Hormonal responses to treatment of high blood pressure with low-salt diet alone and combined with added potassium.

One week strict sodium depletion in essential hypertensive men (n = 17) decreased blood pressure and body weight. Plasma renin concentration increased four-fold (p less than 0.001), plasma noradrenaline with 38% (p less than 0.001), plasma dopamine with 58% while plasma adrenaline remained unchanged. The urinary excretion of vasopressin was reduced with 50% (p less than 0.001). Extra potassium induced only small changes when already sodium depleted. Thus, vasopressin was the only pressor hormone which varied directly with sodium intake, blood pressure and body weight during sodium depletion.