Stimulation of renal afferent fibers leads to activation of catecholaminergic and non-catecholaminergic neurons in the medulla oblongata

Autor(es)

Nishi, Erika E. ; Martins, Beatriz S. ; Milanez, Maycon I. O. ; Lopes, Nathalia R. ; de Melo, Jr., Jose F. ; Pontes, Roberto B. ; Girardi, Adriana C. ; Campos, Ruy R. ; Bergamaschi, Cassia T.

• Tipo de documento: Artigo de Revisão
• Fonte: AUTONOMIC NEUROSCIENCE-BASIC & CLINICAL; v. 204, p. 48-56, MAY 2017.
• Citações Web of Science: 2

Resumo

Presympathetic neurons in the rostral ventrolateral medulla (RVLM) including the adrenergic cell groups play a major role in the modulation of several reflexes required for the control of sympathetic vasomotor tone and blood pressure (BP). Moreover, sympathetic vasomotor drive to the kidneys influence natriuresis and diuresis by inhibiting the cAMP/PKA pathway and redistributing the Na+/H+ exchanger isoform 3 (NHE3) to the body of the microvilli in the proximal tubules. In this study we aimed to evaluate the effects of renal afferents stimulation on (1) the neurochemical phenotype of Fos expressing neurons in the medulla oblongata and (2) the level of abundance and phosphorylation of NHE3 in the renal cortex. We found that electrical stimulation of renal afferents increased heart rate and BP transiently and caused activation of tyrosine hydroxylase (TH)-containing neurons in the RVLM and non-TH neurons in the NTS. Additionally, activation of the inhibitory renorenal reflex over a 30-min period resulted in increased natriuresis and diuresis associated with increased phosphorylation of NHE3 at serine 552, a surrogate for reduced activity of this exchanger, in the contralateral kidney. This effect was not dependent of BP changes considering that no effects on natriuresis or diuresis were found in the ipsilateral-stimulated kidney. Therefore, our data show that renal afferents leads to activation of catecholaminergic and non-catecholaminergic neurons in the medulla oblongata. When renorenal reflex is induced, NHE3 exchanger activity appears to be decreased, resulting in decreased sodium and water reabsorption in the contralateral kidney. (C) 2017 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 13/23741-6 - Avaliação dos mecanismos centrais do reflexo reno-renal e o papel dos nervos aferentes renais na hipertensão renovascular
• Beneficiário: Erika Emy Nishi
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/22522-9 - Papel do nervo simpático renal nas alterações cardiovasculares e renais na hipertensão arterial renovascular
• Beneficiário: Ruy Ribeiro de Campos Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/23858-6 - Efeitos da denervação renal sobre o estresse oxidativo renal na hipertensão renovascular experimental
• Beneficiário: Nathalia Rodrigues Lopes
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 15/23809-5 - Regiões encefálicas envolvidas na regulação do sistema cardiovascular ativadas pelas fibras aferentes renais
• Beneficiário: Beatriz Silva Martins
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica