title: Potassium and ventilation during exercise above and below the ventilatory threshold.
abstract: Increases in arterial plasma potassium during exercise may provide an important drive to ventilation. We examined the changes in arterialized venous plasma potassium concentration ([K +]av) and ventilation that occur during sustained exercise at workloads above and below the ventilatory threshold (Vt) in young health humans. After the onset of exercise at a workload below-Vt, [K +]av rose by 0.3 (+/- 0.1) mmol l-1 (mean +/- SEM). Following 30 min of exercise at this intensity [K +]av had fallen (P < 0.05, ANOVA) by an amount approximately equal to one third of the initial increase. While [K +]av fell, ventilation remained stable. At 5 min after the onset of sustained exercise above the Vt [K +]av had risen by 0.7 (+/- 0.1) mmol l-1 and thereafter remained constant. Ventilation slowly increased throughout the above-Vt protocol. These results show significant differences in the time course of the changes in [K +]av and ventilation. They do not support the hypothesis that changes in [K +]a during moderate exercise cause linearly related changes in ventilation.
authors.affiliation: Department of Human Anatomy and Physiology, University College, Dublin,Ireland.
authors.forename: S M
authors.initials: SM
authors.lastname: Roe
authors.forename: P
authors.initials: P
authors.lastname: Nolan
authors.forename: R G
authors.initials: RG
authors.lastname: O'Regan
authors.forename: W T
authors.initials: WT
authors.lastname: McNicholas
authors.forename: P
authors.initials: P
authors.lastname: McLoughlin
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology*; D001784:Blood Gas Analysis; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010101:Oxygen Consumption / Q000502:physiology; D011188:Potassium / Q000097:blood*; D012119:Respiration / Q000502:physiology*
chemical_list: D011188:Potassium