Document Detail


A mechanism for salt-sensitive hypertension: abnormal dietary sodium-mediated vascular response to angiotensin-II.
MedLine Citation:
PMID:  20216091     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: Several mechanisms have been proposed for salt-sensitive hypertension, with most focusing on impaired renal sodium handling. We tested the hypothesis that abnormalities in peripheral vascular responsiveness to angiotensin-II (ANGII) might also exist in salt-sensitive hypertension because of the interplay of the renin-angiotensin system and dietary sodium.
METHODS: Blood pressure (BP) response to ANGII infusion was studied in 295 hypertensive and 165 normotensive individuals after 7 days of high (200 mEq/day) and low (10 mEq/day) dietary sodium.
RESULTS: Normotensive individuals demonstrated higher BP response to ANGII on high-salt than low-salt diet, whereas hypertensive individuals had similar responses on both diets; that is, the high-salt response was not enhanced as compared with low-salt response. Additionally, hypertensive individuals had a significantly greater high-salt BP response to norepinephrine than to ANGII. There was no correlation between the high-salt hormone levels and the difference in BP response to ANGII between the two diets. When stratified by BP response to dietary salt restriction, individuals with salt sensitivity of BP demonstrated abnormal high-salt BP responsiveness to ANGII. To assess if this represented increased tissue renin-angiotensin system activity in the vasculature, BP responses to angiotensin were compared before and after captopril in 20 hypertensive individuals on a high-salt diet. Individuals with the greatest BP-lowering effect to captopril had similar high and low-salt BP responses to ANGII at baseline and a significant increase in the high-salt response after captopril.
CONCLUSION: Hypertensive individuals have an abnormal vascular response to ANGII infusion on a high-salt diet. Dysregulated tissue renin-angiotensin system activity may play a role in this abnormal response. These findings raise an intriguing novel possibility for the pathophysiologic mechanism of salt-sensitive hypertension.
Authors:
Bindu Chamarthi; Jonathan S Williams; Gordon H Williams
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Journal of hypertension     Volume:  28     ISSN:  1473-5598     ISO Abbreviation:  J. Hypertens.     Publication Date:  2010 May 
Date Detail:
Created Date:  2010-04-16     Completed Date:  2010-07-29     Revised Date:  2014-09-24    
Medline Journal Info:
Nlm Unique ID:  8306882     Medline TA:  J Hypertens     Country:  England    
Other Details:
Languages:  eng     Pagination:  1020-6     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Adult
Angiotensin II / pharmacology*
Blood Pressure / drug effects,  physiology
Case-Control Studies
Diet, Sodium-Restricted
Female
Hemodynamics / drug effects,  physiology
Humans
Hypertension / diet therapy,  etiology*,  physiopathology*
Male
Middle Aged
Norepinephrine / pharmacology
Renin / blood
Renin-Angiotensin System / drug effects,  physiology
Sodium Chloride, Dietary / administration & dosage,  adverse effects*
Grant Support
ID/Acronym/Agency:
#HL47651/HL/NHLBI NIH HHS; #K23 HL084236/HL/NHLBI NIH HHS; DK63214/DK/NIDDK NIH HHS; HL59424/HL/NHLBI NIH HHS; K23 HL084236/HL/NHLBI NIH HHS; K23 HL084236-03/HL/NHLBI NIH HHS; K30 RR022292/RR/NCRR NIH HHS; K30 RR022292-07/RR/NCRR NIH HHS; K30-RR02229207/RR/NCRR NIH HHS; M01 RR000064-400507/RR/NCRR NIH HHS; M01 RR000095/RR/NCRR NIH HHS; M01 RR000095-370563/RR/NCRR NIH HHS; M01 RR002635/RR/NCRR NIH HHS; M01 RR002635-225322/RR/NCRR NIH HHS; M01RR00064/RR/NCRR NIH HHS; M01RR00095/RR/NCRR NIH HHS; M01RR02635/RR/NCRR NIH HHS; P50 HL055000/HL/NHLBI NIH HHS; P50 HL055000-06/HL/NHLBI NIH HHS; P50HL055000/HL/NHLBI NIH HHS; R01 HL047651/HL/NHLBI NIH HHS; R01 HL047651-04/HL/NHLBI NIH HHS; R01 HL059424/HL/NHLBI NIH HHS; R01 HL059424-02/HL/NHLBI NIH HHS; T32 HL007609/HL/NHLBI NIH HHS; T32 HL007609-24/HL/NHLBI NIH HHS; T32HL007609/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Sodium Chloride, Dietary; 11128-99-7/Angiotensin II; EC 3.4.23.15/Renin; X4W3ENH1CV/Norepinephrine
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