title: Effect of potassium supplementation on renal tubular function, ambulatory blood pressure and pulse wave velocity in healthy humans.
abstract: BACKGROUND
  Potassium is the main intracellular cation, which contributes to keeping the intracellular membrane potential slightly negative and elicits contraction of smooth, skeletal and cardiac muscle. A change in potassium intake modifies both cardiovascular and renal tubular function. The purpose of the trial was to investigate the effect of dietary potassium supplementation, 100 mmol daily in a randomized, placebo-controlled, crossover trial of healthy participants during two periods of 28 days duration. The participants (N = 21) received a diet that was standardized regarding energy requirement, and sodium and water intake.
  
  
  METHODS
  24-hour ambulatory blood pressure (ABP) and applanation tonometry were used to assess blood pressure, pulse wave velocity (PWV), augmentation index (AIx) and central blood pressure (CBP). Immunoassays were used for measurements of plasma concentrations of vasoactive hormones: renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), atrial natriuretic peptide (ANP), vasopressin (AVP), pro-brain natriuretic peptide (pro-BNP),endothelin (Endo), urinary excretions of aquaporin 2 (AQP2), cyclic AMP (cAMP), and the β-fraction of the epithelial sodium channel (ENaC(ß)).
  
  
  RESULTS
  AQP2 excretion increased during potassium supplementation, and free water clearance fell. The changes in urinary potassium excretion and urinary AQP2 excretion were significantly and positively correlated. Aldo increased. GFR, u-ENaC- β, PRC, Ang II, ANP, BNP, Endo, blood pressure and AI were not significantly changed by potassium supplementation, whereas PWV increased slightly.
  
  
  CONCLUSIONS
  Potassium supplementation changed renal tubular function and increased water absorption in the distal part of the nephron. In spite of an increase in aldosterone in plasma, blood pressure remained unchanged after potassium supplementation.
authors.affiliation: Department of Medical Research, Holstebro Regional Hospital, Laegaardvej 12, 7500 Holstebro, Denmark. Solveig.Klok.Matthesen@vest.rm.dk
authors.forename: Solveig K
authors.initials: SK
authors.lastname: Matthesen
authors.forename: Thomas
authors.initials: T
authors.lastname: Larsen
authors.forename: Henrik
authors.initials: H
authors.lastname: Vase
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Lauridsen
authors.forename: Erling B
authors.initials: EB
authors.lastname: Pedersen
mesh_terms: D000293:Adolescent; D000328:Adult; D000450:Aldosterone / Q000097:blood; D000804:Angiotensin II / Q000097:blood; D051399:Aquaporin 2 / Q000652:urine; D001127:Arginine Vasopressin / Q000097:blood; D009320:Atrial Natriuretic Factor / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects*; D018592:Cross-Over Studies; D000242:Cyclic AMP / Q000652:urine; D019587:Dietary Supplements; D016232:Endothelins / Q000097:blood; D053503:Epithelial Sodium Channels / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood; D011188:Potassium / Q000494:pharmacology / Q000652:urine; D012083:Renin / Q000097:blood; D012964:Sodium / Q000652:urine; D059289:Vascular Stiffness / Q000187:drug effects*; D055815:Young Adult
chemical_list: D051399:Aquaporin 2; D016232:Endothelins; D053503:Epithelial Sodium Channels; D000804:Angiotensin II; D001127:Arginine Vasopressin; D020097:Natriuretic Peptide, Brain; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D012964:Sodium; D000242:Cyclic AMP; D012083:Renin; D011188:Potassium