title: Change in PGC-1α expression in rat skeletal muscle after low-intensity prolonged swimming exercise.
abstract: After 6-h low-intensity swimming exercise (LIE), peroxisome proliferator-activated receptor γ coactivator -1α (PGC-1α) in whole and nuclear fractions in rat skeletal muscle was higher than the control rats' muscles up to 18 h after LIE. However, no study has reported change in PGC-1α content after that. Therefore, we measured PGC-1α in whole and nuclear fractions in rat skeletal muscle up to 24 h after LIE. Furthermore, we evaluated change in the mRNA of δ-aminolevulinate synthase (ALAS), a mitochondrial protein, to clarify in which fraction of PGC-1α has a physiological role as a transcriptional coactivator for enhancing the mitochondrial oxidative enzymes after exercise. We measured PGC-1α protein content in whole and nuclear fractions in the epitrochlearis (EPI) muscle of male Sprague-Dawley rats (age: 6 w; body weight: 180-200 g) after LIE by Western-blot analysis. The ALAS mRNA content was quantified by RT-PCR. The PGC-1α contents in whole fractions in the rat EPI muscle were 73% and 75% higher than that of the control rats' muscle, 18 h and 24 h after LIE, respectively. The PGC-1α content in nuclear fractions in the muscle and ALAS mRNA was higher than that of the control rats' muscle by 58% and 25%, respectively, while they returned to the control level 24 h after LIE. The present investigation demonstrated that the time-course of PGC-1α content in nuclear fractions in the EPI muscle was the same as the ALAS mRNA, suggesting that PGC-1α in the nucleus may have a physiological function as a transcriptional coactivator for enhancing mitochondrial protein expression after exercise.
authors.affiliation: Health Promotion and Exercise Program, National Institute of Health and Nutrition, Tokyo, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Fujimoto
authors.forename: Wataru
authors.initials: W
authors.lastname: Yamaguchi
authors.forename: Shin
authors.initials: S
authors.lastname: Terada
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Higuchi
authors.forename: Izumi
authors.initials: I
authors.lastname: Tabata
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D005080:Exercise Test; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D016601:RNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013550:Swimming / Q000502:physiology*; D013997:Time Factors; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism
chemical_list: D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C501429:Ppargc1a protein, rat; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D000624:5-Aminolevulinate Synthetase