axonal connection of the olfactory/vomeronasal sensory neurons to the forebrain are not required for GnRH-1 ns migration, and suggest that the terminal nerve, which forms the GnRH-1 migratory scaffold, follows different guidance cues and differs in gene expression from olfactory/vomeronasal sensory neurons.

  17. Consistent high clinical pregnancy rates and low ovarian hyperstimulation syndrome rates in high-risk patients after GnRH agonist triggering and modified luteal support

    DEFF Research Database (Denmark)

    Iliodromiti, Stamatina; Blockeel, Christophe; Tremellen, Kelton P

    2013-01-01

    Are clinical pregnancy rates satisfactory and the incidence of OHSS low after GnRH agonist trigger and modified intensive luteal support in patients with a high risk of ovarian hyperstimulation syndrome (OHSS)?......Are clinical pregnancy rates satisfactory and the incidence of OHSS low after GnRH agonist trigger and modified intensive luteal support in patients with a high risk of ovarian hyperstimulation syndrome (OHSS)?...

  18. A Pharmacokinetic/Pharmacodynamic Study of the Glucocorticoid Receptor Antagonist Mifepristone Combined with Enzalutamide in Castrate-Resistant Prostate Cancer

    Science.gov (United States)

    2017-12-01

    Receptor Antagonist Mifepristone Combined with Enzalutamide in Castrate-Resistant Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER... receptor (AR) targeted therapies, prostate cancer adapts. One way it adapts is by upregulating another hormone receptor , the glucocorticoid receptor (GR...trial. 15. SUBJECT TERMS Castration resistant prostate cancer (CRPC); Androgen Receptor (AR); Glucocorticoid receptor (GR); Enzalutamide;

  19. Gonadotropin-Releasing Hormone Stimulate Aldosterone Production in a Subset of Aldosterone-Producing Adenoma

    Science.gov (United States)

    Kishimoto, Rui; Oki, Kenji; Yoneda, Masayasu; Gomez-Sanchez, Celso E.; Ohno, Haruya; Kobuke, Kazuhiro; Itcho, Kiyotaka; Kohno, Nobuoki

    2016-01-01

    Abstract We aimed to detect novel genes associated with G protein-coupled receptors (GPCRs) in aldosterone-producing adenoma (APA) and elucidate the mechanisms underlying aldosterone production. Microarray analysis targeting GPCR-associated genes was conducted using APA without known mutations (APA-WT) samples (n = 3) and APA with the KCNJ5 mutation (APA-KCNJ5; n = 3). Since gonadotropin-releasing hormone receptor (GNRHR) was the highest expression in APA-WT by microarray analysis, we investigated the effect of gonadotropin-releasing hormone (GnRH) stimulation on aldosterone production. The quantitative polymerase chain reaction assay results revealed higher GNRHR expression levels in APA-WT samples those in APA-KCNJ5 samples (P APA-WT samples, and there was a significant and positive correlation between GNRHR and LHCGR expression in all APA samples (r = 0.476, P APA-WT (n = 9), which showed higher GNRHR and LHCGR levels, had significantly higher GnRH-stimulated aldosterone response than those with APA-KCNJ5 (n = 13) (P APA-WT, and the molecular analysis including the receptor expression associated with clinical findings of GnRH stimulation. PMID:27196470

  20. Synthesis and release of luteinizing hormone in vitro: manipulations of Ca2+ environment

    International Nuclear Information System (INIS)

    Liu, T.C.; Jackson, G.L.

    1985-01-01

    The authors determined if luteinizing hormone (LH) synthesis is Ca2+ dependent and coupled to LH release. They monitored LH synthesis when LH release was stimulated either by specific [gonadotropin-releasing hormone (GnRH)] or nonspecific stimuli (50 mM K+ and 2 or 20 microM Ca2+ ionophore A23187) and inhibited by Ca2+-reduced medium. LH synthesis was estimated by measuring incorporation of [ 3 H]glucosamine (glycosylation) and [ 14 C]alanine (translation) into total (cell and medium) immunoprecipitable LH by cultured rat anterior pituitary cells. Both GnRH (1 nM) and 50 mM K+ significantly stimulated LH release and glycosylation, but had no effect on LH translation. A23187 also stimulated LH release, but significantly depressed glycosylation of LH and total protein and [ 14 C]alanine uptake. Deletion of Ca2+ from the medium depressed both GnRH-induced LH release and glycosylation. Addition of 0.1 mM EGTA to Ca2+-free medium not only inhibited GnRH-induced release and glycosylation of LH but also uptake of precursors and glycosylation and translation of total protein. Thus, glycosylation and release of LH are Ca2+ dependent. Whether parallel changes in LH release and glycosylation reflect a cause and effect relationship remains to be determined

  1. A study on the reproductive endocrine mechanisms of ovulation induced by [D-Leu6,Pro9]-GnRH N-ethylamide in laying Taihe hens

    International Nuclear Information System (INIS)

    Wang Gongjin; Li Zhengkui; Yan Jianmin

    1994-01-01

    Ovulation induced by gonadotropin-releasing hormone agonist [GnRH-A, (D-Leu 6 , Pro 9 ]-GnRH N-ethylamide] was used as a model for studying the endocrine mechanisms of ovulation in laying Taihe hens. The results showed that: (1) GnRH-A had a great stimulating effect on development of reproductive organs of hens, and caused weight increasing of ovary, oviduct and liver in hens, whereas there was no significant weight difference between GnRH-A and control group. Admininstration of GnRH-A seven days before the end of laying could keep normal egg production of the hens. (2) Twenty days after GnRH-A administration the two releasing peaks of plasma LH were induced in GnRH-A group, and plasma LH concentrations were higher in GnRH-A group than that in control group, whereas plasma FSH did not changed significantly compared with control group. (3) After administration of GnRH-A, plasma progesterone increased, and it was higher in GnRH-A group than that in control group out of laying cycle. On contrary, plasma estriol declined obviously 8 days after GnRH-A administration, though it elevated slightly later, it was less than that in control group. It is concluded that GnRH-A induced oviduct and ovalution development is associated with changes in plasma LH, progesterone and estriol concentration and that GnRH-A may be an useful agent for inducing development of ovalution and oviduct and improving egg production

  2. Gonadotropin-releasing hormone for infertility in women with primary hypothalamic amenorrhea. Toward a more-interventional approach.

    Science.gov (United States)

    Kesrouani, A; Abdallah, M A; Attieh, E; Abboud, J; Atallah, D; Makhoul, C

    2001-01-01

    To assess the effectiveness of a protocol of pulsatile gonadotropin releasing-hormone (GnRH) in treating infertility in women with primary hypothalamic amenorrhea. Retrospective analysis of 44 cycles treated at an infertility center. Twenty-four patients with primary hypothalamic amenorrhea were treated intravenously with pulsatile GnRH using 5 micrograms per bolus every 90 minutes. Ultrasound monitoring and cervical assessment by Insler's scoring system allowed timed injection of human chorionic gonadotropin (hCG) and intrauterine insemination if needed. Luteal support was provided with hCG. The ovulation rate was 95% with the 5-microgram dose. A single follicle was produced in 91% of cycles. The overall pregnancy rate per ovulatory cycle was 45%, and the pregnancy rate per patient was 83%. In patients treated previously with exogenous gonadotropins, poor results were observed. Only one case of mild overstimulation was reported. Pulsatile GnRH is an effective and safe method of treating infertility in women with primary hypothalamic amenorrhea, thus simulating normal ovulation; however, more-interventional management, including the qualitative estrogenic response, may lead to optimal results and increase the pregnancy rate.

