Figure 3.

Exercise-induced skeletal muscle mitochondrial fusion is associated with increased Mfn1 expression and activity, mediated by β₂-ARs. DRP1 (mitochondrial fraction) (a), Fis1 (b), OPA1 (c), Mfn2 (d), and Mfn1 (e) protein expression, immunoblotting representative images (f), and Mfn1GTPase activity (g) in tibialis anterior muscles from exercised mice (single bout in a treadmill—80% of Vmax for 1 h, 5° inclination), with or without β₂-AR receptor blockade with ICI 118,551 (single dose—10 mg/kg, i.p., 30 min prior exercise). Enolase and VDAC were used as loading control for total lysate and mitochondrial fraction protein expression, respectively. Data are presented as mean ± SE. * p < 0.05 vs. control and ** p < 0.05 vs. AE. n = 5/group.