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 ...

Stimulation of pituitary gonadotropes by hypothalamic GnRH leads to the rapid expression of several immediate early genes that play key roles in orchestrating the response of the gonadotrope to hypothalamic stimuli. Elucidation of the signaling mechanisms that couple the GnRH receptor to this immediate early gene repertoire is critical for understanding the molecular basis of GnRH action. Here ...

Gonadotrophin-releasing hormone (GnRH) neurones constitute the final output pathway of a neuronal network that controls the preovulatory luteinising hormone (LH) surge and ovulation. Throughout the reproductive cycle, several neurotransmitters stimulate and inhibit the activity of GnRH neurones, including oxytocin. The central administration of oxytocin antiserum abolishes the pro-oestrous LH s...

BACKGROUND AND OBJECTIVES The aim of this study was to compare the in vitro fertilization (IVF) outcomes of long gonadotropin-releasing hormone agonist (GnRH-a) and GnRH-antagonist (GnRH-ant) protocols in endometriosis patients who have undergone laparoscopic endometrioma resection surgery. To our knowledge, there is no study in the current literature that compares the effectiveness of long GnR...

This article is a systematic review of the literature on utilization of gonadotrophin-releasing hormone antagonists (GnRH-ant) for ovarian stimulation for IVF in special patient groups. Summarized by meta-analysis are the data from randomized controlled trials (RCT) in which GnRH-agonist (GnRH-a) and GnRH-ant were compared (eight RCT for poor response, four RCT for PCOS). Also reviewed are the ...

To address whether gonadotropin-releasing hormone (GnRH) regulates its own expression and the expression of its receptor in the hypothalamus and ovary, we treated five groups of prepubertal/peripubertal female rats from postnatal days 25-36 with either the GnRH agonist triptorelin (TRIP) or the GnRH antagonist cetrorelix (CET), each 10 or 100 microgram/day, or a placebo. We compared their effec...

We examined the time course of action of GnRH pulse frequency on gonadotropin subunit gene transcription and assessed the roles of GnRH, follistatin (FS), and activin on differential transcription of the LHbeta and FSHbeta genes. GnRH-deficient male rats were pulsed with 25 ng GnRH either every 30 min (fast frequency) or every 240 min (slow frequency) for 1-24 h. Both GnRH frequencies increased...

Hypothalamic GnRH (GnRH-I) is known and named for its role in regulating reproductive function in vertebrates by controlling release of gonadotropins from the pituitary. However, another form of GnRH of unknown function (pGlu-His-Trp-Ser-His-Gly-Trp-Tyr-Pro-Gly; GnRH-II) is expressed in the mesencephalon of all vertebrate classes except jawless fish. Here we show with immunocytochemical stainin...

abstract 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...

In vertebrates, gonadotropin-releasing hormone (GnRH) is a crucial decapeptide that activates the hypothalamic-pituitary-gonadal axis to ensure successful reproduction. Recently, a GnRH-like molecule has been isolated from a gastropod mollusk, Aplysia californica. This GnRH (ap-GnRH) is deduced to be an undecapeptide, and its function remains to be explored. Our previous study demonstrated that...