  3. Recent progress in the development of small-molecule glucagon receptor antagonists.

    Science.gov (United States)

    Sammons, Matthew F; Lee, Esther C Y

    2015-10-01

    The endocrine hormone glucagon stimulates hepatic glucose output via its action at the glucagon receptor (GCGr) in the liver. In the diabetic state, dysregulation of glucagon secretion contributes to abnormally elevated hepatic glucose output. The inhibition of glucagon-induced hepatic glucose output via antagonism of the GCGr using small-molecule ligands is a promising mechanism for improving glycemic control in the diabetic state. Clinical data evaluating the therapeutic potential of small-molecule GCGr antagonists is currently emerging. Recently disclosed clinical data demonstrates the potential efficacy and possible therapeutic limitations of small-molecule GCGr antagonists. Recent pre-clinical work on the development of GCGr antagonists is also summarized. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Recent advancements in the hormonal stimulation of ovulation in swine

    Directory of Open Access Journals (Sweden)

    Knox RV

    2015-10-01

    Full Text Available Robert V Knox Department of Animal Sciences, 360 Animal Sciences Laboratory, University of Illinois, Champaign Urbana, IL, USA Abstract: Induction of ovulation for controlled breeding is available for use around the world, and conditions for practical application appear promising. Many of the hormones available, such as human chorionic gonadotropin (hCG, gonadotropin-releasing hormone (GnRH and its analogs, as well as porcine luteinizing hormone (pLH, have been shown to be effective for advancing or synchronizing ovulation in gilts and weaned sows. Each of the hormones has unique attributes with respect to the physiology of its actions, how it is administered, its efficacy, and approval for use. The timing for induction of ovulation during the follicle phase is critical as follicle maturity changes over time, and the success of the response is determined by the stage of follicle development. Female fertility is also a primary factor affecting the success of ovulation induction and fixed time insemination protocols. Approximately 80%–90% of female pigs will develop mature follicles following weaning in sows and synchronization of estrus in gilts. However, those gilts and sows with follicles that are less developed and mature, or those that develop with abnormalities, will not respond to an ovulatory surge of LH. To address this problem, some protocols induce follicle development in all females, which can improve the overall reliability of the ovulation response. Control of ovulation is practical for use with fixed time artificial insemination and should prove highly advantageous for low-dose and single-service artificial insemination and for use with frozen-thawed and sex-sorted sperm. Keywords: artificial insemination, follicle, hormone, ovulation, swine

  5. GABAA receptor partial agonists and antagonists

    DEFF Research Database (Denmark)

    Krall, Jacob; Balle, Thomas; Krogsgaard-Larsen, Niels

    2015-01-01

    to the local temporal pattern of GABA impact, enabling phasic or tonic inhibition. Specific GABAAR antagonists are essential tools for physiological and pharmacological elucidation of the different type of GABAAR inhibition. However, distinct selectivity among the receptor subtypes (populations) has been shown...... antagonists have been essential in defining the tonic current but both remaining issues concerning the GABAARs involved and the therapeutic possibilities of modulating tonic inhibition underline the need for GABAAR antagonists with improved selectivity....

  6. Prostate specific antigen in boys with precocious puberty before and during gonadal suppression by GnRH agonist treatment

    DEFF Research Database (Denmark)

    Juul, A; Müller, J; Skakkebaek, N E

    1997-01-01

    antigen (PSA) is a marker of the androgen-dependent prostatic epithelial cell activity and it is used in the diagnosis and surveillance of adult patients with prostatic cancer. We have measured PSA concentrations in serum from boys with precocious puberty before and during gonadal suppression with Gn......RH agonists to evaluate the effect of normal and precocious puberty on PSA levels and to study the correlation between testosterone and PSA in boys....

  7. Role of neuropeptide Y in the regulation of gonadotropin releasing hormone system in the forebrain of Clarias batrachus (Linn.): immunocytochemistry and high performance liquid chromatography-electrospray ionization-mass spectrometric analysis.

    Science.gov (United States)

    Gaikwad, A; Biju, K C; Muthal, P L; Saha, S; Subhedar, N

    2005-01-01

    Although the importance of neuropeptide Y (NPY) in the regulation of gonadotropin releasing hormone (GnRH) and reproduction has been highlighted in recent years, the neuroanatomical substrate within which these substances might interact has not been fully elucidated. Present work was undertaken with a view to define the anatomical-physiological correlates underlying the role exercised by NPY in the regulation of GnRH in the forebrain of the teleost Clarias batrachus. Application of double immunocytochemistry revealed close associations as well as colocalizations of the two peptides in the olfactory receptor neurons (ORNs), olfactory nerve fibers and their terminals in the glomeruli, ganglion cells of nervus terminalis, medial olfactory tract, fibers in the area ventralis telencephali/pars supracommissuralis and cells as well as fibers in the pituitary. NPY containing axons were found to terminate in the vicinity of GnRH cells in the pituitary with light as well as electron microscopy. Double immunoelectron microscopy demonstrated gold particles for NPY and GnRH colocalized on the membrane and in dense core of the secretory granules in the cells distributed in all components of the pituitary gland. To assess the physiological implication of these observations, NPY was injected via the intracranial route and the response of GnRH immunoreactive system was evaluated by relative quantitative morphometry as well as high performance liquid chromatography (HPLC) analysis. Two hours following NPY (20 ng/g body weight) administration, a dramatic increase was observed in the GnRH immunoreactivity in the ORNs, in the fibers of the olfactory bulb (163%) and medial olfactory tract (351%). High performance liquid chromatography-electrospray ionization-mass spectrometric analysis confirmed the immunocytochemical data. Significant rise in the salmon GnRH (sGnRH)-like peptide content was observed in the olfactory organ (194.23%), olfactory bulb (146.64%), telencephalon+preoptic area

  8. The dual trigger study: Rationale and study design of a prospective double-blind randomized clinical trial comparing pregnancy rates after co-administration of low dose hCG at the time of GnRH agonist trigger or 35 h later for the prevention of OHSS

    Directory of Open Access Journals (Sweden)

    Daniel Griffin

    2017-12-01

    Full Text Available Ovarian hyperstimulation syndrome (OHSS is an iatrogenic complication of controlled ovarian stimulation. The use of gonadotropin releasing hormone (GnRH agonist for the trigger of oocyte maturation is effective in the prevention of OHSS although it may result in a lower pregnancy rate. The use of adjuvant low dose human chorionic gonadotropin (hCG at the time of trigger or at the time of oocyte retrieval may improve pregnancy rates. The goal of this dual trigger study is to evaluate the safety and efficacy of the use of low dose hCG administered at the time of GnRH agonist trigger or 35 h later as well as the potential impact on pregnancy rates. The population will consist of 82 women undergoing IVF treatment who are at risk of developing OHSS. This study will be a single center prospective randomized double-blind placebo controlled trial. The randomization schedule will be administered by the Investigational Drug Services of the University. After controlled ovarian stimulation, induction of oocyte maturation will be achieved using a GnRH agonist and patients will be randomized to receive either low dose hCG 1000 IU at the time of trigger and placebo at oocyte retrieval (Study group or placebo at the time of trigger and hCG 1500 IU at the time of oocyte retrieval (Control group. The main outcomes will be live birth rates and incidence of OHSS. Two ancillary studies will include a quality of life survey and serum assessment of independent corpus luteum function.

