title: Circadian rhythm of plasma aldosterone and time dependent alterations of aldosterone regulators.
abstract: In order to investigate the relative contribution of ACTH, the renin angiotensin and dopaminergic system to the circadian rhythm of plasma aldosterone, hormone levels were determined at hourly intervals over a 24 h span in four supine healthy men. Blood was withdrawn under basal conditions (control), after either dexamethasone, captopril or bromocriptine++ (CB-154) administration. Plasma aldosterone rhythmicity was abolished in dexamethasone treated groups but not in captopril or CB treated groups. Time dependent alterations of aldosterone regulators were analyzed by multiple regression methods at 3 hourly intervals. These results indicate that plasma aldosterone rhythmicity is predominantly under the control of ACTH whereas the renin angiotensin or dopaminergic system plays a little role. In supine, sodium repleted states, ACTH is a potent stimulus of aldosterone at 000-0600 h and 1700-1900 h clocktime, whereas during daytime renin-angiotensin is an additional regulator.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000450:Aldosterone / Q000097:blood*; D001971:Bromocriptine / Q000494:pharmacology; D002216:Captopril / Q000494:pharmacology; D002940:Circadian Rhythm; D003907:Dexamethasone / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D011388:Prolactin / Q000097:blood; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System
chemical_list: D001971:Bromocriptine; D000450:Aldosterone; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D002216:Captopril; D012083:Renin; D004298:Dopamine; D006854:Hydrocortisone