title: Alterations of renal hemodynamics in unilateral ureteral obstruction mediated by activation of endothelin receptor subtypes.
abstract: OBJECTIVE
  Unilateral ureteral obstruction (UUO) for 21 hours causes severe renal vasoconstriction. We examined the role of endothelin (ET)-A receptor in renal hemodynamic alterations induced by UUO.
  
  
  METHODS
  Hemodynamic and clearance experiments were performed in 3 groups of anesthetized dogs. In group 1, 6 sham operated dogs received intrarenal infusion of the specific ET-A receptor antagonist BQ-610 (Peninsula Laboratories, Inc., Belmont, California), followed by infusion of the nitric oxide synthase substrate L-arginine. In the 7 group 2 dogs release of 21-hour UUO was followed by intrarenal infusion of BQ-610 and L-arginine. In the 5 group 3 dogs release of 21-hour UUO was followed by L-arginine infusion.
  
  
  RESULTS
  UUO caused marked decreases in renal blood flow (RBF) and glomerular filtration rate (GFR) in groups 2 and 3 compared with group 1. In group 1 BQ-610 and L-arginine infusion did not alter RBF or GFR. In contrast, BQ-610 infusion in group 2 after UUO release led to a significant increase in RBF and GFR as well as additional increases after L-arginine infusion. After UUO release in group 3 L-arginine infusion alone did not change RBF or GFR.
  
  
  CONCLUSIONS
  After UUO release blockade of the ET-A receptor ameliorates renal vasoconstriction. The addition of L-arginine, which is a substrate for nitric oxide synthase, superimposed on ET-A receptor blockade confers a further decrease in renal vascular resistance, suggesting that the ET and L-arginine-nitric oxide systems are involved in renal hemodynamic alterations caused by UUO.
authors.affiliation: Department of Urology, Brookdale University Hospital and Medical Center, Brooklyn, NY, USA.
authors.forename: Darshan K
authors.initials: DK
authors.lastname: Bhangdia
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Gulmi
authors.forename: Shyan-Yih
authors.initials: SY
authors.lastname: Chou
authors.forename: Unni M
authors.initials: UM
authors.lastname: Mooppan
authors.forename: Hong
authors.initials: H
authors.lastname: Kim
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology; D004285:Dogs; D065130:Endothelin A Receptor Antagonists; D016232:Endothelins / Q000502:physiology; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D007668:Kidney / Q000098:blood supply*; D009842:Oligopeptides / Q000494:pharmacology; D044022:Receptor, Endothelin A / Q000502:physiology*; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D014517:Ureteral Obstruction / Q000503:physiopathology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology
chemical_list: D065130:Endothelin A Receptor Antagonists; D016232:Endothelins; D009842:Oligopeptides; D044022:Receptor, Endothelin A; C087220:BQ 610; D001120:Arginine