Document Detail


Angiotensin II enhances carotid body chemoreflex control of sympathetic outflow in chronic heart failure rabbits.
MedLine Citation:
PMID:  16650840     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: We investigated whether Angiotensin II (Ang II) modulates peripheral chemoreflex function through carotid body (CB) chemoreceptors in chronic heart failure (CHF). METHODS: We measured renal sympathetic nerve activity (RSNA) in response to graded hypoxia before and after intravenous administration of Ang II (20 ng/kg/min, i.v. 30 min) or AT1 receptor antagonist (L-158,809, 0.33 mg/kg, i.v.) in conscious sham and pacing-induced CHF rabbits. We also investigated the effects of Ang II (100 pM) and L-158,809 (1 microM) on CB chemoreceptor activity in vascularly isolated-perfused CB preparations from sham and CHF rabbits. RESULTS: Ang II enhanced hypoxia-induced RSNA increases in sham rabbits but not in CHF rabbits. Conversely, L-158,809 attenuated hypoxia-induced responses in RSNA in CHF rabbits but not in sham rabbits. Using RT-PCR, Western blotting, and immunocytochemistry, we found that the mRNA and protein expression of AT1 receptor in the CB from CHF rabbits were greater than that in sham rabbits. CB chemoreceptor afferent activity during normoxia and graded hypoxia was increased in CHF rabbits compared with sham rabbits. Ang II increased the response of CB chemoreceptors to hypoxia in sham rabbits but not CHF rabbits. L-158,809 decreased CB chemoreceptor responses to hypoxia in CHF rabbits but not in sham rabbits. CONCLUSIONS: These results indicate that elevation of Ang II and concomitant upregulation of AT1 receptor in the CB contribute to the increased CB chemoreceptor activity and enhanced peripheral chemoreflex function in CHF.
Authors:
Yu-Long Li; Xiao-Hong Xia; Hong Zheng; Lie Gao; Yi-Fan Li; Dongmei Liu; Kaushik P Patel; Wei Wang; Harold D Schultz
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2006-03-24
Journal Detail:
Title:  Cardiovascular research     Volume:  71     ISSN:  0008-6363     ISO Abbreviation:  Cardiovasc. Res.     Publication Date:  2006 Jul 
Date Detail:
Created Date:  2006-06-13     Completed Date:  2007-03-29     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0077427     Medline TA:  Cardiovasc Res     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  129-38     Citation Subset:  IM    
Affiliation:
Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5850, USA.
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MeSH Terms
Descriptor/Qualifier:
Angiotensin II / antagonists & inhibitors,  pharmacology*
Angiotensin II Type 1 Receptor Blockers / pharmacology
Animals
Anoxia
Blotting, Western / methods
Carotid Body / physiopathology*
Chemoreceptor Cells / drug effects*
Heart Failure / physiopathology*
Imidazoles / pharmacology
Immunohistochemistry / methods
Kidney / innervation
Male
Models, Animal
Rabbits
Reverse Transcriptase Polymerase Chain Reaction
Stimulation, Chemical
Sympathetic Nervous System / physiology*
Tetrazoles / pharmacology
Grant Support
ID/Acronym/Agency:
P01-HL62222/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Angiotensin II Type 1 Receptor Blockers; 0/Imidazoles; 0/Tetrazoles; 11128-99-7/Angiotensin II; 135145-96-9/L 158809

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


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