Beschreibung:
<jats:sec><jats:label /><jats:p>During hibernation, ground squirrels fast for several months and rely solely on adipose stores to fuel metabolism. We showed previously that ionic permeability of hibernating squirrel intestine is 1.5‐fold greater than in summer squirrels, which is consistent with studies in non‐hibernating species that fasting and total parenteral nutrition can increase gut permeability. However, whether macromolecular permeability is also elevated during hibernation is not known. To investigate the severity of the permeability change, we gavaged summer squirrels and hibernators that were fully aroused (T<jats:sub>b</jats:sub>~37 °C) with FITC‐labeled dextran (MW 4kD). Appearance of label in plasma 3 h later was ~10‐fold greater in hibernating (n=6) vs. summer (n=6) squirrels (P<0.05). Western analysis showed that cecal expression of the tight junction protein occludin is 3.5‐fold greater in hibernators (n=12 each group) (P<0.01). We hypothesize that in the setting of elevated gut permeability during hibernation, upregulation of occludin expression may help restrict microbes and their products to the gut lumen, thereby minimizing the risk of mucosal inflammation and sepsis.</jats:p></jats:sec>