eprintid: 10163033 rev_number: 10 eprint_status: archive userid: 699 dir: disk0/10/16/30/33 datestamp: 2023-01-12 09:39:56 lastmod: 2024-01-04 16:24:09 status_changed: 2023-01-12 09:39:56 type: article metadata_visibility: show sword_depositor: 699 creators_name: Martins Sá, Renato W creators_name: Theparambil, Shefeeq M creators_name: Dos Santos, Karoline Martins creators_name: Christie, Isabel N creators_name: Marina, Nephtali creators_name: Cardoso, Barbara V creators_name: Hosford, Patrick S creators_name: Antunes, Vagner R title: Salt-loading promotes extracellular ATP release mediated by glial cells in the hypothalamic paraventricular nucleus of rats ispublished: pub divisions: UCL divisions: B02 divisions: C10 divisions: D17 keywords: Adenosine, Astrocytes, ATP, Hypothalamus, Salt-loading note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: Previously, we have shown that purinergic signalling is involved in the control of hyperosmotic-induced sympathoexcitation at the level of the PVN, via activation of P2X receptors. However, the source(s) of ATP that drives osmotically-induced increases in sympathetic outflow remained undetermined. Here, we tested the two competing hypotheses that either (1) higher extracellular ATP in PVN during salt loading (SL) is a result of a failure of ectonucleotidases to metabolize ATP; and/or (2) SL can stimulate PVN astrocytes to release ATP. Rats were salt loaded with a 2 % NaCl solution replacing drinking water up to 4 days, an experimental model known to cause a gradual increase in blood pressure and plasma osmolarity. Immunohistochemical assessment of glial-fibrillary acidic protein (GFAP) revealed increased glial cell reactivity in the PVN of rats after 4 days of high salt exposure. ATP and adenosine release measurements via biosensors in hypothalamic slices showed that baseline ATP release was increased 17-fold in the PVN while adenosine remained unchanged. Disruption of Ca2+-dependent vesicular release mechanisms in PVN astrocytes by virally-driven expression of a dominant-negative SNARE protein decreased the release of ATP. The activity of ectonucleotidases quantified in vitro by production of adenosine from ATP was increased in SL group. Our results showed that SL stimulates the release of ATP in the PVN, at least in part, from glial cells by a vesicle-mediated route and likely contributes to the neural control of circulation during osmotic challenges. date: 2023-03 date_type: published publisher: Elsevier official_url: https://doi.org/10.1016/j.mcn.2022.103806 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1999355 doi: 10.1016/j.mcn.2022.103806 medium: Print-Electronic pii: S1044-7431(22)00112-9 lyricists_name: Marina-Gonzalez, Nephtali lyricists_id: NGMAR80 actors_name: Flynn, Bernadette actors_id: BFFLY94 actors_role: owner full_text_status: public publication: Molecular and Cellular Neuroscience volume: 124 article_number: 103806 event_location: United States issn: 1044-7431 citation: Martins Sá, Renato W; Theparambil, Shefeeq M; Dos Santos, Karoline Martins; Christie, Isabel N; Marina, Nephtali; Cardoso, Barbara V; Hosford, Patrick S; Martins Sá, Renato W; Theparambil, Shefeeq M; Dos Santos, Karoline Martins; Christie, Isabel N; Marina, Nephtali; Cardoso, Barbara V; Hosford, Patrick S; Antunes, Vagner R; - view fewer <#> (2023) Salt-loading promotes extracellular ATP release mediated by glial cells in the hypothalamic paraventricular nucleus of rats. Molecular and Cellular Neuroscience , 124 , Article 103806. 10.1016/j.mcn.2022.103806 <https://doi.org/10.1016/j.mcn.2022.103806>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10163033/1/1-s2.0-S1044743122001129-main.pdf