TY - JOUR
T1 - Training increases the concentration of [3H]ouabain-binding sites in rat skeletal muscle
AU - Kjeldsen, Keld
AU - Richter, Erik A.
AU - Galbo, Henrik
AU - Lortie, Gilles
AU - Clausen, Torben
PY - 1986/9/11
Y1 - 1986/9/11
N2 - Exercise is associated with a net loss of K+ from the working muscles and an increased plasma K+ concentration, indicating that the capacity for intracellular reaccumulation of K+ is exceeded. Training reduces the exercise-induced rise in plasma K+, and an increased plasma [K+] may interfere with physical performance. Since the clearing of K+ from the extracellular space depends on the capacity for active K+ uptake in skeletal muscle, the effects of training and inactivity on the total concentration of (Na+ + K+)-ATPase was determined. Following 6 weeks of swim training, the concentration of [3H]ouabain-binding sites in rat hindlimb muscles was up to 46% (P < 0.001) higher than in those obtained from age-matched controls. Whereas muscle Na+, K+ contents remained unchanged, the concentration of citrate synthase increased by up to 76% (P < 0.001). Training induced no change in the [3H]ouabain-binding-site concentration in the diaphragm, but in the heart ventricles, the K+-dependent 3-O-methylfluorescein phosphatase activity increased by 20% (P < 0.001). Muscle inactivity induced by denervation, plaster immobilisation or tenotomy reduced the [3H]ouabain-binding-site concentration by 20-30% (P < 0.02-0.001) within 1 week. In conclusion, training leads to a significant and reversible rise in the concentration of (Na+ + K+)-ATPase in muscle cells. This may be of importance for the beneficial effects on physical performance by improving the maximum capacity for K+ clearance.
AB - Exercise is associated with a net loss of K+ from the working muscles and an increased plasma K+ concentration, indicating that the capacity for intracellular reaccumulation of K+ is exceeded. Training reduces the exercise-induced rise in plasma K+, and an increased plasma [K+] may interfere with physical performance. Since the clearing of K+ from the extracellular space depends on the capacity for active K+ uptake in skeletal muscle, the effects of training and inactivity on the total concentration of (Na+ + K+)-ATPase was determined. Following 6 weeks of swim training, the concentration of [3H]ouabain-binding sites in rat hindlimb muscles was up to 46% (P < 0.001) higher than in those obtained from age-matched controls. Whereas muscle Na+, K+ contents remained unchanged, the concentration of citrate synthase increased by up to 76% (P < 0.001). Training induced no change in the [3H]ouabain-binding-site concentration in the diaphragm, but in the heart ventricles, the K+-dependent 3-O-methylfluorescein phosphatase activity increased by 20% (P < 0.001). Muscle inactivity induced by denervation, plaster immobilisation or tenotomy reduced the [3H]ouabain-binding-site concentration by 20-30% (P < 0.02-0.001) within 1 week. In conclusion, training leads to a significant and reversible rise in the concentration of (Na+ + K+)-ATPase in muscle cells. This may be of importance for the beneficial effects on physical performance by improving the maximum capacity for K+ clearance.
KW - (Na + K)-ATPase
KW - (Rat skeletal muscle)
KW - Exercise
KW - K transport
KW - Training
KW - [H]Ouabain binding
UR - http://www.scopus.com/inward/record.url?scp=0022922360&partnerID=8YFLogxK
U2 - 10.1016/0005-2736(86)90570-5
DO - 10.1016/0005-2736(86)90570-5
M3 - Article
C2 - 3017429
AN - SCOPUS:0022922360
VL - 860
SP - 708
EP - 712
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
SN - 0005-2736
IS - 3
ER -