Plasma renin activity and blood pressure during long term treatment with propranolol and diuretic

19 primary hypertensive patients were treated in random succession with diuretic, propranolol and the combination of both. It was found that the diuretic gave a sustained increase in plasma renin activity (PRA). There was a negative correlation between PRA level attained and blood pressure reduction. Propranolol treatment gave a sustained reduction of PRA. There was no correlation between PRA reduction and blood pressure reduction. When diuretic was combined with propranolol, PRA was in average at control level, and there was no correlation between the PRA reduction from diuretic value to combination value and the corresponding additional blood pressure fall. It is concluded that propranolol treatment does not transform patients to "low renin hypertensives" specifically sensitive to diuretic treatment.