Document Detail

Impaired reflex response to volume expansion in NaCl-sensitive spontaneously hypertensive rats.
MedLine Citation:
PMID:  2807513     Owner:  NLM     Status:  MEDLINE    
Abnormal baroreceptor reflex function that antedates or is a consequence of NaCl loading could contribute to the NaCl-induced exacerbation of hypertension in NaCl-sensitive spontaneously hypertensive rats (SHR-S). The current study tested the hypothesis that an impairment in cardiopulmonary baroreceptor reflex function exists in SHR-S before NaCl loading. The reflex response to volume expansion was compared in SHR-S, NaCl-resistant SHR (SHR-R), and normotensive Wistar-Kyoto (WKY) and Sprague-Dawley rats maintained on a normal NaCl diet. Conscious, free-moving SHR-S, SHR-R, WKY, and Sprague-Dawley rats were volume expanded with whole blood to 15% of blood volume within 6 minutes, and mean arterial pressure, heart rate, and lumbar sympathetic nerve activity were recorded. Heart rate and lumbar sympathetic nerve activity decreased significantly in SHR-R, WKY, and Sprague-Dawley rats after volume expansion. In contrast, in SHR-S neither heart rate after volume expansion nor lumbar sympathetic nerve activity was significantly different from levels before volume expansion. The blunted reflex response of heart rate and lumbar sympathetic nerve activity to volume expansion suggests impaired cardiopulmonary volume receptor function in SHR-S. This likely contributes to NaCl-induced hypertension in SHR-S on a high NaCl diet.
R M Thornton; J M Wyss; S Oparil
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Hypertension     Volume:  14     ISSN:  0194-911X     ISO Abbreviation:  Hypertension     Publication Date:  1989 Nov 
Date Detail:
Created Date:  1989-12-19     Completed Date:  1989-12-19     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  518-23     Citation Subset:  IM    
Department of Medicine, University of Alabama, Birmingham.
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MeSH Terms
Blood Pressure
Drug Resistance
Heart Rate / drug effects
Lumbosacral Region
Norepinephrine / blood
Plasma Substitutes / pharmacology*
Pressoreceptors / physiology*
Rats, Inbred SHR / blood,  physiology*
Rats, Inbred Strains / physiology*
Rats, Inbred WKY
Reflex / physiology*
Sodium Chloride / pharmacology*
Sympathetic Nervous System / physiology*
Grant Support
Reg. No./Substance:
0/Plasma Substitutes; 51-41-2/Norepinephrine; 7647-14-5/Sodium Chloride

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

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