This Article Full Text Full Text (PDF) All Versions of this Article: 50/4/756    most recent HYPERTENSIONAHA.107.094706v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ceravolo, G. S. Articles by Carvalho, M. H. C. Search for Related Content PubMed PubMed Citation Articles by Ceravolo, G. S. Articles by Carvalho, M. H. C. Related Collections ACE/Angiotension receptors Endothelium/vascular type/nitric oxide

(Hypertension. 2007;50:756.)
© 2007 American Heart Association, Inc.

XVIIth Scientific Meeting of the Inter-American Society of Hypertension

Angiotensin II Chronic Infusion Induces B1 Receptor Expression in Aorta of Rats

Graziela S. Ceravolo; Liliam Fernandes; Carolina D. Munhoz; Denise C. Fernandes; Rita C.A. Tostes; Francisco R.M. Laurindo; Christoforo Scavone; Zuleica B. Fortes; Maria Helena C. Carvalho

From the Laboratory of Hypertension (G.S.C., R.C.A.T., Z.B.F., M.H.C.C.), Department of Pharmacology (C.D.M., C.S.), Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil; Department of Biological Sciences (L.F.), Federal University of Sao Paulo, Sao Paulo, Brazil; and the Vascular Biology Laboratory (D.C.F., F.R.M.L.), Heart Institute (InCor), University of Sao Paulo School of Medicine, Sao Paulo, Brazil.

Correspondence to Maria Helena C. Carvalho, Laboratory of Hypertension, Department of Pharmacology, Institute of Biomedical Sciences, University of Sáo Paulo, Av Prof Lineu Prestes, 1524-Sáo Paulo, 05508-900 Brazil. E-mail mhcarval{at}icb.usp.br

We investigated whether angiotensin II infusion modulates in vivo the kinin B1 receptor expression and the mechanisms involved in this process. We also evaluated the role of the B1 receptor activation in aorta. Wistar rats received 400 ng/kg per minute of angiotensin II or saline (control rats) infusion during 14 days through an osmotic minipump. To investigate the role of superoxide anion in B1 receptor expression, rats received a reduced nicotinamide-adenine dinucleotide phosphate oxidase inhibitor in the drinking water during 14 days (60 mg/L of apocynin) simultaneously with angiotensin II infusion. Angiotensin II induced B1 receptor expression in the aorta and increased significantly systolic blood pressure, superoxide anion, and the nuclear factor B activity. Apocynin treatment did not alter the blood pressure levels of angiotensin II rats and reduced the B1 receptor expression, superoxide anion generation, and nuclear factor B activity to similar levels of the control rats. Vascular reactivity studies in isolated aorta reveal that B1 receptor agonist promoted endothelium-dependent dilation and increased the NO generation in aorta of angiotensin II rats. NO synthase inhibitor and B1 receptor antagonist inhibited the vasodilation and NO generation, which were not affected by B2 receptor antagonist or indomethacin. These results provide evidence that angiotensin II induces B1 receptor expression in aorta by superoxide anion generation, via reduced nicotinamide-adenine dinucleotide phosphate oxidase, concomitant to nuclear factor B activation. We have also shown that B1 receptor agonist causes endothelium-dependent vasodilation through NO production in aortic rings, suggesting that the B1 receptor expression could be related with the vascular tonus control of angiotensin II rats.

Key Words: angiotensin II • B1 receptor • hypertension • superoxide anion • NF-B

This article has been cited by other articles:

				W. J. Welch Angiotensin II-Dependent Superoxide: Effects on Hypertension and Vascular Dysfunction Hypertension, July 1, 2008; 52(1): 51 - 56. [Full Text] [PDF]

				F. C Luft The Bothrops legacy: Vasoactive peptides from Brazil Journal of Renin-Angiotensin-Aldosterone System, March 1, 2008; 9(1): 57 - 64. [PDF]