Document Detail

Reflex cardiovascular responses to graded stimulations of low- and high-threshold afferents in the carotid sinus and aortic nerves in the cat.
MedLine Citation:
PMID:  7315444     Owner:  NLM     Status:  MEDLINE    
Reflex responses to electrical stimulation of low-threshold and high-threshold afferents in the aortic and carotid sinus nerves were investigated in chloralose-anesthetized cats. Changes in blood pressure, heart rate and muscle resistance were recorded. Low-threshold stimulation induced depressor responses of moderate magnitude. When stimulation intensity was increased to engage also the high threshold aortic nerve afferents a more pronounced reflex response was seen even with stimulation frequencies less than 10 Hz. Furthermore, stimulation of low- and high-threshold aortic nerve afferents induced different reflex patterns. For a given fall in blood pressure, the low-threshold afferents induced a greater reflex decrease in muscle vascular resistance compared with the high-threshold afferents, which reduced heart rate more. The effects seen at low frequency stimulation of high-threshold aortic nerve afferents were interpreted to reflect activation of the non-medullated baroreceptor afferents, while the depressor reflexes at low-threshold stimulation were induced by medullated baroreceptor afferents. Also the reflex effects of continuous and intermittent stimulation patterns of the various afferents were compared. At the same number of imp/s an intermittent stimulation of the low-threshold afferents induced greater reflex changes in blood pressure and muscle vascular resistance but smaller changes in heart rate. No such difference was observed when high-threshold afferents were similarly stimulated.
B Oberg; E Kendrick; P Thorén; G Wennergren
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Acta physiologica Scandinavica     Volume:  113     ISSN:  0001-6772     ISO Abbreviation:  Acta Physiol. Scand.     Publication Date:  1981 Oct 
Date Detail:
Created Date:  1982-02-12     Completed Date:  1982-02-12     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370362     Medline TA:  Acta Physiol Scand     Country:  SWEDEN    
Other Details:
Languages:  eng     Pagination:  129-37     Citation Subset:  IM    
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MeSH Terms
Aorta / innervation*
Atropine / pharmacology
Blood Pressure
Carotid Body / physiology*
Electric Stimulation
Heart / physiology*
Heart Rate
Neurons, Afferent / drug effects,  physiology*
Pressoreceptors / physiology
Reflex / physiology*
Reg. No./Substance:

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