The relation of renin-angiotensin status to general hemodynamics and to neurogenic vascular resistance was studied in patients with border-line hypertension. Plasma renin activity during standing was referred to a standard renin-urinary sodium nomogram derived from 18 normal subjects. Among 22 patients with borderline hypertension the renin level was high in 8, low in 4 and within normal limits...

We have studied the contribution of circulating renin of renal origin to renin-like activity within the arterial wall and to blood pressure. Bolus injections of renin sufficient to elevate blood pressure by 44.7 mm Hg caused aortic renin to rise from 0.13 to 1.48 ng angiotensin I/100 mg/hr in nephrectomized rats. Elevation of aortic renin was still present at 6 hours, and this was associated wi...

1. Because hypertension is the central feature of pre-eclampsia, and because plasma renin activity is known to be elevated in normal pregnancy (with conflicting results published for pre-eclampsia), a prospective study of plasma renin activity was conducted in pregnancy, under conditions of a fixed sodium intake, in 178 initially normotensive volunteer subjects. Thirty of these women developed ...

Peripheral venous renin activity was determined by the method of Boucher in 15 patients with cirrhosis of the liver and ascites who were on an unrestricted sodium intake. Positive sodium balance was present in all subjects. Marked elevation of mean plasma renin activity (43 ng angiotensin II/min per liter, SD ± 38) was present. The mean plasma renin activity in 16 normal ambulatory subjects on ...

Aliskiren, a direct renin inhibitor, blocks the first step of the renin–angiotensin–aldosterone system (RAAS), thereby reducing plasma renin activity and the circulating levels of angiotensin I, angiotensin II, and aldosterone. Extensive RAAS blockade can be achieved through the administration of aliskiren; however, renin blockade is a double-edged sword because the renin/prorenin receptor-asso...

Plasma renin activity and renin substrate were measured in nine groups of rats which were maintained for 7 wk on diets in which the proportions of sodium and potassium were varied. Balance data indicated that the highest dietary intake of potassium employed (92 mEq K(+)/100 g food) consistently induced sodium depletion. With less consistency, the highest sodium intake employed (52 mEq Na(+)/100...

Arterial plasma renin activity in the rabbit was measured at the beginning and end of a brisk hemorrhage and 40 min later. Activity rose to a mean of two and one-half times the control value during the hemorrhage, and was five times greater than the control 40 min later. The rise in plasma renin activity was not due to anesthesia, as light pentobarbitone produced no change. Conscious rabbits, s...

1. Acebutolol, a beta1-receptor blocker, has, at a daily dose of 800 mg, a mild but significant anti-hypertensive effect in moderate sustained essential hypertension with normal or low plasma renin activity. 2. Prediction of its anti-hypertensive effect is better based on the evaluation of the sympathetic nervous system responsiveness to head-up tilt than on the evaluation of plasma renin activ...

Cardiopulmonary receptors modulate renin release in several animals species. However, their involvement in reflex control of this humoral substance in humans is controversial. Furthermore, no information is available on the alteration of this control in hypertension. We studied the modulation of plasma renin activity (radioimmunoassay) in 12 normotensive subjects and in 12 age-matched subjects ...

Inactive renin in rat arterial walls was investigated according to the following experiments. Dialysis at pH 7.4 following dialysis at pH 3.3 of the arterial tissue resulted in a significant rise of renin activity, from a control value of 0.41 +/- 0.07 to 0.62 +/- 0.06 ng/ml/h (p less than 0.01). Treatment with trypsin of the arterial tissue caused a rapid and apparent increase in the renin act...