title: Splanchnic retention of intraduodenal and intrajejunal glucose in healthy adults.
abstract: Estimates of the spanchnic retention and appearance in the systemic circulation of orally administered glucose vary among laboratories even after recently identified sources of error have been accounted for [Livesey, G., P. D. G. Wilson, J. R. Dainty, J. C. Brown, R. M. Faulks, M. A. Roe, T. A. Newman, J. Eagles, F. A. Mellon, and R. Greenwood. Am. J. Physiol. 275 (Endocrinol. Metab. 38): E717-E728, 1998]. We questioned whether, in healthy humans, D-glucose delivered intraluminally to the midjejunum appeared systemically as extensively as that delivered intraduodenally. Subjects were infused over a period of 90 min with 50 g of glucose in 1 liter of isotonic saline (incorporating 0.5 g D-[13C6]glucose) per 70 kg of body weight. Infusions were via enteral tubes terminating approximately 15 and 100 cm postpylorus. The systemic appearance of glucose was monitored by means of a primed-continuous intravenous infusion of D-[6,6-2H2]glucose. Whereas 98 +/- 2% (n = 7) of the duodenally infused glucose appeared in the systemic circulation, only 35 +/- 9% (n = 7) of midjejunally infused glucose did so, implying that 65 +/- 9% was retained in the splanchnic bed. Either glucose was less efficiently absorbed at the midintestinal site or hepatic glucose sequestration was increased 10-fold, or both. The proximal intestine plays a key role in the delivery of glucose to the systemic circulation, and the distal intestine potentially delivers more glucose to the liver.
authors.affiliation: Department of Nutrition, Diet, and Health, Institute of Food Research, Norwich NR4 7UA, United Kingdom.
authors.forename: G
authors.initials: G
authors.lastname: Livesey
authors.forename: P D
authors.initials: PD
authors.lastname: Wilson
authors.forename: M A
authors.initials: MA
authors.lastname: Roe
authors.forename: R M
authors.initials: RM
authors.lastname: Faulks
authors.forename: L M
authors.initials: LM
authors.lastname: Oram
authors.forename: J C
authors.initials: JC
authors.lastname: Brown
authors.forename: J
authors.initials: J
authors.lastname: Eagles
authors.forename: R H
authors.initials: RH
authors.lastname: Greenwood
authors.forename: H
authors.initials: H
authors.lastname: Kennedy
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D002247:Carbon Isotopes; D004386:Duodenum / Q000502:physiology*; D004750:Enteral Nutrition; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism*; D006801:Humans; D007263:Infusions, Parenteral; D007583:Jejunum / Q000502:physiology*; D007700:Kinetics; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D008954:Models, Biological; D012016:Reference Values; D013152:Splanchnic Circulation / Q000502:physiology*; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D002247:Carbon Isotopes; D005947:Glucose