Defective venous beta-adrenergic response in borderline hypertensive subjects is corrected by a low sodium diet

J Clin Invest. 1990 Mar;85(3):647-52. doi: 10.1172/JCI114487.

Abstract

Hypertensive patients have reduced lymphocyte beta-adrenergic responsiveness which is corrected by a low sodium (Na) diet. To determine if this represents a more generalized abnormality in beta adrenoceptor response, we studied beta adrenergic-mediated vasodilation in hand veins of borderline hypertensive subjects and controls. Subjects received a 5-d diet containing high Na/low potassium (K), high Na/high K, or low Na/high K. Venous distension, as evaluated by a linear variable differential transformer, was measured in relation to infusion of phenylephrine followed by isoproterenol and nitroglycerin. On both the high Na/high K and high Na/low K diets, hypertensive subjects had significantly decreased isoproterenol-mediated vasodilation (47% decrease, P less than 0.01 and 36% decrease, P less than 0.01, respectively). On the low Na/high K diet, isoproterenol-mediated vasodilation in hypertensive subjects increased 41% (P less than 0.01) to a level not different from controls. Nitroglycerin-mediated vasodilation was not different in normotensive and hypertensive subjects, nor was it altered with Na intake. Phenylephrine-mediated vasoconstriction did not differ between normotensive and hypertensive groups. Venous beta-adrenergic response correlated with lymphocyte beta adrenoceptor density in normotensive (r = 0.53, P less than 0.005) but not hypertensive subjects. This study demonstrates that beta-adrenergic responsiveness is selectively reduced in peripheral veins of borderline hypertensive subjects, and this is corrected by a low Na diet. In view of our previous findings of reduced lymphocyte beta-adrenergic responsiveness in borderline hypertension, these studies suggest a generalized defect of beta adrenoceptor responsiveness in human hypertension. Further, dietary Na may play an important role in regulating this abnormality.

Publication types

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

MeSH terms

  • Adult
  • Blood Pressure / drug effects
  • Catecholamines / blood
  • Diet, Sodium-Restricted*
  • Electrolytes / urine
  • Humans
  • Hypertension / diet therapy
  • Hypertension / physiopathology*
  • Isoproterenol / pharmacology
  • Male
  • Receptors, Adrenergic, beta / analysis
  • Receptors, Adrenergic, beta / physiology*
  • Renin / blood
  • Vasodilation / drug effects
  • Veins / physiopathology*

Substances

  • Catecholamines
  • Electrolytes
  • Receptors, Adrenergic, beta
  • Renin
  • Isoproterenol