Increased urinary aquaporin-2 excretion in response to furosemide in patients with chronic heart failure

• Published in: Scandinavian journal of clinical and laboratory investigation 2006, Vol.66 (1), p.55-66
• Main Authors: Starklint, J., Bech, J. N., Nyvad, O., Jensen, P., Pedersen, E. B.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Angiotensin II - blood; Aquaporin 2 - urine; Arginine vasopressin; Arginine Vasopressin - blood; Atrial Natriuretic Factor - blood; Blood Pressure - drug effects; Chronic Disease; clinical trial; Cross-Over Studies; Female; Furosemide - therapeutic use; Glomerular Filtration Rate - drug effects; Heart Failure - urine; Humans; loop diuretics; Male; Middle Aged; Natriuresis - drug effects; Natriuretic Peptide, Brain - blood; Renin - blood; water channels
• ISSN: 0036-5513; 1502-7686
• DOI: 10.1080/00365510500452955

Objective. Patients with chronic heart failure (CHF) have decreased ability to excrete water and increased urinary excretion of aquaporin-2 (U-AQP2). The natriuretic and diuretic effects of furosemide are antagonized by an increased reabsorption of sodium and water in the collecting ducts. It is unknown whether aquaporin-2 (AQP2) renal water channels are involved in this compensatory reabsorption. We tested the hypothesis that U-AQP2 increases after a single intravenous dose of furosemide in CHF patients. Material and methods. In a randomized, single-blind, placebo-controlled, crossover study, we measured the effect of furosemide (80 mg) on U-AQP2, urine volume, free water clearance (CH2O) and fractional excretion of sodium (FENa) in 12 CHF patients. Plasma concentrations of vasopressin (AVP), renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), atrial (ANP) and brain natriuretic peptides (BNP) were measured during the study. U-AQP2 and hormones were determined by radioimmunoassays. Results. Furosemide increased U-AQP2 (140 %), urine volume (280 %), CH2O (95 %) and FENa by a factor of 15 (p