Peroxisomal proliferator-activated receptor gamma co-activator-1 alpha gene expression increases above the lactate threshold in human skeletal muscle.
OBJECTIVE
Peroxisomal proliferator-activated receptor gamma co-activator-1 alpha (PGC-1α) plays a role not only as an activator of mitochondrial biogenesis, but also as a suppressor of inflammatory cytokines, which induce chronic diseases. Therefore, increasing PGC-1α expression can be one of the important factors for preventing chronic diseases. PGC-1α expression is activated by adenosine monophosphate-activated protein kinase (AMPK) and cAMP dependent kinase. The activity of these enzymes depends on the exercise intensity. Therefore, this study compared the effects of two different exercise intensities (above lactate threshold (LT) and below LT) with an equal amount of energy expenditure on PGC-1α gene expression in human skeletal muscle.


METHODS
Six young men participated in this study. They performed exercise at 120% and 80% LT intensity. The duration of the 120% LT exercise was 60 minutes and the duration of the session performed at 80% LT was calculated to yield equal energy expenditure as the 120% LT intensity exercise. Skeletal muscle was obtained after 1 hour of exercise.


RESULTS
The working rate, % peak VO2 and HR during exercise were significantly higher in at 120% LT than at 80% LT. PGC-1α gene expression was not significantly different between control (0.087; 0.026-0.284 (the median; inter quartile range)) and 80% LT (0.171; 0.030-0.484). However, PGC-1α gene expression after 120% LT (0.441; 0.121-4.643) was significantly higher than in the control.


CONCLUSIONS
The findings of this study suggest that PGC-1α gene expression depends on exercise intensity.
Fukuoka University, Fukuoka, Japan. tobitaku@ck9.so-net.ne.jp
T
T
Tobina
K
K
Yoshioka
A
A
Hirata
S
S
Mori
A
A
Kiyonaga
H
H
Tanaka
D000328:Adult; D015308:Anaerobic Threshold; D004734:Energy Metabolism; D005080:Exercise Test; D015870:Gene Expression; D006339:Heart Rate; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D005082:Physical Exertion / Q000235:genetics* / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology*; D055815:Young Adult
D006360:Heat-Shock Proteins; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D014157:Transcription Factors