Acute exercise does not cause sustained elevations in AMPK signaling or expression.
OBJECTIVE
No study has examined the response of skeletal muscle AMP-activated protein kinase (AMPK) signaling beyond the first 3 h after an acute exercise bout in humans. The purpose of this study was to assess AMPK signaling in human skeletal muscle immediately after a single bout of moderate-intensity endurance exercise and 3 and 24 h after the exercise bout.


METHODS
We examined AMPK signaling, and protein expression of AMPK alpha, ACC-beta, and nNOS mu in untrained individuals (four females and four males) during the 24-h period after a 60-min bout of moderate-intensity (63 +/- 1% VO2peak) cycling endurance exercise.


RESULTS
AMPK alpha2 activity, AMPK alpha2 Thr172 phosphorylation, and ACC-beta Ser222 phosphorylation were increased immediately after exercise. These increases had all returned to basal levels at 3 and 24 h after exercise. Furthermore, an acute bout of exercise did not alter AMPK alpha1, AMPK alpha2, ACC-beta, or nNOS mu protein expression during the 24-h period after exercise.


CONCLUSIONS
Although an acute bout of exercise elicits increases in AMPK signaling, this alone is not sufficient to induce sustained increases in either AMPK signaling or protein expression during the postexercise period.
Lee-Young
Robert S
RS
Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia. robert.s.lee-young@vanderbilt.edu
Koufogiannis
George
G
Canny
Benedict J
BJ
McConell
Glenn K
GK
D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000103:Acetyl-CoA Carboxylase / Q000378:metabolism*; D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000502:physiology; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism*; D010807:Physical Endurance / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*
D052248:Nitric Oxide Synthase Type I; C526181:PRKAA2 protein, human; D055372:AMP-Activated Protein Kinases; C526180:PRKAA1 protein, human; D000103:Acetyl-CoA Carboxylase