Vascular relaxation probably mediates the antihypertensive effect of a high-potassium diet: a role for enhanced vascular Na,K-ATPase activity

J Hypertens. 1995 Dec;13(12 Pt 1):1433-9.


Objective: to evaluate the effect of dietary potassium on blood pressure and vascular contractility in adult rats of two strains, spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats.

Design: 'Potassium-induced relaxation' was evaluated in aortic rings as a functional measure of Na,K-ATPase activity in the vascular wall. The rats were fed one of three diets: regular (American Institute of Nutrition-76 rat chow); high-sodium (7% sodium chloride) or high-sodium plus potassium (7% sodium chloride and 13.4% potassium citrate) for 12 +/- 1 weeks.

Results: SHR fed the high-sodium diet had a mean blood pressure of 157 +/- 8 mmHg, as compared with 130 +/- 9 mmHg for those on a regular diet (P < 0.01). SHR fed the potassium-supplemented diet had a blood pressure of 122 +/- 9 mmHg (P < 0.01 versus the high-sodium diet group). The mean blood pressure of WKY rats was 78 +/- 3 mmHg and did not differ among the dietary groups. The 'potassium-induced relaxation' response of aortic rings from SHR and WKY rats fed a potassium-supplemented diet was significantly higher (P < 0.05) than that in animals in the corresponding high-sodium dietary group. This observation in potassium-supplemented rats is interpreted as indicative of increased Na,K-ATPase activity in the vascular wall.

Conclusions: A potassium-rich diet in SHR receiving a high sodium intake was associated with lower blood pressure and higher vascular Na,K-ATPase activity. A similar effect of this diet on vascular Na,K-ATPase was observed in WKY. We propose that the antihypertensive effect of a potassium-rich diet is mediated, at least in part, by stimulation of vascular Na,K-ATPase activity.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Aorta / enzymology*
  • Blood Pressure / physiology*
  • Diet
  • In Vitro Techniques
  • Potassium / administration & dosage*
  • Potassium / pharmacology
  • Rats
  • Rats, Inbred SHR
  • Rats, Inbred WKY
  • Sodium-Potassium-Exchanging ATPase / metabolism*
  • Vasodilation / physiology*


  • Sodium-Potassium-Exchanging ATPase
  • Potassium