The captopril test in children with renovascular and renal hypertension.

We used the captopril test (CT) in 32 children, 8 with renovascular hypertension (RVH), 17 with renal hypertension (RH) and 7 with normal blood pressure, in order to study the renin-angiotensin system activation (RASA). All children affected by RVH presented a positive CT: a post-captopril plasma renin activity (PRA) of 12 ng ml-1 h-1 or more, an absolute PRA increase of 10 ng ml-1 h-1 or more and a 150% increase or more, or 400% or more if the baseline PRA was less than 3 ng ml-1 h-1. The CT may be useful for demonstrating the RASA in RVH.