Hemodynamic effects of acute and prolonged administration of nitrendipine in essential hypertension

In six hospitalized subjects with mild or moderate and untreated essential hypertension, we measured mean blood pressure (MBP, brachial artery catheter), heart rate (HR, electrocardiogram), cardiac output (CO, thermodilution), and total peripheral resistance (TPR, MBP divided by CO) at rest and during a cold pressor test (CPT, 60 s), a handgrip exercise (HG, 40% maximum strength for 90 s), and a cyclette exercise (CE, 50 W for 5 min). The study was performed in a no-drug condition, 1 h after 20 mg oral nitrendipine (aN) and 1 week after daily administration of 20 mg oral nitrendipine (pN). Compared with the no-drug condition, aN reduced resting MBP from 137.3 ± 7.3 (mean ± SEM) to 112.3 ±9 mm Hg (p < 0.05), increased resting HR from 72.3 ± 6.9 to 85.3 ± 8.8 beats/min) (p < 0.05), increased resting CO from 6,191 ±508 to 8,700 ± 1,050 ml/min (p < 0.05), and reduced resting TPR from 1,807 ± 119 to 1,140 ± 228 dynes/s/cm5 (p < 0.05). The reduction in resting MBP and TPR were unchanged by p...