title: Effect of aldosterone on renal potassium conservation in the rat.
abstract: 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 and were compared with 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 with 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 is not independent of mineralocorticoid activity and that the rapid fall in PAC during K depletion is necessary for maximal renal K conservation.
authors.affiliation: Department of Medicine, School of Nursing, University of Rochester, New York 14642, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Ornt
authors.forename: K J
authors.initials: KJ
authors.lastname: Radke
authors.forename: J D
authors.initials: JD
authors.lastname: Scandling
mesh_terms: D000315:Adrenalectomy; D000450:Aldosterone / Q000097:blood / Q000494:pharmacology*; D000818:Animals; D066298:In Vitro Techniques; D007668:Kidney / Q000378:metabolism*; D008297:Male; D009994:Osmolar Concentration; D010477:Perfusion; D011188:Potassium / Q000378:metabolism*; D017419:Potassium, Dietary / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D012083:Renin / Q000097:blood
chemical_list: D017419:Potassium, Dietary; D000450:Aldosterone; D012083:Renin; D011188:Potassium