Exercise increases nuclear AMPK α2 in human skeletal muscle

An acute bout of exercise increases skeletal muscle glucose uptake, improves glucose homeostasis and insulin sensitivity, and enhances muscle oxidative capacity. Recent studies have shown an as association between these adaptations and the energy-sensing 5' AMP-activated protein kinase (AMPK). the activity of which is increased in response to exercise. Activation of AMPK hash been associated with enhanced expression of key metabolic proteins such as GLLITT-4, hexokinase II (HKII), and mitochondrial enzymes, similar to exercise. It has. been hypothesized that AMPK might regulate gene and protein expression through direct interaction with the nucleus. The purpose of this study was. to determine if nuclear AMPK alpha(2) Content in human skeletal muscle was increased by exercise. Following 60 min of cycling at 72 +/- 1% of Vo(2peak) in six male volunteers (20.6 +/- 2.1 years; 72.9 +/- 2.1 kg; Vo(2peak) = 3.62 +/- 0.18 1/min), nuclear AMPK alpha(2) content was increased 1.9 +/- 0.4-fold (P = 0.024). There was no change in whole-cell AMPK alpha(2) content or AMPK alpha(2) mRNA abundance. These results suggest that nuclear translocation of AMPK might mediate the effects of exercise on skeletal muscle gene and protein expression.