  9. Female-Specific Glucose Sensitivity of GnRH1 Neurons Leads to Sexually Dimorphic Inhibition of Reproduction in Medaka.

    Science.gov (United States)

    Hasebe, Masaharu; Kanda, Shinji; Oka, Yoshitaka

    2016-11-01

    Close interaction exists between energy-consuming reproduction and nutritional status. However, there are differences in costs and priority for reproduction among species and even between sexes, which leads to diversification of interactions between reproduction and nutritional status. Despite such diversified interactions among species and sexes, most of the analysis of the nutritional status-dependent regulation of reproduction has been limited to an endothermic vertebrate, mammalian species of either sex. Therefore, the mechanisms underlying the diversified interactions remain elusive. In the present study, we demonstrated the effects of malnutritional status on reproduction at both organismal and cellular levels in an ectothermic vertebrate, a teleost medaka of both sexes. First, we analyzed the effects of malnutrition by fasting on gonadosomatic index, number of spawned/fertilized eggs, and courtship behavior. Fasting strongly suppressed reproduction in females but, surprisingly, not in males. Next, we analyzed the effects of fasting on firing activity of hypothalamic GnRH1 neurons, which form the final common pathway for the control of reproduction. An electrophysiological analysis showed that low glucose, which is induced by fasting, directly suppresses the firing activity of GnRH1 neurons specifically in females through intracellular ATP-sensitive potassium channels and AMP-activated protein kinase pathways. Based on the fact that such suppressions occurred only in females, we conclude that nutritional status-dependent, glucose-sensing in GnRH1 neurons may contribute to the most fitted reproductive regulation for each sex.

  10. Action of luteinizing hormone-releasing hormone in rat ovarian cells: Hormone production and signal transduction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian.

    1989-01-01

    The present study was conducted to investigate the hypothesis that the breakdown of membrane phosphoinositides may participate in the actions of luteinizing hormone-releasing hormone (LHRH) on hormone production in rat granulosa cells. In cells prelabeled with ({sup 3}H)inositol or ({sup 3}H)arachidonic acid (AA), treatment with LHRH increased the formation of radiolabeled inositol 1,4,5-trisphosphate (IP{sub 3}) and diacylglycerol (DG), and the release of radiolabeled AA. Since IP{sub 3} induces intracellular Ca{sup 2+} mobilization, changes in the cytosolic free calcium ion concentrations ((Ca{sup 2+})i) induced by LHRH were studied in individual cells using fura-2 microspectrofluorimetry. Alterations in (Ca{sup 2+})i induced by LHRH were rapid and transient, and could be completely blocked by a LHRH antagonist. Sustained perifusion of LHRH resulted in a desensitization of the (Ca{sup 2+})i response to LHRH. LHRH treatment accelerated (Ca{sup 2+})i depletion in the cells perifused with Ca{sup 2+} free medium, indicating the involvement of intracellular Ca{sup 2+} pool(s) in (Ca{sup 2+})i changes. The actions of LHRH on the regulation of progesterone (P{sub 4}) and prostaglandin E{sub 2} (PGE{sub 2}) production were also examined. LHRH increased basal P{sub 4} production and attenuated FSH induced P{sub 4} production. Both basal and FSH stimulated PGE{sub 2} formation were increased by LHRH. Since LHRH also increased the formation of DG that stimulates the activity of protein kinase C, an activator of protein kinase C (12-0-tetradecanolyphorbol-13-acetate: TPA) was used with the Ca{sup 2+} ionophore A23187 and melittin (an activator of phospholipase A{sub 2}) to examine the roles of protein kinase C, Ca{sup 2+} and free AA, respectively, in LHRH action.

  11. Influence of histamine and serotonin antagonists on the growth of xenografted human colorectal tumors.

    Science.gov (United States)

    Barkla, D H; Tutton, P J

    1981-12-01

    Four lines of human colorectal cancer were established and serially propagated as subcutaneous xenographs in immunosuppressed inbred CBA/Lac mice. Established xenografts were then used to investigate the influence of a serotonin antagonist (BW 501c) and a histamine H2 receptor antagonists (Cimetidine) on xenograft growth. The growth of each of the four tumor lines was significantly inhibited by BW 501c throughout the treatment, whereas the growth of only two tumor lines was significantly inhibited by Cimetidine treatment. The response of individual tumor lines was not predictable on the basis of either tumor histopathology or the natural growth rate of the untreated xenograft. A number of alternative, but not mutually exclusive, hypotheses are suggested to explain the results. One hypothesis proposes that colorectal tumors are composed of subpopulations of tumor cells that are variously dependent on or independent of amine hormones. Another hypothesis is that tumor cells exhibit temporal changes in hormone sensitivity to amine hormones during treatment. Finally, it is suggested that serotonin and/or histamine H2 antagonists may be useful in preventing the repopulation of colorectal carcinomas following antineoplastic therapy with the use of conventional drugs.

  12. Gonadotropin Inhibitory Hormone Down-Regulates the Brain-Pituitary Reproductive Axis of Male European Sea Bass (Dicentrarchus labrax).

    Science.gov (United States)

    Paullada-Salmerón, José A; Cowan, Mairi; Aliaga-Guerrero, María; Morano, Francesca; Zanuy, Silvia; Muñoz-Cueto, José A

    2016-06-01

    Gonadotropin-inhibitory hormone (GnIH) inhibits gonadotropin synthesis and release from the pituitary of birds and mammals. However, the physiological role of orthologous GnIH peptides on the reproductive axis of fish is still uncertain, and their actions on the main neuroendocrine systems controlling reproduction (i.e., GnRHs, kisspeptins) have received little attention. In a recent study performed in the European sea bass, we cloned a cDNA encoding a precursor polypeptide that contained C-terminal MPMRFamide (sbGnIH-1) and MPQRFamide (sbGnIH-2) peptide sequences, developed a specific antiserum against sbGnIH-2, and characterized its central and pituitary GnIH projections in this species. In this study, we analyzed the effects of intracerebroventricular injection of sbGnIH-1 and sbGnIH-2 on brain and pituitary expression of reproductive hormone genes (gnrh1, gnrh2, gnrh3, kiss1, kiss2, gnih, lhbeta, fshbeta), and their receptors (gnrhr II-1a, gnrhr II-2b, kiss1r, kiss2r, and gnihr) as well as on plasma Fsh and Lh levels. In addition, we determined the effects of GnIH on pituitary somatotropin (Gh) expression. The results obtained revealed the inhibitory role of sbGnIH-2 on brain gnrh2, kiss1, kiss2, kiss1r, gnih, and gnihr transcripts and on pituitary fshbeta, lhbeta, gh, and gnrhr-II-1a expression, whereas sbGnIH-1 only down-regulated brain gnrh1 expression. However, at different doses, central administration of both sbGnIH-1 and sbGnIH-2 decreased Lh plasma levels. Our work represents the first study reporting the effects of centrally administered GnIH in fish and provides evidence of the differential actions of sbGnIH-1 and sbGnIH-2 on the reproductive axis of sea bass, the main inhibitory role being exerted by the sbGnIH-2 peptide. © 2016 by the Society for the Study of Reproduction, Inc.

  13. Menopause and Hormones

    Science.gov (United States)

    ... Consumer Information by Audience For Women Menopause and Hormones: Common Questions Share Tweet Linkedin Pin it More ... reproduction and distribution. Learn More about Menopause and Hormones Menopause--Medicines to Help You Links to other ...

