Characteristics of renal sympathetic nerve activity in sodium
retaining disorders.
Dibona, Gerald F., Linda L. Sawin, and Susan Y. Jones.
Department of Internal Medicine, University of Iowa College of
Medicine
APStracts 3:0066R, 1996.
Characteristics of renal sympathetic nerve activity in conscious rats
with established congestive heart failure, cirrhosis or nephrotic
syndrome were analyzed using three methods: mean integrated voltage
over time, power spectrum analysis and sympathetic peak detection
analysis. Compared to control rats, all three disease models had
increased mean integrated voltage. On power spectrum analysis, all
three disease models had increased relative power at the heart rate
frequency, indicating that it was related to renal sympathetic nerve
discharge coupled to the cardiac cycle. Congestive heart failure and
nephrotic syndrome rats showed increased relative power in the low
frequency range while cirrhotic and nephrotic syndrome rats showed
decreased relative power in the high frequency range. On sympathetic
peak detection analysis, the frequency of sympathetic peaks was
greater in the three disease models compared to the control rats. In
cirrhotic rats, the distribution of sympathetic peak heights was
shifted towards an increased number of peaks of lesser height. It is
concluded that basal renal sympathetic nerve activity is chronically
increased in these disease models. This is manifest as increased
power coupled to the cardiac cycle which may reflect the disease
specific defects in arterial and cardiac baroreflex control. In
cirrhosis, there is possible selective activation of a subgroup of
renal sympathetic nerve fibers.
Received 7 November 1995; accepted in final form 19 February
1996.
APS Manuscript Number R697-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96