scholarly journals The influence of sGnRH-A and antidopaminergic drug – pimozide – on prolactin mRNA synthesis in female Prussian carp (Carassius gibelio Bloch) in vivo

2013 ◽  
Vol 58 (No. 1) ◽  
pp. 31-36
Author(s):  
J. Chyb ◽  
M. Socha ◽  
P. Szczerbik ◽  
M. Sokolowska-Mikolajczyk ◽  
T. Mikołajczyk ◽  
...  
Keyword(s):  
Gonadotropin Releasing Hormone ◽  
Inhibitory Influence ◽  
Mrna Levels ◽  
Mrna Synthesis ◽  
Releasing Hormone ◽  
Prussian Carp ◽  
Carassius Gibelio ◽  
Prolactin Synthesis ◽  
Prolactin Mrna

Effects of salmon gonadotropin releasing hormone analogue (sGnRH-A) and antidopaminergic drug, pimozide, on the synthesis of prolactin mRNA in vivo in female Prussian carp (Carassius gibelio Bloch) during two different stages of the reproductive cycle were evaluated. The results showed that the lowest dose of sGnRH-A (5 μg/kg body weight) significantly stimulated the mRNA synthesis in fish during the recrudescence as well as during the preovulatory period, higher doses of this compound having no significant effect on prolactin mRNA synthesis. The blocker of dopamine receptors, pimozide, also potentiated prolactin mRNA synthesis – in recrudescent females it increased mRNA levels at the dose of 1 mg/kg, while in the preovulatory period all of the used pimozide doses (1, 5, and 10 mg/kg) were responsible for the increase of prolactin mRNA levels. Taken together, the above results suggest that gonadotropin releasing hormone (GnRH) is the factor responsible for the stimulation of prolactin synthesis, while dopamine has an inhibitory influence on the prolactin production.  

scholarly journals Regulation of gonadotropin-releasing hormone-1 gene transcription by members of the purine-rich element-binding protein family

2010 ◽  
Vol 298 (3) ◽  
pp. E524-E533 ◽  
Author(s):  
Sheng Zhao ◽  
Robert J. Kelm ◽  
Russell D. Fernald
Keyword(s):  
Gene Transcription ◽  
Peptide Mapping ◽  
Cichlid Fish ◽  
Gonadotropin Releasing Hormone ◽  
Protein Family ◽  
Upstream Region ◽  
Mrna Levels ◽  
Releasing Hormone

Gonadotropin-releasing hormone-1 (GnRH1) controls reproduction by stimulating the release of gonadotropins from the pituitary. To characterize regulatory factors governing GnRH1 gene expression, we employed biochemical and bioinformatics techniques to identify novel GnRH1 promoter-binding proteins from the brain of the cichlid fish, Astatotilapia burtoni ( A. burtoni ). Using an in vitro DNA-binding assay followed by mass spectrometric peptide mapping, we identified two members of the purine-rich element-binding (Pur) protein family, Purα and Purβ, as candidates for GnRH1 promoter binding and regulation. We found that transcripts for both Purα and Purβ colocalize in GnRH1-expressing neurons in the preoptic area of the hypothalamus in A. burtoni brain. Furthermore, we confirmed in vivo binding of endogenous Purα and Purβ to the upstream region of the GnRH1 gene in A. burtoni brain and mouse neuronal GT1–7 cells. Consistent with the relative promoter occupancy exhibited by endogenous Pur proteins, overexpression of Purβ, but not Purα, significantly downregulated GnRH1 mRNA levels in transiently transfected GT1–7 cells, suggesting that Purβ acts as a repressor of GnRH1 gene transcription.

Time- and dose-related effects of gonadotropin-releasing hormone on growth hormone and gonadotropin subunit gene expression in the goldfish pituitary

2002 ◽  
Vol 80 (9) ◽  
pp. 915-924 ◽  
Author(s):  
Christian Klausen ◽  
John P Chang ◽  
Hamid R Habibi
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Gonadotropin Releasing Hormone ◽  
Molecular Forms ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Induced Responses ◽  
Releasing Hormone ◽  
Significant Difference

The goldfish brain contains two molecular forms of gonadotropin-releasing hormone (GnRH): salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II). In a preliminary report, we demonstrated the stimulation of gonadotropin hormone (GtH) subunit and growth hormone (GH) mRNA levels by a single dose of GnRH at a single time point in the goldfish pituitary. Here we extend the work and demonstrate time- and dose-related effects of sGnRH and cGnRH-II on GtH subunit and GH gene expression in vivo and in vitro. The present study demonstrates important differences between the time- and dose-related effects of sGnRH and cGnRH-II on GtH subunit and GH mRNA levels. Using primary cultures of dispersed pituitary cells, the minimal effective dose of cGnRH-II required to stimulate GtH subunit mRNA levels was found to be 10-fold lower than that of sGnRH. In addition, the magnitudes of the increases in GtH subunit and GH mRNA levels stimulated by cGnRH-II were found to be higher than the sGnRH-induced responses. However, no significant difference was observed between sGnRH and cGnRH-II-induced responses in vivo. Time-related studies also revealed significant differences between sGnRH- and cGnRH-II-induced production of GtH subunit and GH mRNA in the goldfish pituitary. In general, the present study provides novel information on time- and dose-related effects of sGnRH and cGnRH-II on GtH subunit and GH mRNA levels and provides a framework for further investigation of GnRH mechanisms of action in the goldfish pituitary.Key words: gonadotropin-releasing hormone, gonadotropin hormone, growth hormone, gene expression, goldfish.

