CHRONOBIOLOGICAL ANALYSIS OF PLASMA-CONCENTRATIONS OF ATRIAL-NATRIURETIC-PEPTIDE IN PATIENTS WITH MODERATE ESSENTIAL-HYPERTENSION AND IN NORMAL SUBJECTS

A group of hormones with potent diuretic/natriuretic activity, vasorelaxing properties and aldosterone secretion inhibiting action, are synthesized within the myocytes of cardiac atria and secreted by the stimulation of atrial stretch receptor. They are frequently elevated in hypertensives and may show a circadian rhythmicity in normal subjects. In the present study, to investigate the circadian pattern of ANF, we measured its plasma concentrations in a group of 12 healthy subjects and in a group of 10 patients with mild essential hypertension. None of the 10 hypertensives and of the 12 normotensives showed a significant circadian rhythm of ANF plasma concentrations. Also, we did not demonstrate a significant group rhythm for the two populations studied. Furthermore, no difference was seen in ANF plasma levels between mild hypertensives and healthy control subjects.