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LH surge

A Acharjee, R Chaube, K P Joy
The commercial fish spawning inducer Ovaprim (OVP) containing a salmon gonadotropin-releasing hormone analogue and domperidone (a dopamine receptor-2 antagonist) has been widely used as an effective spawning inducer in artificial breeding of fishes. It induces a preovulatory LH surge resulting in final oocyte maturation (FOM) and ovulation through a mechanism involving a steroidogenic shift to secrete a maturation-inducing steroid (MIS). In the present study, a 0.5μL/g body weight dose of OVP each injected at 0h and 24h intraperitoneally into gravid female catfish, Heteropneustes fossilis resulted in periovulatory changes in gonadotropin (GtH) subunit gene expression and steroid hormone levels...
October 5, 2016: General and Comparative Endocrinology
Katja Czieselsky, Mel Prescott, Robert Porteous, Pauline Campos, Jenny Clarkson, Frederik J Steyn, Rebecca E Campbell, Allan E Herbison
Using a new tail-tip bleeding procedure and a sensitive ELISA, we describe here the patterns of luteinizing hormone (LH) secretion i) throughout the mouse estrous cycle, ii) in ovariectomized mice, iii) in ovariectomized, estradiol-treated mice that model estrogen negative and positive feedback, and iv) in transgenic GNR23 mice that exhibit allele-dependent reductions in GnRH neuron number. Pulsatile LH secretion was evident at all stages of the estrous cycle with LH pulse frequency being approximately one pulse per hour in metestrous, diestrous, and proestrous mice but much less frequent at estrus (<1 pulse/4h)...
October 7, 2016: Endocrinology
Lixian Cheng, Hui Shi, Yan Jin, Xiaoxi Li, Jinshun Pan, Yimei Lai, Yan Lin, Ya Jin, Gaurab Roy, Allan Zhao, Fanghong Li
Adipose tissue plays an important role in regulating female fertility owing to not only its energy stores but also the endocrine actions of secreted adipokines. As one of the adipokines, adiponectin is almost exclusively secreted from the fat and its circulating concentration is paradoxically reduced in obesity. Although recent studies implied a purported positive role of adiponectin in ovarian functions, definitive in vivo evidence has been sorely lacking. We have consistently observed subfertility in female adiponectin null mice, and therefore postulated a protective role of adiponectin in ovarian functions...
October 4, 2016: Endocrinology
Leena Wadhwa, Rupali Khanna, Taru Gupta, Sangeeta Gupta, Sarika Arora, Sumi Nandwani
AIMS AND OBJECTIVE: To evaluate the role of GnRH antagonist in prevention of premature LH surge and increasing pregnancy rates in IUI cycle with mild ovarian hyperstimulation (MOH). STUDY DESIGN: Prospective parallel, randomised controlled study. MATERIAL AND METHODS: Couples diagnosed with unexplained, male factor subfertility and with one or both tubes patent were randomised to receive either a GnRH antagonist (study group) or no intervention (control group)...
October 2016: Journal of Obstetrics and Gynaecology of India
Lorrae Marriott, Michael Zinaman, Keith R Abrams, Michael J Crowther, Sarah Johnson
BACKGROUND: Human chorionic gonadotrophin (hCG) is a marker of early pregnancy. This study sought to determine the possibility of being able to distinguish between healthy and failing pregnancies by utilising patient-associated risk factors and daily urinary hCG levels. METHODS: Data were from a study that collected daily early morning urine samples from women trying to conceive (n=1,505); 250 of whom became pregnant. Data from 129 women who became pregnant (including 44 miscarriages) were included in these analyses...
September 13, 2016: Annals of Clinical Biochemistry
Jorge Rodriguez-Purata, Julian Gingold, Joseph Lee, Michael Whitehouse, Richard Slifkin, Christine Briton-Jones, Alan Copperman, Benjamin Sandler
STUDY QUESTION: Do the reproductive outcomes from the transfer of fully hatched (FH) blastocysts differ from those of not fully hatched (NFH) blastocysts? SUMMARY ANSWER: Biochemical pregnancy rate (BPR), implantation rate (IR), live birth rate (LBR) and early pregnancy loss (EPL) rate are similar in FH and NFH single euploid blastocyst embryo transfers. WHAT IS KNOWN ALREADY: The use of extended culture and PGS often leads to transfer of an embryo that is well developed and frequently FH from the zona pellucida...
September 12, 2016: Human Reproduction
X Tian, K Anthony, Francisco J Diaz
Progesterone production is upregulated in granulosa cells (cumulus and mural) after the LH surge, but the intra-follicular mechanisms regulating this transition are not completely known. Recent findings show that the transition metal chelator, N,N,N',N'-tetrakis-(2-pyridylmethyl)-ethylenediamine (TPEN), impairs ovarian function. In this study, we provide evidence that chelating transition metals, including zinc, enhances progesterone production. The findings show that TPEN (transition metal chelator) increases abundance of Cyp11a1 and Star messenger RNA (mRNA) between 8- and 20-fold and progesterone production more than 3-fold in cultured cumulus-oocyte complexes (COC)...
