[Corticotropin studies in essential hypertension].

The plasma-ACTH of healthy test persons and of patients suffering from spontaneous hypertension were measured by RIA. In the latter group it was decreased in 17 of 21 cases, where as the serum cortisol was increased. Further examinations are necessary for the clarification of this phenomenon. Clonidine clearly reduced plasma ACTH, serum cortisol and renin activity.