Skip Navigation

Cardiovascular Research 1997 36(2):268-275; doi:10.1016/S0008-6363(97)00171-5
© 1997 by European Society of Cardiology
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Newby, D. E
Right arrow Articles by Webb, D. J
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Newby, D. E
Right arrow Articles by Webb, D. J
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 1997, European Society of Cardiology

Endogenous angiotensin II contributes to basal peripheral vascular tone in sodium deplete but not sodium replete man

David E Newbya,*, Satoko Masumorib, Neil R Johnstona, Nicholas A Boona and David J Webba

aClinical Pharmacology Unit and Research Centre, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, UK
bYokohama City University, School of Medicine, Department of Internal Medicine, 3-9 Fukuura Kanazawa-Ku, Yokohama 236, Japan

* Corresponding author. Tel.: +44 131 3321205; Fax: +44 131 3436017; E-mail: d.e.newby@ed.ac.uk

Objective: Both endothelin-1 and nitric oxide make important contributions to the maintenance of basal peripheral arteriolar tone. However, the role of angiotensin II, a key hormone regulating cardiovascular and renal function, in the regulation of peripheral vascular tone has not been fully characterised. Methods: Using local intra-arterial administration of losartan, a selective angiotensin II type 1 (AT1) receptor antagonist, we examined the contribution of endogenous angiotensin II to the maintenance of basal and sympathetically stimulated vascular tone in the forearm of healthy man under conditions of sodium repletion and depletion. The effects of losartan on responses to exogenous angiotensin I, angiotensin II, bradykinin and noradrenaline were also determined. Results: Losartan, in keeping with its actions as a selective AT1 receptor antagonist, inhibited responses to angiotensin I and II, but had no effect on responses to bradykinin or noradrenaline. The dose of angiotensin II required to cause a 20% vasoconstriction was 40- and 250-fold greater with 30 and 300 µg/min of losartan, respectively. However, in sodium replete subjects, losartan alone caused no significant changes in basal forearm blood flow (95% confidence interval of –7.2 to +8.0%), forearm vascular resistance or sympathetically stimulated forearm vasoconstriction. Sodium depletion elevated plasma renin activity and angiotensin II concentrations (p≤0.002) after which acute local administration of losartan increased forearm blood flow in a dose dependent manner (maximum of 69±17%; p<0.001). Conclusions: Endogenous angiotensin II does not contribute to the acute local maintenance of basal peripheral vascular tone in healthy man except under conditions of renin-angiotensin system activation such as sodium depletion.

KEYWORDS Angiotensin II; Losartan; Sodium depletion; Arteries; Blood flow; Human


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 HypertensionHome page
J. P. Langrish, N. L. Mills, L. E. Bath, P. Warner, D. J. Webb, C. J. Kelnar, H. O.D. Critchley, D. E. Newby, and W. H. B. Wallace
Cardiovascular Effects of Physiological and Standard Sex Steroid Replacement Regimens in Premature Ovarian Failure
Hypertension, May 1, 2009; 53(5): 805 - 811.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.