NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Neural blockade during exercise augments central command's contribution to carotid baroreflex resettingThis investigation was designed to determine central command's role on carotid baroreflex (CBR) resetting during exercise. Nine volunteer subjects performed static and rhythmic handgrip exercise at 30 and 40% maximal voluntary contraction (MVC), respectively, before and after partial axillary neural blockade. Stimulus-response curves were developed using the neck pressure-neck suction technique and a rapid pulse train protocol (+40 to -80 Torr). Regional anesthesia resulted in a significant reduction in MVC. Heart rate (HR) and ratings of perceived exertion (RPE) were used as indexes of central command and were elevated during exercise at control force intensity after induced muscle weakness. The CBR function curves were reset vertically with a minimal lateral shift during control exercise and exhibited a further parallel resetting during exercise with neural blockade. The operating point was progressively reset to coincide with the centering point of the CBR curve. These data suggest that central command was a primary mechanism in the resetting of the CBR during exercise. However, it appeared that central command modulated the carotid-cardiac reflex proportionately more than the carotid-vasomotor reflex.
Document ID
20040112526
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Querry, R. G.
(Department of Integrative Physiology and Cardiovascular Research Institute, University of North Texas Health Science Center Fort Worth, Texas 76107, United States)
Smith, S. A.
Stromstad, M.
Ide, K.
Raven, P. B.
Secher, N. H.
Date Acquired
August 21, 2013
Publication Date
April 1, 2001
Publication Information
Publication: American journal of physiology. Heart and circulatory physiology
Volume: 280
Issue: 4
ISSN: 0363-6135
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Cardiopulmonary
Non-NASA Center

Available Downloads

There are no available downloads for this record.
No Preview Available