  14. Thyroid Hormone Treatment

    Science.gov (United States)

    ... THYROID HORMONES? Desiccated ( dried and powdered ) animal thyroid ( Armour ®), now mainly obtained from pigs, was the most ... hormone can increase the risk or heart rhythm problems and bone loss making the use of thyroxine ...

  15. Antidiuretic hormone blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003702.htm Antidiuretic hormone blood test To use the sharing features on this page, please enable JavaScript. Antidiuretic blood test measures the level of antidiuretic hormone (ADH) in ...

  16. Hormonal effects in newborns

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001911.htm Hormonal effects in newborns To use the sharing features on this page, please enable JavaScript. Hormonal effects in newborns occur because in the womb, babies ...

  17. Growth hormone stimulation test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003377.htm Growth hormone stimulation test To use the sharing features on this page, please enable JavaScript. The growth hormone (GH) stimulation test measures the ability of ...

  18. Aptamer based peptide enrichment for quantitative analysis of gonadotropin-releasing hormone by LC-MS/MS.

    Science.gov (United States)

    Richards, S L; Cawley, A T; Cavicchioli, R; Suann, C J; Pickford, R; Raftery, M J

    2016-04-01

    Over recent years threats to racing have expanded to include naturally occurring biological molecules, such as peptides and proteins, and their synthetic analogues. Traditionally, antibodies have been used to enable detection of these compounds as they allow purification and concentration of the analyte of interest. The rapid expansion of peptide-based therapeutics necessitates a similarly rapid development of suitable antibodies or other means of enrichment. Potential alternative enrichment strategies include the use of aptamers, which offer the significant advantage of chemical synthesis once the nucleic acid sequence is known. A method was developed for the enrichment, detection and quantitation of gonadotropin-releasing hormone (GnRH) in equine urine using aptamer-based enrichment and LC-MS/MS. The method achieved comparable limits of detection (1 pg/mL) and quantification (2.5 pg/mL) to previously published antibody-based enrichment methods. The intra- and inter-assay precision achieved was less than 10% at both 5 and 20 pg/mL, and displayed a working dynamic range of 2.5-100 pg/mL. Significant matrix enhancement (170 ± 8%) and low analytical recovery (29 ± 15%) was observed, although the use of an isotopically heavy labelled GnRH peptide, GnRH (Pro(13)C5,(15)N), as the internal standard provides compensation for these parameters. Within the current limits of detection GnRH was detectable up to 1h post administration in urine and identification of a urinary catabolite extended this detection window to 4h. Based on the results of this preliminary investigation we propose the use of aptamers as a viable alternative to antibodies in the enrichment of peptide targets from equine urine. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Estriol administration modulates luteinizing hormone secretion in women with functional hypothalamic amenorrhea.

    Science.gov (United States)

    Genazzani, Alessandro D; Meczekalski, Blazej; Podfigurna-Stopa, Agnieszka; Santagni, Susanna; Rattighieri, Erica; Ricchieri, Federica; Chierchia, Elisa; Simoncini, Tommaso

    2012-02-01

    To evaluate the influence of estriol administration on the hypothalamus-pituitary function and gonadotropins secretion in patients affected by functional hypothalamic amenorrhea (FHA). Controlled clinical study. Patients with FHA in a clinical research environment. Twelve hypogonadotropic patients affected by FHA. Pulsatility study of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and a gonadotropin-releasing hormone (GnRH) test (10 μg in bolus) at baseline condition and after 8 weeks of therapy with 2 mg/day of estriol. Measurements of plasma LH, FSH, estradiol (E(2)), androstenedione (A), 17α-hydroxyprogesterone (17-OHP), cortisol, androstenedione (A), testosterone (T), thyroid-stimulating hormone (TSH), free triiodothyronine (fT(3)), free thyroxine (fT(4)), and insulin, and pulse detection. After treatment, the FHA patients showed a statistically significant increase of LH plasma levels (from 0.7 ± 0.1 mIU/mL to 3.5 ± 0.3 mIU/mL) and a statistically significant increase of LH pulse amplitude with no changes in LH pulse frequency. In addition, the LH response to the GnRH bolus was a statistically significant increase. Estriol administration induced the increase of LH plasma levels in FHA and improved GnRH-induced LH secretion. These findings suggest that estriol administration modulates the neuroendocrine control of the hypothalamus-pituitary unit and induces the recovery of LH synthesis and secretion in hypogonadotropic patients with FHA. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  20. Repeat dose of gonadotropin-releasing hormone agonist trigger in polycystic ovarian syndrome undergoing In Vitro fertilization cycles provides a better cycle outcome - a proof-of-concept study

    Directory of Open Access Journals (Sweden)

    Krishna Deepika

    2017-01-01

    Full Text Available Objective: Is a single dose of gonadotropin-releasing hormone agonist (GnRHa trigger to induce final oocyte maturation in polycystic ovarian syndrome (PCOS undergoing in vitro fertilization (IVF cycles with GnRH antagonist protocol sufficient to provide optimal oocyte maturity? Design: This is a prospective, randomized, double-blind, proof-of-concept study. Setting: This study was carried out at a tertiary care center. Material and Methods: A total of 125 patients diagnosed with PCOS defined as per the ESHRE/ASRM Rotterdam criteria (2003 undergoing IVF in antagonist protocol were randomized into two groups. Group A: single dose of GnRHa 0.2 mg, 35 h prior to oocyte retrieval, and Group B: 0.2 mg GnRHa 35 h prior to oocyte retrieval + repeat dose of 0.1 mg 12 h following the 1st dose. 12 h post-trigger, luteinizing hormone (LH, progesterone (P4, and follicle-stimulating hormone (FSH values were estimated. Statistical Analysis: Continuous variables were expressed as mean ± standard deviation and categorical variables as proportions where applicable. Independent sample t-test was used for continuous variables which were normally distributed and Mann–Whitney U-test for data not normally distributed. Chi-square test or Fisher's exact test was used for categorical variables where appropriate. Odds ratio (OR with 95% confidence intervals (CIs was calculated. In addition, receiver operating characteristic curve was used to evaluate the post-trigger LH, P4, and FSH values at 12 h as predictors of oocyte maturity. Main Outcome Measures: Primary outcome: maturity rate of the oocytes. Secondary outcomes: oocyte yield, fertilization rate, availability of good quality embryos on day 3, blastocyst conversion, OHSS rates, post-trigger serum LH (IU/L, FSH (IU/L, and P4 (ng/mL levels implantation rate and clinical pregnancy rate. Results: A higher number of mature (metaphase II oocytes were obtained in Group B compared to Group A (OR of 0.47; CI: 0.38–0

  1. Interleukin-1 antagonists for diabetes

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, Thomas

    2013-01-01

    pathways. The testing of specific anti-inflammatory biologics targeting single pro-inflammatory cytokines has provided clinical proof-of-concept. EXPERT OPINION: IL-1 antagonists have so far failed to meet primary end points in recent-onset type 1 diabetes in Phase IIa, and promising Phase I and IIa trials......INTRODUCTION: Diabetes is a currently incurable, epidemically growing global health concern. Contemporary symptomatic treatment targets acute and chronic metabolic consequences of relative or absolute insulin deficiency. Intensive multifactorial therapy is required to attenuate morbidity...... and mortality from late micro- and macrovascular complications, and despite current best clinical practice diabetes is still associated with shortened lifespan. There is an unmet need for interventions targeting pathogenetic mechanisms in diabetes, and the market for such therapies is huge. AREAS COVERED...

