title: Effects of dietary salt changes on renal renin-angiotensin system in rats.
abstract: Renin (RA) and angiotensin-converting enzyme (ACE) activities and angiotensinogen, ANG I, and ANG II levels were measured in the kidney (cortex and medulla) and plasma of Wistar-Kyoto rats on a low-sodium (LS; 0.025% NaCl; n = 8), normal-sodium (NS; 1% NaCl; n = 7), or high-sodium (HS; 8% NaCl; n = 7) diet for 21 days. RA, ANG I, and ANG II levels increased in a manner inversely related to sodium content of the diet in both plasma and renal tissues. The LS diet resulted in a 16-, 2.8-, and 1.8-fold increase in plasma RA, ANG I, and ANG II levels, respectively, compared with those in HS rats. In the renal cortex and medulla, RA, ANG I, and ANG II levels were also increased by diminution of dietary salt content but, in contrast to plasma, ANG II levels increased much more than RA or ANG I levels [5.4 (cortex)- and 4.7 (medulla)-fold compared with HS rats]. In summary, we demonstrated variations of ANG II levels in the kidney during dietary salt modifications. Our results confirm that RA and ACE activity are not the steps limiting intrarenal ANG II levels. Nevertheless, despite RA and ACE activity differences between renal cortex and medulla, ANG I and ANG II levels are equivalent in these two tissues; these results argue against a compartmentalization of RAS in these two intrarenal areas.
authors.affiliation: Institut de Pharmacologie, Faculté de Médecine, Université Louis Pasteur, 67085 Strasbourg, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Ingert
authors.forename: Michèle
authors.initials: M
authors.lastname: Grima
authors.forename: Catherine
authors.initials: C
authors.lastname: Coquard
authors.forename: Mariette
authors.initials: M
authors.lastname: Barthelmebs
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Imbs
mesh_terms: D000803:Angiotensin I / Q000032:analysis / Q000097:blood; D000804:Angiotensin II / Q000032:analysis / Q000097:blood; D000808:Angiotensinogen / Q000032:analysis / Q000097:blood; D000818:Animals; D007672:Kidney Cortex / Q000737:chemistry / Q000201:enzymology; D007679:Kidney Medulla / Q000737:chemistry / Q000201:enzymology; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000032:analysis / Q000097:blood; D051381:Rats; D011921:Rats, Inbred WKY; D012083:Renin / Q000032:analysis / Q000097:blood; D012084:Renin-Angiotensin System / Q000187:drug effects*; D017673:Sodium Chloride, Dietary / Q000494:pharmacology*
chemical_list: D017673:Sodium Chloride, Dietary; D000808:Angiotensinogen; D000804:Angiotensin II; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A; D012083:Renin