Use of captopril in the diagnostic work-up of renovascular hypertension.

A total of 179 patients were selected for a diagnostic work-up of renovascular hypertension from a consecutive series of hypertensive patients referred to a single outpatient clinic between January 1978 and January 1985. Selection criteria were: (1) diagnostic blood pressure > 120 mmHg in patients of 40 years or younger, irrespective of whether they were on treatment or not, and/or (2) diastolic blood pressure > 100 mmHg despite combination therapy with at least three drugs. All patients underwent renal angiography.

Asynchronous changes in prorenin and renin secretion after captopril in patients with renal artery stenosis.

An assay of plasma prorenin was developed in which the conversion to renin occurred under apparently optimal conditions. Some characteristics of the assay were 1) prorenin was activated by Sepharose-bound trypsin at 4 degrees C; 2) the concentration of activator was not critical provided that incubation was prolonged until renin activity had reached a plateau; and 3) this plateau was stable and had the same height as after maximal activation with acid, pepsin, plasmin or urokinase. Maximal activity with Sepharose-bound trypsin at 4 degrees C was higher than with cryoactivation, and optimal conditions were more readily reproduced than with trypsin at 37 degrees C or with acid-activation.