Endocrine Abstracts

The Kiss1 gene, originally identified as having anti-metastatic properties encodes several overlapping amidated peptides called kisspeptins. Within the last 5 years, kisspeptin signalling has been shown to also play a crucial role in the initiation of puberty and the maintenance of mammalian fertility by signalling through the G-protein coupled receptor GPR54. Five transgenic mouse lines have been generated with mutations in the Gpr54 gene and two lines with muta...

The mammalian reproductive axis is activated at puberty by neuroendocrine events within the hypothalamus that initiate the pulsatile secretion of GnRH. GnRH acts on the anterior pituitary to stimulate production of the gonadotrophic hormones (LH and FSH) which bring about maturation of the gonads. Both naturally occuring and genetically modified mutant mice have provided insights into the molecular events that maintain the function of each part of this reproductive axis. The c...

Activation of the G-protein coupled receptor GPR54 (AXOR12, OT7T175) by peptide ligands (kisspeptins) encoded by the Kiss-1gene is central to acquisition of reproductive competency in mammals. Administration of exogenous kisspeptins stimulates GnRH release from hypothalamic neurons in several species including humans. To confirm that kisspeptins are the natural agonist of GPR54 in vivo and to determine if these ligands have additional physiological functions, we ...

The posterodorsal medial amygdala (MePD) is a neural site in the limbic brain involved in regulating emotional and sexual behaviours. There is however limited information on the specific neuronal cell type in the MePD functionally mediating these behaviours in rodents. The recent discovery of a significant kisspeptin neurone population in the MePD has raised interest in the possible role of kisspeptin and its cognate receptor in sexual be...

The posterodorsal medial amygdala (MePD) is a neural site in the limbic brain involved in regulating emotional and sexual behaviours. There is however limited information on the specific neuronal cell type in the MePD functionally mediating these behaviours in rodents. The recent discovery of a significant kisspeptin neurone population in the MePD has raised interest in the possible role of kisspeptin and its cognate receptor in sexual be...

Coupling the release of pituitary hormones to the developmental stage of the oocyte is essential for female fertility. It requires estrogen to have simultaneous positive and negative feedback effects on spatially-distinct regions of the hypothalamus. However, the mechanistic basis for this differential effect is not known. We have found that negative-feedback is mediated by the nuclear receptor Dax1, which is present in the arcuate hypothalamic nucleus and serves as a ligand-d...

Coupling the release of pituitary hormones to the developmental stage of the oocyte is essential for female fertility. It is thought to require estrogen to have simultaneous positive and negative feedback effects on two spatially-distinct regions of the hypothalamus, the arcuate nucleus and ‘AVPV’ nucleus. However, the mechanistic basis for this differential effect is not known. Therefore, we mapped the genomic binding of the estrogen receptor alpha (ERα) in bot...