Effects of acute bouts of running and swimming exercise on PGC-1alpha protein expression in rat epitrochlearis and soleus muscle.
The purpose of this study was to elucidate the mechanisms underlying low-intensity exercise-induced peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) protein expression in rat skeletal muscles. Rats (5-6 wk old) swam without a load and ran on the treadmill at a speed of 13 m/min, respectively, in two 3-h sessions separated by 45 min of rest. PGC-1alpha content in epitrochlearis muscle (EPI) was increased by 75 and 95%, immediately and 6 h after swimming, respectively, with no increase in PGC-1alpha content in the soleus (SOL). After running, PGC-1alpha content in EPI was unchanged, whereas a 107% increase in PGC-1alpha content was observed in SOL 6 h after running. Furthermore, in EPI and SOL as well as other muscles (triceps, plantaris, red and white gastrocnemius), PGC-1alpha expression was enhanced concomitant with reduced glycogen postexercise, suggesting that expression of PGC-1alpha occurs in skeletal muscle recruited during exercise. PGC-1alpha content in EPI was increased after 18-h in vitro incubation with 0.5 mM 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and 4 mM caffeine. However, AICAR incubation did not affect PGC-1alpha content in the SOL, whereas caffeine incubation increased it. These results suggest that exercise-induced PGC-1alpha expression in skeletal muscle may be mediated by at least two exercise-induced signaling factors: AMPK activation and Ca2+ elevation. The number of factors involved (both AMPK and Ca2+, or Ca2+ only) in exercise-induced PGC-1alpha expression may differ among muscles.
Division of Health Promotion and Exercise, National Institute of Health and Nutrition, Shinjuku City, Tokyo 162-8636, Japan.
Shin
S
Terada
Izumi
I
Tabata
D000375:Aging / Q000378:metabolism; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D005552:Forelimb; D006003:Glycogen / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012265:Ribonucleotides / Q000494:pharmacology; D012420:Running; D013550:Swimming; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*
D020033:Protein Isoforms; D012265:Ribonucleotides; D014157:Transcription Factors; C111264:peroxisome-proliferator-activated receptor-gamma coactivator-1; D000620:Aminoimidazole Carboxamide; D002110:Caffeine; D006003:Glycogen; C031143:AICA ribonucleotide