The effects of verapamil SR and bisoprolol on reducing the sympathetic nervous system's activity

To assess the response of the sympathetic nervous system (SNS) to the handgrip test in essential hypertensive patients and to evaluate the effects of verapamil SR and bisoprolol on the reduction of the SNS's activity. Seventy eight essential hypertensive patients (50 receiving verapamil SR treatment and 28 receiving bisoprolol treatment) took the handgrip test while the SBP, DBP, and HR were measured on three occasions during the test (before test, 3 min after the patients squeezed the handgrip, and 2 min after the handgrip was released). Before and after the patients received Verapamil SR or Bisoprolol treatment, the plasma concentrations of epinephrine(E), norepinephrine (NE), angiotensin-II (AII), aldosterone (ALD), endothelin-1 (ET-1) and renin activity (RA) were measured post-test. 1) In about 70% of the essential hypertensive patients, SNS activity was above normal. Their HR and BP exceeded 20% when responding to stress. 2) In these patients, the baseline plasma concentrations of E, NE, AII, ET-1, ALD, and RA were higher than those whose SNS's activity was normal. 3) After 6 weeks of treatment, all the patients' BPs decreased remarkably. Verapamil SR could reduce the plasma concentrations of NE, AII, and ET-1 and increase RA. Bisoprolol could reduce E and RA. These two antihypertension drugs can both decrease BP and reduce the activity of SNS through different mechanisms.