Document Detail

Effect of nucleus ambiguus lesion on the development of neurogenic hypertension.
MedLine Citation:
PMID:  3346049     Owner:  NLM     Status:  MEDLINE    
These studies evaluated the role of the nucleus ambiguus in regulating heart rate and cardiovascular activity. Three days after lesion of the nucleus ambiguus, arterial pressure and heart rate were unchanged; however, subsequent sinoaortic deafferentation produced a significantly greater increase of pressure (156 +/- 4 vs 124 +/- 6 mm Hg) compared to sham lesion. In both groups the heart rate was increased after deafferentation and the intrinsic heart rate (rate seen after autonomic blockade with atropine and propranolol) was significantly reduced. When the sequence was reversed (deafferentation before lesion), pressure (126 +/- 6 vs 126 +/- 7 mm Hg) and heart rate (334 +/- 17 and 340 +/- 16 beats/min) were not altered; however, intrinsic rate fell more. When the nucleus ambiguus was stimulated electrically, two responses emerged: increased pressure without rate changes and increased pressure with bradycardia. These data indicate that 1) lesion of the nucleus ambiguus facilitates hypertension produced by sinoaortic deafferentation unless lesioning follows deafferentation; and 2) stimulation of the nucleus ambiguus produces a pressor effect that is independent of the bradycardic response. We conclude that the nucleus ambiguus may be related to autonomic control of both heart rate and arterial pressure.
B H Machado; M J Brody
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Hypertension     Volume:  11     ISSN:  0194-911X     ISO Abbreviation:  Hypertension     Publication Date:  1988 Feb 
Date Detail:
Created Date:  1988-04-11     Completed Date:  1988-04-11     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  I135-8     Citation Subset:  IM    
Department of Pharmacology, University of Iowa, Iowa City 52242.
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MeSH Terms
Blood Pressure*
Electric Stimulation
Heart Rate*
Hypertension / etiology*
Medulla Oblongata / physiology*
Pressoreceptors / physiology
Rats, Inbred Strains
Reflex / physiology

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

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