| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan; and 2 Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37203
Recently, studies in our laboratory involving the use of a Gaussian white noise technique demonstrated that the transfer function from sympathetic stimulation frequency to heart rate (HR) response showed dynamic characteristics of a second-order low-pass filter. However, determinants for the characteristics remain to be established. We examined the effect of an increase in mean sympathetic stimulation frequency and that of a blockade of the neuronal uptake mechanism on the transfer function in anesthetized rabbits. We found that increasing mean sympathetic stimulation frequency from 1 to 4 Hz significantly (P < 0.01) decreased the dynamic gain of the transfer function without affecting other parameters, such as the natural frequency, lag time, or damping coefficient. In contrast, the administration of desipramine (0.3 mg/kg iv), a neuronal uptake blocking agent, significantly (P < 0.01) decreased both the dynamic gain and the natural frequency and prolonged the lag time. These results suggest that the removal rate of norepinephrine at the neuroeffector junction, rather than the amount of available norepinephrine, plays an important role in determining the low-pass filter characteristics of the HR response to sympathetic stimulation.
dynamic stimulation; Gaussian white noise; neuronal uptake mechanism; systems analysis; transfer function
This article has been cited by other articles:
|
|
 |
|
  T. Kawada, T. Miyamoto, K. Uemura, K. Kashihara, A. Kamiya, M. Sugimachi, and K. Sunagawa Effects of neuronal norepinephrine uptake blockade on baroreflex neural and peripheral arc transfer characteristics Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2004; 286(6): R1110 - R1120. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. C. Malpas Neural influences on cardiovascular variability: possibilities and pitfalls Am J Physiol Heart Circ Physiol, January 1, 2002; 282(1): H6 - H20. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Kawada, S.-L. Chen, M. Inagaki, T. Shishido, T. Sato, T. Tatewaki, M. Sugimachi, and K. Sunagawa Dynamic sympathetic control of atrioventricular conduction time and heart period Am J Physiol Heart Circ Physiol, April 1, 2001; 280(4): H1602 - H1607. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Bertram, C. Barres, Y. Cheng, and C. Julien Norepinephrine reuptake, baroreflex dynamics, and arterial pressure variability in rats Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2000; 279(4): R1257 - R1267. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
