Plasma renin activity in patients with renovascular hypertension.

Changes of plasma renin activity (PRA) were studied in 45 patients with renovascular hypertension. Peripheral PRA was assayed by Serebovskaya's modification of Pickens' biological method; in 13 patients it was additionally assayed in blood samples taken from both renal veins. In some of the patients who were not surgically treated PRA was followed up over a period of 1 to 5 years. The interrelation between PRA and the sex and age of the patients, the duration and the severity of the disease, the clinical and the morphological type of renovascular hypertension, as well as uni- or bilateral involvement of the renal artery is discussed. PRA was increased during the early stage of renovascular hypertension, while later it became normal. PRA of renal vein blood samples, from the kidney with a constricted renal artery, reflects more exactly the dynamics of the changes in the pressor system of the kidney. The assay of PRA is of special importance in the evaluation of the indications for surgical treatment and of the effect of reconstructive surgery.