title: Potassium restores vasorelaxation of resistance arterioles in non-hypertensive DOCA/salt fed mice.
abstract: BACKGROUND
  Potassium-enriched diets exert renal and cardiovascular protective effects, but the underlying mechanisms are largely unknown.
  
  
  METHODS
  Using the dorsal skinfold chamber model for intravital microscopy, we examined endothelium-dependent vasorelaxation of precapillary resistance arterioles in response to acetylcholine or the NO donor SNAP in awake mice. Experiments were performed in uni-nephrectomized one renin gene (Ren-1c) C57BL/6 mice (control group) and in mice having received a continuous administration of deoxycorticosterone acetate and a dietary supplementation of 1% sodium chloride for 8 weeks (DOCA/salt group). An additional group of DOCA/salt treated animals received a dietary supplement of 0.4% KCl for 3 weeks prior to the experiments (DOCA/salt + potassium group).
  
  
  RESULTS
  DOCA/salt treatment for 8 weeks resulted in hypokalemia, but blood pressure remained unchanged. In DOCA/salt mice, relaxation of resistance arterioles was blunted in response to acetylcholine, and to a lesser extent to SNAP, suggesting endothelial dysfunction. Endothelium-dependent vasorelaxation was restored by the potassium-enriched diet.
  
  
  CONCLUSIONS
  This study is the first to demonstrate a protective effect of potassium on endothelium-dependent vasorelaxation in the absence of confounding anti-hypertensive effects, as observed in most animal models and the clinical situation. We propose that the known cardio- and nephro-protective effects of potassium might - at least in part - be mediated by the salutary effects on endothelium-dependent arteriolar relaxation.
authors.affiliation: Institute of Pathology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Wyss
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: D
authors.initials: D
authors.lastname: Golshayan
authors.forename: J
authors.initials: J
authors.lastname: Nussberger
authors.forename: M
authors.initials: M
authors.lastname: Burnier
authors.forename: H A
authors.initials: HA
authors.lastname: Lehr
authors.forename: S C
authors.initials: SC
authors.lastname: Schaefer
mesh_terms: D000821:Animal Feed; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001160:Arterioles / Q000187:drug effects* / Q000473:pathology; D001794:Blood Pressure; D003900:Desoxycorticosterone / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000473:pathology; D006973:Hypertension / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008853:Microscopy / Q000379:methods; D008901:Mineralocorticoids / Q000494:pharmacology; D011188:Potassium / Q000737:chemistry / Q000494:pharmacology*; D017673:Sodium Chloride, Dietary / Q000494:pharmacology; D014664:Vasodilation / Q000502:physiology*
chemical_list: D000959:Antihypertensive Agents; D008901:Mineralocorticoids; D017673:Sodium Chloride, Dietary; D003900:Desoxycorticosterone; D011188:Potassium