Document Detail


Aldosterone impairs baroreflex sensitivity in healthy adults.
MedLine Citation:
PMID:  16920805     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Animal studies suggest that acute and chronic aldosterone administration impairs baroreceptor/baroreflex responses. We tested the hypothesis that aldosterone impairs baroreflex control of cardiac period [cardiovagal baroreflex sensitivity (BRS)] and muscle sympathetic nerve activity (MSNA, sympathetic BRS) in humans. Twenty-six young (25 +/- 1 yr old, mean +/- SE) adults were examined in this study. BRS was determined by using the modified Oxford technique (bolus infusion of nitroprusside, followed 60 s later by bolus infusion of phenylephrine) in triplicate before (Pre) and 30-min after (Post) beginning aldosterone (experimental, 12 pmol.kg(-1).min(-1); n = 10 subjects) or saline infusion (control; n = 10). BRS was quantified from the R-R interval-systolic blood pressure (BP) (cardiovagal BRS) and MSNA-diastolic BP (sympathetic BRS) relations. Aldosterone infusion increased serum aldosterone levels approximately fourfold (P < 0.05) and decreased (P < 0.05) cardiovagal (19.0 +/- 2.3 vs. 15.6 +/- 1.7 ms/mmHg Pre and Post, respectively) and sympathetic BRS [-4.4 +/- 0.4 vs. -3.0 +/- 0.4 arbitrary units (AU).beat(-1).mmHg(-1)]. In contrast, neither cardiovagal (19.3 +/- 3.3 vs. 20.2 +/- 3.3 ms/mmHg) nor sympathetic BRS (-3.8 +/- 0.5 vs. -3.6 +/- 0.5 AU.beat(-1).mmHg(-1)) were altered (Pre vs. Post) in the control group. BP, heart rate, and MSNA at rest were similar in experimental and control subjects before and after the intervention. Additionally, neural and cardiovascular responses to a cold pressor test and isometric handgrip to fatigue were unaffected by aldosterone infusion (n = 6 subjects). These data provide direct experimental support for the concept that aldosterone impairs baroreflex function (cardiovagal and sympathetic BRS) in humans. Therefore, aldosterone may be an important determinant/modulator of baroreflex function in humans.
Authors:
Kevin D Monahan; Urs A Leuenberger; Chester A Ray
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2006-08-18
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  292     ISSN:  0363-6135     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2007 Jan 
Date Detail:
Created Date:  2007-01-10     Completed Date:  2007-02-20     Revised Date:  2007-12-03    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H190-7     Citation Subset:  IM    
Affiliation:
Penn State Heart and Vascular Institute, The Milton S. Hershey Medical Center, Campus Box H047, 500 University Dr., Hershey, PA 17033-2390, USA. kmonahan@psu.edu
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological / drug effects,  physiology
Adult
Aldosterone / administration & dosage*,  blood
Baroreflex / drug effects,  physiology*
Blood Pressure / drug effects,  physiology*
Dose-Response Relationship, Drug
Female
Heart Rate / drug effects,  physiology*
Humans
Male
Sympathetic Nervous System / drug effects,  physiology*
Vagus Nerve / drug effects,  physiology*
Grant Support
ID/Acronym/Agency:
AG-024420/AG/NIA NIH HHS; C06-RR-016499/RR/NCRR NIH HHS; DC-006459/DC/NIDCD NIH HHS; HL-68699/HL/NHLBI NIH HHS; HL-77670/HL/NHLBI NIH HHS; M01-RR-10732/RR/NCRR NIH HHS
Chemical
Reg. No./Substance:
52-39-1/Aldosterone

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


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