[The renin angiotensin system in the pathology of arterial hypertension of aortic coarctation].

Nine patients with aortic coarctation were studied. On the fourth day of a low diet, blood samples were obtained for plasma renin activity (PRA) at 8:00 A.M., 11:00 A.M. and 5:00 P.M. On the same day a 24 hour urinary collection was obtained for the determination of aldosterone excretion. The following day 60 mg. of furosemide were given orally at 8:00 A.M. and another blood sample was drawn at noon. This study protocol was done before and after surgical correction of the aortic lesion. Mean systolic and diastolic blood pressure decreased significantly (P less than 0.005), while mean PRA and urinary aldosterone values showed no significant modifications after surgery. With these results, it is concluded that the renin-angiotensin-aldosterone system, does not seem to play a role in the chronic hypertension of the coarctation of the aorta. However, tests with angiotensin II specific blockers have to be performed before a definite conclusion can be drawn on this point.