|
|
||||||||
1 Department of Physiology, National Defense Medical College, Namiki, Saitama 359-8513; and 3 Second Department of Physiology, Kagawa Medical University, Miki, Kita, Kagawa 761-0793, Japan; and 2 Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78284-7756
It has been speculated that if baroafferent signals are only related to the negative feedback control of arterial pressure (AP), then physical activity would increase the range of AP fluctuation in baroafferent-denervated animals. Mean AP (MAP), heart rate (HR), and cardiac output (CO) were measured for 24 h in free-moving conscious rabbits. On the basis of hydrostatic pressure and electromyogram, MAP data taken during periods of physical activity and rest were selected from the overall 24-h MAP data and then converted into histograms. During physical activity, the mode of MAP histogram increased in intact rabbits and was unchanged in sinoaortic-denervated (SAD) rabbits. Movement increased the mode of total peripheral resistance (TPR) but did not significantly change CO in intact rabbits. Conversely in SAD rabbits, movement slightly decreased TPR and slightly increased CO. These findings indicate that arterial baroafferent signals are required to shift MAP to a higher pressure level by an increase in TPR but not in CO during a moving phase. These results suggest that baroafferent signals may not only minimize the fluctuating range of MAP through negative feedback control but also be involved in actively resetting MAP toward a higher pressure level during daily physical activity.
24-h arterial pressure; histogram; exercise pressor response; baroreflex; chemoreflex; cardiac output; negative feedback; feedforward control; homeodynamic; mean arterial pressure
This article has been cited by other articles:
![]() |
O. Ziv, E. Morales, Y.-k. Song, X. Peng, K. E. Odening, A. E. Buxton, A. Karma, G. Koren, and B.-R. Choi Origin of complex behaviour of spatially discordant alternans in a transgenic rabbit model of type 2 long QT syndrome J. Physiol., October 1, 2009; 587(19): 4661 - 4680. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Masuki and H. Nose Arterial baroreflex control of muscle blood flow at the onset of voluntary locomotion in mice J. Physiol., November 15, 2003; 553(1): 191 - 201. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Komine, K. Matsukawa, H. Tsuchimochi, and J. Murata Central command blunts the baroreflex bradycardia to aortic nerve stimulation at the onset of voluntary static exercise in cats Am J Physiol Heart Circ Physiol, July 11, 2003; 285(2): H516 - H526. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-K. Liu, S.-J. Guild, J. V. Ringwood, C. J. Barrett, B. L. Leonard, S.-K. Nguang, M. A. Navakatikyan, and S. C. Malpas Dynamic baroreflex control of blood pressure: influence of the heart vs. peripheral resistance Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2002; 283(2): R533 - R542. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |