[Secretory regulation and episodic secretion of aldosterone in patients with primary aldosteronism (author's transl)].

In nine patients with primary aldosteronism (PA), plasma aldosterone was measured in order to evaluate a role of the renin-angiotensin system, ACTH and potassium in the secretion of aldosterone. The circadian rhythm and the episodic secretion were also studied in three patients. The results were as follows: 1) In seven out of nine patients, plasma aldosterone levels (PAL) decreased after the two-hours standing, and it run parallel with plasma cortisol levels (PCL), but not with plasma renin activity (PRA). 2) An intravenous infusion of saline of 2000 ml during four hours failed to suppress PAL in all of five patients and the change of PAL was parallel with that of PCL. 3) PAL decreased markedly after the oral administration of 1 mg of dexamethasone (Dexa), and there was a significantly positive correlation (r = 0.898, p less than 0.01) between basal PAL and the its decrement. 4) Following an intravenous infusion of angiotensin-II at a rate of 0.015 microgram/Kg/min after the pretreatment with Dexa, no significant increase of PAL was observed in any of the five patients. 5) Following a single injection of 0.25 mg of ACTH after the pretreatment with Dexa, PAL rose rapidly, and its peak level was found 60 minutes after the injection. In four out of eight patients this rise was greater than that in the normal subjects. 6) An intravenous infusion of 20 mEq of KCl after the pretreatment with Dexa, produced normal response i.e., an increase of PAL in all seven of the patients. 7) The circadian rhythm and the episodic secretion of PAL in the patients were synchronous with those of PCL throughout twenty four hours.