title: Control of renin release by dietary NaCl in the rat.
abstract: The purpose of the present study is to determine whether changes of plasma renin activity (PRA) induced by dietary NaCl are mediated by a renal tubular mechanism or by a neural mechanism. Male Sprague-Dawley rats were placed on low-, normal-, or high-NaCl diets for 1 wk (n = 8 for each group). There were no group differences of glomerular filtration rate (GFR), renal plasma flow, Na+ or Cl- delivery to the loop, Na+ or Cl- reabsorption in the loop, Na+ or Cl- concentration in early distal tubular fluid, or Na+ or Cl- delivery to the early distal tubule. PRA of rats on normal NaCl (4.8 ng.ml-1.h-1 +/- 0.8) was greater (P less than 0.05) than that of rats on high NaCl (3.3 +/- 0.4) and less (P less than 0.05) than that of animals on low NaCl (9.1 +/- 1.8). To determine whether alterations of PRA by dietary NaCl might be related to low-pressure baroreceptors with vagal afferents, animals were bilaterally vagotomized after micropuncture. Forty-five minutes after vagotomy, PRA increased (P less than 0.05) on each of the diets, however, after vagotomy mean PRA in animals fed normal (10.9 +/- 1.8) and low NaCl (13.2 +/- 2.2) did not differ. Thus our results do not support the hypothesis that suppression of PRA by dietary NaCl loading is related to a renal tubular mechanism. A vagally mediated mechanism may contribute to renin suppression by dietary NaCl.
authors.affiliation: Department of Medicine, University of Kentucky School of Medicine, Lexington 40536.
authors.forename: W J
authors.initials: WJ
authors.lastname: Welch
authors.forename: C E
authors.initials: CE
authors.lastname: Ott
authors.forename: J N
authors.initials: JN
authors.lastname: Lorenz
authors.forename: T A
authors.initials: TA
authors.lastname: Kotchen
mesh_terms: D000818:Animals; D001835:Body Weight; D002712:Chlorides / Q000378:metabolism; D004573:Electrolytes / Q000652:urine; D005919:Glomerular Filtration Rate / Q000187:drug effects; D007668:Kidney / Q000098:blood supply; D007684:Kidney Tubules / Q000187:drug effects / Q000502:physiology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects; D012083:Renin / Q000097:blood*; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D012982:Sodium, Dietary / Q000494:pharmacology*
chemical_list: D002712:Chlorides; D004573:Electrolytes; D012982:Sodium, Dietary; D012965:Sodium Chloride; D012964:Sodium; D012083:Renin