Document Detail


Aldosterone antagonist facilitates the cardioprotective effects of angiotensin receptor blockers in hypertensive rats.
MedLine Citation:
PMID:  15097243     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: There is increasing evidence to support the importance of blocking aldosterone to prevent target-organ damage in hypertension. We recently demonstrated an aldosterone breakthrough phenomenon during administration of an angiotensin type 1 receptor blocker (ARB). OBJECTIVE: To elucidate the pathophysiological significance of residual aldosterone by investigating the influence of the aldosterone antagonist on the cardioprotective effects of the ARB in hypertensive rats. METHODS: Injection vehicle alone, ARB (1.0 mg/kg per day candesartan by mouth), aldosterone antagonist (10 mg/kg per day spironolactone, subcutaneously), or combined treatment were administered to male stroke-prone spontaneously hypertensive rats for 24 weeks from the age of 4 weeks. Blood pressure, plasma angiotensin II and aldosterone concentrations, left ventricular weight, expression of type I and type III collagen mRNA, and histological findings were determined. RESULTS: In the ARB-treated group, aldosterone concentrations remained unchanged (1.10 +/- 0.20 nmol/l, compared with 1.17 +/- 0.46 nmol/l in the control group), whereas systolic blood pressure (178 +/- 9 mmHg), left ventricular weight (0.372 +/- 0.035 g/100 g body weight), expression of collagen mRNA, and cardiac interstitial and perivascular fibrosis all decreased significantly compared with the control group (systolic blood pressure: 222 +/- 10 mmHg, P < 0.05; left ventricular weight: 0.483 +/- 0.021 g/100 g body weight, P < 0.05). Although blood pressure (217 +/- 9 mmHg) and left ventricular weight (0.467 +/- 0.027 g/100 g body weight) remained unchanged in the group receiving spironolactone, the expression of both types of collagen mRNA and cardiac interstitial and perivascular fibrosis showed a significant decrease compared with the vehicle-treated group. In the rats receiving combined treatment with the ARB and spironolactone, left ventricular weight (0.352 +/- 0.005 g/100 g body weight, P < 0.05), expression of collagen mRNA, and cardiac interstitial and perivascular fibrosis all showed a further improvement compared with both the ARB and spironolactone groups. CONCLUSIONS: These results demonstrate that residual aldosterone has a significant impact on target-organ damage in hypertension, even during chronic administration of an ARB. The addition of an aldosterone antagonist has an advantage in facilitating the cardioprotective effects of ARBs.
Authors:
Akiyo Tanabe; Mitsuhide Naruse; Yoshiko Hara; Atsuhisa Sato; Ken Tsuchiya; Toshio Nishikawa; Toshihiro Imaki; Kazue Takano
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of hypertension     Volume:  22     ISSN:  0263-6352     ISO Abbreviation:  J. Hypertens.     Publication Date:  2004 May 
Date Detail:
Created Date:  2004-04-20     Completed Date:  2004-12-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8306882     Medline TA:  J Hypertens     Country:  England    
Other Details:
Languages:  eng     Pagination:  1017-23     Citation Subset:  IM    
Affiliation:
Department of Medicine, Institute of Clinical Endocrinology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan. akiyotana@endm.twmu.ac.jp
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MeSH Terms
Descriptor/Qualifier:
Aldosterone / blood
Aldosterone Antagonists / pharmacology*
Angiotensin II / blood
Animals
Antihypertensive Agents / pharmacology*
Benzimidazoles / pharmacology*
Body Weight
Cardiomegaly / pathology,  physiopathology
Cardiotonic Agents / pharmacology
Collagen Type I / genetics
Collagen Type III / genetics
Drug Synergism
Fibrosis
Hypertension / complications,  drug therapy*,  physiopathology
Male
Myocardium / pathology
RNA, Messenger / analysis
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Receptor, Angiotensin, Type 1 / metabolism
Spironolactone / pharmacology*
Tetrazoles / pharmacology*
Chemical
Reg. No./Substance:
0/Aldosterone Antagonists; 0/Antihypertensive Agents; 0/Benzimidazoles; 0/Cardiotonic Agents; 0/Collagen Type I; 0/Collagen Type III; 0/RNA, Messenger; 0/Receptor, Angiotensin, Type 1; 0/Tetrazoles; 11128-99-7/Angiotensin II; 139481-59-7/candesartan; 52-01-7/Spironolactone; 52-39-1/Aldosterone

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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