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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Salt-induced sympathoexcitation involves vasopressin V-1a receptor activation in the paraventricular nucleus of the hypothalamus

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Ribeiro, Natalia [1] ; Panizza, Helena do Nascimento [1] ; dos Santos, Karoline Martins [1] ; Ferreira-Neto, Hildebrando C. [1] ; Antunes, Vagner Roberto [1]
Total Authors: 5
[1] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508900 Sao Paulo, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Web of Science Citations: 10

A high-salt diet can lead to hydromineral imbalance and increases in plasma sodium and osmolality. It is recognized as one of the major contributing factors for cardiovascular diseases such as hypertension. The paraventricular nucleus (PVN) plays a pivotal role in osmotically driven sympathoexcitation and high blood pressure, the precise mechanisms of which are not fully understood. Recent evidence indicates that AVP released from magnocellular neurons might be involved in this process. Using a combination of in vivo and in situ studies, we sought to investigate whether AVP, acting on PVN neurons, can change mean arterial pressure (MAP) and sympathetic nerve activity (SNA) in euhydrated male rats. Furthermore, we wanted to determine whether V-1a receptors on PVN neurons would be involved in salt-induced sympathoexcitation and hypertension. In rats, 4 days of salt loading (NaCl 2%) elicited a significant increase in plasma osmolality (39 +/- 7 mosmol/kgH(2)O), an increase in MAP (26 +/- 2 mmHg, P < 0.001), and sympathoexcitation compared with euhydrated rats. Microinjection of AVP into the PVN of conscious euhydrated animals (100 nl, 3 mu M) elicited a pressor response (14 +/- 2 mmHg) and a significant increase in lumbar SNA (100 nl, 1 mM) (19 +/- 5%). Pretreatment with a V-1a receptor antagonist, microinjected bilaterally into the PVN of salt-loaded animals, elicited a decrease in lumbar SNA (-14 +/- 5%) and MAP (-19 +/- 5 mmHg), when compared with the euhydrated group. Our findings show that AVP plays an important role in modulating the salt-induced sympathoexcitation and high blood pressure, via V-1a receptors, within the PVN of male rats. As such, V-1a receptors in the PVN might contribute to neurogenic hypertension in individuals consuming a high-salt diet. (AU)

FAPESP's process: 13/06206-0 - Gene expression changes of neuropeptides and proinflammatory factors of the hypothalamus and brainstem nucleus involved with cardiovascular regulation in diet-induced obesity animals
Grantee:Vagner Roberto Antunes
Support Opportunities: Regular Research Grants
FAPESP's process: 10/05037-1 - Role of purinergic receptors of paraventricular nucleus of the hypothalamus in the neurogenic hypertension
Grantee:Hildebrando Candido Ferreira Neto
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 10/17997-0 - Purinergic mechanisms at the hypothalamus level on sympathetic outflow and its correlation to neurogenic hypertension
Grantee:Vagner Roberto Antunes
Support Opportunities: Regular Research Grants
FAPESP's process: 09/13047-0 - Role of the autonomic nervous system in the hepatic production of glucose via central action of insulin in hypertensive animals
Grantee:Izabela Martina Ramos Ribeiro de Toledo
Support Opportunities: Scholarships in Brazil - Master