title: Pathways for glucose disposal after meal ingestion in humans.
abstract: To characterize postprandial glucose disposal more completely, we used the tritiated water technique, a triple-isotope approach (intravenous [3-H(3)]glucose and [(14)C]bicarbonate and oral [6,6-(2)H(2)]glucose) and indirect calorimetry to assess splanchnic and peripheral glucose disposal, direct and indirect glucose storage, oxidative and nonoxidative glycolysis, and the glucose entering plasma via gluconeogenesis after ingestion of a meal in 11 normal volunteers. During a 6-h postprandial period, a total of approximately 98 g of glucose were disposed of. This was more than the glucose contained in the meal ( approximately 78 g) due to persistent endogenous glucose release ( approximately 21 g): splanchnic tissues initially took up approximately 23 g, and an additional approximately 75 g were removed from the systemic circulation. Direct glucose storage accounted for approximately 32 g and glycolysis for approximately 66 g (oxidative approximately 43 g and nonoxidative approximately 23 g). About 11 g of glucose appeared in plasma as a result of gluconeogenesis. If these carbons were wholly from glucose undergoing glycolysis, only approximately 12 g would be available for indirect pathway glycogen formation. Our results thus indicate that glycolysis is the main initial postprandial fate of glucose, accounting for approximately 66% of overall disposal; oxidation and storage each account for approximately 45%. The majority of glycogen is formed via the direct pathway ( approximately 73%).
authors.affiliation: Department of Medicine, University of Rochester School of Medicine, Rochester, New York 14642, USA.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Woerle
authors.forename: Christian
authors.initials: C
authors.lastname: Meyer
authors.forename: Jean M
authors.initials: JM
authors.lastname: Dostou
authors.forename: Niyaz R
authors.initials: NR
authors.lastname: Gosmanov
authors.forename: Nazmul
authors.initials: N
authors.lastname: Islam
authors.forename: Emilia
authors.initials: E
authors.lastname: Popa
authors.forename: Steven D
authors.initials: SD
authors.lastname: Wittlin
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Welle
authors.forename: John E
authors.initials: JE
authors.lastname: Gerich
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002250:Carbon Radioisotopes; D005260:Female; D005934:Glucagon / Q000097:blood; D005943:Gluconeogenesis / Q000502:physiology*; D005947:Glucose / Q000493:pharmacokinetics*; D006003:Glycogen / Q000378:metabolism*; D006019:Glycolysis / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D019518:Postprandial Period / Q000502:physiology; D014316:Tritium
chemical_list: D001786:Blood Glucose; D002250:Carbon Radioisotopes; D007328:Insulin; D014316:Tritium; D006003:Glycogen; D005934:Glucagon; D005947:Glucose