title: Endocrine and renal response to water loading and water restriction in normal man.
abstract: 1. Nine normal subjects (eight male, one female) on a fixed daily intake of 150 mmol of sodium and 80 mmol of potassium, were randomized to receive either 3 days of 1.0 litre total water intake/24 h (food + fluid) or 4 days of 6.8 litres total water intake/24 h, and were then crossed over after a 3 day control period (2.7 litres water/24 h). 2. During water restriction, urine volume fell from 1.94 litres/24 h to less than 1 litre/24 h by the first day and was 0.77 litre/24 h on the final day. Plasma atrial natriuretic peptide levels were unchanged from baseline despite a large increase in plasma vasopressin and plasma and urine osmolality. Urinary sodium was unaltered throughout, while urinary potassium was increased on the final 2 days of water restriction. 3. During water loading, urine volume increased from 1.85 litres/24 h to 5.44 litres/24 h on the first day and remained at approximately 6 litres/24 h for the final 3 days. Plasma atrial natriuretic peptide showed no change. Plasma vasopressin and plasma and urine osmolality were reduced. Urinary sodium and potassium output were unchanged from baseline. 4. These results suggest that changes in plasma atrial natriuretic peptide are unlikely to be involved in the normal homoeostatic response to changes in water balance in man.
authors.affiliation: Department of Medicine, Charing Cross and Westminster Medical School, London.
authors.forename: A C
authors.initials: AC
authors.lastname: Shore
authors.forename: N D
authors.initials: ND
authors.lastname: Markandu
authors.forename: G A
authors.initials: GA
authors.lastname: Sagnella
authors.forename: D R
authors.initials: DR
authors.lastname: Singer
authors.forename: M L
authors.initials: ML
authors.lastname: Forsling
authors.forename: M G
authors.initials: MG
authors.lastname: Buckley
authors.forename: A L
authors.initials: AL
authors.lastname: Sugden
authors.forename: G A
authors.initials: GA
authors.lastname: MacGregor
mesh_terms: D000293:Adolescent; D000328:Adult; D009320:Atrial Natriuretic Factor / Q000097:blood*; D004326:Drinking; D004573:Electrolytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D009994:Osmolar Concentration; D011188:Potassium / Q000097:blood / Q000652:urine; D012084:Renin-Angiotensin System; D012964:Sodium / Q000097:blood / Q000652:urine; D013997:Time Factors; D014868:Water Deprivation
chemical_list: D004573:Electrolytes; D009320:Atrial Natriuretic Factor; D012964:Sodium; D011188:Potassium