Role of renal nerves in sodium depletion-induced salt appetite.
Thunhorst, Robert L., Robert F. Kirby, and Alan Kim Johnson.
Departments of Psychology and Pharmacology and the Cardiovascular
Center, University of Iowa, Iowa City, IA
APStracts 3:0097R, 1996.
The ingestion of water and 0.3 M NaCl solution and the secretion of
key hormones were studied in groups of intact and bilaterally renal
-denervated rats after extracellular fluid depletion. Hypovolemia with
mild hypotension was produced by subcutaneous (sc) injections of the
diuretic, furosemide (10 mg/kg) followed by injections of the
angiotensin-converting enzyme (ACE) inhibitor, captopril (5 mg/kg,
sc). Denervated rats drank significantly less of a concentrated
saline solution in response to depletion compared to intact control
rats but drank similar amounts of water. Denervated rats finished
testing in significantly greater negative water and sodium balance
compared to controls. Renal denervation did not impair the secretion
of renin and aldosterone, or the formation of angiotensin I. The
diminished sodium intake of denervated rats is not attributable to
reduced water and sodium excretion in response to the hypovolemic
protocol. These results indicate that the integrity of the renal
nerves is important for the normal elaboration of salt appetite in
response to hypovolemia/hypotension.
Received 6 September 1995; accepted in final form 6 March 1996.
APS Manuscript Number R595-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 20 March 96