Evidence indicates that gonadotropin releasing hormone-1 [GnRH-1, also known as luteinizing hormone releasing hormone (LHRH)] neurons can exhibit synchronized neuroendocrine secretory activity before entrance into the CNS. In this study, we used calcium imaging to evaluate patterns of activity in individual, embryonic, GnRH-1 neurons as well as population dynamics of GnRH-1 neurons in mouse nas...

The amino acid gamma-aminobutyric acid (GABA) plays an important role in the regulation of the GnRH neurons. We examined whether GABA depolarizes or hyperpolarizes GnRH neurons over postnatal development using gramicidin, perforated-patch electrophysiology combined with GnRH-LacZ transgenic mice in whom GnRH neurons can be made to fluoresce. The basic membrane properties and GABA responsiveness...

Gonadotropin-releasing hormone (GnRH) is exclusively expressed in a unique population of hypothalamic neurons that controls reproductive function. GnRH gene expression is highly dynamic. Its transcriptional activity is regulated in a complex spatiotemporal manner during embryonic development and postnatal life. Although a variety of transcription factors have been identified as regulators of Gn...

BACKGROUND Since increased LH in the early follicular phase in PCOS patients especially in GnRH antagonist protocol could be associated with reduced oocyte quality and pregnancy and impared implantation. The current study was conducted to determine ART outcomes in GnRH antagonist protocol (flexible) and long GnRH agonist protocol and compare them with adding GnRH antagonist in GnRH antagonist (...

GnRH acts via GnRH receptors (GnRH-R) in the pituitary to cause the release of gonadotropins that regulate vertebrate reproduction. In the teleost fish, Haplochromis burtoni, reproduction is socially regulated through the hypothalamus-pituitary-gonadal axis, making the pituitary GnRH-R a likely site of action for this control. As a first step toward understanding the role of GnRH-R in the socia...

Objectives of the current studies were to characterize the pattern of GnRH secretion in the cerebrospinal fluid of the bovine third ventricle, determine its correspondence with the tonic and surge release of LH in ovariectomized cows, and examine the dynamics of GnRH pulse generator activity in response to known modulators of LH release (suckling; neuropeptide Y [NPY]). In ovariectomized cows, ...

The effect of immunoneutralization of gonadotropin-releasing hormone (GnRH) on LH secretion and concentrations of GnRH receptor, GnRH receptor mRNA, and gonadotropin subunit mRNA in pituitary tissue of orchidectomized sheep (wethers) was assessed. Thirty-six wethers were assigned at random to one of six treatment groups (six wethers per group). Thirty wethers (groups 2 to 6) received 200 ml, (i...

The aims of this study were (a) to establish the occurrence, duration and intensity of behavioral estrus symptoms, and (b) to determine the relationship between behavioral estrus symptoms with the total estrogen profiles in cycling Murrah buffaloes (n=10) subjected to Doublesynch protocol (0 PGF2α, 2 GnRH, 9 PGF2α and 11 GnRH). After both GnRH injections, estrus and its behavioral signs were de...

We describe the preliminary characterization of GnRH-binding protein(s) in human placental cytosol. Samples were analysed by chromatography on Sephadex G25. Radiolabelled GnRH and its analogues elute significantly later than the total column volume (V(t)) on Sephadex G25 column chromatography. However, incubation of GnRH II or GnRH agonist tracers with human placental cytosol reduced the intact...