Warning: Undefined variable $zfal in C:\Inetpub\vhosts\kidney.de\httpdocs\mlpefetch.php on line 525
Deprecated: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated in C:\Inetpub\vhosts\kidney.de\httpdocs\mlpefetch.php on line 525
Warning: Undefined variable $sterm in C:\Inetpub\vhosts\kidney.de\httpdocs\mlpefetch.php on line 530
free
Warning: Undefined variable $sterm in C:\Inetpub\vhosts\kidney.de\httpdocs\mlpefetch.php on line 531
free free
English Wikipedia
Nephropedia Template TP (
Twit Text
DeepDyve Pubget Overpricing |
lüll Recent discoveries on the control of gonadotrophin-releasing hormone neurones in nonhuman primates Terasawa E; Kurian JR; Guerriero KA; Kenealy BP; Hutz ED; Keen KLJ Neuroendocrinol 2010[Jul]; 22 (7): 630-8Since Ernst Knobil proposed the concept of the gonadotrophin-releasing hormone (GnRH) pulse-generator in the monkey hypothalamus three decades ago, we have made significant progress in this research area with cellular and molecular approaches. First, an increase in pulsatile GnRH release triggers the onset of puberty. However, the question of what triggers the pubertal increase in GnRH is still unclear. GnRH neurones are already mature before puberty but GnRH release is suppressed by a tonic GABA inhibition. Our recent work indicates that blocking endogenous GABA inhibition with the GABA(A) receptor blocker, bicuculline, dramatically increases kisspeptin release, which plays an important role in the pubertal increase in GnRH release. Thus, an interplay between the GABA, kisspeptin, and GnRH neuronal systems appears to trigger puberty. Second, cultured GnRH neurones derived from the olfactory placode of monkey embryos exhibit synchronised intracellular calcium, [Ca(2+)](i), oscillations and release GnRH in pulses at approximately 60-min intervals after 14 days in vitro (div). During the first 14 div, GnRH neurones undergo maturational changes from no [Ca(2+)](i) oscillations and little GnRH release to the fully functional state. Recent work also shows GnRH mRNA expression increases during in vitro maturation. This mRNA increase coincides with significant demethylation of a CpG island in the GnRH 5'-promoter region. This suggests that epigenetic differentiation occurs during GnRH neuronal maturation. Third, oestradiol causes rapid, direct, excitatory action in GnRH neurones and this action of oestradiol appears to be mediated through a membrane receptor, such as G-protein coupled receptor 30.|Animals[MESH]|Epigenesis, Genetic[MESH]|Estradiol/metabolism[MESH]|Gonadotropin-Releasing Hormone/genetics/*metabolism[MESH]|Neurons/cytology/*physiology[MESH]|Primates/*anatomy & histology/*metabolism[MESH]|Puberty/physiology[MESH]|Sexual Maturation/physiology[MESH]|Tumor Suppressor Proteins/metabolism[MESH]|gamma-Aminobutyric Acid/metabolism[MESH] |