1. Lab. Members 

PI

Miyata Hirofumi, PhD., Professor Emeritus (Yamaguchi Univ) 

Students

PhD: 9 students

Master: 33 students

UG 4: 93 students

　2. Research Interests

　Our research interests encompass several areas of motoneuron and muscle plasticity, including 1) accommodation of skeletal muscle and motoneuron functions during altered use; 2) neurophysiology in locomotion and the respiratory motor system during development and aging; and 3) optimal training stimulation for muscle adaptation in mammalian animals. My laboratory is well equipped for histochemical (confocal microscope), biochemical (real time RT-PCR), and basic electrophysiological studies.

　Several ongoing projects in the laboratory include 1) morphological changes in endplate on type-identified muscle fiber in aged rat diaphragms; 2) training and detraining effect on satellite cell response after exhaustive exercise in thoroughbred horses; 3) muscle fiber properties in mammals including humans; and 4) the effect of eccentric contraction on satellite cell activation in human anti-gravity muscle.

 　We are embarking on collaborative efforts both inside and outside Yamaguchi University with Dr. Takao Sugiura and Dr. Naomi Wada, Department of Education and Veterinary Medicine, Yamaguchi University and Drs in Japanese Racing Horse Society (JRA).

　 References (Review)

　1) Muscle adaptation to training in thoroughbred horses. J Phys Fitness Sports Med, 55(5): 447-460 (2006) https://doi.org/10.7600/jspfsm.55.447

　2) Plasticity of skeletal muscle and variability of myonuclear domain J Phys Fitness Sports Med, 62（3）189-198（2013）https://doi.org/10.7600/jspfsm.62.189

　3) Age and activity-related changes in the respiratory motor system (Invited Review). J Phys Fitness Sports Med, 2(1): 77-83 (2013) https://doi.org/10.7600/jpfsm.2.77

　4) Effects of hypoxia exposure on skeletal muscle in vivo. J Phys Fitness Sports Med, 68(6), pp. 357-367 (2019) https://doi.org/10.7600/jspfsm.68.357

3. Main Publications (Last decade, peer-reviewed, Corresponding author only)

1. Relationships between myonuclear domain size and fibre properties in the muscles of Thoroughbred horsese. Equine Vet. Journal 42:311-316(2010)

2. Differences in muscle fiber recruitment patterns between continuous and interval exercises. Journal of Equine Science 21:59-65 (2010)

3. 筋力トレーニングとしてのロングストライド歩行の可能性、臨床スポーツ医学28(4):469-475（2011）

4. 慢性閉塞性肺疾患モデルモルモットの横隔膜筋におけるミオシン重鎖表現型の変化、総合リハビリテーション39（10），995-1000，（2011）

5. Free radical formation after intensive exercise in Thoroughbred skeletal muscles. Journal of Equine Science 22:21-28 (2011)

6. Age-related changes in satellite cell proliferation by compensatory activation in rat diaphragm muscles. Biomedical research　33(3) : 167-173 (2012)

7. Muscle satellite cells are activated after exercise to exhaustion in Thoroughbred horses. Equine Veterinary Journal 45 (4)：512-517（2013）

8. 骨格筋の可塑性と筋核ドメインの多様性（Review）体力科学　62(3)　骨格筋の可塑性と筋核ドメインの多様性（総説） 体力科学62（3）189-198（2013）

9. Age and activity-related changes in the respiratory motor system (Invited review). J Phys Fitness Sports Med, 2(1): 77-83 (2013）

10.　競走馬のトレーニングおよび脱トレーニングが骨格筋サテライトセルの反応性に及ぼす影響、体力科学63（1）177-187（2014）

11. Effect of eccentric contraction on satellite cell activation in human vastus lateralis muscle. J Physiol Sci 65: 461-469. DOI 10.1007/s12576-015-0385-4 (2015）

12. Characteristics of skeletal muscle fibers of SOD1 knockout mice. Oxidative Medicine and Cellular Longevity. ID 9345970, 8 pages http://dx.doi.org/10.1155/2016/9345970 (2016）