  2. Molecular mechanism of action of pharmacoperone rescue of misrouted GPCR mutants: the GnRH receptor.

    Science.gov (United States)

    Janovick, Jo Ann; Patny, Akshay; Mosley, Ralph; Goulet, Mark T; Altman, Michael D; Rush, Thomas S; Cornea, Anda; Conn, P Michael

    2009-02-01

    The human GnRH receptor (hGnRHR), a G protein-coupled receptor, is a useful model for studying pharmacological chaperones (pharmacoperones), drugs that rescue misfolded and misrouted protein mutants and restore them to function. This technique forms the basis of a therapeutic approach of rescuing mutants associated with human disease and restoring them to function. The present study relies on computational modeling, followed by site-directed mutagenesis, assessment of ligand binding, effector activation, and confocal microscopy. Our results show that two different chemical classes of pharmacoperones act to stabilize hGnRHR mutants by bridging residues D(98) and K(121). This ligand-mediated bridge serves as a surrogate for a naturally occurring and highly conserved salt bridge (E(90)-K(121)) that stabilizes the relation between transmembranes 2 and 3, which is required for passage of the receptor through the cellular quality control system and to the plasma membrane. Our model was used to reveal important pharmacophoric features, and then identify a novel chemical ligand, which was able to rescue a D(98) mutant of the hGnRHR that could not be rescued as effectively by previously known pharmacoperones.

  3. Analogues of luteinizing hormone-releasing hormone containing cytotoxic groups.

    Science.gov (United States)

    Janáky, T; Juhász, A; Bajusz, S; Csernus, V; Srkalovic, G; Bokser, L; Milovanovic, S; Redding, T W; Rékási, Z; Nagy, A

    1992-02-01

    In an attempt to produce better cytotoxic analogues, chemotherapeutic antineoplastic radicals including an alkylating nitrogen mustard derivative of D-phenylalanine (D-melphalan), reactive cyclopropane, anthraquinone derivatives [2-(hydroxymethyl)anthraquinone and the anticancer antibiotic doxorubicin], and an antimetabolite (methotrexate) were coupled to suitably modified agonists and antagonists of luteinizing hormone-releasing hormone (LH-RH). Analogues with D-lysine6 and D-ornithine6 or N epsilon-(2,3-diaminopropionyl)-D-lysine and N delta-(2,3-diaminopropionyl)-D-ornithine were used as carriers for one or two cytotoxic moieties. The enhanced biological activities produced by the incorporation of D amino acids into position 6 of the agonistic analogues were further increased by the attachment of hydrophobic cytotoxic groups, resulting in compounds with 10-50 times higher activity than LH-RH. Most of the monosubstituted agonistic analogues showed high affinities for the membrane receptors of human breast cancer cells, while the receptor binding affinities of peptides containing two cytotoxic side chains were lower. Antagonistic carriers [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Trp3,Arg5,D-Lys6,D-Ala10] LH-RH [where Nal(2) is 3-(2-naphthyl)alanine], [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Trp3,Arg5,N epsilon-(2,3-diaminopropionyl)-D-Lys6,D-Ala10]LH-RH, and their D-Pal(3)3 homologs [Pal(3) is 3-(3-pyridyl)alanine] as well as [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Pal(3)3,Tyr5,N epsilon-(2,3-diamino-propionyl)-D-Lys6,D-Ala10]LH-RH were linked to cytotoxic compounds. The hybrid molecules inhibited ovulation in rats at doses of 10 micrograms and suppressed LH release in vitro. The receptor binding of cytotoxic analogues was decreased compared to the precursor peptides, although analogues with 2-(hydroxymethyl)anthraquinone hemiglutarate had high affinities. All of the cytotoxic analogues tested inhibited [3H]thymidine incorporation into DNA in cultures of human breast and prostate cancer cell lines

  4. Growth Hormone Utilization Review in a Pediatric Primary Care Setting.

    Science.gov (United States)

    Sayarifard, Fatemeh; Imcheh, Fereshteh Bakhshi; Badri, Shirinsadat; Faghihi, Toktam; Qorbani, Mostafa; Radfar, Mania

    2017-01-01

    One of the main problems facing public health providers and administrators in many countries is ensuring the rational use of high-cost drugs. In this regard, on-going process of medication use evaluation can be considered as a useful tool. In this study, we evaluated certain usage aspects of a highly-cost medication, that is, recombinant growth hormone (GH). This cross-sectional study conducted from August 2012 to August 2014. Children receiving GH ± gonadotropin releasing hormone (GnRH) analogs were included in the study. A researcher-designed checklist was developed to evaluate the GH utilization in these patients. Baseline demographic characteristics and background clinical and growth data, as well as any aspects of drug therapy including indications, dosing, monitoring, and discontinuation were collected from the patients' medical records. Seventy children receiving GH entered the study, of which 23 patients (32.85%) received GH and GnRH analogs simultaneously. At the baseline, 67 children (95.7%) had GH stimulation test, whereas serum insulin-like growth factor-1 (IGF-1) levels were measured in 63 (90%) patients. Sixty-seven patients (95.71%) had thyroid function test, whereas bone age was determined in 68 children (97.14%). The mean ± standard deviation of GH dose for idiopathic short stature, GH deficiency, Turner's syndrome and born small for gestational age in our study was 0.22 ± 0.025 mg/kg/week, 0.23 ± 0.04 mg/kg/week, 0.22 ± 0.015 mg/kg/week, and 0.23 ± 0.02 mg/kg/week, respectively. Height and weight of all patients were followed every 3-6 months, regularly. Thirty patients were treated with GH for at least 1 year, of which thyroid hormones and IGF-1 levels were measured annually in 25 (83.33%) and 26 (86.66%) patients, respectively; while bone age was evaluated in 13 (43.33%) children, annually. GH treatment was discontinued in 15 patients (21.42%), while financial problem was the major reason. Diagnostic tests and monitoring of height, weight

  5. Antagonistic Phenomena in Network Dynamics

    Science.gov (United States)

    Motter, Adilson E.; Timme, Marc

    2018-03-01

    Recent research on the network modeling of complex systems has led to a convenient representation of numerous natural, social, and engineered systems that are now recognized as networks of interacting parts. Such systems can exhibit a wealth of phenomena that not only cannot be anticipated from merely examining their parts, as per the textbook definition of complexity, but also challenge intuition even when considered in the context of what is now known in network science. Here, we review the recent literature on two major classes of such phenomena that have far-reaching implications: (a) antagonistic responses to changes of states or parameters and (b) coexistence of seemingly incongruous behaviors or properties - both deriving from the collective and inherently decentralized nature of the dynamics. They include effects as diverse as negative compressibility in engineered materials, rescue interactions in biological networks, negative resistance in fluid networks, and the Braess paradox occurring across transport and supply networks. They also include remote synchronization, chimera states, and the converse of symmetry breaking in brain, power-grid, and oscillator networks as well as remote control in biological and bioinspired systems. By offering a unified view of these various scenarios, we suggest that they are representative of a yet broader class of unprecedented network phenomena that ought to be revealed and explained by future research.

  6. Highly potent analogues of luteinizing hormone-releasing hormone containing D-phenylalanine nitrogen mustard in position 6.