September 7, 2016: Biological Trace Element Research
Masami Shimizu-Albergine, Brian Van Yserloo, Martin G Golkowski, Shao-En Ong, Joseph A Beavo, Karin E Bornfeldt
Luteinizing hormone (LH) stimulates steroidogenesis largely through a surge in cyclic AMP (cAMP). Steroidogenic rates are also critically dependent on the availability of cholesterol at mitochondrial sites of synthesis. This cholesterol is provided by cellular uptake of lipoproteins, mobilization of intracellular lipid, and de novo synthesis. Whether and how these pathways are coordinated by cAMP are poorly understood. Recent phosphoproteomic analyses of cAMP-dependent phosphorylation sites in MA10 Leydig cells suggested that cAMP regulates multiple steps in these processes, including activation of the SCAP/SREBP pathway...
September 20, 2016: Proceedings of the National Academy of Sciences of the United States of America
Jurate Aleknaviciute, Joke H M Tulen, Mirjam Timmermans, Yolanda B de Rijke, Elisabeth F C van Rossum, Frank H de Jong, Steven A Kushner
STUDY QUESTION: Does adrenocorticotropic hormone (ACTH) induce gonadotropin release in premenopausal women? SUMMARY ANSWER: Administration of ACTH stimulates gonadotropin release, most likely by stimulation of the production of cortisol, in premenopausal women. WHAT IS KNOWN ALREADY: In animal models, acute activation of the hypothalamic-pituitary-adrenal (HPA) axis has been shown to induce gonadotropin release in the presence of sufficiently high estrogen levels...
October 2016: Human Reproduction
Bartosz Pawliński, Małgorzata Domino, Olga Aniołek, Adam Ziecik, Zdzislaw Gajewski
It is widely accepted that uterine contraction is initiated by spontaneous generation of electrical activity at a cellular level in the form of action potentials. Such action potential events, when they involve many myometrial cells and occur in immediate succession, are described by their amplitude and duration. In an effort to improve clinical management of uterine contractions, research has focused on determination of the properties of the reproductive tract's electrical activity under hormonal stimulation...
August 4, 2016: Theriogenology
J Gobernado, C Alvarez-Colomo, L Rodriguez-Tabernero, L Barrero, J M F Fernández-Gómez, J Schneider
BACKGROUND: In Spanish public hospital Reproduction Units it is very problematic to perform programmed intrauterine insemination (IUI) on weekends, if indicated. Small previous pilot studies suggest that using a GnRH antagonist to avoid an LH weekend surge would allow to perform IUI on the following Monday, not impairing the expected pregnancy rate. METHODS: Between 1st January 2007 and 31st December 2015, 4.782 intrauterine inseminations were performed at Valladolid University Clinic, Spain, corresponding to 1...
2016: Reproductive Biology and Endocrinology: RB&E
Cristiane M Leite, Bruna Kalil, Ernane T Uchôa, José Antunes-Rodrigues, Lucila K L Elias, Jon E Levine, Janete A Anselmo-Franci
The time course effects of ovarian steroids on kisspeptin and GnRH/LH systems is not totally clarified. We investigated the temporal relationship among kisspeptin and GnRH mRNA and kisspeptin content in the preoptic area (POA), GnRH content and release in the medial basal hypothalamus (MBH) and plasma LH levels under different steroid treatments. Ovariectomized rats treated with oil (OVOO), oil plus single dose of estradiol (OVOE), oil plus single dose of progesterone (OVOP), estradiol for 3 days plus oil (OVEO) or estradiol for 3 days plus progesterone (OVEP) were hourly decapitated from 10:00 to 17:00 or had the MBH microdialyzed from 09:00 to 19:00...
November 1, 2016: Brain Research
O J Ginther
Selection of the dominant follicle (DF) during a follicular wave is manifested by diameter deviation or continued growth rate of the largest follicle (F1) and decreased growth rate of the next largest follicle (F2) when F1 reaches about 8.5 mm in cattle. The process of deviation in the future DF begins about 12 h before diameter deviation and involves an F1 increase in granulosa LH receptors and estradiol and maintenance of intrafollicular free insulin-like growth factor 1 (IGF1). Thereby, only F1 is developmentally prepared to use the declining FSH in the wave-stimulating FSH surge and to respond to a transient increase in LH to become the DF...
