title: Atrial natriuretic factor during hypoxia and mild exercise.
abstract: The effect of hypoxia on plasma atrial natriuretic factor (ANF), plasma renin activity (PRA), and plasma aldosterone concentration (PAC) was evaluated during 2 h of treadmill exercise at 2 km/h, 0 grade at sea level. Six male subjects exercised on 2 separate days during normoxia (21% O2) and hypoxia (13.3 +/- 0.3% O2). No significant changes in ANF or PRA occurred during either normoxic or hypoxic exercise. However, PAC fell significantly during normoxic exercise (17.5 +/- 3.6 vs. 12.7 +/- 2.6 ng/dl, p less than 0.05) but not during hypoxic exercise. Serum potassium concentration fell during hypoxic exercise (5.0 +/- 0.1 vs. 4.4 +/- 0.1 mmol/l, p less than 0.05) along with bicarbonate (27.8 +/- 0.7 vs. 25.8 +/- 0.6 mmol/l, p less than 0.01). Between normoxic and hypoxic studies there was a significantly higher heart rate during hypoxic exercise (78 +/- 5 vs. 90 +/- 6 b/min, p less than 0.01). The major conclusion of this study is that hypoxia resulting in arterial oxygen saturations of 81 +/- 0.7% does not affect plasma atrial natriuretic factor levels during mild exercise in normal male subjects.
authors.affiliation: Department of Respiratory Medicine, Alfred Hospital, Prahran, Victoria, Australia.
authors.forename: D A
authors.initials: DA
authors.lastname: Story
authors.forename: B R
authors.initials: BR
authors.lastname: Miller
authors.forename: C M
authors.initials: CM
authors.lastname: Shield
authors.forename: G
authors.initials: G
authors.lastname: Bowes
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood*; D000532:Altitude Sickness / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D009320:Atrial Natriuretic Factor / Q000097:blood*; D001784:Blood Gas Analysis; D004573:Electrolytes / Q000032:analysis; D015444:Exercise / Q000502:physiology*; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D008297:Male; D012083:Renin / Q000097:blood*; D012084:Renin-Angiotensin System / Q000502:physiology*
chemical_list: D004573:Electrolytes; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D012083:Renin