    Science.gov (United States)

    Bajusz, S; Janaky, T; Csernus, V J; Bokser, L; Fekete, M; Srkalovic, G; Redding, T W; Schally, A V

    1989-08-01

    The nitrogen mustard derivatives of 4-phenylbutyric acid and L-phenylalanine, called chlorambucil (Chl) and melphalan (Mel), respectively, have been incorporated into several peptide hormones, including luteinizing hormone-releasing hormone (LH-RH). The alkylating analogues of LH-RH were prepared by linking Chl, as an N-acyl moiety, to the complete amino acid sequence of agonistic and antagonistic analogues. These compounds, in particular the antagonistic analogues, showed much lower potency than their congeners carrying other acyl groups. To obtain highly potent alkylating analogues of LH-RH, the D enantiomer of Mel was incorporated into position 6 of the native hormone and some of its antagonistic analogues. Of the peptides prepared, [D-Mel6]LH-RH (SB-05) and [Ac-D-Nal(2)1,D-Phe(pCl)2,D-Pal(3)3,Arg5,D-Mel6,D-Ala10++ +]LH-RH [SB-86, where Nal(2) is 3-(2-naphthyl)alanine and Pal(3) is 3-(3-pyridyl)alanine] possessed the expected high agonistic and antagonistic activities, respectively, and also showed high affinities for the membrane receptors of rat pituitary cells, human breast cancer cells, human prostate cancer cells, and rat Dunning R-3327 prostate tumor cells. These two analogues exerted cytotoxic effects on human and rat mammary cancer cells in vitro. Thus these two D-Mel6 analogues seem to be particularly suitable for the study of how alkylating analogues of LH-RH could interfere with intracellular events in certain cancer cells.

  7. Highly potent analogues of luteinizing hormone-releasing hormone containing D-phenylalanine nitrogen mustard in position 6

    International Nuclear Information System (INIS)

    Bajusz, S.; Janaky, T.; Csernus, V.J.; Bokser, L.; Fekete, M.; Srkalovic, G.; Redding, T.W.; Schally, A.V.

    1989-01-01

    The nitrogen mustard derivatives of 4-phenylbutyric acid and L-phenylalanine, called chlorambucil (Chl) and melphalan (Mel), respectively, have been incorporated into several peptide hormones, including luteinizing hormone-releasing hormone (LH-RH). The alkylating analogues of LH-RH were prepared by linking Chl, as an N-acyl moiety, to the complete amino acid sequence of agonistic and antagonistic analogues. These compounds, in particular the antagonistic analogues, showed much lower potency than their congeners carrying other acyl groups. To obtain highly potent alkylating analogues of LH-RH, the D enantiomer of Mel was incorporated into position 6 of the native hormone and some of its antagonistic analogues. Of the peptides prepared, [D-Mel 6 ]LH-RH (SB-05) and [Ac-D-Nal(2) 1 ,D-Phe(pCl) 2 ,D-Pal(3) 3 ,Arg 5 ,D-Mel 6 ,D-Ala 10 ]LH-RH [SB-86, where Nal(2) is 3-(2-naphthyl)alanine and Pal(3) is 3-(3-pyridyl)alanine] possessed the expected high agonistic and antagonistic activities, respectively, and also showed high affinities for the membrane receptors of rat pituitary cells, human breast cancer cells, human prostate cancer cells, and rat Dunning R-3327 prostate tumor cells. These two analogues exerted cytotoxic effects on human and rat mammary cancer cells in vitro. Thus these two D-Mel 6 analogues seem to be particularly suitable for the study of how alkylating analogues of LH-RH could interfere with intracellular events in certain cancer cells

  8. Neuroanatomical organization of gonadotropin-releasing hormone neurons during the oestrus cycle in the ewe

    Science.gov (United States)

    Batailler, Martine; Caraty, Alain; Malpaux, Benoît; Tillet, Yves

    2004-01-01

    Background During the preovulatory surge of gonadotropin-releasing hormone (GnRH), a very large amount of the peptide is released in the hypothalamo-hypophyseal portal blood for 24-36H00. To study whether this release is linked to a modification of the morphological organization of the GnRH-containing neurons, i.e. morphological plasticity, we conducted experiments in intact ewes at 4 different times of the oestrous cycle (before the expected LH surge, during the LH surge, and on day 8 and day 15 of the subsequent luteal phase). The cycle stage was verified by determination of progesterone and LH concentrations in the peripheral blood samples collected prior to euthanasia. Results The distribution of GnRH-containing neurons throughout the preoptic area around the vascular organ of the lamina terminalis was studied following visualisation using immunohistochemistry. No difference was observed in the staining intensity for GnRH between the different groups. Clusters of GnRH-containing neurons (defined as 2 or more neurons being observed in close contact) were more numerous during the late follicular phase (43 ± 7) than during the luteal phase (25 ± 6), and the percentage of clusters was higher during the beginning of the follicular phase than during the luteal phase. There was no difference in the number of labelled neurons in each group. Conclusions These results indicate that the morphological organization of the GnRH-containing neurons in ewes is modified during the follicular phase. This transitory re-organization may contribute to the putative synchronization of these neurons during the surge. The molecular signal inducing this plasticity has not yet been identified, but oestradiol might play an important role, since in sheep it is the only signal which initiates the GnRH preovulatory surge. PMID:15555074

  9. Neuroanatomical organization of gonadotropin-releasing hormone neurons during the oestrus cycle in the ewe

    Directory of Open Access Journals (Sweden)

    Malpaux Benoît

    2004-11-01

    Full Text Available Abstract Background During the preovulatory surge of gonadotropin-releasing hormone (GnRH, a very large amount of the peptide is released in the hypothalamo-hypophyseal portal blood for 24-36H00. To study whether this release is linked to a modification of the morphological organization of the GnRH-containing neurons, i.e. morphological plasticity, we conducted experiments in intact ewes at 4 different times of the oestrous cycle (before the expected LH surge, during the LH surge, and on day 8 and day 15 of the subsequent luteal phase. The cycle stage was verified by determination of progesterone and LH concentrations in the peripheral blood samples collected prior to euthanasia. Results The distribution of GnRH-containing neurons throughout the preoptic area around the vascular organ of the lamina terminalis was studied following visualisation using immunohistochemistry. No difference was observed in the staining intensity for GnRH between the different groups. Clusters of GnRH-containing neurons (defined as 2 or more neurons being observed in close contact were more numerous during the late follicular phase (43 ± 7 than during the luteal phase (25 ± 6, and the percentage of clusters was higher during the beginning of the follicular phase than during the luteal phase. There was no difference in the number of labelled neurons in each group. Conclusions These results indicate that the morphological organization of the GnRH-containing neurons in ewes is modified during the follicular phase. This transitory re-organization may contribute to the putative synchronization of these neurons during the surge. The molecular signal inducing this plasticity has not yet been identified, but oestradiol might play an important role, since in sheep it is the only signal which initiates the GnRH preovulatory surge.

