title: Protective effects of dietary potassium chloride on hemodynamics of Dahl salt-sensitive rats in response to chronic administration of sodium chloride.
abstract: BACKGROUND
  Dietary potassium supplementation decreases blood pressure and prevents strokes in humans, and prevents strokes and renal damage in Dahl salt-sensitive (DSS) rats.
  
  
  OBJECTIVE
  To study the effects of various concentrations of dietary potassium chloride (KCl) on the hemodynamics of Dahl salt-resistant (DSR) and DSS rats receiving a 1% sodium chloride (NaCl) diet for 8 months, to determine whether there is an optimal dietary concentration of KCl that minimizes increases in blood pressure and causes least impairment of blood flow in the brain and kidneys.
  
  
  RESULTS
  We found a biphasic effect on hemodynamic parameters as a function of dietary KCl in DSS rats of the Rapp strain fed 1% NaCl with increasing dietary KCl (0.7, 2.6, 4 and 8%). After 8 months receiving a diet containing 1% NaCl and 0.7% KCl, DSS rats had mean arterial pressures (MAP), plasma volumes, cardiac outputs and renal and cerebral vascular resistances that were significantly increased compared with those of DSR rats receiving the same diet. With a 2.6% KCl diet, all these parameters were significantly reduced compared with those in DSS rats fed the 0.7% KCl diet and were similar to those in DSR rats fed 2.6% KCl. Total peripheral resistance in DSR and DSS rats was similar on all diets. When KCl was increased to 4 and 8%, MAP, plasma volume, cardiac output and renal vascular resistance progressively increased in DSR and DSS rats, without changing total peripheral resistance. These changes paralleled increases in plasma aldosterone, which resulted from adrenocortical stimulation by the increasing dietary KCl; however, cerebral vascular resistance of DSR and DSS rats decreased significantly with a 4% KCl diet, despite increased aldosterone and sodium retention. Only DSS rats fed a 2.6% KCl diet had hemodynamics similar to those of DSR control rats fed the same diet, and hyperaldosteronism, sodium retention and increased plasma volume did not occur.
  
  
  CONCLUSIONS
  'Optimal' dietary KCl (2.6%) prevents hypertension and preserves cerebral and renal hemodynamics in DSS rats fed a diet containing 1% NaCl for 8 months, which causes hypertension when dietary KCl is limited or excessive.
authors.affiliation: Department of Medicine, New York University, NY, USA.
authors.forename: William M
authors.initials: WM
authors.lastname: Manger
authors.forename: Shlomoh
authors.initials: S
authors.lastname: Simchon
authors.forename: Charles T
authors.initials: CT
authors.lastname: Stier
authors.forename: Joseph
authors.initials: J
authors.lastname: Loscalzo
authors.forename: Kung-Ming
authors.initials: KM
authors.lastname: Jan
authors.forename: Rex
authors.initials: R
authors.lastname: Jan
authors.forename: Francis
authors.initials: F
authors.lastname: Haddy
mesh_terms: D000450:Aldosterone / Q000097:blood; D000818:Animals; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001794:Blood Pressure / Q000187:drug effects; D001806:Blood Urea Nitrogen; D001921:Brain / Q000098:blood supply / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000187:drug effects; D003404:Creatinine / Q000097:blood; D003971:Diastole / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006439:Hemodynamics / Q000187:drug effects*; D007668:Kidney / Q000098:blood supply / Q000378:metabolism; D023421:Models, Animal; D008955:Models, Cardiovascular; D010953:Plasma Volume / Q000187:drug effects; D017419:Potassium, Dietary / Q000008:administration & dosage* / Q000378:metabolism; D051381:Rats; D020303:Rats, Inbred Dahl; D012039:Regional Blood Flow / Q000187:drug effects; D012079:Renal Circulation / Q000187:drug effects; D012083:Renin / Q000097:blood; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage* / Q000378:metabolism; D013599:Systole / Q000187:drug effects; D013997:Time Factors
chemical_list: D015415:Biomarkers; D017419:Potassium, Dietary; D017673:Sodium Chloride, Dietary; D000450:Aldosterone; D003404:Creatinine; D012083:Renin