Chronic Antioxidant Treatment Improves Arterial Renovascular Hypertension and Oxidative Stress Markers in the Kidney in Wistar Rats

Autor(es)

Nishi, Erika Emy ^[1] ; Oliveira-Sales, Elizabeth Barbosa ^[1] ; Bergamaschi, Cassia T. ^[2] ; Cesar Oliveira, Thais Galvao ^[1] ; Boim, Mirian A. ^[3] ; Campos, Ruy R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Physiol, Div Cardiovasc, Sao Paulo - Brazil

^[2] Univ Fed Sao Paulo Baixada Santista, Dept Biosci, Sao Paulo - Brazil

^[3] Univ Fed Sao Paulo, Dept Med, Div Nephrol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: AMERICAN JOURNAL OF HYPERTENSION; v. 23, n. 5, p. 473-480, MAY 2010.
• Citações Web of Science: 36

Resumo

BACKGROUND Sympathetic vasomotor hyperactivity and baroreflex dysfunction are involved in the development and maintenance of renovascular arterial hypertension. We hypothesized that angiotensin (Ang) II-dependent oxidative stress contributes to the pathophysiology of the two-kidney, one-clip (2K-1C) model. METHODS The mean arterial pressure (MAP), baroreflex, and renal sympathetic nerve activity (rSNA) were evaluated after chronic administration of an antioxidant, vitamin C (vitC 150 mg/kg/day) in male Wistar 2K-1C rats. Additionally, the mRNA levels of Ang II subtype 1 receptor (AT(1)R), NAD(P)H oxidase subunits (p47phox and gp91phox), and major antioxidant enzymes were evaluated in the renal cortex. RESULTS After vitC treatment, the MAP (170 +/- 4 vs. 133 +/- 6 mm Hg; P < 0.05) and rSNA (161 +/- 5 vs. 118 +/- 12 spikes/s; P < 0.05) were significantly reduced only in the 2K-1C group. VitC improved the baroreflex control of heart rate (HR) and rSNA. The expression of AT(1)R, p47phox, and gp91phox was elevated (51, 184, and 132%, respectively) in the clipped kidney of 2K-1C group. VitC downregulated AT(1)R in the clipped kidney (31%). Catalase (CAT) expression was reduced in clipped (70%) and nonclipped (83%) kidneys of 2K-1C rats. VitC treatment augmented the expression of glutathione peroxidase (GPx) in both clipped (185%) and nonclipped (212%) kidneys of the 2K-1C group. CONCLUSIONS The present study suggests a role for oxidative stress in the cardiovascular and sympathetic alterations in renovascular hypertension, associated with changes in the expression of AT,R, NAD(P)H oxidase subunits, and antioxidant enzymes in the kidney. (AU)

• Processo FAPESP: 07/56925-1 - Papel do estresse oxidativo na hipertensao renovascular experimental.
• Beneficiário: Erika Emy Nishi
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 04/15969-8 - Mecanismos de sinalizacao a ativacao simpatica na insuficiencia cardiaca.
• Beneficiário: Ruy Ribeiro de Campos Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 06/59047-2 - Efeitos cardiovasculares ao tratamento cronico com acido ascorbico na hipertensao renovascular experimental.
• Beneficiário: Erika Emy Nishi
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica