Document Detail

Arterial baroreflex resetting mediates postexercise reductions in arterial pressure and heart rate.
MedLine Citation:
PMID:  9815070     Owner:  NLM     Status:  MEDLINE    
We tested the hypothesis that postexercise reductions in arterial pressure and heart rate (HR) are mediated by a lowering of the operating point and a reduction in the gain of the arterial baroreflex. To test this hypothesis, spontaneous changes in arterial pressure and the reflex responses of HR were examined before and after a single bout of mild to moderate dynamic exercise in 19 spontaneously hypertensive rats (SHR, 10 male and 9 female). Eleven SHR subjected to sinoaortic denervation (SAD) (6 male, 5 female) were also studied. All rats were instrumented with an arterial catheter for the measurement of arterial pressure and HR. After exercise, arterial pressure and HR were reduced below preexercise levels. Furthermore, the operating point and spontaneous gain (G) of the arterial baroreflex were reduced. Specifically, after exercise, the spontaneous range of HR (P1, 50%), the pressure at the midpoint of the pressure range (P3, 13%) and the HR at the midpoint of the HR range (H3, 10%), the spontaneous minimum HR (P4, 8%) and maximum HR (10%), and G (76%) were significantly attenuated. SAD significantly attenuated the relationship between arterial pressure and HR by reducing G (males 94%, females 95%). These results demonstrate that acute exercise resulted in a postexercise resetting of the operating point and a reduction in the gain of the arterial baroreflex. Furthermore, these data suggest that postexercise reductions in arterial pressure and HR are mediated by a lowering of the operating point of the arterial baroreflex.
M P Chandler; D W Rodenbaugh; S E DiCarlo
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  275     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1998 Nov 
Date Detail:
Created Date:  1998-12-10     Completed Date:  1998-12-10     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H1627-34     Citation Subset:  IM; S    
Department of Physiology, Wayne State University, School of Medicine, Detroit, Michigan 48201, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Arteries / innervation,  physiopathology*
Autonomic Denervation
Baroreflex / physiology*
Blood Pressure / physiology
Heart Rate / physiology
Hypertension / blood,  physiopathology*
Physical Conditioning, Animal
Rats, Inbred SHR
Grant Support

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

Previous Document:  Endothelin-receptor blockade does not alter closure of the ductus arteriosus.
Next Document:  Dynamic restitution of action potential duration during electrical alternans and ventricular fibrill...