scholarly journals p53 Mediates GnRH Secretion via Lin28/let-7 System in GT1-7 Cells

2020 ◽  
Vol Volume 13 ◽  
pp. 4681-4688
Author(s):  
Ting Chen ◽  
Haiying Wu ◽  
Xiuli Chen ◽  
Rongrong Xie ◽  
Fengyun Wang ◽  
...  
Keyword(s):  
Gnrh Secretion

Pulsatile GnRH secretion from primary cultures of sheep olfactory placode explants

Reproduction ◽  
2000 ◽  
pp. 391-396 ◽  
Author(s):  
AH Duittoz ◽  
M Batailler
Keyword(s):  
Culture Medium ◽  
Primary Cultures ◽  
Pulsatile Secretion ◽  
Olfactory Placode ◽  
Gnrh Secretion ◽  
Individual Culture ◽  
Pulsatile Gnrh

The aim of this study was to investigate the development of pulsatile GnRH secretion by GnRH neurones in primary cultures of olfactory placodes from ovine embryos. Culture medium was collected every 10 min for 8 h to detect pulsatile secretion. In the first experiment, pulsatile secretion was studied in two different sets of cultures after 17 and 24 days in vitro. In the second experiment, a set of cultures was tested after 10, 17 and 24 days in vitro to investigate the development of pulsatile GnRH secretion in each individual culture. This study demonstrated that (i) primary cultures of GnRH neurones from olfactory explants secreted GnRH in a pulsatile manner and that the frequency and mean interpulse duration were similar to those reported in castrated ewes, and (ii) pulsatile secretion was not present at the beginning of the culture but was observed between 17 and 24 days in vitro, indicating the maturation of individual neurones and the development of their synchronization.

Gonadal steroids effect similar regulation of gonadotrophin subunit mRNA expression in both male and female rats

1992 ◽  
Vol 132 (1) ◽  
pp. 39-45 ◽  
Author(s):  
A. C. Dalkin ◽  
S. J. Paul ◽  
D. J. Haisenleder ◽  
G. A. Ortolano ◽  
M. Yasin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Steady State ◽  
Gnrh Antagonist ◽  
Gonadal Steroids ◽  
Female Rats ◽  
Plasma Testosterone ◽  
Subunit Gene ◽  
Gnrh Secretion ◽  
Male And Female Rats ◽  
Males And Females

ABSTRACT Gonadal steroids can act both indirectly via gonadotrophin-releasing hormone (GnRH) and directly on the pituitary to regulate gonadotrophin subunit gene expression. Recent studies to assess a possible direct action at the pituitary have shown that testosterone, when given to males in the absence of endogenous GnRH action, selectively increases FSH-β mRNA concentrations. Conversely, in females, oestradiol appears to regulate gonadotrophin subunit mRNAs primarily via GnRH. The present study was designed to determine whether these differing results reflect specific actions of the gonadal steroids themselves or different responses of the pituitary gonadotroph cells in males and females. Rats which had been castrated 7 days earlier were given silicone elastomer implants (s.c.) containing oestradiol (plasma oestradiol 68 ± 4 ng/l) in males or testosterone (plasma testosterone 3·5 ± 0·3 μg/l) in females in the absence or presence of a GnRH antagonist. Seven days later pituitaries were removed and steady-state mRNA concentrations measured by dotblot hybridization. In males, oestradiol reduced LH-β and FSH-β but not α mRNA. The antagonist reduced levels of all three subunit mRNAs in males and the addition of oestradiol had no further effect, suggesting that oestradiol regulates gonadotrophin subunit gene expression in males by suppressing GnRH secretion. In females, testosterone reduced all three subunit mRNAs though FSH-β remained threefold higher than in intact animals. The GnRH antagonist was as effective as testosterone alone and reduced α and LH-β to levels found in intact animals. FSH-β mRNA was partially reduced by antagonist alone in ovariectomized females but the addition of testosterone increased FSH-β twofold versus antagonist alone (as has been observed in males). These findings, together with earlier data, suggest that testosterone increased FSH-β twofold versus antagonist alone (as has been observed in males). These findings, together with earlier data, suggest that testosterone reduces gonadotrophin subunit mRNAs by inhibiting GnRH secretion and also acts directly on the gonadotroph to increase steady-state FSH-β mRNA concentrations in both males and females. Journal of Endocrinology (1992) 132, 39–45

Interplay of KNDy and nNOS neurons: A new possible mechanism of GnRH secretion in the adult brain

2021 ◽  
Vol 21 (4) ◽  
pp. 100558
Author(s):  
Vikash Prashar ◽  
Tania Arora ◽  
Randeep Singh ◽  
Arti Sharma ◽  
Jyoti Parkash
Keyword(s):  
Adult Brain ◽  
Gnrh Secretion

scholarly journals Minireview: The Neuroendocrine Regulation of Puberty: Is the Time Ripe for a Systems Biology Approach?

Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1166-1174 ◽  
Author(s):  
Sergio R. Ojeda ◽  
Alejandro Lomniczi ◽  
Claudio Mastronardi ◽  
Sabine Heger ◽  
Christian Roth ◽  
...  
Keyword(s):  
Global Analysis ◽  
Single Gene ◽  
Functional Integration ◽  
Cell Communication ◽  
Cell Interaction ◽  
Specific Cell ◽  
Gnrh Secretion ◽  
Cell Functions ◽  
Hierarchical Arrangement ◽  
Cell Cell

The initiation of mammalian puberty requires an increase in pulsatile release of GnRH from the hypothalamus. This increase is brought about by coordinated changes in transsynaptic and glial-neuronal communication. As the neuronal and glial excitatory inputs to the GnRH neuronal network increase, the transsynaptic inhibitory tone decreases, leading to the pubertal activation of GnRH secretion. The excitatory neuronal systems most prevalently involved in this process use glutamate and the peptide kisspeptin for neurotransmission/neuromodulation, whereas the most important inhibitory inputs are provided by γ-aminobutyric acid (GABA)ergic and opiatergic neurons. Glial cells, on the other hand, facilitate GnRH secretion via growth factor-dependent cell-cell signaling. Coordination of this regulatory neuronal-glial network may require a hierarchical arrangement. One level of coordination appears to be provided by a host of unrelated genes encoding proteins required for cell-cell communication. A second, but overlapping, level might be provided by a second tier of genes engaged in specific cell functions required for productive cell-cell interaction. A third and higher level of control involves the transcriptional regulation of these subordinate genes by a handful of upper echelon genes that, operating within the different neuronal and glial subsets required for the initiation of the pubertal process, sustain the functional integration of the network. The existence of functionally connected genes controlling the pubertal process is consistent with the concept that puberty is under genetic control and that the genetic underpinnings of both normal and deranged puberty are polygenic rather than specified by a single gene. The availability of improved high-throughput techniques and computational methods for global analysis of mRNAs and proteins will allow us to not only initiate the systematic identification of the different components of this neuroendocrine network but also to define their functional interactions.

scholarly journals Neonatal Immunization against Gonadotropin-Releasing Hormone (GnRH) Results in Diminished GnRH Secretion in Adulthood

Endocrinology ◽  
1998 ◽  
Vol 139 (4) ◽  
pp. 2007-2014 ◽  
Author(s):  
I. J. Clarke ◽  
B. W. Brown ◽  
V. V. Tran ◽  
C. J. Scott ◽  
R. Fry ◽  
...  
Keyword(s):  
Gonadotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Gnrh Secretion

scholarly journals Endogenous circannual rhythm in luteinizing hormone secretion: insight from signal analysis coupled with mathematical modelling

2009 ◽  
Vol 367 (1908) ◽  
pp. 4759-4777 ◽  
Author(s):  
Alexandre Vidal ◽  
Claire Médigue ◽  
Benoît Malpaux ◽  
Frédérique Clément
Keyword(s):  
Luteinizing Hormone ◽  
Day Length ◽  
Ovarian Activity ◽  
Circannual Rhythm ◽  
Time Frequency ◽  
Gnrh Secretion ◽  
Plasmatic Level ◽  
Lh Secretion ◽  
Experimental Sampling ◽  
Sampling Times

In sheep, as in many vertebrates, the seasonal pattern of reproduction is timed by the annual photoperiodic cycle, characterized by seasonal changes in the day length. The photoperiodic information is translated into a circadian profile of melatonin secretion. After multiple neuronal relays (within the hypothalamus), melatonin affects gonadotrophin-releasing hormone (GnRH) secretion, which in turn controls ovarian cyclicity. The pattern of GnRH secretion is mirrored by that of luteinizing hormone (LH) secretion, whose plasmatic level can be easily measured. We addressed the question of whether there exists an endogenous circannual rhythm in a tropical sheep (Blackbelly) population that exhibits clear seasonal ovarian activity when ewes are subject to temperate latitudes. We based our analysis on LH time series collected in the course of 3 years from ewes subject to a constant photoperiodic regime. Owing to intra- and interanimal variability and unequal sampling times, the existence of an endogenous rhythm is not straightforward. We have used time–frequency signal processing methods, and especially the smooth pseudo-Wigner–Ville distribution, to extract possible hidden rhythms from the data. To further investigate the low-frequency (LF) and high-frequency (HF) components of the signals, we have designed a simple mathematical model of the LH plasmatic level accounting for the effect of experimental sampling times. The model enables us to (i) confirm the existence of an endogenous circannual rhythm as detected by the LF signal component, (ii) investigate the action mechanism of the photoperiod on the pulsatile pattern of LH secretion (control of the interpulse interval), and (iii) conclude that the HF component is mainly due to the experimental sampling protocol.

The m6A mRNA demethylase FTO regulates GnRH secretion in Mn-induced precocious puberty

2021 ◽  
pp. 111523
Author(s):  
Xinxin Yang ◽  
Zhipeng Qi ◽  
Haibo Yang ◽  
Jiashuo Li ◽  
Yanan Liu ◽  
...  
Keyword(s):  
Precocious Puberty ◽  
Gnrh Secretion
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