title: Effect of aldosterone on potassium excretion during potassium chloride infusion in sheep.
abstract: Experiments were performed on normal mature ewes to quantitate the effect of acute variations in aldosterone activity on renal K excretion. Six-hour clearance studies were performed on three sheep. Treatments were control (no infusion), infusion of KCl (140 meq in 2 h) alone or with superimposed infusions of aldosterone (20 micrograms/h), or infusion of aldosterone antagonist potassium canrenoate (100 mg/h). During KCl infusion there were simultaneous increases in plasma K, K excretion, and Na excretion. Aldosterone treatment diminished the increase in plasma K and in Na excretion but increased the rate of K excretion. Canrenoate had opposite effects. The rate of change of K excretion relative to the change in plasma K was 417 for aldosterone and 102 microeq/min per meq/l for canrenoate treatments, P less than 0.05. Before KCl infusion aldosterone decreased the rate of Na excretion and the salivary Na-to-K ratio but did not alter plasma K or K excretion. Aldosterone has a potent kaliuretic action in sheep when plasma K is elevated.
mesh_terms: D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D002191:Canrenoic Acid / Q000494:pharmacology; D005260:Female; D006706:Homeostasis; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D000451:Mineralocorticoid Receptor Antagonists / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology*; D012756:Sheep / Q000502:physiology*; D012964:Sodium / Q000378:metabolism
chemical_list: D000451:Mineralocorticoid Receptor Antagonists; D000450:Aldosterone; D011189:Potassium Chloride; D002191:Canrenoic Acid; D012964:Sodium; D011188:Potassium