Prior muscular contraction enhances disposal of glucose analog in the liver and muscle.
To noninvasively investigate in vivo glucose disposal in muscle and liver after exercise, 19F magnetic resonance spectroscopy (19F-MRS) was applied using 3-fluoro-3-deoxy-D-glucose (3FDG) as a metabolic probe. After 30 minutes of muscle contraction of rabbit hindlimb by a 1-Hz electrical stimulation, 3FDG 250 mg/kg was injected intravenously and 19F-MRS was performed on the postcontracted hindlimb or the liver. Rabbits subjected to muscle contraction showed 1.5- and 1.7-fold higher peaks for 3FDG signal intensity in the liver and muscle than those not subjected to it. 3FDG was converted to 3-fluoro-3-deoxy-gluconic acid (3FGA) in the muscle and liver, and 3FDG oxidation was not affected by muscle contraction. During intraportal 3FDG infusion for 120 minutes at a dose of 2 mg x kg-1 x min-1 after termination of muscle contraction, the postcontracted rabbits showed a continuous increase in the signal intensity of 3FDG and a 2.1-fold higher total signal intensity of 3FDG than those not subjected to muscle contraction. In conclusion, 19F-MRS allows direct noninvasive observation of 3FDG disposal in rabbit muscle and liver. The increased intensity of 3FDG in the liver after muscle contraction suggests that exercise enhances disposal of the glucose analog in the liver, as well as in muscle, and these effects persist for at least 2 hours after exercise.
Matsuhisa
M
M
First Department of Medicine, Osaka University School of Medicine, Suita, Japan.
Nishizawa
H
H
Ikeda
M
M
Kubota
M
M
Arai
S
S
Kawamori
R
R
Yamasaki
Y
Y
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D004558:Electric Stimulation; D005942:Gluconates / Q000378:metabolism; D007328:Insulin / Q000097:blood; D008099:Liver / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D011817:Rabbits
D001786:Blood Glucose; D005942:Gluconates; D007328:Insulin; C007253:3-deoxy-3-fluoro-D-glucose; D003847:Deoxyglucose