[Diurnal variation and responses of corticoids to dexamethasone and ACTH before and after adrenal surgery in primary aldosteronism].

We studied diurnal variation and the responses of plasma corticoids to dexamethasone and ACTH before and after adrenal surgery in 11 patients with primary aldosteronism. Diurnal variation of plasma corticoids was examined in all cases. Before adrenal surgery, plasma aldosterone (Ald) was higher at all times, deoxycorticosterone (DOC) was high value at 5:00 and then normal value, 11-deoxycortisol (S) was high value at 5:00 and 9:00, thereafter normal value, while corticosterone (B) and cortisol (F) were almost normal value at all times. The circadian rhythm was observed in these corticoids. Dexamethasone (2 mg/day) was administered to 8 patients for 10 days. Plasma Ald and DOC were significantly suppressed only at 5:00, while B, S and F almost suppressed at all times. After dexa suppression, the circadian rhythm of Ald still observed, while the diurnal variation of the other corticoids was even. ACTH (1 microgram) was injected intravenously to 9 patients. Responses of DOC, B and Ald were higher, and of S and F were almost normal. Diurnal variation of plasma corticoids was observed after 1 month of adrenal surgery. Ald was lower, the other corticoids were normal values. ACTH (1 microgram) was injected to the same case before surgery. Responses of these corticoids to ACTH were slightly lower. Contents of Ald in adenoma tissues were higher than those in adjacent and normal adrenal tissues, and the contents of the other corticoids in adenoma tissue were almost normal value. As these results showed, before surgery these corticoids were secreted from adenoma without ACTH, although these were responsible to ACTH, and the presence of regulative factor of circadian rhythm except ACTH was suggested. After surgery, not only the responses to ACTH of mineralocorticoids but these of glucocorticoids decreased.