1. In eight normal subjects, ten patients with labile hypertension, six with advanced essential hypertension and six with renovascular hypertension, plasma renin concentration, cardiac output, mean arterial pressure, clearances of creatinine and p-aminohippurate (PAH), and sodium excretion were measured before and after 30 min of 45" upright tilting. Changes in plasma adrenaline and noradrenali...

Hemodynamic and biochemical effects of the new renin inhibitor CGP 38560A (molecular weight 826) were tested in 15 healthy volunteers after a single-blind, randomized, placebo-controlled protocol. At a 2-week interval, groups of five subjects received a 30-minute infusion of either 5% dextrose or CGP 38560A 50, 125, or 250 micrograms/kg. Blood pressure, heart rate, plasma renin activity, active...

The relationship of active renin and inactive renin (trypsin-activated angiotensin-I-forming enzyme) to sodium depletion was examined in renal and peripheral plasma and at the subcellular level in the kidneys of dogs. Subcellular fractionation was carried out by discontinuous sucrose density (1.5 and 1.6 M) centrifugation. Sodium depletion selectively caused a six- to sevenfold increase in the ...

The interrelationships of arterial pressure, plasma volume (PV), and plasma renin activity were studied in 152 consecutive male patients with uncomplicated essential hypertension. Of these, 22 (17 white and 5 black) subjects had normal plasma volumes and because of the small number were not included in the analysis of results. The remaining 130 (35 black and 95 white) patients were classified a...

1. The role of the sympathetic nervous system in the release of renin during head-up tilt has been studied in five normal subjects and in four tetraplegic patients with cervical spinal-cord transection above the sympathetic outflow. Blood pressure, heart rate and concentrations of plasma noradrenaline, plasma adrenaline and plasma renin activity were measured during head-up tilt to 45 degrees b...

Plasma renin activity and one-dimensional echocardiographic measurements of the left atrium and left ventricle as well as function indices were studied repeatedly in 20 children with various cardiopathies (ages: 9 months to 15 years) before and after corrective surgery. Nine children had tetralogy of Fallot, four had pulmonary stenosis, four had rheumatic heart disease, two had ventricular sept...

The effect of the renin inhibitor enalkiren (Abbott-64662) was evaluated in eight normal volunteer subjects on a standardized sodium diet (100 mmol/day) by measurement of various components of the renin-angiotensin system and drug levels in plasma. On day 1, vehicle and doses of 0.001, 0.003, and 0.01 mg/kg i.v. were administered within 2 minutes at 90-minute intervals. On day 2, vehicle and do...

Hepatic blood flow, hepatic extraction of renin, and hepatic clearance of renin were compared in normal conscious dogs, in dogs with constriction of the thoracic inferior vena cava (as a model of low-output heart failure), and in dogs with an aortic-caval fistula (high-output heart failure). Both "failure" preparations showed marked sodium retention. Renin was measured by methods described prev...

Excretion of renin into urine was studied using specific assay methods in normal subjects and hospital patients. Urinary renin output and renal clearance of renin varied widely among normal subjects but remained similar over months in any one subject. Renin clearance was significantly less in normal males (range 12 to 893 ml/24 hours) than females (79 to 3,149 ml/24 hours), but no reason for th...

Simplified methods are described for the measurement of human plasma renin "concentration" (PRC) and "activity" (PRA) based on the denaturation of renin substrate in which separation and concentration steps are avoided and recovery of renin is complete. In the PRA method effective inhibition of angiotensinase is achieved by warming plasma at pH 4.5 with EDTA followed by dialysis to pH 7.5. Neit...