Rates of appearance and disappearance of plasma lactate after oral glucose: implications for indirect-pathway hepatic glycogen repletion in man.
3-14C-lactate and 6-3H-glucose were infused to determine rates of plasma lactate appearance (Ra), disappearance (Rd) and conversion to plasma glucose following ingestion of 75 g glucose in 10 healthy volunteers. Lactate Ra (mumol/kg/min) increased from 10.2 +/- 0.9 to a peak of 15.7 +/- 0.8 at 60 min (p less than 0.01). Lactate Rd increased from 10.2 +/- 0.9 to a peak of 15.9 +/- 4.2 at 120 min (p less than 0.001). During the 3-hour experiment, 15.0 +/- 1.1 g of lactate appeared in plasma, and 14.1 +/- 1.2 g disappeared from plasma. Of lactate Rd, approximately 20% (2.8 +/- 0.2 g) was converted to plasma glucose leaving a maximum 11.3 +/- 0.8 g lactate available for indirect-pathway glycogen synthesis. The present data indicate that in man the indirect pathway could account for about 40% of hepatic glycogen repletion via uptake of circulating gluconeogenic precursors.
Consoli
A
A
Department of Medicine, University of Pittsburgh School of Medicine, Pa.
Nurjhan
N
N
Gerich
J
J
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005943:Gluconeogenesis; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood; D007700:Kinetics; D007773:Lactates / Q000097:blood*; D019344:Lactic Acid; D008112:Liver Glycogen / Q000096:biosynthesis*; D008297:Male; D011849:Radioactive Tracers
D001786:Blood Glucose; D007328:Insulin; D007773:Lactates; D008112:Liver Glycogen; D011849:Radioactive Tracers; D019344:Lactic Acid; D005947:Glucose