Figure 3
Forced expression of β2-AR in red-type skeletal muscle of β-less mice restores leptin-induced glucose uptake. (a) RT-PCR analysis of β2-AR mRNA in soleus, Gastro-R, and EDL muscles of β-less mice at 8 days after in vivo electroporation with an expression vector for β2-AR in the soleus and Gastro-R of the right hind limb (+) as well as with the corresponding empty vector in the same muscles of the left hind limb (−). Representative data for two manipulated β-less mice and one intact WT mouse are shown. (b) Rate constant of 2DG uptake in soleus, Gastro-R, and EDL muscles of the left (−) and right (+) hind limbs of β-less mice (n = 5) measured at 8 days after in vivo electroporation as in (a) and at 6 h after leptin injection into the VMH. (c,d) Representative immunoblot analysis of phosphorylated (p) and total forms of IR (c) and Akt (d) in soleus and EDL muscles of the (−) and (+) hind limbs of β-less mice treated as in (b) is shown together with quantitation of the corresponding pIR/IR and pAkt/Akt ratios (n = 4). (e) Representative immunoblot analysis and quantitation (n = 4) of GLUT4 and α-tubulin in soleus muscle of the (−) and (+) hind limbs of β-less mice treated as in (b). *P < 0.05 versus corresponding value for the β2-AR(−) muscle in the left hind limb (paired Student’s t test). (f) Representative immunoblot analysis and quantitation (n = 4) of phosphorylated (pAMPKα) and total (AMPKα1 and AMPKα2) forms of the α1 and α2 subunits of AMPK in soleus muscle of the (−) and (+) hind limbs of β-less mice measured at 8 days after in vivo electroporation as in (a) and at 6 h after leptin (+) or saline (−) injection into the VMH. *P < 0.05 versus corresponding value for the β2-AR(−) muscle after saline injection; # P < 0.05 versus corresponding value for the β2-AR(+) muscle after saline injection. All quantitative data are means ± S.E.M.
