Melatonin attenuates renal sympathetic overactivity and reactive oxygen species in the brain in neurogenic hypertension

Autor(es)

Nishi, Erika E. ^[1] ; Almeida, Vitor R. ^[1] ; Amaral, Fernanda G. ^[1] ; Simon, Karin A. ^[2] ; Futuro-Neto, Henrique A. ^[3] ; Pontes, Roberto B. ^[1] ; Cespedes, Juliana G. ^[4] ; Campos, Ruy R. ^[1] ; Bergamaschi, Cassia T. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Escola Paulista Med, Dept Physiol, Campus Sao Paulo, Sao Paulo - Brazil

^[2] Univ Fed Sao Paulo, Dept Biol Sci, Campus Diadema, Sao Paulo - Brazil

^[3] Univ Fed Espirito Santo, Dept Morphol, Vitoria, ES - Brazil

^[4] Univ Fed Sao Paulo, Inst Sci & Technol, Campus Sao Jose dos Campos, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: HYPERTENSION RESEARCH; v. 42, n. 11, p. 1683-1691, NOV 2019.
• Citações Web of Science: 1

Resumo

Sympathetic overactivation contributes to the pathogenesis of both experimental and human hypertension. We have previously reported that oxidative stress in sympathetic premotor neurons leads to arterial baroreflex dysfunction and increased sympathetic drive to the kidneys in an experimental model of neurogenic hypertension. In this study, we hypothesized that melatonin, a potent antioxidant, may be protective in the brainstem regions involved in the tonic and reflex control of blood pressure (BP) in renovascular hypertensive rats. Neurogenic hypertension was induced by placing a silver clip (gap of 0.2 mm) around the left renal artery, and after 5 weeks of renal clip placement, the rats were treated orally with melatonin (30 mg/kg/day) by gavage for 15 days. At the end of melatonin treatment, we evaluated baseline mean arterial pressure (MAP), renal sympathetic nerve activity (rSNA), and the baroreflex control of heart rate (HR) and rSNA. Reactive oxygen species (ROS) were detected within the brainstem regions by dihydroethidium staining. Melatonin treatment effectively reduced baseline MAP and sympathoexcitation to the ischemic kidney in renovascular hypertensive rats. The baroreflex control of HR and rSNA were improved after melatonin treatment in the hypertensive group. Moreover, there was a preferential decrease in ROS within the rostral ventrolateral medulla (RVLM) and the nucleus of the solitary tract (NTS). Therefore, our study indicates that melatonin is effective in reducing renal sympathetic overactivity associated with decreased ROS in brainstem regions that regulate BP in an experimental model of neurogenic hypertension. (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: 10/09003-4 - Papel da atividade nervosa simpática renal na hipertensão renovascular experimental
• Beneficiário: Erika Emy Nishi
• Modalidade de apoio: Bolsas no Brasil - 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