A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
PET/CT imaging of age- and task-associated differences in muscle activity during fatiguing contractions
Tekijät: Rudroff T, Kalliokoski KK, Block DE, Gould JR, Klingensmith WC, Enoka RM
Julkaisuvuosi: 2013
Journal: Journal of Applied Physiology
Numero sarjassa: 9
Vuosikerta: 114
Numero: 9
Aloitussivu: 1211
Lopetussivu: 1219
Sivujen määrä: 9
ISSN: 8750-7587
DOI: https://doi.org/10.1152/japplphysiol.01439.2012
Verkko-osoite: PM:23412899
Tiivistelmä
The study compared positron emission tomography/computed tomography (PET/CT) of [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]-FDG) uptake by skeletal muscles and the amount of muscle activity as indicated by surface electromyographic (EMG) recordings when young and old men performed fatiguing isometric contractions that required either force or position control. EMG signals were recorded from thigh muscles of six young men (26 +/- 6 yr) and six old men (77 +/- 6 yr) during fatiguing contractions with the knee extensors. PET/CT scans were performed immediately after task failure. Glucose uptake in 24 leg muscles, quantified as standardized uptake values, was greater for the old men after the force task and differed across tasks for the young men (force, 0.64 +/- 0.3 g/ml; position, 0.73 +/- 0.3 g/ml), but not the old men (force, 0.84 +/- 0.3 g/ml; position, 0.79 +/- 0.26 g/ml) (age x task interaction; P < 0.001). In contrast, the rate of increase in EMG amplitude for the agonist muscles was greater for the young men during the two contractions and there was no difference for either group of subjects in the rate of increase in EMG amplitude across the two tasks. The imaging estimates of glucose uptake indicated age- and task-dependent differences in the spatial distribution of [(18)F]-FDG uptake by skeletal muscles during fatiguing contractions. The findings demonstrate that PET/CT imaging of [(18)F]-FDG uptake, but not surface EMG recordings, detected the modulation of muscle activity across the fatiguing tasks by the young men but not the old men
The study compared positron emission tomography/computed tomography (PET/CT) of [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]-FDG) uptake by skeletal muscles and the amount of muscle activity as indicated by surface electromyographic (EMG) recordings when young and old men performed fatiguing isometric contractions that required either force or position control. EMG signals were recorded from thigh muscles of six young men (26 +/- 6 yr) and six old men (77 +/- 6 yr) during fatiguing contractions with the knee extensors. PET/CT scans were performed immediately after task failure. Glucose uptake in 24 leg muscles, quantified as standardized uptake values, was greater for the old men after the force task and differed across tasks for the young men (force, 0.64 +/- 0.3 g/ml; position, 0.73 +/- 0.3 g/ml), but not the old men (force, 0.84 +/- 0.3 g/ml; position, 0.79 +/- 0.26 g/ml) (age x task interaction; P < 0.001). In contrast, the rate of increase in EMG amplitude for the agonist muscles was greater for the young men during the two contractions and there was no difference for either group of subjects in the rate of increase in EMG amplitude across the two tasks. The imaging estimates of glucose uptake indicated age- and task-dependent differences in the spatial distribution of [(18)F]-FDG uptake by skeletal muscles during fatiguing contractions. The findings demonstrate that PET/CT imaging of [(18)F]-FDG uptake, but not surface EMG recordings, detected the modulation of muscle activity across the fatiguing tasks by the young men but not the old men
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