Document Detail

Location of the area postrema pressor pathway in the dog brain stem.
MedLine Citation:
PMID:  6746082     Owner:  NLM     Status:  MEDLINE    
Electrical stimulation of the dog's area postrema (AP) induces a response that mimics the pressor response produced by intravertebral infusion of low-dose angiotensin II, which causes an increase in mean arterial pressure associated with transient tachycardia and increased peripheral resistance. The present study investigated in morphine-chloralose anesthetized dogs whether: 1) the characteristics of the AP pressor response are influenced by the presence of carotid sinus afferents; 2) structures rostral to the medulla influence the AP pressor response; and 3) the pressor pathway is initiated by neurons within the AP. Since bilateral cervical sinovagal denervation, which potentiated the phenylephrine pressor response, did not affect the pressor response to AP stimulation, the data provide evidence for an inhibitory influence exerted upon the central baroreflex mechanism by the AP pressor mechanism. The unaltered AP pressor response after midcollicular transection suggests that the efferent pathway is contained within the brain stem caudal to the pons. Finally, the elimination of the pressor response following kainic acid microinjection into the AP provides evidence that the AP pressor mechanism is initiated by neurons within the AP, rather than by fibers of passage from other pressor centers. These results suggest that the AP produces its facilitation of central sympathetic vasomotor outflow via a pathway contained within the medulla.
K L Barnes; C M Ferrario
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Hypertension     Volume:  6     ISSN:  0194-911X     ISO Abbreviation:  Hypertension     Publication Date:    1984 Jul-Aug
Date Detail:
Created Date:  1984-09-14     Completed Date:  1984-09-14     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  482-8     Citation Subset:  IM    
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MeSH Terms
Blood Pressure* / drug effects
Brain Stem / anatomy & histology*
Carotid Sinus / innervation
Cerebral Ventricles / anatomy & histology*
Kainic Acid / pharmacology
Neural Pathways / anatomy & histology
Tectum Mesencephali / physiology
Grant Support
Reg. No./Substance:
487-79-6/Kainic Acid

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