2012 Volume 1 Issue 1 Pages 139-144
In this review, we discuss the anabolic and metabolic responses of skeletal muscles to β2-agonists and exercise. β2-agonists increase muscle mass, particularly in fast-twitch muscles. Exercise positively regulates glucose homeostasis, mitochondrial biogenesis, and metabolic enzyme levels in skeletal muscles; whereas treatment with β2-agonists attenuates these beneficial effects. This review also describes the role of β2-adrenergic receptor (β2-AR) signaling molecules, such as cyclic adenosine monophosphate response element-binding protein, mitogen-activated protein kinase, and Akt/protein kinase B, in the response of skeletal muscles to β2-agonist treatment and exercise. For example, β2-agonists and exercise increase the phosphorylation of p38 mitogen-activated protein kinase in slow-twitch muscles. Our interpretation of these findings is that β2-adrenergic receptor signaling plays a functional role in the anabolic and metabolic responses of skeletal muscles to β2-agonists and exercise.
