Glucose production during exercise in humans: a-hv balance and isotopic-tracer measurements compared.
The present study compared the arteriohepatic venous (a-hv) balance technique and the tracer-dilution method for estimation of hepatic glucose production during both moderate and heavy exercise in humans. Eight healthy young men (aged 25 yr; range, 23-30 yr) performed semisupine cycling for 40 min at 50.4 +/- 1.5(SE)% maximal O(2) consumption, followed by 30 min at 69.0 +/- 2.2% maximal O(2) consumption. The splanchnic blood flow was estimated by continuous infusion of indocyanine green, and net splanchnic glucose output was calculated as the product of splanchnic blood flow and a-hv blood glucose concentration differences. Glucose appearance rate was determined by a primed, continuous infusion of [3-(3)H]glucose and was calculated by using formulas for a modified single compartment in non-steady state. Glucose production was similar whether determined by the a-hv balance technique or by the tracer-dilution method, both at rest and during moderate and intense exercise (P > 0. 05). It is concluded that, during exercise in humans, determination of hepatic glucose production can be performed equally well with the two techniques.
Bergeron
R
R
Department of Physical Education, University of Montreal, Montreal, Quebec, Canada H3C 3J7.
Kjaer
M
M
Simonsen
L
L
Bülow
J
J
Galbo
H
H
D000328:Adult; D004396:Coloring Agents; D005069:Evaluation Studies as Topic; D015444:Exercise / Q000502:physiology*; D005947:Glucose / Q000096:biosynthesis*; D006801:Humans; D007208:Indocyanine Green; D008099:Liver / Q000378:metabolism; D008297:Male; D010101:Oxygen Consumption; D013152:Splanchnic Circulation; D014316:Tritium
D004396:Coloring Agents; D014316:Tritium; D007208:Indocyanine Green; D005947:Glucose