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 < 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 < 0.05) along with bicarbonate (27.8 ± 0.7 vs. 25.8 ± 0.6 mmol/..