β-adrenergic signaling pathway represents a novel therapeutic target for skeletal muscle wasting and weakness due to its role in the mechanisms controlling protein metabolism. However, the intracellular pathways that elicit these responses are far from being completely understood. In turn, this study was performed to shed light on the molecular mechanisms induced by chronic treatment with clenbuterol, a selective β2-agonist, in denervated muscles. For this, C57/BL6 male mice (~30g) were previously anesthetized and submitted to motor denervation (DEN) by unilateral sciatic nerve section. In the same day, the treatment with saline or clenbuterol (CB, 3mg/kg/day; s.c.) was started (n=5/group). After 3, 7, 14 and 21 days, tibialis anterior (TA) muscles were harvested to examine mRNA levels of atrophy-related genes (MuRF1, Atrogin-1 and cathepsin L) and Sik1, a CREB-target gene, by RT-qPCR, phospho-PKA substrates by western blot, and cAMP levels by ELISA. All experiments were approved by local Ethics Committee (044/2012). Comparisons were made by using Student’s t test or two-way ANOVA followed by Bonferroni test (p<0.05). DEN induced loss of muscle mass at 7th day (13%) that was prevented by CB. At 3rd day, CB increased muscle cAMP (857.12 ± 30.68 vs. 709.48 ±22.66 fmol/mg muscle in DEN treated with saline) and reduced the mRNA levels of MuRF1 (151% vs. 553% in DEN treated with saline), Atrogin-1 (-27% vs. 243%) and cathepsin L (129% vs. 208%). A similar profile was obtained to protein content. At 7th day, the expression of Ub-ligases (MuRF1 and Atrogin-1) were normalized in both groups, and DEN by itself increased the content of muscle cAMP (25%), phospho-PKA substrates (~2.2-fold), and Sik1 mRNA expression (~5.2 fold). The data show that the chronic treatment with CB in vivo suppresses the DEN-induced up-regulation of genes involved in muscle atrophy (atrogin-1, MuRF1, and cathepsin L) and suggest that these effects may be mediated by cAMP/PKA/CREB signaling. Additionally, it seems that this signaling pathway integrates a fine-tuning adaptative mechanism responsible for preventing excessive muscle loss in the progression of DEN.