Document Detail


Chronic administration of aldosterone depresses baroreceptor reflex function in the dog.
MedLine Citation:
PMID:  7960015     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In a previous study it was shown that acute perfusion of aldosterone into the isolated carotid sinus decreased baroreceptor activity. The aim of the present study was to determine whether chronic, systemic administration of aldosterone also depresses baroreflex function. In six conscious dogs, the baroreflex was determined before and 10 days after an osmotic minipump containing aldosterone (100 micrograms/kg in 2 mL) was implanted. The slope of the relation between systolic arterial pressure and heart rate was significantly blunted after aldosterone administration (9.1 +/- 0.7 versus 13.3 +/- 1.2 for nitroglycerin, P < .01; 23.4 +/- 5.0 versus 40.1 +/- 5.0 for phenylephrine, P < .01). Baroreflex slopes did not change in a sham group (minipump with saline) and an aldosterone plus spironolactone (600 mg/d) group. Plasma aldosterone levels were significantly elevated after the aldosterone minipump was implanted (443 +/- 72 versus 37 +/- 11 pg/mL, P < .001). Mean arterial pressure was not significantly increased after aldosterone (106.5 +/- 3.8 versus 100.4 +/- 2.6 mm Hg, P = .2). On the 10th day after aldosterone or saline infusion, an acute experiment was carried out. Single baroreceptor fibers were recorded from the carotid sinus nerve. Compared with the sham group, the threshold was significantly elevated in the aldosterone group (111.3 +/- 2.1 versus 85.8 +/- 2.8 mm Hg), and the peak discharge rate was markedly decreased (32.5 +/- 1.5 versus 54.7 +/- 2.5 spikes per second, P < .01). The depressed baroreceptor function could be partially restored after a bolus injection of the Na+,K(+)-ATPase inhibitor ouabain (5 micrograms/kg i.v.).(ABSTRACT TRUNCATED AT 250 WORDS)
Authors:
W Wang
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Hypertension     Volume:  24     ISSN:  0194-911X     ISO Abbreviation:  Hypertension     Publication Date:  1994 Nov 
Date Detail:
Created Date:  1994-12-02     Completed Date:  1994-12-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  571-5     Citation Subset:  IM    
Affiliation:
Department of Physiology and Biophysics, University of Nebraska, College of Medicine, Omaha 68198-4575.
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MeSH Terms
Descriptor/Qualifier:
Aldosterone / administration & dosage,  pharmacology*
Animals
Baroreflex / drug effects*
Blood Pressure / drug effects*
Catheters, Indwelling
Dogs
Female
Heart Rate / drug effects*
Infusions, Parenteral
Male
Nitroglycerin / pharmacology
Ouabain / pharmacology
Phenylephrine / pharmacology
Pressoreceptors / drug effects,  physiology
Reference Values
Regression Analysis
Spironolactone / pharmacology
Time Factors
Chemical
Reg. No./Substance:
52-01-7/Spironolactone; 52-39-1/Aldosterone; 55-63-0/Nitroglycerin; 59-42-7/Phenylephrine; 630-60-4/Ouabain

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


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