HANAI Yoshiteru

写真a

Affiliation Department etc.

Department of Life Science and Applied Chemistry
Department of Life Science and Applied Chemistry

Title

Associate Professor

 

Papers

  • Interaction between myoglobin and mitochondria in rat skeletal muscle

    Yamada T, Furuichi Y, Takakura H, Hashimoto T, Hanai Y, Jue T, Masuda K.

    Journal of Applied Physiology   114 ( 4 ) 490 - 497   2013.02  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    The mechanisms underlying subcellular oxygen transport mediated by myoglobin (Mb) remain unclear. Recent evidence suggests that, in the myocardium, transverse diffusion of Mb is too slow to effectively supply oxygen to meet the immediate mitochondrial oxygen demands at the onset of muscle contractions. The cell may accommodate the demand by maintaining the distribution of Mb to ensure a sufficient O(2) supply in the immediate vicinity of the mitochondria. The present study has verified the co-localization of Mb with mitochondria by using biochemical histological and electron microscopy analyses. Immunohistochemical and electron microscopy analysis indicates a co-localization of Mb with mitochondria. Western blotting confirms the presence of Mb colocalizes with the mitochondrial fraction and appears more prominently in slow-twitch oxidative than in fast-twitch glycolytic muscle. In particular, Mb interacts with cytochrome c oxidase-subunit IV. These results suggest that a direct Mb-mediated O2 delivery to the mitochondria, which may play a potentially significant role for respiration.

  • Muscle contraction increases carnitine uptake via translocation of OCTN2

    Furuichi Y, Sugiura T, Kato Y, Takakura H, Hanai Y, Hashimoto T, Masuda K.

    Biochemical and Biophysical Research Communications   418 ( 4 ) 774 - 779   2012.01  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    Since carnitine plays an important role in fat oxidation, influx of carnitine could be crucial for muscle metabolism. OCTN2 (SLC22A5), a sodium-dependent solute carrier, is assumed to transport carnitine into skeletal muscle cells. Acute regulation of OCTN2 activity in rat hindlimb muscles was investigated in response to electrically induced contractile activity. The tissue uptake clearance (CL(uptake)) of l-[(3)H]carnitine during muscle contraction was examined in vivo using integration plot analysis. The CL(uptake) of [(14)C]iodoantipyrine (IAP) was also determined as an index of tissue blood flow. To test the hypothesis that increased carnitine uptake involves the translocation of OCTN2, contraction-induced alteration in the subcellular localization of OCTN2 was examined. The CL(uptake) of l-[(3)H]carnitine in the contracting muscles increased 1.4-1.7-fold as compared to that in the contralateral resting muscles (p<0.05). The CL(uptake) of [(14)C]IAP was much higher than that of l-[(3)H]carnitine, but no association between the increase in carnitine uptake and blood flow was obtained. Co-immunostaining of OCTN2 and dystrophin (a muscle plasma membrane marker) showed an increase in OCTN2 signal in the plasma membrane after muscle contraction. Western blotting showed that the level of sarcolemmal OCTN2 was greater in contracting muscles than in resting muscles (p<0.05). The present study showed that muscle contraction facilitated carnitine uptake in skeletal muscles, possibly via the contraction-induced translocation of its specific transporter OCTN2 to the plasma membrane.

Presentations

  • Muscle contraction increases carnitine uptake via the cellular redistribution of OCTN2

    Furuichi Y, Sugiura T, Kato Y, Takakura H, Hanai Y and Masuda K:

    American College of Sports Medicine 58th Annual Meeting   ((Denver, CO, USA)  2011.06  -  2011.06  American College of Sports Medicine

  • Interaction of myoglobin with mitochondria in skeletal muscles

    Masuda K, Yamada T, Furuichi Y, Takakura H, Hashimoto T, Hanai Y, Jue

    European College of Sport Science 16th Annual Congress   ((Liverpool, UK)  2011.06  -  2011.06  European College of Sport Science 16th Annual Congress

  • Interaction of mitochondria and oxygen binding protein in skeletal muscles

    Yamada T, Furuichi Y, Takakura H, Hashimoto T, Hanai Y, Jue T and Masuda K

    American College of Sports Medicine 58th Annual Meeting   (Denver, CO, USA)  2011.06  -  2011.06  American College of Sports Medicine