Document Detail


Effects of the arterial vasodilator minoxidil on cardiovascular structure and sympathetic activity in spontaneously hypertensive rats.
MedLine Citation:
PMID:  8133016     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE AND DESIGN: In spontaneously hypertensive rats (SHR) arterial vasodilators do not cause regression and might cause further progression of cardiac hypertrophy. To assess whether these effects extend to the vasculature, and to examine the possible mechanisms involved, cardiac and mesenteric arterial structure was evaluated with respect to changes in cardiac volume load and cardiac and arterial sympathetic activity during long-term (5- and 10-week) treatment of 16-week-old SHR with the arterial vasodilator minoxidil, alone or in combination with the diuretic hydrochlorothiazide. RESULTS: Despite causing a persistent decrease in blood pressure in SHR, minoxidil further increased left and right ventricular weights and left ventricular internal diameter. In combination with hydrochlorothiazide, minoxidil caused concentric, rather than eccentric, left ventricular hypertrophy. In the mesenteric arterial bed of SHR, minoxidil increased the lumen of the superior mesenteric artery, and prevented further increases in the medial area of the large and small mesenteric arteries. The increase in lumen size of the superior mesenteric artery by minoxidil was abolished when hydrochlorothiazide was added to the treatment. After 10 weeks' treatment with minoxidil, noradrenaline turnover rates were still significantly increased in the left ventricle but were decreased in the mesenteric arteries in the SHR. Minoxidil increased plasma and blood volumes, the increases being largely prevented by concomitant diuretic treatment. CONCLUSIONS: We conclude that there are regional differences in the response of the cardiovascular system to minoxidil in SHR. Some of these differences may be related to differences in regional sympathetic activity, whereas volume load appears to play a modulatory role.
Authors:
J Tsoporis; N Fields; R M Lee; F H Leenen
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of hypertension     Volume:  11     ISSN:  0263-6352     ISO Abbreviation:  J. Hypertens.     Publication Date:  1993 Dec 
Date Detail:
Created Date:  1994-04-15     Completed Date:  1994-04-15     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8306882     Medline TA:  J Hypertens     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  1337-45     Citation Subset:  IM    
Affiliation:
Hypertension Unit, University of Ottawa Heart Institute, Ontario, Canada.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / drug effects
Blood Volume / drug effects
Cardiomegaly / chemically induced,  pathology
Heart / drug effects*
Heart Ventricles / drug effects,  pathology
Hydrochlorothiazide / administration & dosage
Hypertension / drug therapy*,  pathology,  physiopathology
Male
Mesenteric Artery, Superior / drug effects,  pathology
Minoxidil / administration & dosage,  toxicity*
Norepinephrine / metabolism
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Sympathetic Nervous System / drug effects,  physiopathology
Chemical
Reg. No./Substance:
38304-91-5/Minoxidil; 51-41-2/Norepinephrine; 58-93-5/Hydrochlorothiazide

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


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