(A) Atrogin-1 mRNA expression was measured by real-time PCR in samples of total RNA extracted from C2C12 myotubes treated with 0, 1, 2.5, 5.0, and 10 μM lovastatin for 6 hours, 20 hours, and 36 hours, respectively. (B) C2C12 myotubes were treated with lovastatin for 48 hours at the indicated concentrations, protein lysates were prepared, and immunodetection using polyclonal anti–atrogin-1 antibody was performed as described in Methods. Atrogin-1 band intensity was quantitated by densitometry. Atrogin-1 expression induced by dexamethasone (5 μM) (45) was used as a positive control. (C) Protein degradation was measured as described in Methods. Rates are presented as the percentage increase from proteolytic rate in nontreated control cultures. Dexamethasone (10 μM) was used as a positive control.