APStracts 2:0180R, 1995.

Spectral analysis of arterial pressure lability in rats with sinoaortic deafferentation. Jacob, Howard J., Arvind Ramanathan, Shaugun G. Pan, Glenn A. Myers, and Michael J. Brody. Departments of Pharmacology and Cardiovascular Center and Biomedical Engineering, University of Iowa Colleges of Medicine and Engineering, Iowa City, Iowa 52242

APStracts 2:0180R, 1995.

Traditionally, the standard deviation (SD) of the mean arterial pressure has been used as an index for the arterial pressure lability produced by interruption of baroreceptor afferents. Although a useful measure of variance about the mean, the SD does not provide any information about the temporal characteristics of this variability. We employed two different spectral analytical techniques to characterize arterial pressure (AP) waveforms in sinoaortic deafferented (SAD) and Sham-operated (Sham) rats, to determine if the AP waveform in SAD animals was qualitatively and/or quantitatively different from that of Sham animals. The SAD and Sham animals exhibited qualitatively different spectral profiles suggesting that lability of arterial pressure in SAD animals is not simply an exaggeration of normal fluctuations. In addition, a low frequency (0.3-0.5 Hz) spectral peak was found in Sham but not SAD animals suggesting that it is associated with the baroreflex. Finally, we observed in both normal rats and rats without intact baroreceptors that the spectral components of arterial pressure are not static but rather vary continuously across time.

Received 16 September 1994; accepted in final form 7 June 1995
APS Manuscript Number R0521-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 11 July 1995.