13. Effect of High-Intensity Training in Normobaric Hypoxia on Thoroughbred Skeletal Muscle, Oxidative Medicine and Cellular Longevity.Volume2016, Article ID 1535367，doi:10.1155/2016/1535367.(2016)

14. Effect of acute high-intensity exercise in normobaric hypoxia on Thoroughbred skeletal muscle. J Sports Med Phys Fitness 57(5):711-719. doi: 10.23736/S0022-4707.16.06154-5(2017)

15. アイシング処置がラット損傷筋の回復過程に及ぼす影響. 体力科学 第66巻 第5 号 345-354（2017）DOI：10.7600/jspfsm.66.345 (2017)

16. Effect of Myostatin SNP on muscle fiber properties in male Thoroughbred horses during training period. J Physiol Sci 68:639–646 (2018)

17. Effect of acute high-intensity exercise in normobaric hypoxia on Thoroughbred skeletal muscle. J Sports Med Phys Fitness 57(5):711-719.

18. Activation of adiponectin receptors has negative impact on muscle mass in C2C12 myotubes and fast-type mouse skeletal muscle. PLOS ONE 0205645. (2018)

19. Preconditioning contractions suppress muscle pain markers after damaging eccentric contractions. Pain Research and Management, Pain Research and Management ID 3080715 (2018)

20. Influence of hypoxic stimulation on angiogenesis and satellite cells in mouse skeletal muscle, PLoS ONE 13(11):e0207040 (2018)

21. 低酸素曝露が生体内の骨格筋細胞に及ぼす影響. 体力科学 第68巻 第6号 357-367（2019） DOI：10.7600/jspfsm.68.35

22. Muscle fibre distribution in forelimb, hindlimb and trunk muscles in three bat species. Anat Histol Embryol.doi.org/10.1111/ahe.12670(2021)

23. Differential expression of myosin heavy chain isoforms type in skeletal muscles of polar and black bears. Anatomia, Histologia, Embryologia doi.org/10.1111/ahe.12893 (2022)

24.  Acute exercise in a hot environment increases heat shock protein 70 and peroxisome proliferator-activated receptor γ coactivator 1α mRNA in Thoroughbred horse skeletal muscle. Frontiers in Veterinary Science 10,1230212（2023）

25. Heat acclimation improves exercise performance in hot conditions and increases heat shock protein 70 and 90 of skeletal muscles in Thoroughbred horses. Physiological Reports 12(10) doi: 10.14814/phy2.16083 ( 2024)

26. 哺乳 動物の体重と筋線維タイプ組成の関係. 体育の科学 75 巻699-703， 9 月号(2025)

27. Physiological adaptations to 6 weeks of high-intensity interval and moderate-intensity continuous training in horses: A randomized crossover study.  Physiological Reports 14(4) 14(4):e70785. doi: 10.14814/phy2.70785 （2026） 

　1. Age-Related Changes in Satellite Cell Activation in The Rat Diaphragm　 Medicine & Science in Sports & Exercise, (Baltimore, USA) (2010) 

　2. Relationships between myonuclear domain size and muscle fibre properties in Thoroughbred horse muscles. 8th International Conference on Equine Exercise Physiology (Cape town, South Africa) (2010)

　3. Age-related changes in Pax7 mRNA Expression in the Rat Activated Diaphragm. Medicine & Science in Sports & Exercise, (Denver, USA) (2011)

　4. Age-Related Changes in Serotonergic Input on Respiratory-Related Motoneurons in Rats. Medicine & Science in Sports & Exercise, (Denver, USA) (2011)

　5. Developmental Change in Domain Size of Endplate Nucleus in the Rat Diaphragm. Medicine & Science in Sports & Exercise (San Francisco) (2012)

　6. Training Effect on Satellite Cell Response after Exhaustive Exercise in Thoroughbred Horses. Medicine & Science in Sports & Exercise (San Francisco) (2012)

