title: Hibernation reduces pancreatic amylase levels in ground squirrels.
abstract: Pancreatic enzyme levels in mammals are influenced by food intake and dietary composition. In this study, we examined the activity and expression of pancreatic amylase in a hibernating mammal, a natural model for long-term fasting. Pancreatic tissues were obtained from summer-active 13-lined ground squirrels and hibernating squirrels that had not eaten for at least 6 weeks. Amylase specific activity was reduced by approximately 50% in the torpid hibernators compared with summer squirrels, and immunoblot analysis revealed that amylase protein expression was reduced by approximately 40% in the hibernators. Similar reductions in amylase specific activity were observed in interbout euthermic hibernators. These results support a strong influence of food intake on pancreatic enzyme expression in hibernating mammals. The maintenance of basal levels of this key digestive enzyme at approximately 50% of summer values despite the extended winter fast likely facilitates the rapid resumption of digestive function after terminal arousal in the spring.
authors.affiliation: Department of Comparative Biosciences, University of Wisconsin, School of Veterinary Medicine, 2015 Linden Drive, Madison, WI 53706, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Balslev-Clausen
authors.forename: Julia M
authors.initials: JM
authors.lastname: McCarthy
authors.forename: Hannah V
authors.initials: HV
authors.lastname: Carey
mesh_terms: D000681:Amylases / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D001835:Body Weight; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006605:Hibernation / Q000502:physiology*; D008297:Male; D010179:Pancreas / Q000201:enzymology*; D012589:Sciuridae / Q000502:physiology*; D012621:Seasons; D014922:Wisconsin
chemical_list: D000681:Amylases