Fat oxidation is activated in liver during hibernation.

A) Representative western blot of activated and total AMP-activated protein kinase (P-AMPK, AMPK), inactivated and total ACC (P-ACC, ACC), phosphorylated and total LKB1 (P-LKB1 and LKB1), alpha1 and alpha2 subunits of AMPK, carnitine palmitoyltransferase 1A (CPT1A), and enoyl-CoA hydratase 1 (ECH1) in livers from animals in eight circannual stages (see Fig 2 legend). B-F) Western blot densitometry and P-AMPK/AMPK, P-ACC/ACC ratios from all ground squirrels analyzed. G) Intrahepatic β-hydroxybutyrate (a marker of fat oxidation) levels from all ground squirrels analyzed, n≥6 animals per physiological stage, small letters indicate significantly different groups).