運動時の細胞内pHとクレアチンリン酸濃度の変化に及ぼすNaHCO<SUB>3</SUB>摂取の影響―<SUP>31</SUP>P NMRによる検討― STUDIES ON THE EFFECT OF NaHCO<SUB>3</SUB> INTAKE ON INTRACELLULAR pH AND PCr CONCENTRATION DURING EXERCISE BY <SUP>31</SUP>P NMR

Access this Article

Search this Article

Author(s)

    • 久野 譜也 KUNO SHIN-YA
    • 筑波大学臨床医学系放射線科 <I>Department of Radiology, Institute of Clinical Medicine, University of Tsukuba</I>
    • 阿武 泉 ANNO IZUMI
    • 筑波大学臨床医学系放射線科 <I>Department of Radiology, Institute of Clinical Medicine, University of Tsukuba</I>
    • 板井 悠二 ITAI YUJI
    • 筑波大学臨床医学系放射線科 <I>Department of Radiology, Institute of Clinical Medicine, University of Tsukuba</I>

Abstract

NaHCO<SUB>3</SUB>摂取が運動時の細胞内pHおよびPCr濃度にどのような影響を及ぼすかについて明らかにするために, 7名の被検者に対し, NaCl (Cont.Tr.) およびNaHCO<SUB>3</SUB>摂取 (Alka.Tr.) 後の運動時において31PNMRの測定を行なった.<BR>結果の要約は次の通りである.<BR>1) 運動時の細胞内pHの経時的低下は, Cont.Tr.と比較すると, Alka.Tr.において遅延傾向にあり, 運動終了時の細胞内pHは, Alka.Tr. (6.69±0.11) が1Cont.Tr. (6.51±0.15) より高値を示す傾向にあった.<BR>2) 運動時におけるPCr/ (PCr+Pi) の比の経時的低下は, Cont.Tr., Alka.Tr.の両トライアルにおいて差は認められず, 運動終了時のPCr/ (PCr+Pi) の比はCont.Tr.で0.50±0.06, Alka.Tr.で0.54±0.06を示した.<BR>3) 運動終了時の細胞内pHとPCr/ (PCr+Pi) の比との間には, 有意な指数関数的関係が認められ, PCr/ (PCr+Pi) の比は, 細胞内pHが6.6~6.7に低下するまで顕著な減少を示したが, より低いレベルにおいてはほとんど変化を示さなかった.<BR>以上のことより, NaHCO<SUB>3</SUB>摂取は運動時の細胞内pHの低下を抑制する傾向にあることが示唆された.また, 細胞内pHとPCr濃度との間には指数関数的関係があり, PCr貯備の減少が軽減されるには, 細胞内pHの低下が6.6~6.7より高いレベルで抑制される必要性のあることが示唆された.

To evaluate the changes in muscle energetics following NaHCO<SUB>3</SUB> intake, we measured the phosphorus-31 nuclear magnetic resonance (<SUP>31</SUP>P NMR) spectra of human muscle <I>in vivo</I> during exercise. Seven male subjects performed two trials, a NaHCO<SUB>3</SUB> (Alka, Tr.) and a NaCI trial (Cont. Tr.), on two occasions. <SUP>31</SUP>P NMR spectra were obtained serially during leg-elevating exercises. Before and during exercise, the intracellular phosphocreatine (PCr), inorganic phosphate (Pi) and pH were determined from the NMR spectra. The decrease of intracellular pH during exercise showed a tendency to be inhibited by NaHCO<SUB>3</SUB> intake, and the intracellular pH at the end of the exercise was 6.69 for Alka. Tr, and 6.51 for Cont. Tr. The decline of the PCr/ (PCr+Pi) ratio during exercise was not influenced by NaHCO<SUB>3</SUB> intake. The PCr/ (PCr+Pi) ratio was related exponentially to the intracellular pH. A remarkable decline of PCr/ (PCr+Pi) ratio occurred until the intracellular pH fell to about 6.7, but did not decrease below that. It was suggested that the intake of NaHCO<SUB>3</SUB> could decrease the rate of fall in the intracellular pH during exercise, and that the PCr store could be influenced by the intracellular pH when the pH was above 6.7, but not below that level.

Journal

  • Japanese Journal of Physical Fitness and Sports Medicine

    Japanese Journal of Physical Fitness and Sports Medicine 40(5), 493-500, 1991

    The Japanese Society of Physical Fitness and Sport Medicine

Codes

  • NII Article ID (NAID)
    110006368207
  • NII NACSIS-CAT ID (NCID)
    AN00137986
  • Text Lang
    UNK
  • Article Type
    journal article
  • ISSN
    0039-906X
  • NDL Article ID
    3750213
  • NDL Source Classification
    SC741(運動医学)
  • NDL Source Classification
    ZF21(教育--体育)
  • NDL Call No.
    Z7-301
  • Data Source
    NDL  NII-ELS  IR  J-STAGE 
Page Top