Muscle blood flow during intermittent exercise: comparison of the microdialysis ethanol technique and 133Xe clearance.
1. Local skeletal muscle blood flow was monitored using the microdialysis ethanol technique and 133Xe clearance during intermittent isometric contractions (5 s on/10 s off) of the thigh at 0-60% of the maximal voluntary isometric contraction force. 2. A linear increase in blood flow over a 25-fold range was detected using both 133Xe clearance and the microdialysis ethanol technique. 3. The median correlation coefficient between percentage maximal voluntary isometric contraction force and the ethanol outflow/inflow ratio, a marker of blood flow, was r = -0.98 (-0.94 to -0.99) (median and range, n = 6). The corresponding correlation coefficient for 133Xe clearance was r = 0.97 (0.92-0.98), the correlation coefficient between the ethanol outflow/inflow ratio and 133Xe clearance being r = -0.92 (-0.89 to -0.94). 4. Dialysate glucose concentration, although affected by blood flow, was not always significantly correlated with blood flow changes (r = 0.70; 0.51-0.95). 5. It may be concluded that the ethanol technique provides a valid measure of changes in local skeletal muscle blood flow. The data furthermore show that a linear increase in thigh skeletal muscle blood flow exists during the studied protocol of intermittent isometric contractions.
Hickner
R C
RC
Department of Physiology III, Karolinska Institutet, Stockholm, Sweden.
Bone
D
D
Ungerstedt
U
U
Jorfeldt
L
L
Henriksson
J
J
D000328:Adult; D000431:Ethanol / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D017551:Microdialysis / Q000379:methods*; D009132:Muscles / Q000098:blood supply*; D012039:Regional Blood Flow / Q000502:physiology; D014980:Xenon Radioisotopes / Q000378:metabolism
D014980:Xenon Radioisotopes; D000431:Ethanol