title: Effect of the angiotensin II receptor antagonist losartan on uric acid and oxypurine metabolism in healthy subjects.
abstract: OBJECTIVE
  The acute effects of the angiotensin II receptor antagonist losartan on uric acid and oxypurine metabolism were evaluated.
  
  
  METHODS
  Losartan (50 mg) was administered orally to 6 healthy males. Blood and urine samples for uric acid and oxypurine were collected before and up to 6 hours after losartan administration. The same examinations were performed later using enalapril (5 mg).
  
  
  RESULTS
  Losartan decreased the serum uric acid concentration (from 5.9 +/- 0.9 to 5.2 +/- 1.0 mg/dl) and increased its fractional clearance, which reached a maximum after 2 hours, while enalapril did not. Losartan also induced an increase in the plasma concentration of hypoxanthine, peaking in the fourth hour, and a decrease in its urinary clearance, while the plasma xanthine concentration and its urinary clearance were unchanged. The extent of uric acid excretion was much greater than that of the oxypurines.
  
  
  CONCLUSIONS
  Losartan, which has a high affinity for the urate/anion exchanger, has a transient uricosuric effect. Our data indicate that losartan induces a significant decrease in the urinary excretion of hypoxanthine without changes in xanthine.
authors.affiliation: Department of Cardiovascular Medicine, Tottori University Hospital, Yonago.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Hamada
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hisatome
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kinugasa
authors.forename: Koichi
authors.initials: K
authors.lastname: Matsubara
authors.forename: Hideki
authors.initials: H
authors.lastname: Shimizu
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Masako
authors.initials: M
authors.lastname: Furuse
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Sonoyama
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Akira
authors.initials: A
authors.lastname: Ohtahara
authors.forename: Osamu
authors.initials: O
authors.lastname: Igawa
authors.forename: Chiaki
authors.initials: C
authors.lastname: Shigemasa
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000328:Adult; D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents / Q000494:pharmacology*; D004656:Enalapril / Q000494:pharmacology; D006801:Humans; D019271:Hypoxanthine / Q000652:urine; D019808:Losartan / Q000494:pharmacology*; D008297:Male; D010117:Oxypurinol / Q000652:urine*; D014527:Uric Acid / Q000097:blood*; D019820:Xanthine / Q000652:urine
chemical_list: D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents; D019820:Xanthine; D014527:Uric Acid; D019271:Hypoxanthine; D004656:Enalapril; D010117:Oxypurinol; D019808:Losartan