AMP-activated protein kinase (AMPK) has been studied extensively and postulated to be a target for the treatment and/or prevention of metabolic disorders such as
insulin resistance. Exercise training has been deemed a beneficial treatment for
obesity and
insulin resistance. Furthermore, exercise is a feasible method to combat high-fat diet (HFD)-induced alterations in
insulin sensitivity. The purpose of this study was to determine whether AMPK-α2 activity is required to gain beneficial effects of exercise training with high-fat feeding. Wild-type (WT) and AMPK-α2 dominant-negative (DN) male mice were fed standard diet (SD), underwent voluntary wheel running (TR), fed HFD, or trained with HFD (TR + HFD). By week 6, TR, irrespective of genotype, decreased
blood glucose and increased
citrate synthase activity in both diet groups and decreased
insulin levels in HFD groups. Hindlimb perfusions were performed, and, in WT mice with SD, TR increased
insulin-mediated
palmitate uptake (76.7%) and oxidation (>2-fold). These training-induced changes were not observed in the DN mice. With HFD, TR decreased
palmitate oxidation (61-64%) in both WT and DN and increased
palmitate uptake (112%) in the WT with no effects on
palmitate uptake in the DN. With SD, TR increased ERK1/2 and JNK1/2 phosphorylation, regardless of genotype. With HFD, TR reduced JNK1/2 phosphorylation, regardless of genotype,
carnitine palmitoyltransferase 1 expression in WT, and CD36 expression in both DN and WT. These data suggest that low AMPK-α2 signaling disrupts, in part, the exercise training-induced adaptations in
insulin-stimulated metabolism in skeletal muscle following HFD.