Skip Navigation

Cardiovascular Research 1998 40(2):402-409; doi:10.1016/S0008-6363(98)00124-2
© 1998 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 Dijkhorst-Oei, L.-T.
Right arrow Articles by Rabelink, T. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dijkhorst-Oei, L.-T.
Right arrow Articles by Rabelink, T. J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 1998, European Society of Cardiology

Divergent effects of ACE-inhibition and calcium channel blockade on NO-activity in systemic and renal circulation in essential hypertension

Lioe-Ting Dijkhorst-Oei, Jaap J. Beutler, Erik S.G. Stroes, Hein A. Koomans and Ton J. Rabelink*

Department of Nephrology and Hypertension, University Hospital, Utrecht, The Netherlands

* Corresponding author. Tel.: +31 (30) 250 7329; Fax: +31 (30) 254 3492; E-mail: t.rabelink@digd.azu.nl

Objective: Nitric oxide is a vasodilating and blood pressure lowering substance. To investigate whether calcium antagonists or angiotensin-converting enzyme (ACE) inhibitors increase vascular nitric oxide activity, we assessed systemic and renal vascular sensitivity to nitric oxide synthase inhibition in hypertensives on and off medication. Methods: Ten essential hypertensive patients, aged 22–51 years, were studied 3 times: ≥4 weeks off medication, after 3 weeks treatment with enalapril 20 mg twice a day and after 3 weeks nifedipine 60 mg/day. Each time, 24-h blood pressure registration was performed, followed by a clearance study to obtain a 3-h dose-response curve for intravenously infused NG-monomethyl-L-arginine (L-NMMA, respectively 0.75, 1.5 and 3.0 mg/kg/h). Results: L-NMMA dose-dependently increased mean arterial pressure with 5±2 mmHg and systemic vascular resistance with 24±5% at maximum dose, whereas cardiac output decreased (all P<0.001). Enalapril and nifedipine treatment decreased blood pressure, while the L-NMMA-induced increase in systemic vascular resistance was potentiated (enalapril: 45±7% and nifedipine: 46±8%; both P<0.01). L-NMMA also dose-dependently decreased renal blood flow by 58±8% at maximum dose (P<0.001), but neither drug potentiated these effects. Conclusion: These results indicate that, in essential hypertensives, antihypertensive therapy with enalapril or nifedipine increases nitric oxide dependency of systemic vascular tone, which may play a role in the blood pressure lowering effect of these drugs. However, this phenomenon cannot be observed in the renal circulation, suggesting a different regulation of endothelium-dependent vasomotion in the hypertensive kidney.

KEYWORDS Essential hypertension; Nitric oxide; L-NMMA; Angiotensin; Converting enzyme inhibitor; Calcium channel blocker; Systemic vascular resistance; Renal hemodynamics


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




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.