Salt-loading (SL) impairs GABA inhibition of arginine vasopressin (AVP) neurones in the supraoptic nucleus (SON) of the hypothalamus. Based on previous studies, we hypothesised that SL activates tyrosine receptor kinase B (TrkB), down-regulating the activity of K /Cl co-transporter2 (KCC2) and up-regulating Na /K /Cl co-transporter1 (NKCC1). These changes in chloride transport would result in increased [Cl ] in SON AVP neurones. The study combined virally-mediated chloride imaging with ClopHensorN with a single-cell western blot analysis. An adeno-associated virus with ClopHensorN and a vasopressin promoter (AAV2-0VP1-ClopHensorN) was bilaterally injected in the SON of adult male Sprague-Dawley rats that were either euhydrated (Eu) or salt-loaded (SL) for 7 days. Acutely dissociated SON neurones expressing ClopHensorN were tested for decreases or increases in [Cl ] in response to focal application of the GABA agonist muscimol (100 μmol L ). SON AVP neurones from Eu rats showed muscimol-induced chloride influx (P < 0.05;23/35). SON AVP neurones from SL rats either significantly increased chloride efflux (P < 0.05;27/39) or did not change chloride flux (12/39). The SON AVP neurones that responded to muscimol appeared to be viable and expressed KCC2 and β-actin. Neurones that did not respond during chloride imaging did not show KCC2 and β-actin protein expression. The KCC2 antagonist (VU0240551,10 μmol L ) significantly blocked the chloride influx in cells from Eu rats but did not affect cells from SL rats. A NKCC1 antagonist (bumetanide,10 μmol L ) significantly blocked the chloride efflux in cells from SL rats but had no effect on cells from Eu rats. Blocking NKCC1 using bumetanide had less of an effect on the muscimol-induced Cl influx in Eu rat neurones compared to the KCC2 antagonist. The TrkB antagonist (AnA-12) (50 μmol L ) and protein kinase inhibitor (K252a) (100 nmol L ) each significantly blocked chloride efflux in SON AVP neurones from SL rats. Salt-loading increases [Cl ] in SON AVP neurones via a TrKB-KCC2-NKCC1-dependent mechanism in rats.
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http://dx.doi.org/10.1111/jne.12752 | DOI Listing |
Int J Mol Sci
December 2024
Department of Experimental and Clinical Physiology, Centre for Preclinical Research, Medical University of Warsaw, 02-097 Warsaw, Poland.
Numerous compounds involved in the regulation of the cardiovascular system are also engaged in the control of metabolism. This review gives a survey of literature showing that arginine vasopressin (AVP), which is an effective cardiovascular peptide, exerts several direct and indirect metabolic effects and may play the role of the link adjusting blood supply to metabolism of tissues. Secretion of AVP and activation of AVP receptors are regulated by changes in blood pressure and body fluid osmolality, hypoxia, hyperglycemia, oxidative stress, inflammation, and several metabolic hormones; moreover, AVP turnover is regulated by insulin.
View Article and Find Full Text PDFbioRxiv
December 2024
Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount Sinai, New York, NY 10029.
Vasopressin (AVP), a nonapeptide synthesized predominantly by magnocellular hypothalamic neurons, is conveyed to the posterior pituitary the pituitary stalk, where AVP is secreted into the circulation. Known to regulate blood pressure and water homeostasis, it also modulates diverse social behaviors, such as pair-bonding, social recognition and cognition in mammals including humans. Importantly, AVP modulates social behaviors in a gender-specific manner, perhaps, due to gender differences in the distribution in the brain of AVP and its main receptor AVPR1a.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2025
Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan. Electronic address:
Pain is a major non-motor symptom of Parkinson's disease (PD). The relationship between hyperalgesia and neuropeptides originating from paraventricular nucleus (PVN) in 6-hydroxydopamine (6-OHDA) rats has already been investigated for oxytocin (OXT), but not yet for arginine vasopressin (AVP) and corticotropin-releasing hormone (CRH). The present study aimed to investigate the alterations in these neuropeptides following nociceptive stimulation in PD model rats and to examine the mechanisms of hyperalgesia.
View Article and Find Full Text PDFPLoS Comput Biol
December 2024
Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America.
Transcranial magnetic stimulation (TMS) is a non-invasive, FDA-cleared treatment for neuropsychiatric disorders with broad potential for new applications, but the neural circuits that are engaged during TMS are still poorly understood. Recordings of neural activity from the corticospinal tract provide a direct readout of the response of motor cortex to TMS, and therefore a new opportunity to model neural circuit dynamics. The study goal was to use epidural recordings from the cervical spine of human subjects to develop a computational model of a motor cortical macrocolumn through which the mechanisms underlying the response to TMS, including direct and indirect waves, could be investigated.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
November 2024
State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University, 550004 Guiyang, Guizhou, China.
Background: To explore the therapeutic role of arginine vasopressin (AVP) and its possible mechanisms in autism.
Methods: Mid-trimester pregnant rats treated with valproate on embryonic day 12.5 and their offspring were selected as autism model.
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