Does nifedipine reveal a functional abnormality of arteriolar smooth muscle cell in essential hypertension--the effect of altering sodium balance.

Nifedipine, given to both normotensive and hypertensive subjects, caused a greater fall in blood pressure the higher the initial blood pressure. Increasing salt intake enhanced the acute blood-pressure-lowering effect of nifedipine in both normotensive and hypertensive subjects. In hypertensive subjects on longer-term treatment with nifedipine tablets, the addition of bendrofluazide caused no further significant fall in blood pressure. These findings provide circumstantial evidence that there may be a link between sodium intake, sodium balance, and inhibitor of sodium transport, and a functional abnormality of the smooth muscle cell to calcium-entry antagonists.