Bone blood flow and metabolism in humans: Effect of muscular exercise and other physiological perturbations

Authors

  • Ilkka Heinonen,

    Corresponding author
    1. Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
    2. Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku and Turku University Hospital, Turku, Finland
    3. Division of Experimental Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
    • PhD, Turku PET Centre, PO Box 52, FI-20521 Turku, Finland.
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  • Jukka Kemppainen,

    1. Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
    2. Department of Clinical Physiology and Nuclear Medicine, University of Turku and Turku University Hospital, Turku, Finland
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  • Kimmo Kaskinoro,

    1. Department of Anaesthesiology, University of Turku and Turku University Hospital, Turku, Finland
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  • Henning Langberg,

    1. CopenRehab, Institute of Social Medicine, Department of Public Health and Centre for Healthy Ageing, Faculty of Heath Sciences, University of Copenhagen, Copenhagen, Denmark
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  • Juhani Knuuti,

    1. Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
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  • Robert Boushel,

    1. Heart & Circulatory Section, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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  • Michael Kjaer,

    1. Institute of Sports Medicine, Department of Orthopedic Surgery M81, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
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  • Kari K Kalliokoski

    1. Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
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Abstract

Human bone blood flow and metabolism during physical exercise remains poorly characterized. In the present study we measured femoral bone blood flow and glucose uptake in young healthy subjects by positron emission tomography in three separate protocols. In 6 women, blood flow was measured in femoral bone at rest and during one-leg intermittent isometric exercise with increasing exercise intensities. In 9 men, blood flow in the femur was determined at rest and during dynamic one-leg exercise and two other physiological perturbations: moderate systemic hypoxia (14 O2) at rest and during exercise, and during intrafemoral infusion of high-dose adenosine. Bone glucose uptake was measured at rest and during dynamic one-leg exercise in 5 men. The results indicate that isometric exercise increased femoral bone blood flow from rest (1.8 ± 0.6 mL/100 g/min) to low intensity exercise (4.1 ± 1.5 mL/100 g/min, p = 0.01), but blood flow did not increase further with increasing intensity. Resting femoral bone blood flow in men was similar to that of women and dynamic one-leg exercise increased it to 4.2 ± 1.2 mL/100 g/min, p < 0.001. Breathing of hypoxic air did not change femoral bone blood flow at rest or during exercise, but intra-arterial infusion of adenosine during resting conditions increased bone blood flow to 5.7 ± 2.4 mL/100 g/min, to the level of moderate-intensity dynamic exercise. Dynamic one-leg exercise increased femoral bone glucose uptake 4.7-fold compared to resting contralateral leg. In conclusion, resting femoral bone blood flow increases by physical exercise, but appears to level off with increasing exercise intensities. Moreover, although moderate systemic hypoxia does not change bone blood flow at rest or during exercise, intra-arterially administered adenosine during resting conditions is capable of markedly enhancing bone blood flow in humans. Finally, bone glucose uptake also increases substantially in response to exercise. © 2013 American Society for Bone and Mineral Research.

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