Effects of Moderate Salt Restriction and High Potassium Intake on Intralymphocytic Sodium Content and Pressor Response to Stress in Borderline Hypertension

Abstract

1. Twenty young subjects with borderline hypertension were studied to evaluate the effects of moderate salt restriction and/or of a high potassium intake on intralymphocytic sodium content and blood pressure. Blood pressure was measured after 1 min (casual) and after 5 min (baseline) of rest and during handgrip. 2. Moderate sodium restriction (from 170 to 100 mmol of sodium/day) decreased both intralymphocytic sodium content and diastolic blood pressure at rest and during handgrip. During a high potassium diet (130 mmol of potassium/day) both intralymphocytic sodium content and baseline diastolic blood pressure rose significantly whereas casual diastolic blood pressure remained unchanged and pressor response to handgrip was reduced by 50%. 3. The increase in intralymphocytic sodium content induced by the high potassium diet was dose-dependent. A daily dose of 0.8 mmol of potassium/kg body weight produced the maximal protective effect on blood pressure during exercise with minimal effects on intralymphocytic sodium content and baseline blood pressure. 4. In borderline subjects a low sodium/high potassium diet seems to produce the most favourable effect, since intralymphocytic sodium content and baseline blood pressure remain unchanged whereas the pressor response to handgrip is reduced.