title: Beta-adrenergic regulation of circadian rhythmicity of the renin-angiotensin-aldosterone system in five subtypes of essential hypertension.
abstract: The possible implication of the beta-sympathoadrenergic system in regulating the rhythmicity of the renin-angiotensin-aldosterone system (RAAS) was studied in ten normotensive volunteers and in thirty-nine essential hypertensive patients. The study was carried out by simultaneous radioimmunological measurements of diurnal levels of plasma renin and aldosterone before and during acute oral medication of beta-adrenoceptors with propranolol. Acute beta-blockade was seen to blunt the circadian periodicity of plasma renin and aldosterone in normotensives and in hypertensives with normal or high renin patterns. Conversely propranolol was seen to be ineffective in low-renin patients. The disappearance of the circadian rhythms under beta-adrenoceptor blockade tends to suggest the existence of a beta-adrenergic control of RAAS cyclicity in normal condition, as well as in normal or high renin essential hypertension. The inefficacy of propranolol in hyporeninemic hypertensives is consistent with the hypothesis that low-renin essemtoa; juertemsopm os a state in which the sympatho beta-adrenergic mechanism controlling the function of RAAS has no biologic time structure.
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D000450:Aldosterone / Q000097:blood*; D000804:Angiotensin II / Q000097:blood*; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000503:physiopathology; D008297:Male; D012083:Renin / Q000097:blood*; D013564:Sympathetic Nervous System / Q000503:physiopathology
chemical_list: D000319:Adrenergic beta-Antagonists; D000804:Angiotensin II; D000450:Aldosterone; D012083:Renin