October 2016: Domestic Animal Endocrinology
Pra da Rosa, Amp Dau, M P De Cesaro, J T Dos Santos, B G Gasperin, R Duggavathi, V Bordignon, Pbd Gonçalves
The LH surge induces functional and morphological changes in granulosa cells. Mechanistic target of rapamycin (mTOR) is an integrator of signalling pathways in multiple cell types. We hypothesized that mTOR kinase activity integrates and modulates molecular pathways induced by LH in granulosa cells during the preovulatory period. Cows were ovariectomized and granulosa cells collected at 0, 3, 6, 12 and 24 hr after GnRH injection. While RHEB mRNA levels increased at 3 and 6 hr, returning to basal levels by 12 hr after GnRH treatment, RHOA mRNA levels increased at 6 hr and remained high thereafter...
October 2016: Reproduction in Domestic Animals, Zuchthygiene
O J Ginther, J M Baldrighi, M A R Siddiqui, E R Araujo
Follicle deviation during a follicular wave is a continuation in growth rate of the dominant follicle (F1) and decreased growth rate of the largest subordinate follicle (F2). The reliability of using an F1 of 8.5 mm to represent the beginning of expected deviation for experimental purposes during waves 1 and 2 (n = 26 per wave) was studied daily in heifers. Each wave was subgrouped as follows: standard subgroup (F1 larger than F2 for 2 days preceding deviation and F2 > 7.0 mm on the day of deviation), undersized subgroup (F2 did not attain 7...
November 2016: Theriogenology
Aritro Sen, Michael T Sellix
The internal or circadian timing system is deeply integrated in female reproductive physiology. Considerable details of rheostatic timing function in the neuroendocrine control of pituitary hormone secretion, adenohypophyseal hormone gene expression and secretion, gonadal steroid hormone biosynthesis and secretion, ovulation, implantation, and parturition have been reported. The molecular clock, an autonomous feedback loop oscillator of interacting transcriptional regulators, dictates the timing and amplitude of gene expression in each tissue of the female hypothalamic-pituitary-gonadal (HPG) axis...
September 2016: Endocrinology
Rui Yang, Hongzhen Li, Rong Li, Ping Liu, Jie Qiao
PURPOSE: This study aimed at comparing the effects of different methods of letrozole combined with gonadotropin (Gn) and high-dose Gn ovarian stimulation in antagonist protocol. METHODS: Retrospectively reviewed 220 poor responders from August 2012 to July 2014 at Peking University Third Hospital Reproductive Medical Center. Patients were divided into Group 1 (LZ 5 mg for 5 days sequentially overlapping with Gn cycles; n = 60), group 2 (LZ 7.5 mg for 3 days sequentially with Gn cycles; n = 60), and group 3 (high-dose Gn cycles; n = 100)...
November 2016: Archives of Gynecology and Obstetrics
Marcela Vargas Trujillo, Bruna Kalil, Suresh Ramaswamy, Tony M Plant
The aim of this immunohistochmical study was to evaluate the distribution of kisspeptin neurons in the pre-optic area (POA) of gonadally intact adult male and female rhesus monkeys, and to determine whether imposition of an estradiol (E2) positive feedback signal in the castrate male increased kisspeptin in the POA. Additionally, kisspeptin in POA of the intact female was examined during an LH surge induced prematurely by E2 administered in the early follicular phase. The number of kisspeptin neurons in POA of males and females was similar...
July 25, 2016: Neuroendocrinology
Arnon Gal, Po-Ching Lin, Joseph A Cacioppo, Patrick R Hannon, Megan M Mahoney, Andrew Wolfe, Rodrigo Fernandez-Valdivia, John P Lydon, Carol F Elias, CheMyong Ko
Ovarian steroids, estradiol and progesterone, play central roles in regulating female reproduction by acting as both positive and negative regulators of gonadotropin-releasing hormone (GnRH) secretion in the hypothalamus. Recent studies have identified kisspeptin neurons of the hypothalamus as the target of estrogenic regulation of GnRH secretion. In this study, we aimed to determine the significance of progesterone receptor (PGR) expression in the kisspeptin neurons. To this end, the Pgr gene was selectively ablated in mouse kisspeptin neurons and the reproductive consequence assessed...
2016: PloS One
Lauren M Stein, Chloe W Tullock, Stacy K Mathews, David Garcia-Galiano, Carol F Elias, Willis K Samson, Gina L C Yosten
Sexual maturation and maintenance of reproductive function are regulated by neurohormonal communication between the hypothalamus, pituitary, and gonads (referred to as the HPG axis). Phoenixin (PNX) is a newly identified, endogenous peptide abundantly produced in the hypothalamus and shown to be an important mediator of ovarian cyclicity. However, the underlying mechanisms by which phoenixin functions within the HPG axis are unknown. Previous in vitro studies demonstrated a direct action of PNX on gonadotrophs to potentiate gonadotrophin-releasing hormone (GnRH) induced luteinizing hormone (LH) secretion...
September 1, 2016: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
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