Increased Expression of Angiotensin II Type 2 Receptors in the Solitary-Vagal Complex Blunts Renovascular Hypertension
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Data
2014-10-01
Autores
Blanch, Graziela Torres [UNESP]
Freiria-Oliveira, Andre Henrique [UNESP]
Fina Speretta, Guilherme Fleury [UNESP]
Carrera, Eduardo J.
Li, Hongwei
Speth, Robert C.
Colombari, Eduardo [UNESP]
Sumners, Colin
Colombari, Debora S. A. [UNESP]
Título da Revista
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Editor
Lippincott Williams & Wilkins
Resumo
Angiotensin II increases and decreases arterial pressure by acting at angiotensin type 1 and type 2 receptors, respectively. Renovascular hypertensive rats exhibit a high level of activity of the peripheral and central renin-angiotensin system. Therefore, in the present study, we evaluated the effect of increasing the expression of angiotensin type 2 receptors in the solitary-vagal complex (nucleus of the solitary tract/dorsal motor nucleus of the vagus), a key brain stem region for cardiovascular regulation, on the development of renovascular hypertension. Holtzman normotensive rats were implanted with a silver clip around the left renal artery to induce 2-kidney 1-clip renovascular hypertension. Three weeks later, rats were microinjected in the solitary-vagal complex with either an adenoassociated virus to increase the expression of angiotensin type 2 receptors or with a control vector. We observed that increasing angiotensin type 2 receptor expression in the solitary-vagal complex attenuated the development of renovascular hypertension and also reversed the impairment of the baroreflex and the increase in the low-frequency component of systolic blood pressure observed in renovascular hypertensive rats. Furthermore, an observed decrease in mRNA levels of angiotensin-converting enzyme 2 in the solitary-vagal complex of renovascular hypertensive rats was restored to control levels after viral-mediated increases in angiotensin type 2 receptors at this site. Collectively, these data demonstrate specific and beneficial effects of angiotensin type 2 receptors via the brain of hypertensive rats and suggest that central angiotensin type 2 receptors may be a potential target for therapeutics in renovascular hypertension.
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Palavras-chave
angiotensin II, angiotensin-converting enzyme 2, angiotensin receptor blockers, baroreflex
Como citar
Hypertension. Philadelphia: Lippincott Williams & Wilkins, v. 64, n. 4, p. 777-+, 2014.