TY - JOUR

T1 - Exercise-induced translocation of Na+-K+ pump subunits to the plasma membrane in human skeletal muscle

AU - Juel, Carsten

AU - Nielsen, Jens Jung

AU - Bangsbo, Jens

PY - 2000

Y1 - 2000

N2 - Six human subjects performed one-legged knee extensor exercise (90 ± 4 W) until fatigue (exercise time 4.6 ± 0.8 min). Needle biopsies were obtained from vastus lateralis muscle before and immediately after exercise. Production of giant sarcolemmal vesicles from the biopsy material was used as a membrane purification procedure, and Na+-K+ pump α-and β-subunits were quantified by Western blotting. Exercise significantly increased (P < 0.05) the vesicular membrane content of the α2-, total α-, and β1-subunits by 70 ± 29, 35 ± 10, and 26 ± 5%, respectively. The membrane content of α1 was not changed by exercise, and the densities of subunits in muscle homogenates were unchanged. The ratio of vesicular to crude muscle homogenate content of the α2-, total α-, and β1-subunits was elevated during exercise by 67 ± 33 (P < 0.05), 23 ± 6 (P < 0.05), and 40 ± 14% (P = 0.06), respectively. It is concluded that translocation of subunits is an important mechanism involved in the short time upregulation of the Na+-K+ pumps in association with human muscle activity.

AB - Six human subjects performed one-legged knee extensor exercise (90 ± 4 W) until fatigue (exercise time 4.6 ± 0.8 min). Needle biopsies were obtained from vastus lateralis muscle before and immediately after exercise. Production of giant sarcolemmal vesicles from the biopsy material was used as a membrane purification procedure, and Na+-K+ pump α-and β-subunits were quantified by Western blotting. Exercise significantly increased (P < 0.05) the vesicular membrane content of the α2-, total α-, and β1-subunits by 70 ± 29, 35 ± 10, and 26 ± 5%, respectively. The membrane content of α1 was not changed by exercise, and the densities of subunits in muscle homogenates were unchanged. The ratio of vesicular to crude muscle homogenate content of the α2-, total α-, and β1-subunits was elevated during exercise by 67 ± 33 (P < 0.05), 23 ± 6 (P < 0.05), and 40 ± 14% (P = 0.06), respectively. It is concluded that translocation of subunits is an important mechanism involved in the short time upregulation of the Na+-K+ pumps in association with human muscle activity.

KW - Muscle activity

KW - Sodium-potassium homeostasis

KW - Sodium-potassium pump regulation

UR - http://www.scopus.com/inward/record.url?scp=0033993842&partnerID=8YFLogxK

M3 - Letter

C2 - 10749801

AN - SCOPUS:0033993842

VL - 278

SP - R1107-R1110

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6119

IS - 4

ER -