title: Regional Differences of Metabolic Response During Dynamic Incremental Exercise by (31)P-CSI.
abstract: The aim of this study was to detect the differences in muscle metabolic response of the quadriceps during incremental dynamic knee exercise using regional (31)Phosphorus Chemical Shift Imaging ((31)P-CSI). Sixteen healthy men participated in this study (age 28 ± 5 years, height 171.4 ± 3.9 cm, weight 67.1 ± 9.8 kg). The experiments were carried out with a 1.5-T superconducting magnet with a 5-in. diameter circular surface coil. The subjects performed isometric unilateral knee extension exercise to detect their maximum voluntary contraction (MVC) in prone position. Then they performed dynamic unilateral knee extension exercise in the magnet at 10, 20, 30 and 40 % of their MVC with the transmit-receive coil placed under the right quadriceps. The subjects pulled down a rope with the adjusted weight attached to the ankle at a frequency of 0.5 Hz for 380 s. Intracellular pH (pHi) was calculated from the median chemical shift of the inorganic phosphate (Pi) peak relative to phosphocreatine (PCr). The quadriceps were divided into three regions, (1) medial, (2) anterior, (3) lateral, and in comparison, there was no significant difference in Pi/PCr nor in pHi between regions, except Pi/PCr of the medial region was significantly higher than the anterior region at maximum intensity (p < 0.05). These results suggest that regional muscle metabolic response is similar in the quadriceps except at maximum intensity.
authors.affiliation: Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan. ykaneko@tokyo-med.ac.jp.|Department of Oriental Medicine, Kuretake College of Medical Arts and Sciences, Tokyo, Japan. ykaneko@tokyo-med.ac.jp.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan.
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Kime
authors.affiliation: Kuretake Medical Clinic, Kuretake College of Medical Arts and Sciences, Tokyo, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Hongo
authors.affiliation: Kuretake Medical Clinic, Kuretake College of Medical Arts and Sciences, Tokyo, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ohno
authors.affiliation: Department of Oriental Medicine, Kuretake College of Medical Arts and Sciences, Tokyo, Japan.|Kuretake Medical Clinic, Kuretake College of Medical Arts and Sciences, Tokyo, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Sakamoto
authors.affiliation: Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan.
authors.forename: Toshihito
authors.initials: T
authors.lastname: Katsumura
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D064368:Healthy Volunteers; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007537:Isometric Contraction; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010710:Phosphates / Q000378:metabolism*; D010725:Phosphocreatine / Q000378:metabolism*; D010759:Phosphorus Isotopes; D011237:Predictive Value of Tests; D016684:Prone Position; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging* / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010710:Phosphates; D010759:Phosphorus Isotopes; D010725:Phosphocreatine
keywords: Dynamic exercise; Magnetic resonance spectroscopy; Quadriceps; pH