Changes of Na-K-ATPase, sodium and potassium concentration in erythrocytes during and after exercise

Abstract

There were some reports concerned about sudden unexplained death syndrome in soldiers after military training, and in labers after work hard. These studies some electrolytes imbalance. Therefore the objective of this study were to investigate the changes in plasma electrolytes, intraerythrocyte cationic concertration, activity and number of Na-K-ATPase during and after exercise, in 12 athletes and 12 control male subjects. 3A11 subjects performed an uninterrupted incremental exercise test on a bicycle ergometer, starting at an initial work load of 20 % of the subjects’ maximal exercise capacity, as determined in a pretest. The work rate was increased with an additional 20 % each 6 min. up to a final work load of 80 %. Blood samples were taken at rest, 80 % of maximal exercise capacity and 10 min. after cessation of exercise. At 80 % of maximal exercise capacity, the plasma concentrations of electrolvtes and lactate arc elevated both in control subjects and athletes. However, the plasma potassium in the athletes was not increased so much as in control subjects. The baseline erythrocyte ouabain binding sites (OBS) and plasma magnesium in the athletes were more than in the control groups. The studies also show that exercise docs not change the intraerythrocytc cations and the activity of the erythrocyte Na-K-ATPase pump in athletes but decrease the intraerythrocyte sodium and the activity of the erythrocyte Na-K-ATPase pump after 10 minute exercise in the control subjects. It is concluded that exercise in athletes and control subjects have different effects on intraerythrocyte sodium and the activity of Na-K-ATPase.