Document Detail

Two sites for modulation of human sympathetic activity by arterial baroreceptors?
MedLine Citation:
PMID:  11251065     Owner:  NLM     Status:  MEDLINE    
1. Peroneal muscle sympathetic nerve activity (MSA), finger blood pressure and cardiac intervals were recorded at rest in 60 healthy subjects, aged 18-71 years. Arterial baroreflex control of MSA was analysed by relating each spontaneous sympathetic burst to the diastolic blood pressure and the cardiac interval of the heart beat during which the burst was generated. The results were expressed as blood pressure/cardiac interval threshold for occurrence of bursts, and as baroreflex sensitivity (i.e. the relationship between diastolic pressure/cardiac interval and burst strength). 2. Significant blood pressure/cardiac interval thresholds were present in all subjects and old subjects had less variability of thresholds than young subjects. In contrast, significant baroreflex sensitivity for diastolic pressure and cardiac interval was present in only 55 and 73 % of the subjects, respectively. There was no age-related difference in sensitivity. 3. In 40 subjects, two 5 min periods from the same recording were analysed. The number of sympathetic bursts and the threshold for occurrence of bursts were reproducible in all subjects. In contrast, significant baroreflex sensitivity in both periods was present in only 30 % (diastolic pressure) and 40 % (cardiac interval) of the subjects. 4. The results show that the baroreflex mechanisms regulating the occurrence and strength of sympathetic bursts are not identical. We suggest that the modulation occurs at two sites, one which determines whether or not a burst will occur, and another at which the strength of the discharge is determined.
P Kienbaum; T Karlssonn; Y B Sverrisdottir; M Elam; B G Wallin
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of physiology     Volume:  531     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  2001 Mar 
Date Detail:
Created Date:  2001-03-19     Completed Date:  2001-05-17     Revised Date:  2013-06-11    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  861-9     Citation Subset:  IM    
Institute of Clinical Neuroscience, Unit of Clinical Neurophysiology, Sahlgren Hospital, University of Göteborg, Sweden.
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MeSH Terms
Arteries / innervation*
Baroreflex / physiology
Blood Pressure / physiology
Differential Threshold
Fingers / blood supply
Heart Rate / physiology
Middle Aged
Muscle, Skeletal / innervation
Pressoreceptors / physiology*
Reproducibility of Results
Sympathetic Nervous System / physiology*

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