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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Mechanisms of renal sympathetic activation in renovascular hypertension

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Autor(es):
Campos, Ruy R. [1] ; Oliveira-Sales, Elizabeth Barbosa [1] ; Nishi, Erika E. [1] ; Paton, Julian F. R. [2] ; Bergamaschi, Cassia T. [1]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Fed Sao Paulo, Div Cardiovasc, Dept Physiol, BR-04023060 Sao Paulo, SP - Brazil
[2] Univ Bristol, Bristol CardioVasc, Sch Physiol & Pharmacol, Bristol BS8 1TD, Avon - England
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Experimental Physiology; v. 100, n. 5, p. 496-501, MAY 1 2015.
Citações Web of Science: 24
Resumo

What is the topic of this review? This review addresses the underlying mechanisms involved in sympathoexcitation during renovascular hypertension, focusing on the importance of increased oxidative stress in the paraventricular nucleus and rostral ventrolateral medulla. What advances does it highlight? Whether renal or autonomic dysfunction is the major contributor to systemic hypertension following a renovascular insult is still a matter of debate. Here, we take an integrative approach by describing the crosstalk between the kidney and brain. We show how changes in the CNS, and in sympathetic premotor neurons in particular, are activated by ischaemic renal disease in an experimental model of renovascular hypertension. This review addresses the underlying mechanisms involved in the sympathoexcitation in renovascular hypertension. We focus on the importance of increased oxidative stress in the paraventricular nucleus of hypothalamus (PVN) and rostral ventrolateral medulla (RVLM) for the autonomic dysfunction associated with renovascular hypertension in the two-kidney, one-clip (2K-1C) model. We found in 2K-1C rats, 6weeks after clipping, a significant increase in the mRNA and protein expression of the angiotensinII type1 receptor within the RVLM and PVN. In addition, mRNA from NADPH oxidase subunits (p47phox and gp91phox) was greater in the RVLM and PVN of 2K-1C rats than in a sham-operated group. However, CuZn superoxide dismutase gene expression in these regions was not changed, suggesting that excessive production of reactive oxygen species overwhelms any endogenous antioxidant system in the RVLM and PVN in renovascular hypertension. In fact, acute administration of tempol or vitaminC (either i.v. or directly into the PVN or RVLM) caused a significant decrease in blood pressure and renal sympathetic nerve activity in 2K-1C rats, but not in control animals. Thus, we suggest that an increase in the activity of RVLM and PVN neurons triggered by angiotensinII and oxidative stress is a major mechanism involved in the maintenance of sympathoexcitation of the cardiovascular system in renovascular 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
Linha de fomento: Bolsas no Brasil - Pós-Doutorado