In vivo action of a new octadecaneuropeptide antagonist on neuropeptide Y and corticotropin-releasing hormone mRNA levels in rat

2005 ◽  
Vol 141 (2) ◽  
pp. 156-160 ◽  
Author(s):  
V. Compère ◽  
S. Li ◽  
J. Leprince ◽  
M.C. Tonon ◽  
H. Vaudry ◽  
...  
Keyword(s):  
Neuropeptide Y ◽  
Mrna Levels ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone

scholarly journals Hexarelin exerts neuroprotective and antioxidant effects against hydrogen peroxide-induced toxicity through the modulation of MAPK and PI3K/Akt patways in Neuro-2A cells

2020 ◽  
Author(s):  
Ramona Meanti ◽  
Laura Rizzi ◽  
Elena Bresciani ◽  
Laura Molteni ◽  
Vittorio Locatelli ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Apoptotic Cell ◽  
Neuroblastoma Cell ◽  
Neuroblastoma Cell Line ◽  
Inhibitory Influence ◽  
No Production ◽  
Mrna Levels

AbstractHexarelin, a synthetic hexapeptide, protects cardiac and skeletal muscles by inhibiting apoptosis, both in vitro and in vivo. Moreover, evidence suggests that hexarelin could have important neuroprotective bioactivity.Oxidative stress and the generation of free radicals has been implicated in the etiologies of several neurodegenerative diseases, including amyotrophic lateral sclerosis, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease and multiple sclerosis. In addition to direct oxidative stress, exogenous hydrogen peroxide (H2O2) can penetrate biological membranes and enhance the formation of other reactive oxygen species.The aim of this study was to examine the inhibitory influence of hexarelin on H2O2-induced apoptosis in Neuro-2A cells, a mouse neuroblastoma cell line. Our results indicate that H2O2 reduced the viability of Neuro-2A cells in a dose-related fashion. Furthermore, H2O2 induced significant changes in the morphology of Neuro-2A cells, reflected in the formation of apoptotic cell bodies, and an increase of nitric oxide (NO) production. Hexarelin effectively antagonized H2O2 oxidative damage to Neuro-2A cells as indicated by improved cell viability, normal morphology and reduced nitrite (NO2−) release. Hexarelin treatment of Neuro-2A cells also reduced mRNA levels of caspases−3 and −7 and those of the pro-apoptotic molecule Bax; by contrast, hexarelin treatment increased anti-apoptotic Bcl-2 mRNA levels. Hexarelin also reduced MAPKs phosphorylation induced by H2O2 and concurrently increased p-Akt protein expression.In conclusion, our results identify several neuroprotective and anti-apoptotic effects of hexarelin. These properties suggest that further investigation of hexarelin as a neuroprotective agent in an investigational and therapeutic context are merited.

scholarly journals Live View of Gonadotropin-Releasing Hormone Containing Neuron Migration

Endocrinology ◽  
2005 ◽  
Vol 146 (1) ◽  
pp. 463-468 ◽  
Author(s):  
Elizabeth P. Bless ◽  
Heather J. Walker ◽  
Kwok W. Yu ◽  
J. Gabriel Knoll ◽  
Suzanne M. Moenter ◽  
...  
Keyword(s):  
Real Time ◽  
Direct Evidence ◽  
Gonadotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Reproductive Axis ◽  
Gnrh Neurons ◽  
Migratory Route ◽  
The Brain

Neurons that synthesize GnRH control the reproductive axis and migrate over long distances and through different environments during development. Prior studies provided strong clues for the types of molecules encountered and movements expected along the migratory route. However, our studies provide the first real-time views of the behavior of GnRH neurons in the context of an in vitro preparation that maintains conditions comparable to those in vivo. The live views provide direct evidence of the changing behavior of GnRH neurons in their different environments, showing that GnRH neurons move with greater frequency and with more changes in direction after they enter the brain. Perturbations of guiding fibers distal to moving GnRH neurons in the nasal compartment influenced movement without detectable changes in the fibers in the immediate vicinity of moving GnRH neurons. This suggests that the use of fibers by GnRH neurons for guidance may entail selective signaling in addition to mechanical guidance. These studies establish a model to evaluate the influences of specific molecules that are important for their migration.

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