title: Inappropriately high circulating and intrarenal angiotensin II levels during dietary salt loading exacerbate hypertension in Cyp1a1-Ren-2 transgenic rats.
abstract: OBJECTIVE
  We evaluated the effects of salt restriction and of increasing dietary salt loading on blood pressure and the renin-angiotensin system in transgenic rats with inducible hypertension.
  
  
  METHODS
  Hypertension was induced in Cyp1a1-Ren-2 rats through dietary administration of the natural xenobiotic indole-3-carbinol (0.3%), which activates the renin gene. Rats were fed either a normal-salt diet (0.6% NaCl), three different high-salt diets (2, 4 and 8% NaCl) or a low-salt diet (<0.04% NaCl). Blood pressure was monitored by radiotelemetry. Angiotensin II (ANG II) levels were determined by radioimmunoassay.
  
  
  RESULTS
  Induction of the renin gene by administration of indole-3-carbinol resulted in normal-salt diet fed animals in the development of severe hypertension that was accompanied by marked increases in plasma and kidney ANG II levels. Feeding the low-salt diet substantially attenuated the development of hypertension. Treatment with the 2 and 4% high-salt diet did not worsen the course of hypertension and did not alter ANG II levels when compared with rats on the normal salt diet. Feeding the 8% high-salt diet exacerbated the course of hypertension and was associated with further strong increases in plasma and kidney ANG II levels.
  
  
  CONCLUSIONS
  Our results demonstrate that after induction of the renin gene in Cyp1a1-Ren-2 transgenic rats inappropriate increases in plasma and kidney ANG II levels in response to very high dietary salt intake are responsible for the development of severe hypertension in this model of inducible renin transgenic rats.
authors.affiliation: Department for Experimental Medicine, Institute for Clinical and Experimental Medicine, 1958/9 Vídenská, Prague, Czech Republic.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Husková
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Vanourková
authors.forename: Michaela
authors.initials: M
authors.lastname: Erbanová
authors.forename: Monika
authors.initials: M
authors.lastname: Thumová
authors.forename: Martin
authors.initials: M
authors.lastname: Opocenský
authors.forename: John J
authors.initials: JJ
authors.lastname: Mullins
authors.forename: Herbert J
authors.initials: HJ
authors.lastname: Kramer
authors.forename: Marcela
authors.initials: M
authors.lastname: Bürgelová
authors.forename: Ludek
authors.initials: L
authors.lastname: Cervenka
mesh_terms: D000450:Aldosterone / Q000097:blood; D000804:Angiotensin II / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure; D003404:Creatinine / Q000652:urine; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics / Q000378:metabolism*; D006973:Hypertension / Q000378:metabolism* / Q000503:physiopathology; D007668:Kidney / Q000378:metabolism*; D008297:Male; D051381:Rats; D055647:Rats, Transgenic; D012083:Renin / Q000235:genetics / Q000378:metabolism*; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*
chemical_list: C535029:Ren2 protein, rat; D017673:Sodium Chloride, Dietary; D000804:Angiotensin II; D000450:Aldosterone; D003404:Creatinine; D019363:Cytochrome P-450 CYP1A1; D012083:Renin