Sodium intake, brain c-Fos protein and gastric emptying in cell-dehydrated rats treated with methysergide into the lateral parabrachial nucleus

Autor(es)

David, Richard B. ^[1] ; Roncari, Camila F. ^[1] ; Lauar, Mariana R. ^[1] ; Vendramini, Regina C. ^[2] ; Antunes-Rodrigues, Jose ^[3] ; Menani, Jose V. ^[1] ; De Luca, Jr., Laurival A. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, UNESP, Sch Dent, Dept Physiol & Pathol, BR-14801903 Sao Paulo - Brazil

^[2] Sao Paulo State Univ, UNESP, Sch Pharmaceut Sci, Dept Clin Anal, BR-14801903 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-09500900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physiology & Behavior; v. 151, p. 111-120, NOV 1 2015.
• Citações Web of Science: 1

Resumo

Previous studies from our laboratory have shown that methysergide, a serotonergic antagonist, injected into the lateral parabrachial nucleus (LPBN) combined with a pre-load of 2 M NaCl, given by gavage, induces 03 M NaCl intake. The mechanisms involved in this paradoxical behavior are still unknown. In the present work, we investigated the effect of serotonergic blockade into the LPBN on hindbrain and hypothalamic activity, gastric emptying and arterial blood pressure in cell-dehydrated rats. Methysergide plus 2 M NaCl infused intragastrically or intravenously promoted 0.3 M NaCl intake in two-bottle tests. In cell-dehydrated rats with no access to fluids, methysergide compared to vehicle increased Fos immunoreactivity in the medial nucleus of the solitary tract, area postrema and non-oxytocinergic cells of the ventral portion of the hypothalamic paraventricular nucleus (PVN). There was no alteration in the number of neurons double-labeled for Fos-ir and oxytocin in the PVN and supraoptic nuclei. There was also no alteration in plasma oxytocin and vasopressin, or arterial pressure. In rats cell-dehydrated by i.v. 2 M NaCl, methysergide also did not change the amount of an intragastric load of 0.3 M NaCl retained in the stomach or intestine. The results suggest that methysergide injected into the LPBN of cell-dehydrated rat does not alter primary inhibitory signals that control sodium intake. The inhibitory signals blocked by methysergide in the LPBN possibly originated from activation of brain osmoreceptors, second order visceral/hormonal signals or a combination of both. (C) 2015 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 11/50770-1 - Mecanismos neurais de regulação do equilíbrio hidroeletrolítico e controle cardiorrespiratório
• Beneficiário: José Vanderlei Menani
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 10/20407-0 - Interação entre mecanismos facilitatórios e os mecanismos do núcleo parabraquial lateral no controle da ingestão de sódio e secreção de ocitocina
• Beneficiário: Camila Ferreira Roncari
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/05189-4 - Envolvimento do estresse oxidativo e das citocinas pró-inflamatórias na hipertensão
• Beneficiário: Mariana Ruiz Lauar
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 07/54523-3 - Natriorexigenese induzida por desidratacao intracelular: papel do nucleo parabraquial lateral (npbl) na integracao de mecanismos centrais e sistemicos.
• Beneficiário: Richard Boarato David
• Modalidade de apoio: Bolsas no Brasil - Doutorado