Document Detail

Dynamic characteristics of baroreflex neural and peripheral arcs are preserved in spontaneously hypertensive rats.
MedLine Citation:
PMID:  21048073     Owner:  NLM     Status:  MEDLINE    
Although baroreceptors are known to reset to operate in a higher pressure range in spontaneously hypertensive rats (SHR), the total profile of dynamic arterial pressure (AP) regulation remains to be clarified. We estimated open-loop transfer functions of the carotid sinus baroreflex in SHR and Wistar Kyoto (WKY) rats. Mean input pressures were set at 120 (WKY₁₂₀ and SHR₁₂₀) and 160 mmHg (SHR₁₆₀). The neural arc transfer function from carotid sinus pressure to efferent splanchnic sympathetic nerve activity (SNA) revealed derivative characteristics in both WKY and SHR. The slope of dynamic gain (in decibels per decade) between 0.1 and 1 Hz was not different between WKY₁₂₀ (10.1 ± 1.0) and SHR₁₂₀ (10.4 ± 1.1) but was significantly greater in SHR₁₆₀ (13.2 ± 0.8, P < 0.05 with Bonferroni correction) than in SHR₁₂₀. The peripheral arc transfer function from SNA to AP showed low-pass characteristics. The slope of dynamic gain (in decibels per decade) did not differ between WKY₁₂₀ (-34.0 ± 1.2) and SHR₁₂₀ (-31.4 ± 1.0) or between SHR₁₂₀ and SHR₁₆₀ (-32.8 ± 1.3). The total baroreflex showed low-pass characteristics and the dynamic gain at 0.01 Hz did not differ between WKY₁₂₀ (0.91 ± 0.08) and SHR₁₂₀ (0.84 ± 0.13) or between SHR₁₂₀ and SHR₁₆₀ (0.83 ± 0.11). In both WKY and SHR, the declining slope of dynamic gain was significantly gentler for the total baroreflex than for the peripheral arc, suggesting improved dynamic AP response in the total baroreflex. In conclusion, the dynamic characteristics of AP regulation by the carotid sinus baroreflex were well preserved in SHR despite significantly higher mean AP.
Toru Kawada; Shuji Shimizu; Atsunori Kamiya; Yusuke Sata; Kazunori Uemura; Masaru Sugimachi
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-11-03
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  300     ISSN:  1522-1490     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2011 Jan 
Date Detail:
Created Date:  2010-12-24     Completed Date:  2011-01-20     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R155-65     Citation Subset:  IM    
Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan.
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MeSH Terms
Baroreflex / physiology*
Blood Pressure / physiology*
Carotid Sinus / physiology
Disease Models, Animal
Heart Rate / physiology
Hypertension / physiopathology*
Peripheral Nervous System / physiopathology*
Pressoreceptors / physiology
Rats, Inbred SHR
Rats, Inbred WKY

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

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