  10. Seasonal heat stress: Clinical implications and hormone treatments for the fertility of dairy cows.

    Science.gov (United States)

    De Rensis, F; Garcia-Ispierto, I; López-Gatius, F

    2015-09-15

    Heat stress has consequences on both the physiology and reproductive performance of cows, but the most dramatic effect for dairy producers is the decrease produced in fertility. The effects of heat stress on fertility include an increased number of days open, reduced conception rate, and larger number of cows suffering different types of anestrus. Once becomes pregnant, heat stress affects also the reproductive success of the cow through its direct effects on the ovary, uterus, gametes, embryo, and early fetus. This article reviews current knowledge of the effects of heat stress on fertility in dairy cows and the hormonal strategies used to mitigate these effects at the farm level. Administration of GnRH at the moment of artificial insemination can improve the conception rate. Breeding synchronization protocols for fixed-time insemination may reduce the calving conception interval and the number of services per conception. Progesterone-based protocols seem resolve better the reproductive disorders related to a hot environment (anestrus) than GnRH-based protocols. The use of combinations of GnRH, eCG, and hCG in progesterone-based protocols can improve results. Progesterone supplementation during the late embryonic and/or early fetal period would be useful in curtailing pregnancy losses, mainly in single pregnancies, whereas a more positive effect of treatment with GnRH than progesterone has been found in twin pregnancies. Melatonin therapy is emerging as a promising strategy to improve the natural reproductive performance of cows suffering conditions of heat stress. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. GnRH Agonist Trigger and LH Activity Luteal Phase Support versus hCG Trigger and Conventional Luteal Phase Support in Fresh Embryo Transfer IVF/ICSI Cycles—A Systematic PRISMA Review and Meta-analysis

    Directory of Open Access Journals (Sweden)

    Thor Haahr

    2017-06-01

    Full Text Available IntroductionThe use of GnRH agonist (GnRHa for final oocyte maturation trigger in oocyte donation and elective frozen embryo transfer cycles is well established due to lower ovarian hyperstimulation syndrome (OHSS rates as compared to hCG trigger. A recent Cochrane meta-analysis concluded that GnRHa trigger was associated with reduced live birth rates (LBRs in fresh autologous IVF cycles compared to hCG trigger. However, the evidence is not unequivocal, and recent trials have found encouraging reproductive outcomes among couples undergoing GnRHa trigger and individualized luteal LH activity support. Thus, the aim was to compare GnRHa trigger followed by luteal LH activity support with hCG trigger in IVF patients undergoing fresh embryo transfer.Material and methodsWe conducted a systematic review and meta-analysis of randomized trials published until December 14, 2016. The population was infertile patients submitted to IVF/ICSI cycles with GnRH antagonist cotreatment who underwent fresh embryo transfer. The intervention was GnRHa trigger followed by LH activity luteal phase support (LPS. The comparator was hCG trigger followed by a standard LPS. The critical outcome measures were LBR and OHSS rate. The secondary outcome measures were number of oocytes retrieved, clinical and ongoing pregnancy rates, and miscarriage rates.ResultsA total of five studies met the selection criteria comprising a total of 859 patients. The LBR was not significantly different between the GnRHa and hCG trigger groups (OR 0.84, 95% CI 0.62, 1.14. OHSS was reported in a total of 4/413 cases in the GnRHa group compared to 7/413 in the hCG group (OR 0.48, 95% CI 0.15, 1.60. We observed a slight, but non-significant increase in miscarriage rate in the GnRHa triggered group compared to the hCG group (OR 1.85; 95% CI 0.97, 3.54.ConclusionGnRHa trigger with LH activity LPS resulted in comparable LBRs compared to hCG trigger. The most recent trials reported LBRs close to unity

  12. Effects of triclosan on hormones and reproductive axis in female Yellow River carp (Cyprinus carpio): Potential mechanisms underlying estrogen effect.

    Science.gov (United States)

    Wang, Fan; Guo, Xiangmeng; Chen, Wanguang; Sun, Yaowen; Fan, Chaojie

    2017-12-01

    Triclosan (TCS), a member of the class of compounds called pharmaceutical and personal care products (PPCPs), is a broad antibacterial and antifungal agent found in a lot of consumer products. However, TCS hormone effect mechanism in teleost female fish is not clear. Female Yellow River carp (Cyprinus carpio) were exposed to 1/20, 1/10 and 1/5 LC 50 TCS (96h LC 50 of TCS to carp) under semi-static conditions for 42days. Vitellogenin (Vtg), 17β-estradiol (E 2 ), testosterone(T), estrogen receptor (Er), gonadotropin (GtH), and gonadotropin-releasing hormone (GnRH) levels were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we also examined the mRNA expressions of aromatase, GtHs-β, GnRH, and Er by quantitative real-time PCR (qRT-PCR). The results indicated that 1/5 LC 50 TCS induced Vtg in hepatopancreas of female carps by interference with the hypothalamic-pituitary-gonadal (HPG) axis at multiple potential loci through three mechanisms: (a) TCS exposure enhanced the mRNA expression of hypothalamus and gonadal aromatase which converts androgens into estrogens, subsequently increasing serum concentrations of E 2 to induce Vtg in hepatopancreas; (b) TCS treatment increased GnRH and GtH-β mRNA expression and secretion, causing the disturbance of reproductive endocrine and the increase of E 2 to induce Vtg in hepatopancreas; (c) TCS exposure enhanced synthesis and secretion of Er, then it bound to Er to active Vtg synthesis. These mechanisms showed that TCS may induce Vtg production in female Yellow River carp by Er-mediated and non-Er-mediated pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Peri-pubertal gonadotropin-releasing hormone agonist treatment affects sex biased gene expression of amygdala in sheep.

    Science.gov (United States)

    Nuruddin, Syed; Krogenæs, Anette; Brynildsrud, Ola Brønstad; Verhaegen, Steven; Evans, Neil P; Robinson, Jane E; Haraldsen, Ira Ronit Hebold; Ropstad, Erik

    2013-12-01

    The nature of hormonal involvement in pubertal brain development has attracted wide interest. Structural changes within the brain that occur during pubertal development appear mainly in regions closely linked with emotion, motivation and cognitive functions. Using a sheep model, we have previously shown that peri-pubertal pharmacological blockade of gonadotropin releasing hormone (GnRH) receptors, results in exaggerated sex-differences in cognitive executive function and emotional control, as well as sex and hemisphere specific patterns of expression of hippocampal genes associated with synaptic plasticity and endocrine signaling. In this study, we explored effects of this treatment regime on the gene expression profile of the ovine amygdala. The study was conducted with 30 same-sex twin lambs (14 female and 16 male), half of which were treated with the GnRH agonist (GnRHa) goserelin acetate every 4th week, beginning before puberty, until approximately 50 weeks of age. Gene expression profiles of the left and right amygdala were measured using 8×15 K Agilent ovine microarrays. Differential expression of selected genes was confirmed by qRT-PCR (Quantitative real time PCR). Networking analyses and Gene Ontology (GO) Term analyses were performed with Ingenuity Pathway Analysis (IPA), version 7.5 and DAVID (Database for Annotation, Visualization and integrated Discovery) version 6.7 software packages, respectively. GnRHa treatment was associated with significant sex- and hemisphere-specific differential patterns of gene expression. GnRHa treatment was associated with differential expression of 432 (|logFC|>0.3, adj. p value expressed as a result of GnRHa treatment in the male animals. The results indicated that GnRH may, directly and/or indirectly, be involved in the regulation of sex- and hemisphere-specific differential expression of genes in the amygdala. This finding should be considered when long-term peri-pubertal GnRHa treatment is used in children. Copyright

  14. Eel Kisspeptins: Identification, Functional Activity, and Inhibition on both Pituitary LH and GnRH Receptor Expression

    Directory of Open Access Journals (Sweden)

