Figure 2

Chronic systemic administration of formoterol alters the expression of genes associated with skeletal muscle hypertrophy and myogenesis at multiple timepoints. Quantitative RT-PCR was used to assay the expression of A. Stat3, B. Idb1, C. Smad1, D. Acvr2b, E. Smad3, and F.Myostatin mRNAs in tibialis anterior over chronic timepoints. Muscles were removed at 1, 7 and 28 days following daily intraperitoneal injection of formoterol or saline vehicle (NT = no treatment). Results were normalized against 36B4 at each timepoint. Data are expressed as mean ± SEM (n = 5). Statistical significance was assessed using a one-way ANOVA with Bonferroni's post-test where p < 0.05 (*), p < 0.01 (**) and p < 0.001 (***). Unmarked data points are non-significant. G. Protein levels of Myostatin precursor (pro-Myostatin), Smad3, phosphorylated Smad3, and Gapdh were visualized by Western blotting performed on tibialis anterior muscle following 28 days of formoterol/saline administration in four animals for each treatment. H. Diagrammatic representation of acute and chronic gene expression changes related to skeletal muscle hypertrophy and myogenesis in response to formoterol.