Effect of hypoxia on arterial potassium concentration at rest and during exercise in man.
Barlow CW., Qayyum MS., Davey PP., Paterson DJ., Robbins PA.
Hypoxia has been reported to increase arterial potassium concentration ([K+]a) in anaesthetized cats (Paterson, Estavillo & Nye, 1988). The purpose of this study was to determine whether this phenomenon occurs in humans. The effect of hypoxia on [K+]a was measured in ten male subjects, at rest and during light exercise, before and after 8 weeks of physical training. The [K+]a increased by 0.15 +/- 0.04 mM (mean +/- S.E.M.) at rest, when end-tidal PO2 (PET,O2) was lowered from 100 to 51 +/- 1.6 Torr, and by 0.10 +/- 0.02 mM during exercise, when PET,O2 was lowered from 100 to 66 +/- 6.2 Torr. Physical training did not alter the rise in [K+]a significantly. The magnitude of this effect is small in comparison with that of exercise-induced hyperkalaemia, and is unlikely to be of great physiological significance at moderate levels of hypoxia.