title: Renal cyclic 3',5'-guanosine monophosphate and sodium excretion in Dahl salt-resistant and Dahl salt-sensitive rats: comparison of the roles of bradykinin and nitric oxide.
abstract: OBJECTIVE
  The purpose of this study was to determine the relative importance of bradykinin and nitric oxide (NO) in mediating renal responses to altered sodium intake in Dahl salt-resistant (Dahl-SR) and salt-sensitive (Dahl-SS) rats.
  
  
  METHODS
  Dahl-SR and Dahl-SS rats consumed a diet containing 0.15% (low) or 4.0% (high) sodium chloride for 10 days. A microdialysis technique was then used to measure renal cortical interstitial fluid (RIF) cyclic 3',5'-guanosine monophosphate (cGMP) production in anesthetized rats, under baseline conditions and during acute cortical infusion of either the bradykinin B2 receptor antagonist icatibant or the NO synthase inhibitor nitro-L-arginine methyl ester (L-NAME). Urine sodium excretion was monitored simultaneously by ureter cannulation. Results Baseline sodium excretion was similar in the two types of rats, but RIF cGMP was significantly elevated in Dahl-SR compared to Dahl-SS rats on both low and high sodium diets. Icatibant infusion significantly reduced both RIF cGMP and sodium excretion in Dahl-SR rats during low sodium intake, but had no effect in Dahl-SS rats on either diet L-NAME infusion significantly reduced sodium excretion in Dahl-SR and Dahl-SS rats, during both low and high sodium intake. L-NAME infusion caused a significant reduction in RIF cGMP in Dahl-SR and Dahl-SS rats on low sodium diet, but reduced RIF cGMP only in Dahl-SR rats on high sodium diet. Conclusion These data suggest a potential role for cortical bradykinin, but not NO, in mediating the differences in the renal response to low sodium intake between Dahl-SR and Dahl-SS rats.
authors.affiliation: Department of Internal Medicine, University of Virginia Health System, Charlottesville 22908, USA.
authors.forename: L J
authors.initials: LJ
authors.lastname: Millatt
authors.forename: H M
authors.initials: HM
authors.lastname: Siragy
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000502:physiology*; D006152:Cyclic GMP / Q000378:metabolism*; D005260:Female; D006973:Hypertension / Q000209:etiology*; D007668:Kidney / Q000378:metabolism*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D051381:Rats; D020303:Rats, Inbred Dahl; D012964:Sodium / Q000378:metabolism*
chemical_list: D009569:Nitric Oxide; D012964:Sodium; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP; D001920:Bradykinin; D019331:NG-Nitroarginine Methyl Ester