Recently, we could show that gonadotropin-releasing hormone (GnRH)-II antagonists induce apoptosis in human endometrial, ovarian, and breast cancer cells in vitro and in vivo. In the present study, we have ascertained receptor binding and effects of GnRH-II antagonists on mitogenic signal transduction and on activation of proapoptotic protein Bax. The GnRH-II antagonists tested showed EC50 valu...

Abstract The objective was to compare pregnancy rates (PR) on day 30 and loss between days 60 (PL) after timed artificial insemination (TAI; 0) using 2 synchronization protocols, plasma progesterone 18 in suckled beef cows. Angus cows were randomly assigned either 7-d CoSynch (7-d P + GnRH) or 8-d estradiol (8-d ES) protocols for TAI. On -10, the GnRH treatment group (n=574) received a progeste...

We have cloned the full-length complementary DNA (cDNA) for a GnRH receptor from Xenopus laevis pituitary cDNA and determined its gene structure. The cDNA encodes a 368-amino acid protein that has a 46% amino acid identity to the human GnRH receptor. The X laevis GnRH receptor has all of the amino acids identified in the mammalian GnRH receptors as sites of interaction with the GnRH ligand. How...

Using the Reverse Transcription-Polymerase Chain Reaction (RT-PCR) technique, the gonadotropin releasing-hormone (GnRH) mRNA and GnRH receptor (GnRH-R) mRNA were analyzed in the preoptic area (POA), anterior (AH) and ventromedial (VM) hypothalamus, stalk/median eminence (SME) and anterior pituitary gland (AP) of anestrous ewes subjected to short or prolonged footshock stimulation. No GnRH gene ...

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...

To investigate the effects of alterations in GnRH pulse frequency on gonadotrophin secretion, we administered low dose GnRH pulses (25 ng/kg) at hourly or 2-hourly frequencies to eight normal men. All subjects received GnRH pulses i.v. every 2 h for 88 h. Following this, exogenous GnRH was discontinued in four normal men (Group A, GnRH withdrawal), and the frequency of GnRH injections was incre...

The presence of gonadotropin-releasing hormone (GnRH)-like protein has been previously demonstrated in the bovine folicle. This GnRH-like protein was purified and concluded to be histone H2A. However. neither GnRH peptide nor specific GnRH-immunoreactivity (GnRH IR) has been demonstrated in the bovine folicIe 50 far. Thus. this study focused 00 the detection of specific GnRH-IR using the second...

The continued presence of gonadotropin-releasing hormone (GnRH) neurons is required for a healthy reproductive lifespan, but factors that maintain postnatal GnRH neurons have not been identified. To begin to understand these factors, we investigated whether 1) fibroblast growth factor (FGF) signaling and 2) interactions with the opposite sex are involved in the maintenance of the postnatal GnRH...

BACKGROUND GnRH agonist was recently suggested as a novel luteal-phase support that may act at different levels, including the pituitary gonadotrophs, the endometrium and the embryo itself. This prospective randomized study evaluates the effect of GnRH agonist administered in the luteal phase on ICSI outcomes in both GnRH agonist- and GnRH antagonist-treated ovarian stimulation protocols. MET...