TY - JOUR

T1 - Bone blood flow and metabolism in humans

T2 - Effect of muscular exercise and other physiological perturbations

AU - Heinonen, Ilkka

AU - Kemppainen, Jukka

AU - Kaskinoro, Kimmo

AU - Langberg, Henning

AU - Knuuti, Juhani

AU - Boushel, Robert

AU - Kjaer, Michael

AU - Kalliokoski, Kari K

N1 - Copyright © 2012 American Society for Bone and Mineral Research.

PY - 2012/12/21

Y1 - 2012/12/21

N2 - Human bone blood flow and metabolism during physical exercise remains poorly characterised. 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 six women, blood flow was measured in femoral bone at rest and during one leg intermittent isometric exercise with increasing exercise intensities. In nine men, blood flow in femur was determined at rest and during dynamic one leg exercise, and two other physiological perturbations: moderate systemic hypoxia (14 O(2) ) at rest and during exercise, and during intra-femoral infusion of high-dose adenosine. Bone glucose uptake was measured at rest and during dynamic one leg exercise in five men. The results indicate that isometric exercise increased femoral bone blood flow from rest (1.8 ± 0.6 ml/100g/min) to low intensity exercise (4.1 ± 1.5 ml/100g/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/100g/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/100g/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, while moderate systemic hypoxia does not change bone blood flow at rest or during exercise, intra-arterially administered adenosine during resting conditions is capable of enhancing bone blood flow in humans markedly. Finally, also bone glucose uptake increases substantially in response to exercise. © 2012 American Society for Bone and Mineral Research.

AB - Human bone blood flow and metabolism during physical exercise remains poorly characterised. 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 six women, blood flow was measured in femoral bone at rest and during one leg intermittent isometric exercise with increasing exercise intensities. In nine men, blood flow in femur was determined at rest and during dynamic one leg exercise, and two other physiological perturbations: moderate systemic hypoxia (14 O(2) ) at rest and during exercise, and during intra-femoral infusion of high-dose adenosine. Bone glucose uptake was measured at rest and during dynamic one leg exercise in five men. The results indicate that isometric exercise increased femoral bone blood flow from rest (1.8 ± 0.6 ml/100g/min) to low intensity exercise (4.1 ± 1.5 ml/100g/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/100g/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/100g/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, while moderate systemic hypoxia does not change bone blood flow at rest or during exercise, intra-arterially administered adenosine during resting conditions is capable of enhancing bone blood flow in humans markedly. Finally, also bone glucose uptake increases substantially in response to exercise. © 2012 American Society for Bone and Mineral Research.

U2 - 10.1002/jbmr.1833

DO - 10.1002/jbmr.1833

M3 - Journal article

C2 - 23280932

VL - 28

SP - 1068

EP - 1074

JO - Journal of Bone and Mineral Research

JF - Journal of Bone and Mineral Research

SN - 0884-0431

IS - 5

ER -