Research Experience 【 display / non-display 】

Research Experience 【 display / non-display 】

• 2022.04

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  Now

  Sapporo Medical University   Department of Cellular Physiology and Signal Transduction   Adjunct Assistant Professor

• 2015.04

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  2022.03

  Sapporo Medical University   Department of Orthopedic Surgery   研究生

• 2013.04

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  2015.03

  Uji Tokushukai Hospital   resident

Affiliation 【 display / non-display 】

Affiliation 【 display / non-display 】

• Sapporo Medical University   Department of Cellular Physiology and Signal Transduction and the Department of Orthopedic Surgery   Adjunct Assistant Professor  

Research Interests 【 display / non-display 】

Research Interests 【 display / non-display 】

• skeletal muscle

• Pediatric Orthopaedics

• Sports medicine

• Gait analysis

Papers 【 display / non-display 】

Papers 【 display / non-display 】

• Effects of contraction frequency during high-intensity training on fatigue resistance and aerobic adaptations in mouse skeletal muscle.

  Azuma Naito, Tatsuya Sato, Iori Kimura, Nao Tokuda, Nao Yamauchi, Hiroyori Fusagawa, Takashi Yamada

  Journal of applied physiology (Bethesda, Md. : 1985)    2024.12  [International journal]

  　View Summary

  In high-intensity and sprint interval training, the frequency of contractions is typically higher compared to moderate-intensity continuous training, but it remains unclear whether this contributes to the effective increase in fatigue resistance mechanisms. Here, we investigated the role of contraction frequency in high-intensity training on endurance adaptations of mouse skeletal muscle. Male C57BL/6 mice were divided into groups based on high (0.25 s contraction every 0.5 s) and low (0.25 s contraction every 4.5 s) contraction frequencies, with either 360 contractions per session (Hi360 and Lo360) or 30 contractions per session (Hi30 and Lo30). The plantar flexor muscles were stimulated using in vivo supramaximal electrical stimulation, where all muscle fibers were maximally activated, every other day for 5 weeks. In both the Hi360 and Lo360 groups, where force production declined to less than 40% of the initial value during the training session, muscle endurance, as well as mitochondrial content and respiratory capacity, were increased to a similar extent. In contrast, the rate of torque decline during the training session was more pronounced in the Hi30 group compared to the Lo30 group. In response, the Hi30 group, but not the Lo30 group, exhibited increased fatigue resistance and mitochondrial respiration, which was accompanied by increased PGC-1α expression and an activation of AMPK/Ulk1 pathway. These data suggest that the frequency of contractions is a critical factor in determining the efficient enhancement of mitochondrial respiratory capacity and muscle endurance through high-intensity training, presumably due to promotion of mitochondrial quality control.

  DOI PubMed

• Platelet‐rich plasma does not accelerate the healing of damaged muscle following muscle strain

  Hiroyori Fusagawa, Takashi Yamada, Tatsuya Sato, Yuki Ashida, Atsushi Teramoto, Hiroyuki Takashima, Azuma Naito, Nao Tokuda, Nao Yamauchi, Nobutoshi Ichise, Izaya Ogon, Toshihiko Yamashita, Noritsugu Tohse

  Journal of Orthopaedic Research ( Wiley )  42 ( 6 ) 1190 - 1199  2024.01

  　View Summary

  Abstract Although platelet‐rich plasma (PRP) has been widely used regardless of the severity of muscle strain, there have been very few basic studies in which its effects on muscle injury were examined by using models that accurately mimic the clinical muscle strain injury process. Therefore, the aim of this study was to confirm by physiological and structural analyses whether PRP purified by a general preparation method has a muscle healing effect on muscle damage caused by eccentric contraction (ECC). Male Wistar rats were subjected to muscle injury induced by ECC in bilateral plantar flexor muscles using electrical stimulation and an automatically dorsiflexing footplate. The rats were randomly assigned to three groups by type of injection: phosphate‐buffered saline (PBS), leukocyte‐poor PRP (LP‐PRP), or leukocyte‐rich PRP (LR‐PRP) injection into gastrocnemius muscles three times at weekly intervals. The platelet concentrations of the LP‐PRP and LR‐PRP were three to five times higher than that of whole blood. The recovery process of torque strength in the plantar flexor muscle, signal changes in MRI images, and histological evaluation 3 weeks after injury showed no obvious differences among the three groups, and every muscle recovered well from the injury without marked fibrosis. The results that neither LP‐PRP nor LR‐PRP was found to accelerate healing of muscle injuries suggested that conventional preparation and use of PRP for simple muscle injuries caused by muscle strain should be carefully considered, and further basic research using models that accurately mimic clinical practice should be carried out to determine the optimal use of PRP.