　7. Detraining Effect on Satellite Cell Response after Exhaustive Exercise in Thoroughbred Horses (Indianapolis, USA) (2013)

　8. Effect of Eccentric Contraction on Satellite Cell Activation in Human Vastus Lateralis Muscle ACSM (Orland, USA) (2014) MSSE 46(5) S494

　9. Sex-related Differences in Muscle Satellite Cell Response to Step Exercise ACSM (San Diego, USA) (2015) MSSE 47(5)

　10. Effects of acute high-intensity exercise in normobaric hypoxia and hyperoxia on Thoroughbred skeletal muscle. ACSM (Boston, USA) (2016) MSSE

　11. The Effect of Myostatin SNP on Muscle Fiber Properties in Thoroughbred Horses during Training Period ACSM（Denver, USA) (2017) MSSE

　12. mRNA Expression in The Rat Spinal Cord Including Motoneurons Innervating Damaged Muscle. ACSM（2018 Minneapolis, USA）MSSE

　13. Effects of Mild Hypoxic Conditions on mRNA Expression of Spinal Cord in the Young and Old Mouse ACSM（2020 San Francisco, USA）Opened on MSSE 52:5 Supplement.

    14. Acute physiological responses to high-intensity continuous and interval exercise in horses. 11th, ICEEP (2022, Uppsala, Sweden)

    15. Acute physiological responses to hypoxic high-intensity interval exercise in horses. The International Biochemistry of Exercise Conference (2022 Tronto, Canada)

    16. Acute physiological responses to hyperoxic high-intensity interval exercise in horses, 2023 ECSS (Paris, FRA)

    17. Physiological Adaptation to High-Intensity Interval Training and Moderate-Intensity Continuous Training in Horses 2023 ACSM (Denver, USA)

    18. Effects of Breathing Hyperoxic Gas during High-intensity Interval Exercise on Post-exercise mRNA Responses in Equine Skeletal Muscle  2025 ECSS (Rimini，Italy)

　5. Budgets for research (Last decade, Representative only)

　科学研究費（代表者：宮田）

（基盤B）:呼吸筋支配運動ニューロンの加齢変化とトレーナビリティー、2005-2008年：約1000万円

（基盤B）:神経筋接合部におけるシナプス核の加齢変化と可塑性、2009-2014年：約1100万円

（挑戦的萌芽）:サテライトセルの活性化に対するエキセントリック運動の効果、20011-2013年：300万円

（挑戦的萌芽）: ヒトの骨格筋線維特性は他の哺乳動物と異なるか？　20015-2017年：290万円

（基盤B）:筋サテライトセルを活性化する踏み台昇降運動の性別，年齢別検討、2016-2019年：約1300万円

（基盤C）: 脊髄中の遺伝子発現の変動から神経筋システムの可塑性を調べる方法，2020-2024：330万円

　共同・受託研究（代表者：宮田）

（日本中央競馬会：運動科学）: 競走馬における運動強度と筋線維動員パターンに関する研究、2003-2005：900万円

（日本中央競馬会：運動科学）：サラブレッド骨格筋の収縮・弛緩機能に関する研究、 2006年 - 2008年：900万円

（大塚製薬-佐賀）: アミノ酸投与が運動誘発性損傷の炎症・再生期へ及ぼす影響、2008-2010：255万円

（日本中央競馬会：運動科学）: サラブレッド骨格筋細胞の筋核およびサテライトセルの適応変化、2009-2010：400万円

（日本中央競馬会：運動科学）: サラブレッド骨格筋組織における毛細血管新生を促進するトレーニング形態、2014-2016：600万円

（日本中央競馬会：日高育成牧場）: 育成後期サラブレッドの筋肥大に及ぼすミオスタチン遺伝子多型の影響、2017-2019：750万円

（日本中央競馬会：運動科学）: 高強度インターバルトレーニングがサラブレッドの骨格筋に与える影響、2020-2022：900万円

（日本馬事協会 ）：ばんえい競馬・輓曳 の運動学、解剖学的研究、2023-2024：200万円