Release of plasma atrial natriuretic peptide after volume expansion is not related to pituitary-adrenal axis diurnal variation in normal subjects

• Published in: Brazilian journal of medical and biological research Vol. 30; no. 5; pp. 621 - 625
• Main Authors: Elias, L L, Antunes-Rodrigues, J, Moreira, A C
• Format: Journal Article
• Language: English; Portuguese
• Published: Brazil Associação Brasileira de Divulgação Científica 01.05.1997
• Subjects: ACTH; Adrenal Glands - metabolism; Adrenocorticotropic Hormone - blood; Adult; ANP; Atrial Natriuretic Factor - blood; BIOLOGY; Circadian Rhythm - physiology; cortisol; diurnal variation; Female; Humans; Hydrocortisone - blood; Male; MEDICINE, RESEARCH & EXPERIMENTAL; Pituitary Gland - metabolism; Plasma Substitutes; ACTH; cortisol; ANP; diurnal variation
• ISSN: 0100-879X; 1414-431X; 0100-879X; 0034-7310
• DOI: 10.1590/S0100-879X1997000500008

The existence of a circadian rhythm of atrial natriuretic peptide (ANP) in humans is controversial. We studied the plasma ANP response to isotonic blood volume expansion in the morning and in the afternoon and its relationship with adrenocorticotropic hormone (ACTH)-cortisol diurnal variation in seven normal subjects. Basal plasma ANP level was similar in the morning (19.6 +/- 2.4 pg/ml) and in the afternoon (21.8 +/- 4.8 pg/ml). The ANP peak obtained with saline infusion (0.9% NaCl, 12 ml/kg) in the morning (49.4 +/- 8 pg/ml) did not differ from that obtained in the afternoon (60.3 +/- 10.1 pg/ml). There was no correlation between the individual mean cortisol and ACTH levels and the ANP peak obtained with saline infusion. These data indicate no diurnal variation in plasma ANP secretion induced by blood volume expansion and no relationship between plasma ANP peak and ACTH-cortisol diurnal variation.