ABSTRACT
Mammalian hibernators exhibit dramatic changes in food intake, body weight, metabolic rate, and other physiological parameters over the course of their annual cycles. This chapter highlights previous studies that document the effect of hibernation on gut structure and transport function, and then describes current studies that address the question of how one hibernator, the 13-lined ground squirrel, retains digestive function during hibernation despite the extended winter fast. The apparent upregulation of sucrase specific activity may reflect the relatively greater maturity of enterocytes in the hibernating gut compared with actively feeding animals, because expression of sucrase is minimal in crypt cells and increases as cells mature and migrate towards villus tips. Hamsters differ from ground squirrels in that they rely on feeding during periodic arousals to sustain them through the winter months; upon refeeding during an arousal, sucrase activity significantly increased in the hamsters.
