Relationship between plasma potassium and ventilation during successive periods of exercise in men.
During and after two successive incremental cycle ergometer tests (tests A and B), plasma potassium concentration ([K+]p), plasma pH (pHp), plasma partial pressure of carbon dioxide, blood lactate concentration ([Lac-]b) and ventilation (VE) were measured. While there was a good correlation between the increase in [K+]p and VE or pHp, respectively, in test A, in test B a close correlation was found only between the increase in VE and [K+]p (r greater than 0.9 for nearly all single cases; r was 0.84 and 0.89 for all (pooled) cases in tests A and B, respectively; the correlation coefficients between changes in pHp and VE in tests A and B were r = 0.74 and r = 0.28, respectively, and r = 0.89 and r = 0.10 between the changes in [Lac-]b and VE in tests A and B). The close relationship for individuals between VE and [K+]p in tests A and B supported the hypothesis that the extracellular increase in [K+] may contribute to the ventilatory drive during exercise. The comparison of the results of tests A and B further indicated that the relationship between pHp and VE was dependent on the experimental design, and that pHp and VE changes are unlikely to be cause and effect.
Busse
M W
MW
Abteilung Sport- und Arbeitsphysiologie, Medizinische Hochschule Hannover, Federal Republic of Germany.
Scholz
J
J
Saxler
F
F
Maassen
N
N
Böning
D
D
D000328:Adult; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D008297:Male; D011188:Potassium / Q000097:blood*; D013997:Time Factors; D014692:Ventilation-Perfusion Ratio / Q000502:physiology*
D007773:Lactates; D002245:Carbon Dioxide; D011188:Potassium