title: Maintenance of a fully functional digestive system during hibernation in the European hamster, a food-storing hibernator.
abstract: Some small mammals limit energy expenditure during winter conditions through torpor bouts, which are characterized by a decrease in body temperature and metabolic rate. Individuals arise periodically from torpor to restore critical functions requiring euthermia. Although most of the species involved do not feed during hibernation and rely on body reserves to fulfil energy requirements (fat-storing species), others hoard food in a burrow (food-storing species) and can feed during interbout euthermy. Whereas fat-storing species undergo a marked atrophy of the digestive tract, food-storing species have to maintain a functional digestive system during hibernation. Our study aimed to evaluate the absorption capacities of a food-storing species, the European hamster, throughout the annual cycle. In vivo intestinal perfusions were conducted in different groups of hamsters (n=5) during the different life periods, namely before hibernation, in torpor, during interbout euthermy, and during summer rest. The triglyceride, non-esterified free fatty acid, starch, glucose and protein composition of the perfusate was evaluated before and after the 1h perfusion of a closed intestinal loop. Triglyceride, starch and protein hydrolysis rates were similar in hibernating (torpid and euthermic) and non-hibernating hamsters. Intestinal absorption of free fatty acid was also similar in all groups. However, glucose uptake rate was higher during hibernation than during the summer. In contrast with fat-storing species, the intestinal absorption capacities of food-storing species are fully maintained during hibernation to optimize nutrient assimilation during short interbout euthermy. In particular, glucose uptake rate is increased during hibernation to restore glycaemia and ensure glucose-dependent pathways.
authors.affiliation: Université de Strasbourg, IPHC, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR 7178, 67037 Strasbourg, France. Electronic address: mathieu.weitten@iphc.cnrs.fr.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Weitten
authors.affiliation: INSERM U1118/UdS, Mécanismes centraux et périphérique de la neurodégénérescence, 11 rue Humann, 67085 Strasbourg, France.
authors.forename: Hugues
authors.initials: H
authors.lastname: Oudart
authors.affiliation: Université de Strasbourg, IPHC, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR 7178, 67037 Strasbourg, France. Electronic address: caroline.habold@iphc.cnrs.fr.
authors.forename: Caroline
authors.initials: C
authors.lastname: Habold
mesh_terms: D000818:Animals; D001831:Body Temperature; D006224:Cricetinae / Q000378:metabolism / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D061353:Food Storage; D041981:Gastrointestinal Tract / Q000378:metabolism / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D006605:Hibernation / Q000502:physiology*; D007408:Intestinal Absorption / Q000502:physiology; D008322:Mammals / Q000378:metabolism / Q000502:physiology; D011506:Proteins / Q000378:metabolism; D012621:Seasons; D013213:Starch / Q000378:metabolism; D064348:Torpor / Q000502:physiology; D014280:Triglycerides / Q000378:metabolism
chemical_list: D005230:Fatty Acids, Nonesterified; D011506:Proteins; D014280:Triglycerides; D013213:Starch; D005947:Glucose
keywords: Arousal; Cricetus cricetus; Food-storing; In vivo intestinal uptake measurements; Small intestine; Torpor