Comparison of the acute effects of acebutolol and propranolol on blood pressure, heart rate and hormonal changes during graded treadmill exercise in patients with essential hypertension.

The acute effects of propranolol and acebutolol on blood pressure, heart rate and hormonal changes during graded treadmill exercise were studied in patients with essential hypertension. Both of propranolol (2 mg i.v.) and acebutolol (10 mg i.v.) lowered the pre-exercise hemodynamic parameters and suppressed the elevation of systolic blood pressure, heart rate and pressure-rate product during exercise, but did not show any significant effect on diastolic blood pressure. Although these drugs increased plasma norepinephrine concentration (PNE) at rest and during moderate exercise, they failed to affect PNE at submaximal exercise. Plasma renin activity at rest and during exercise were more strongly suppressed by propranolol than acebutolol. Plasma aldosterone concentration was not affected by these drugs. Propranolol and acebutolol showed similar acute effects on blood pressure, heart rate and hormonal profiles at rest and during exercise within the doses used in this study. These results indicate that beta 1 adrenoceptor selectivity and intrinsic sympathomimetic activity may not play an important role in the acute antihypertensive effect at rest and during exercise and that both beta blockers have beneficial antihypertensive effects during exercise on patients with essential hypertension.