title: Effects of uroguanylin on natriuresis in experimental nephrotic rats.
abstract: OBJECTIVE
  Uroguanylin, isolated from human and opossum urine, is a candidate intestinal natriuretic hormone that controls the sodium and water balance between the intestine and the kidneys. Levels of immunoreactive (ir)-uroguanylin in the plasma and urine are increased in rats and humans with nephrotic syndrome, which is physiologically characterized by sodium retention with massive proteinuria. The present study evaluates the effect of natriuresis induced by uroguanylin on nephrotic rats.
  
  
  METHODS
  Normal rats and rats rendered nephrotic by injections of puromycin aminonucleoside (PAN) were treated with uroguanylin (0.5 nmol/h, delivered by an osmotic pump) or with vehicle during the sodium retention phase. All rats consumed the same quantity of sodium.
  
  
  RESULTS
  Uroguanylin did not increase urinary excretion of sodium and water in normal rats, but significantly increased urinary sodium excretion during the sodium retention phase in nephrotic rats (untreated vs uroguanylin-treated nephrotic rats in mmol/mmol creatinine; 2.92 +/- 0.65 vs 8.93 +/- 2.53 on day 6, P < 0.05; 3.55 +/- 0.47 vs 10.37 +/- 1.73 on day 7, P < 0.01; 14.88 +/- 2.32 vs 24.47 +/- 2.86 on day 8, P < 0.05). Plasma levels of ir-uroguanylin in uroguanylin-treated nephrotic rats on day 6 were significantly increased compared with those in uroguanylin-treated control and untreated nephrotic rats.
  
  
  CONCLUSIONS
  Uroguanylin increased urinary sodium excretion in rats with PAN-induced nephrosis, and might be useful for treating sodium retention in patients with nephrotic syndrome.
authors.affiliation: Department of Internal Medicine, University of Miyazaki, Japan. akikob@fc.miyazaki-u.ac.jp
authors.forename: Akiko
authors.initials: A
authors.lastname: Baba
authors.forename: Shouichi
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Masao
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kita
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kitamura
mesh_terms: D000818:Animals; D006162:Guanylate Cyclase / Q000502:physiology; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D045265:Natriuretic Peptides / Q000494:pharmacology*; D009404:Nephrotic Syndrome / Q000652:urine*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D045265:Natriuretic Peptides; C084362:uroguanylin; D006162:Guanylate Cyclase