  DOI

• Skeletal muscle endurance declines with impaired mitochondrial respiration and inadequate supply of acetyl-CoA during muscle fatigue in 5/6 nephrectomized rats

  Hiroyori Fusagawa, Tatsuya Sato, Takashi Yamada, Yuki Ashida, Iori Kimura, Azuma Naito, Nao Tokuda, Nao Yamauchi, Nobutoshi Ichise, Yoshinori Terashima, Izaya Ogon, Atsushi Teramoto, Toshihiko Yamashita, Noritsugu Tohse

  Journal of Applied Physiology ( American Physiological Society )  135 ( 4 ) 731 - 746  2023.10

  　View Summary

  Mitochondrial dysfunction is associated with decreased skeletal muscle endurance in chronic kidney disease (CKD), but the muscle physiological phenotype and major changes in intramuscular metabolites during muscle fatigue in CKD-related cachexia remain unclear. By using a 5/6 nephrectomized CKD rat model, the present study revealed that CKD is associated with reduced tetanic force in response to repetitive stimuli in a subacute phase, impaired mitochondrial respiration, and inadequate supply of acetyl-CoA during muscle fatigue.

  DOI

• High-intensity interval training using electrical stimulation improves mitochondrial dysfunction and muscle endurance in rats with chronic kidney disease

  Hiroyori Fusagawa, Takashi Yamada, Tatsuya Sato, Yuki Ashida, Asuma Naito, Nao Tokuda, Nao Yamauchi, Nobutoshi Ichise, Takuro Karaushi, Atsushi Teramoto, Toshihiko Yamashita, Noritsugu Tohse

  Biophysical Journal ( Elsevier BV )  122 ( 3 ) 114a - 114a  2023.02

  DOI

• Ultrastructural Assessment and Proteomic Analysis in Myofibrillogenesis in the Heart Primordium After Heartbeat Initiation in Rats

  Nobutoshi Ichise, Tatsuya Sato, Hiroyori Fusagawa, Hiroya Yamazaki, Taiki Kudo, Izaya Ogon, Noritsugu Tohse

  Frontiers in Physiology ( Frontiers Media SA )  13  2022.05

  　View Summary

  Myofibrillogenesis is an essential process for cardiogenesis and is closely related to excitation-contraction coupling and the maintenance of heartbeat. It remains unclear whether the formation of myofibrils and sarcomeres is associated with heartbeat initiation in the early embryonic heart development. Here, we investigated the association between the ultrastructure of myofibrils assessed by transmission electron microscopy and their proteomic profiling assessed by data-independent acquisition mass spectrometry (DIA-MS) in the rat heart primordia before and after heartbeat initiation at embryonic day 10.0, when heartbeat begins in rats, and in the primitive heart tube at embryonic day 11.0. Bundles of myofilaments were scattered in a few cells of the heart primordium after heartbeat initiation, whereas there were no typical sarcomeres in the heart primordia both before and after heartbeat initiation. Sarcomeres with Z-lines were identified in cells of the primitive heart tube, though myofilaments were not aligned. DIA-MS proteome analysis revealed that only 43 proteins were significantly upregulated by more than 2.0 fold among a total of 7,762 detected proteins in the heart primordium after heartbeat initiation compared with that before heartbeat initiation. Indeed, of those upregulated proteins, 12 (27.9%) were constituent proteins of myofibrils and 10 (23.3%) were proteins that were accessories and regulators for myofibrillogenesis, suggesting that upregulated proteins that are associated with heartbeat initiation were enriched in myofibrillogenesis. Collectively, our results suggest that the establishment of heartbeat is induced by development of bundles of myofilaments with upregulated proteins associated with myofibrillogensis, whereas sarcomeres are not required for the initial heartbeat.

