Effect of aldosterone on renal potassium conservation in the
rat.
Ornt, Daniel B., Karen J. Radke, John D. Scandling,.
Departments of Medicine and Pediatrics, University of Rochester,
Rochester, New York, 14642, School of Nursing, and Department of
Physiology, School of Medicine and Dentistry, University of
Rochester, Rochester, New York, 14642, Department of Medicine,
University of Rochester, Rochester, New York, 14642
APStracts 3:0037E, 1996.
The importance of reduced plasma aldosterone concentration (PAC) in
renal potassium (K) conservation is unclear. Thus, we examined the
effect of aldosterone on incipient, developing and established renal
K conservation. Adrenalectomized (ADX), dexamethasone-replaced rats
were continuously treated with high, normal, or low dosages of
aldosterone during 4 days of dietary K restriction as compared to
rats without aldosterone replacement. High and normal aldosterone
replacement reduced the fall in urinary K excretion and led to
significantly lower plasma [K], skeletal muscle tissue K content,
renal tissue K content, and greater negative cumulative balance of K
compared to low aldosterone replacement. Likewise, plasma [K] and
skeletal muscle tissue K content were significantly less in intact
rats after 3 days of K deprivation and chronic treatment with
aldosterone. Acute aldosterone treatment significantly increased
urinary K excretion by isolated perfused kidneys. We conclude that
incipient, developing and established renal K conservation are not
independent of mineralocorticoid activity, and that the rapid fall in
PAC during K depletion is necessary for maximal renal K conservation.
Received 7 August 1995; accepted in final form 10 January 1996.
APS Manuscript Number E371-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 14 February 96