Background: The inverse relationship between GnRH transcript level and GABA neurons activity has suggested that GABA at the hypothalamic level may exert a suppressive effect on subsequent steps of the GnRH biosynthesis. In the present study, we analyzed the effects of GABA type A receptor agonist (muscimol) or antagonist (bicuculline) on molecular mechanisms governing GnRH/LH secretion in follicular-phase sheep.
Methods: ELISA technique was used to investigate the effects of muscimol and/or bicuculline on levels of post-translational products of genes encoding GnRH ligand and GnRH receptor (GnRHR) in the preoptic area (POA), anterior (AH) and ventromedial (VMH) hypothalamus, stalk/median eminence (SME), and GnRHR in the anterior pituitary (AP). Real-time PCR was chosen for determination of the effect of drugs on kisspeptin (Kiss 1) mRNA level in POA and VMH including arcuate nucleus (VMH/ARC), and on Kiss1 receptor (Kiss1r) mRNA abundance in POA-hypothalamic structures. These analyses were supplemented by RIA method for measurement of plasma LH concentration.
Results: The study demonstrated that muscimol and bicuculline significantly decreased or increased GnRH biosynthesis in all analyzed structures, respectively, and led to analogous changes in plasma LH concentration. Similar muscimol- and bicuculline-related alterations were observed in levels of GnRHR. However, the expression of Kiss 1 and Kiss1r mRNAs in selected POA-hypothalamic areas of either muscimol- and bicuculline-treated animals remained unaltered.
Conclusions: Our data suggest that GABAergic neurotransmission is involved in the regulatory pathways of GnRH/GnRHR biosynthesis and then GnRH/LH release in follicular-phase sheep conceivably via indirect mechanisms that exclude involvement of Kiss 1 neurons.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.pharep.2019.02.019 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Ultrasmall Au-GRHa Nanosystem for FL/CT Dual-Mode Imaging-Guided Targeting Photothermal Therapy of Ovarian Cancer.
Anal Chem
January 2025
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
As the most common and lethal cancer of the female gonads, ovarian cancer (OC) has a grave impact on people's health. OC is asymptomatic, insidious in onset, difficult to diagnose and treat, fast-growing, and easy to metastasize and has poor prognosis and high mortality. How to detect OC as early as possible and treat it without side effects has become a challenging medical problem.
View Article and Find Full Text PDFFood intake and the HPT axis in the cichlid fish: The implications of the gut-brain peptide cholecystokinin.
Comp Biochem Physiol A Mol Integr Physiol
January 2025
Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad 580 003, India. Electronic address:
This work aimed to investigate the response of cholecystokinin (CCK) to starvation and its impact on food intake and the reproductive axis of the tilapia Oreochromis mossambicus. The fish subjected to 21 days of starvation showed a significant decrease in CCK immunoreactivity in the hypothalamus, pituitary gland, and intestine. The administration of injections of 0.
View Article and Find Full Text PDFKisspeptin and Neurokinin B: roles in reproductive health.
Physiol Rev
January 2025
Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom.
Kisspeptin and neurokinin B (NKB) play a key role in several physiological processes including in puberty, adult reproductive function including the menstrual cycle, as well as mediating the symptoms of menopause. Infundibular kisspeptin neurons, which co-express NKB, regulate the activity of gonadotropin releasing hormone (GnRH) neurons, and thus the physiological pulsatile secretion of GnRH from the hypothalamus. Outside of their hypothalamic reproductive roles, these peptides are implicated in several physiological functions including sexual behavior and attraction, placental function, and bone health.
View Article and Find Full Text PDFA synthetic cyclic peptide for promoting antigen presentation and immune activation.
NPJ Vaccines
January 2025
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia.
Cyclic peptides are often used as scaffolds for the multivalent presentation of drug molecules due to their structural stability and constrained conformation. We identified a cyclic deca-peptide incorporating lipoamino acids for delivering T helper and B cell epitopes against group A Streptococcus (GAS), eliciting robust humoral immune responses. In this study, we assessed the function-immunogenicity relationship of the multi-component vaccine candidate (referred to as VC-13) to elucidate a mechanism of action.
View Article and Find Full Text PDFIs There a Role for Hormonal Therapy in Men with Oligoasthenoteratozoospermia (OAT)?
J Clin Med
December 2024
Global Andrology Forum, Moreland Hills, OH 44022, USA.
Hormonal factors play an essential role as an underlying causative factor of oligoasthenoteratozoospermia (OAT), and these patients can benefit from hormonal medications that modulate the hypothalamic-pituitary-gonadal axis. This review aims to outline the various medications used as hormonal therapy in treating infertile men with OAT. This manuscript focuses on essential hormonal evaluation, identifying men who would benefit from treatment, selecting the appropriate medication, determining the duration of therapy, and evaluating hormonal treatment outcomes.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!