1. Chronic ambulatory peritoneal dialysis allows good control of blood pressure in patients with hypertensive end-stage renal disease. The role of the renin-angiotensin-aldosterone system has therefore been studied in seven patients during the first 6 months of chronic ambulatory peritoneal dialysis treatment.
2. Steady increases in plasma renin activity and aldosterone were observed with a good correlation between these two variables. Plasma electrolytes, renin substrate and body weight did not change significantly.
3. Angiotensin II perfusion tests, performed at the end of the study, showed a relative vascular resistance to angiotensin II.
4. Stimulation of the renin-angiotensin-aldosterone system may be partially explained by this last observation or by removal of an unknown vasopressor substance responsible for the inhibition of the plasma renin activity.