We have previously shown that global deletion of
the androgen receptor (AR) in mice results in a 15-22% decrease in hind-limb
muscle mass compared to wildtype (WT), while the reduction in muscle mass in
mice in which the AR is only deleted in muscle is much lower at 0-6%. These
results suggest that there is another major target of androgen action in the regulation of muscle mass. To
investigate the role of androgens acting via the AR in neurons on muscle mass
and strength, we generated a neuron-specific AR knockout (KO) mouse model, in
which exon 3 of the AR gene has been
deleted from neurons only by breeding floxed AR mice with CamKII-Cre mice. Preliminary
data shows that 6 week old neuron-specific ARKO male mice have a 15% decrease in
gastrocnemius muscle mass compared to WT littermates (n≥5 mice/group, p<0.01).
Total body mass of neuron-specific ARKO mice is decreased by 8% compared to WT (n≥5
mice/group, p<0.05). These data provide evidence for a role of androgens to
increase muscle mass, at least in part, via neurons.