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The effect of graded exercise on IL‐6 release and glucose uptake in human skeletal muscle
Author(s) -
Helge Jørn W.,
Stallknecht Bente,
Pedersen Bente Klarlund,
Galbo Henrik,
Kiens Bente,
Richter Erik A.
Publication year - 2003
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2002.030437
Subject(s) - thigh , femoral artery , vo2 max , medicine , blood flow , endocrinology , glucose uptake , skeletal muscle , chemistry , anatomy , heart rate , blood pressure , insulin
In this study, the hypothesis that the release of interleukin (IL)‐6 from human muscle is linked to exercise intensity and muscle glucose uptake was investigated. In the overnight fasted state, seven healthy males performed knee extension exercise, kicking with both legs, each at 25 % of maximal power ( W max ) for 45 min (eliciting 23 ± 1 % of pulmonary maximal oxygen uptake, V̇ O2,max ) and then simultaneously with one leg at 65 % and the other leg at 85 % W max for 35 min (40 ± 1 % of pulmonary V̇ O2,max ). Blood was sampled from a femoral artery and both femoral veins, and blood flow was determined by thermodilution. Thigh plasma flow (0.15 ± 0.01, 1.4 ± 0.2, 2.0 ± 0.1 and 2.3 ± 0.2 l min −1 thigh −1 at rest and 25 %, 65 % and 85 % W max , respectively) and thigh oxygen uptake (0.02 ± 0.01, 0.27 ± 0.03, 0.48 ± 0.04 and 0.55 ± 0.05 l min −1 thigh −1 at rest and 25 %, 65 % and 85 % W max , respectively) increased with increasing exercise intensity ( P < 0.05 ). Also, thigh IL‐6 release (0.4 ± 0.1, 1.3 ± 0.5, 1.5 ± 0.6 and 2.5 ± 0.7 ng min −1 thigh −1 at rest and 25 %, 65 % and 85 % W max , respectively) and thigh glucose uptake (0.05 ± 0.01, 0.3 ± 0.05, 0.75 ± 0.16, 1.07 ± 0.15 mmol min −1 thigh −1 at rest and 25 %, 65 % and 85 % W max , respectively) increased with increasing exercise intensity ( P < 0.05 ). During the last 35 min of exercise, arterial catecholamine concentrations were higher ( P < 0.05 ) than at rest and during low‐intensity exercise. During exercise, thigh IL‐6 release was positively related to both thigh glucose uptake ( P < 0.001 ) and thigh glucose delivery ( P < 0.005 ), but not to thigh glucose extraction. Thigh IL‐6 release was also positively related to arterial plasma adrenaline concentration. The pre‐exercise muscle glycogen concentration tended to correlate with the arteriovenous IL‐6 concentration difference at rest, and the postexercise glycogen concentration was inversely correlated with IL‐6 release during the final 35 min of exercise. In conclusion, the study indicates that IL‐6 release from human muscle is positively related to exercise intensity, arterial adrenaline concentration and muscle glucose uptake. This supports the hypothesis that IL‐6 may be linked to the regulation of glucose homeostasis during exercise. The observation of a relationship between IL‐6 release and muscle glycogen store both at rest and after exercise suggests that IL‐6 may act as a carbohydrate sensor.