title: Intestinal oxygen uptake and glucose metabolism during nutrient absorption in the pig.
abstract: Intestinal transport of nutrients coincides with their partial catabolism in the gut. The aim of the present study was to measure intestinal oxygen consumption and nutrient metabolism after a meal or during a short fast. Nutrient and oxygen balances across the small intestine were measured in conscious 50 kg (live wt) pigs. Jejunal enterocytes were also isolated from 1-hr postprandial, postabsorptive, or 3-day fasted pigs, in order to evaluate their capacities to metabolize 5 mM glucose and 2 mM glutamine. Whatever the nutritional state, intestinal oxygen consumption was high, since 26 +/- 2% (n = 6) of the oxygen arterial supply was extracted by the small intestine. Furthermore, the consumption of a mixed meal induced a rapid and transient rise in oxygen consumption. In the postabsorptive state, the intestinal uptake of glucose (0.31 +/- 0.08 mmole/min, n = 6) was twice higher than that of glutamine. The role of glucose as a fuel was also evidenced after a 3-day fast. During nutrient absorption, glutamine was highly utilized, and lactate was produced. The capacity of enterocytes isolated from fed pigs to metabolize glucose was dramatically reduced, as was 6-phosphofructo 1-kinase activity. In contrast, intestinal muscle presented a high glycolytic capacity from glucose, suggesting that the main site of intestinal lactate production during nutrient absorption would be the muscular rather than the epithelial layer.
authors: Institut National de la Recherche Agronomique, Unité d'Ecologie et de Physiologie du Système Digestif, Jouy-en-Josas, France.
authors: P
authors: P
authors: Vaugelade
authors: L
authors: L
authors: Posho
authors: B
authors: B
authors: Darcy-Vrillon
authors: F
authors: F
authors: Bernard
authors: M T
authors: MT
authors: Morel
authors: P H
authors: PH
authors: Duée
mesh_terms: D000818:Animals; D005260:Female; D005947:Glucose / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism; D006019:Glycolysis; D007328:Insulin / Q000097:blood; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism*; D007773:Lactates / Q000096:biosynthesis; D019344:Lactic Acid; D010101:Oxygen Consumption; D013552:Swine
chemical_list: D007328:Insulin; D007773:Lactates; D005973:Glutamine; D019344:Lactic Acid; D005947:Glucose