Muscle-specific androgen receptor deletion shows limited actions in myoblasts but not in myofibers in different muscles in vivo

Abstract

The aim of this study was to investigate the direct muscle cell-mediated actions of androgens by comparing two different mouse lines. The cre-loxP system was used to delete the DNA-binding activity of the androgen receptor (AR) in mature myofibers (MCK mARΔZF2) in one model and the DNA-binding activity of the AR in both proliferating myoblasts and myofibers (α-actin mARΔZF2) in another model. We found that hind-limb muscle mass was normal in MCK mARΔZF2 mice and that relative mass of only some hind-limb muscles was reduced in α-actin mARΔZF2 mice. This suggests that myoblasts and myofibers are not the major cellular targets mediating the anabolic actions of androgens on male muscle during gr..