Effects of high‐intensity intermittent swimming on PGC‐1α protein expression in rat skeletal muscle

S Terada, K Kawanaka, M Goto… - Acta physiologica …, 2005 - Wiley Online Library
S Terada, K Kawanaka, M Goto, T Shimokawa, I Tabata
Acta physiologica scandinavica, 2005Wiley Online Library
Aim: The aim of the present investigation was to elucidate the effects of exercise intensity on
exercise‐induced expression of peroxisome proliferator‐activated receptor γ coactivator‐1α
(PGC‐1α) protein in rat skeletal muscle. Methods: We measured PGC‐1α content in the
skeletal muscles of male Sprague–Dawley rats (age: 5–6 weeks old; body weight: 150–170
g) after a single session of high‐intensity intermittent exercise (HIE) or low‐intensity
prolonged swimming exercise (LIE). During HIE, the rats swam for fourteen 20‐s periods …
Abstract
Aim:  The aim of the present investigation was to elucidate the effects of exercise intensity on exercise‐induced expression of peroxisome proliferator‐activated receptor γ coactivator‐1α (PGC‐1α) protein in rat skeletal muscle.
Methods:  We measured PGC‐1α content in the skeletal muscles of male Sprague–Dawley rats (age: 5–6 weeks old; body weight: 150–170 g) after a single session of high‐intensity intermittent exercise (HIE) or low‐intensity prolonged swimming exercise (LIE). During HIE, the rats swam for fourteen 20‐s periods carrying a weight (14% of body weight), and the periods of swimming were separated by a 10‐s pause. LIE rats swam with no load for 6 h in two 3‐h sessions, separated by 45 min of rest.
Results:  After HIE, the PGC‐1α protein content in rat epitrochlearis muscle had increased by 126, 140 and 126% at 2, 6 and 18 h, respectively, compared with that of the age‐matched sedentary control rats’ muscle. Immediately, 6 and 18‐h after LIE, the PGC‐1α protein content in the muscle was significantly elevated by 84, 95 and 67% respectively. The PGC‐1α protein content observed 6 h after HIE tended to be higher than that observed after LIE. However, there was no statistically significant difference between the two values (P = 0.12).
Conclusion:  The present investigation suggests that irrespective of the intensity of the exercise, PGC‐1α protein content in rat skeletal muscle increases to a comparable level when stimuli induced by different protocols are saturated. Further, HIE is a potent stimulus for enhancing the expression of PGC‐1αprotein, which may induce mitochondrial biogenesis in exercise‐activated skeletal muscle.
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