| Co-Investigator(Kenkyū-buntansha) |
KATSUMURA Toshihito Tokyo Medical University, Department of Preventive Medicine and Public Health, Professor, 医学部, 教授 (80214352)
NAKAYAMA Kiyoshi Sophia University, Faculty of Science and Technology, Professor, 理工学部, 教授 (00053653)
OHNO Hideki Kyorin University School of Medicine, Department of Molecular Predictive Medicine and Sport Science, Professor, 医学部・衛生学, 教授 (00133819)
TAKEMASA Tohru University of Tsukuba, Institute of Health and Sport Sciences, Assistant Professor, 体育科学系, 講師 (50236501)
HAMAOKA Takafumi Tokyo Medical University, Department of preventive Medicine and Public Health, Assistant Professor, 医学部, 講師 (70266518)
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| Research Abstract |
The molecular mechanisms mediating the cellular adaptations to exercise training in human skeletal muscle are very poorly understood. The current study was undertaken to investigate the effect of endurance training on the expression of various genes at the messenger RNA (mRNA) levels in human skeletal muscle, focusing on angiogeneic factors, antioxidant enzymes, and uncoupling proteins (UCPs), untrained male students underwent an intensive interval swimming at 80-90%V02max and 30-min long distance swimming at 70%VO2max, five times a week for 3 months. Muscle biopsies were taken before training and about 48 h after the last session. Muscle sample were obtained from the middle portion of the vastus lateralis muscle by use of the percutaneous needle biopsy technique with suction. All the subjects markedly increased their maximal oxygen uptake levels due to training (P < 0.001) using a Monark bicycle ergomater, indicating an improvement in aerobic capacity. After training there were significant (P < 0.04) decreases in the expression of mRNAs for heat shock protein 70, Cu, Zn-superoxide dismutase (Cu, Zn-SOD), and Mn-SOD but a significant (P < 0.02) increase in UCP2 mRNA expression, whereas no definite changes were observed in the levels of mRNAs for vascular endothelial growth factor (VEGF), basic fibroblast growth factor, hypoxia-inducible factor-la (HIF1a), myoglobin, or UCP3. The changes in HIF1a mRNA expression correlated well with those in VEGF mRNA expression after training (r=0.875, P < 0.01), suggesting that HIF1a influences the training-induced VEGF gene expression or alternatively that VEGF and HIE1a expressions are coregulated at the transcriptional level in human skeletal muscle. Taken together, it is envisioned that cumulative effects of transient changes in transcription during recovery from successive bouts of exercise may represent the underlying kinetic basis for the cellular adaptations associated with endurance training.
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