Effects of beta-adrenergic blockade on diurnal variability of blood pressure and plasma noradrenaline levels.

The effect of propranolol on diurnal variability of BP and plasma noradrenaline levels was assessed in 15 patients with uncomplicated essential hypertension. While total variability and average noradrenaline level remained unaltered, the pressor range (difference between basal and maximum BP readings) was reduced in most patients. An inverse relationship was observed between changes in pressor range and noradrenaline.