    Jérémy Pasquier

    2018-01-01

    Full Text Available The European eel (Anguilla anguilla presents a blockade of sexual maturation at a prepubertal stage due to a deficient production of gonadotropins. We previously initiated, in the eel, the investigation of the kisspeptin system, one of the major gatekeepers of puberty in mammals, and we predicted the sequence of two Kiss genes. In the present study, we cloned and sequenced Kiss1 and Kiss2 cDNAs from the eel brain. The tissue distributions of Kiss1 and Kiss2 transcripts, as investigated by quantitative real-time PCR, showed that both genes are primarily expressed in the eel brain and pituitary. The two 10-residue long sequences characteristic of kisspeptin, eel Kp1(10 and Kp2(10, as well as two longer sequences, predicted as mature peptides, eel Kp1(15 and Kp2(12, were synthesized and functionally analyzed. Using rat Kiss1 receptor-transfected Chinese hamster ovary cells, we found that the four synthesized eel peptides were able to induce [Ca2+]i responses, indicating their ability to bind mammalian KissR-1 and to activate second messenger pathways. In primary culture of eel pituitary cells, all four peptides were able to specifically and dose-dependently inhibit lhβ expression, without any effect on fshβ, confirming our previous data with heterologous kisspeptins. Furthermore, in this eel in vitro system, all four peptides inhibited the expression of the type 2 GnRH receptor (gnrh-r2. Our data revealed a dual inhibitory effect of homologous kisspeptins on both pituitary lhβ and gnrh-r2 expression in the European eel.

  15. Hormonal changes over the spawning cycle in the female three-spined stickleback, Gasterosteus aculeatus.

    Science.gov (United States)

    Roufidou, Chrysoula; Schmitz, Monika; Mayer, Ian; Sebire, Marion; Katsiadaki, Ioanna; Shao, Yi Ta; Borg, Bertil

    2018-02-01

    Female three-spined sticklebacks are batch spawners laying eggs in a nest built by the male. We sampled female sticklebacks at different time points, when they were ready to spawn and 6, 24, 48 and 72h post-spawning (hps) with a male. Following spawning, almost all females (15 out of 19) had ovulated eggs again at Day 3 post-spawning (72hps). At sampling, plasma, brain and pituitaries were collected, and the ovary and liver were weighed. Testosterone (T) and estradiol (E2) were measured by radioimmunoassay. Moreover, the mRNA levels of follicle-stimulating hormone (fsh-β) and luteinizing hormone (lh-β) in the pituitary, and of the gonadotropin-releasing hormones (GnRHs: gnrh2, gnrh3) and kisspeptin (kiss2) and its G protein-coupled receptor (gpr54) in the brain were measured by real-time qPCR. Ovarian weights peaked in "ready to spawn" females, dropped after spawning, before again progressively increasing from 6 to 72hps. Plasma T levels showed peaks at 24 and 48hps and decreased at 72hps, while E2 levels increased already at 6hps and remained at high levels up to 48hps. There was a strong positive correlation between T and E2 levels over the spawning cycle. Pituitary lh-β mRNA levels showed a peak at 48hps, while fsh-β did not change. The neuropeptides and gpr54 did not show any changes. The changes in T and E2 over the stickleback spawning cycle were largely consistent with those found in other multiple-spawning fishes whereas the marked correlation between T and E2 does not support T having other major roles over the cycle than being a precursor for E2. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  16. Fertility of Angus cross beef heifers after GnRH treatment on day 23 and timing of insemination in 14-day CIDR protocol.

    Science.gov (United States)

    Kasimanickam, R K; Hall, J B; Whittier, W D

    2017-02-01

    This study compared artificial insemination pregnancy rate (AI-PR) between 14-day CIDR-GnRH-PGF2α-GnRH and CIDR-PGF2α-GnRH synchronization protocol with two fixed AI times (56 or 72 hr after PGF2α). On day 0, heifers (n = 1311) from nine locations assigned body condition score (BCS: 1, emaciated; 9, obese), reproductive tract score (RTS: 1, immature, acyclic; 5, mature, cyclic) and temperament score (0, calm; and 1, excited) and fitted with a controlled internal drug release (CIDR, 1.38 g of progesterone) insert for 14 days. Within herd, heifers were randomly assigned either to no-GnRH group (n = 635) or to GnRH group (n = 676), and heifers in GnRH group received 100 μg of GnRH (gonadorelin hydrochloride, IM) on day 23. All heifers received 25 mg of PGF2α (dinoprost, IM) on day 30 and oestrous detection aids at the same time. Heifers were observed for oestrus thrice daily until AI. Within GnRH groups, heifers were randomly assigned to either AI-56 or AI-72 groups. Heifers in AI-56 group (n = 667) were inseminated at 56 hr (day 32 PM), and heifers in AI-72 group (n = 644) were inseminated at 72 hr (day 33 AM) after PGF2α administration. All heifers were given 100 μg of GnRH concurrently at the time AI. Controlling for BCS (p < .05), RTS (p < .05), oestrous expression (p < .001), temperament (p < .001) and GnRH treatment by time of insemination (p < .001), the AI-PR differed between GnRH treatment [GnRH (Yes - 60.9% (412/676) vs. No - 55.1% (350/635); p < .05)] and insemination time [AI-56 - 54.6% (364/667) vs. AI-72 - 61.8% (398/644); (p < .01)] groups. The GnRH treatment by AI time interaction influenced AI-PR (GnRH56 - 61.0% (208/341); GnRH72 - 60.9% (204/335); No-GnRH56 - 47.9% (156/326); No-GnRH72 - 62.8% (194/309); p < .001). In conclusion, 14-day CIDR synchronization protocol for FTAI required inclusion of GnRH on day 23 if inseminations were to be performed at 56 hr after PGF2α in order to achieve greater AI-PR.

  17. Calcium antagonists for aneurysmal subarachnoid haemorrhage

    NARCIS (Netherlands)

    Dorhout Mees, S. M.; Rinkel, G. J. E.; Feigin, V. L.; Algra, A.; van den Bergh, W. M.; Vermeulen, M.; van Gijn, J.

    2007-01-01

    BACKGROUND: Secondary ischaemia is a frequent cause of poor outcome in patients with subarachnoid haemorrhage (SAH). Its pathogenesis has been incompletely elucidated, but vasospasm probably is a contributing factor. Experimental studies have suggested that calcium antagonists can prevent or reverse

  18. Benzodiazepine receptor antagonists for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Als-Nielsen, B; Gluud, L L; Gluud, C

    2004-01-01

    Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy....

  19. Effects of kisspeptin1 on electrical activity of an extrahypothalamic population of gonadotropin-releasing hormone neurons in medaka (Oryzias latipes).

    Science.gov (United States)

    Zhao, Yali; Wayne, Nancy L

    2012-01-01

    Kisspeptin (product of the kiss1 gene) is the most potent known activator of the hypothalamo-pituitary-gonadal axis. Both kiss1 and the kisspeptin receptor are highly expressed in the hypothalamus of vertebrates, and low doses of kisspeptin have a robust and long-lasting stimulatory effect on the rate of action potential firing of hypophysiotropic gonadotropin releasing hormone-1 (GnRH1) neurons in mice. Fish have multiple populations of GnRH neurons distinguished by their location in the brain and the GnRH gene that they express. GnRH3 neurons located in the terminal nerve (TN) associated with the olfactory bulb are neuromodulatory and do not play a direct role in regulating pituitary-gonadal function. In medaka fish, the electrical activity of TN-GnRH3 neurons is modulated by visual cues from conspecifics,