[The renin-angiotensin system in hypertensive patients with scleroderma and polyarteritis nodosa (author's transl)].

The renin-angiotensin system was studied in 14 normotensive and hypertensive patients with scleroderma and polyarteritis nodosa (PAN). The variations in blood pressure, plasma renin activity (PRA) and serum aldosterone were compared after the Captopril test. Mean arterial pressure fell 15,7 +/- 2,6 p. 100 (p less than 0,01) in hypertensive patients, but no change was observed in normotensive subjects. PRA and serum aldosterone did not change significantly in hypertensives with scleroderma. Large variations in blood pressure, PRA and serum aldosterone were observed in 2 out of 3 patients with PAN, the third one presenting a fall in blood pressure without significant changes in PRA or serum aldosterone. These results suggest that other mechanisms are responsible for hypertension in these patients and that the Captopril acted on other factors than the renin-angiotensin system.