  DOI

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Misc 【 display / non-display 】

Misc 【 display / non-display 】

• 二分脊椎症児の足部変形に影響を与える歩容の非対称性

  房川 祐頼, 藤田 裕樹, 西部 寿人, 野坂 利也, 松山 敏勝, 樋室 伸顕, 山下 敏彦

  日本整形外科学会雑誌 ( (公社)日本整形外科学会 )  94 ( 3 ) S954 - S954  2020.03

• 二分脊椎症患児の足部変形に影響を与える歩容の非対称性

  房川 祐頼, 藤田 裕樹, 西部 寿人, 野坂 利也, 松山 敏勝, 樋室 伸顕

  日本足の外科学会雑誌 ( (一社)日本足の外科学会 )  40 ( Suppl. ) S321 - S321  2019.07

• 変形治癒に対して骨切り術を施行した2例

  房川 祐頼, 鈴木 智之, 加谷 光規, 渡邉 耕太, 寺本 篤史, 舘田 健児, 木井 雄一郎, 岡田 葉平, 山下 敏彦, 名越 智

  北海道整形災害外科学会雑誌 ( 北海道整形災害外科学会 )  58 ( 2 ) 308 - 308  2017.03

• 内側楔状開大型高位脛骨骨切り術の患者立脚評価に影響を与える因子の検討

  房川 祐頼, 鈴木 智之, 名越 智, 渡邉 耕太, 寺本 篤史, 舘田 健児, 小助川 維摩, 興村 慎一郎, 木井 雄一郎, 山下 敏彦

  日本整形外科学会雑誌 ( (公社)日本整形外科学会 )  91 ( 2 ) S583 - S583  2017.03

• 内側楔状開大型高位脛骨骨切り術の臨床成績に影響を与える因子の検討

  房川 祐頼, 鈴木 智之, 加谷 光規, 渡邉 耕太, 寺本 篤史, 舘田 健児, 木井 雄一郎, 岡田 葉平, 山下 敏彦

  JOSKAS ( (一社)日本関節鏡・膝・スポーツ整形外科学会 )  41 ( 4 ) 201 - 201  2016.07

Awards 【 display / non-display 】

Awards 【 display / non-display 】

• Best Poster award

  2018.12   The Japanese Pediatric Orthopaedic Association  

Research Projects 【 display / non-display 】

Research Projects 【 display / non-display 】

• Establishment of new treatment method for dedifferentiated chondrosarcoma

  Grant-in-Aid for Scientific Research (C)

  Project Year :

  2024.04

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  2027.03

   

  清水 淳也, 高澤 啓, 江森 誠人, 房川 祐頼, 佐藤 達也, 高田 弘一, 中橋 尚也

• 腎不全サルコペニアの運動時エネルギー代謝障害の解明と神経-筋電気刺激療法の確立

  基盤研究(C)

  Project Year :

  2023.04

  -

  2026.03

   

  房川 祐頼, 佐藤 達也, 山田 崇史

• Roles of mitochondrial function in temperature intervention during recovery from muscle fatigue

  Grant-in-Aid for Early-Career Scientists

  Project Year :

  2020.04

  -

  2023.03

   

  房川 祐頼

  　View Summary

  運動後筋疲労に対してスポーツ現場で様々な対症療法が行われている。運動直後にはアイシング、冷却が行われているがエネルギー会社の観点からはむしろ温熱の方が有効であるという報告も多く温度介入はいまだ根拠が乏しい。筋疲労の発生には複数の分子機序が関与するが、興奮収縮連関の過程において必要なエネルギー (特にアデノシン三リン酸:ATP)の需要を賄えないことが機序の主要因として注目されている。ATPの主要な供給源であるミトコンドリアの機能が大きな役割を担っているが、ミトコンドリアは絶えず融合 (fusion)、分裂 (fission)、オートファジーにより品質管理されている。運動によりfissionを制御するDRP1のSer616リン酸化が活性化することが知られている。運動後の温熱、冷却介入によって筋ミトコンドリアのDRP1の変化について調査した。Wistar ratに10-20m/minの速度で30分トレッドミル走行をさせた後30分の温度介入（室温、温熱42度水槽、冷却16度水槽に下腿を暴露）を行い、採取した筋サンプルを用いてWestern blotを行った。DRP1-Ser616のリン酸化レベルは、運動直後に比べ温度介入直後では、冷却群で増加し、温熱群、室温群でむしろ低下した。また安静時に温度介入30分を同様におこなう実験を追加したが、冷却、温熱ともにDRP1-Ser616のリン酸化レベルは増加しなかった。以上から冷却介入は運動後のDRP1のSer616リン酸化の状態に影響を与えていることを確認した。